Audra Miracle This is the go-to for anyone struggling with exposure. Your knowledge and conceptual way of teaching gave me the “a ha” moment.I finally understand it! Chords for Meg & Dia - Monster (DotEXE Dubstep Remix). Play along with guitar, ukulele, or piano with interactive chords and diagrams. Includes transpose. Stream Meg & Dia - Monster (DotEXE Remix) by DotEXE from desktop or your mobile device.
Meg
Release date
Also known as
Examine
• She's an adventurer in training with lots to learn.
• She's an adventurer in training who could use some pointers.
• An adventurer in training who really looks up to you.
• Rumour has it she is also known as Swagatha.
• It looks like this a little too much adventure for her.
• For the first four years of her life, her parents thought she was a housecat.
• An adventurer that makes you just a little bit proud.
Megatha Christie, commonly known as Meg, is an aspiring adventurer who describes herself as the player's biggest fan. Meg can be found in the player's player-owned port in the south-west corner. Once a week, resetting on Wednesday at approximately 00:00 UTC, Meg will ask the player for advice on how to deal with three situations that she is expecting on her adventures. After hearing some advice, she will teleport out to her adventures.
When Meg returns the following Wednesday, players receive a chatbox message upon logging in: 'You receive word that Meg has returned from her latest adventure.' The next time a player talks to Meg, she will tell them how well she did and give them a treasure chest, with a reward that depends on the quality of the advice she was given.
The advice that Meg is given acts as a bonus to her skills. It is always best to give the best possible advice from the choices offered; however, even she may fail to have a perfect result regardless of whether she was given the best possible advice to all three questions. Excellent answers only give big boosts to Meg's own skills - if the mission is above her league, she will still fail it, although excellent answers guarantee that the player will be rewarded with at least a medium lamp. Players do not need to meet the skill requirements for player-owned ports to speak with and advise Meg.
Exiting the conversation and offering to Help her again before completing the dialogue forces a player to begin the dialogue again from the beginning, allowing a player to choose different advice to give, but Meg will teleport away after she is answered three times.
Meg's cases
During the Mega May event in 2016, players assisted Meg a.k.a. Megatha Christie with her detective agency by investigating cases for her. One case was unlocked each day, and rewards included experience lamps, pets, and an outfit.
Kindred Spirits
During the course of her investigations into various thefts and kidnappings, Meg was herself kidnapped by a dragonkinesque creature. She was used as bait alongside Major Mary Rancour, Linza and Brother Samwell to force the World Guardian to play a series of games designed by Sliske involving the Barrows brothers. Brother Samwell was killed while the others were forced to help the World Guardian defeat the games. During Ahrim's trial, she was possibly tortured, and during Verac's trial, she may have been hurt making a key. During Guthan's trial, she badly impersonated the World Guardian, who was investigating Sliske's secret laboratory. Sliske saw through the guise and, when the World Guardian arrived, beat them and turned Linza into a wight. Meg, alongside Major Rancour and the World Guardian, fled to the surface after the Barrows brothers refused to kill them. She returned back to her post in the player-owned ports afterwards.
Player-owned port
The reward comes in the form of a treasure chest that contains two items: a stack of coins and an experience lamp giving experience in a random skill. Players will always receive at least a small experience lamp no matter how poorly Meg did. The lamps are equivalent to those awarded by Treasure Hunter.
Meg's response | Reward |
---|---|
Oh, wow! I can't believe how amazing that was. Nothing went wrong. I didn't fall over my feet - not that I do that much - and no one threw rocks at me or anything like that. I even found some amazing treasure. Here, you deserve a big share, I couldn't have done it without you! | Huge XP lamp + coins |
Oh, it was amazing! I followed your advice and - while I did encounter a few problems - I prevailed. I brought you back a share of my treasure, just as I promised. | Large XP lamp + coins |
That did not go as well as I expected. I'm sorry, but I wasn't able to get the loot that I intended to. Here's what I did find though. I'm sorry, I'll do better next time. | Medium XP lamp + coins |
Oh, good Guthix, it was horrible! I barely escaped with my life. I-I must have gotten your advice mixed up, I'm so sorry. Oh, I'm such a fool. I'll do better next time, I really will. Please, don't give up on me - I know I can be a better adventurer. I just need practice. | Small XP lamp + coins |
Meg's questions
The first question will have four answers to select from, while the remaining two questions will have three. The responses available to you depend on your level in the skill being asked about, with the best responses only being available at higher levels. The possible types of answers are excellent, good, bad, neutral or terrible. For some questions there are two possible answers for each type, for a total of ten possible answers per question, and for others there is only one possible choice for each level of answer.
If any of your levels are lower than their base levels, the best possible responses might sometimes not be available. This includes Prayer and Summoning levels that have been drained from maximum.[source needed]
Answers in this table are colour coded as follows:
Excellent |
Good |
Neutral |
Bad |
Terrible |
A suggested method of navigating this table is searching for phrases in the question using the 'Find' function (CTRL+F, or ⌘+F on Mac).
Question | Skill | Answer | Rating |
---|---|---|---|
A friend of mine told me about this rare breed of shark that can walk on land. I’ve decided to go and hunt one down – It’d look great mounted on my wall at home. Erm..do you have any idea how I would go about doing that? | Hunter | They'll probably use sound to track prey. | Excellent |
Dance on the ground to attract them. | Excellent | ||
Use kebbits as bait | Good | ||
I think your friend is pulling your leg, Meg. | Good | ||
Dig a moat to trap them | Neutral | ||
Stay on rock. They won't swim through that | Bad | ||
Dig underground to find them. | Bad | ||
You'll need a strong harpoon. | Bad | ||
Keep above the ground | Terrible | ||
Use fire to trap them in one place. | Terrible | ||
After defeating a gang of scurvy seadogs - which I've not done, but am very close to nearly-maybe doing - what's the best way to haul off my loot? | Thieving | Take the most valuable pieces with you. | Excellent |
Don't get carried away by greed. Take what you need. | Good | ||
Get a big, sturdy bag. | Neutral | ||
Throw the loot into the sea for safekeeping. | Bad | ||
Ask the seadogs to carry it for you. | Terrible | ||
Any general tips on being stealthy? I want to sneak my way past some rather scary looking people. | Thieving | Keep to the shadows and cover yourself in dark colours. | Excellent |
Keep to the shadows. | Good | ||
Move slowly and carefully. | Neutral | ||
Move quickly. | Bad | ||
Make yourself stand out, they won't expect that. | Terrible | ||
Do you have any advice for dealing with magical traps? | Runecrafting | Research them carefully | Excellent |
Try setting them off remotely. | Good | ||
Warding spells are your friend. | Neutral | ||
Shoot them first. | Bad | ||
Just use brute force. | Terrible | ||
Have you heard the stories of zombies in Karamja? A terrible curse that turns people into monsters? It's horrible and I'm going to find a way to put a stop to it. I hear tales of an artefact that can cure it - a bag filled with strange magical powder, so I'm going to find it. Any idea of where I should look? | Herblore | The jungles would be a good place to hide it. | Excellent |
Look in the caves around Karamja. | Excellent | ||
Sneak into the Legends' Guild and see if they know. | Good | ||
Investigate sources of magic. | Good | ||
Try the villages. | Neutral | ||
Ask the local populace. | Neutral | ||
Interrogate a broodoo victim. | Bad | ||
Interrogate a jogre. | Bad | ||
Look in the heart of the volcano. | Terrible | ||
Try the broodoo ritual yourself for inspiration. | Terrible | ||
I have heard about a great way to improve my connection to the spiritual, something called an... erm... ecto-fungus? Yeah, the ecto-fungus is in Morytania somewhere, and I shall quest to find this ghostly mushroom... thing. Any tips? | Prayer | I hear it's near Port Phasmatys. | Excellent |
Work on your agility - it'll help. | Excellent | ||
It's called the Ectofuntus, Meg. | Good | ||
You'll need bones, pots and buckets. | Good | ||
I think you should do more research before going. | Neutral | ||
Morytania is dangerous. Be careful. | Neutral | ||
Fungus grows in dark damp areas. | Bad | ||
Follow the ghasts. They'll lead you there. | Bad | ||
Beat up some werewolves. They'll tell you where it is. | Terrible | ||
I hear it's in the heart of the vampyre city. | Terrible | ||
I have heard stories of strange lobsters that lie deep within the swamps of Morytania. Lobsters that have been twisted by the malevolent forces that reside there. So twisted, that their skin has turned into obsidian blackness. So I'm going to find some. Any suggestions? | Cooking | They're just burnt lobsters, Meg. | Excellent |
Someone was trying to trick you, Meg. | Excellent | ||
Don't go Meg. They're lies. | Good | ||
Were they very crispy? | Good | ||
Bring a lobster net. | Neutral | ||
Be prepared for disappointment. | Neutral | ||
They'll hide in deep ponds. | Bad | ||
They'll be near ghasts. | Bad | ||
Sure, but first, let me cut your gems for you. | Terrible | ||
I hear they taste particularly good. | Terrible | ||
I have heard that deep within the swamps of Morytania, there lives a witch with terrible and dark power. So, I'm going to go and steal her book of spells. Any advice? | Magic | Reconsider. Witches can be unpredictable. | Excellent |
Make sure you have a strong magic defence. | Excellent | ||
Bring some allies for support. | Good | ||
Be stealthy; wait till she leaves. | Good | ||
Offer to trade for it. | Neutral | ||
Ask another witch first. | Neutral | ||
Set her house on fire. | Bad | ||
Throw rocks at her. | Bad | ||
Research life as a toad. | Terrible | ||
Poke her with spoons. Witches hate spoons. | Terrible | ||
I heard there's a cup that never runs out of water. I was wondering if I could use that to my advantage... if I could find it. | Magic | Learn the enchantment that makes it work. | Excellent |
You could help the needy during droughts. | Good | ||
It could keep you hydrated in the desert. | Neutral | ||
Put it on its side and gradually wear a fortress wall away. | Bad | ||
Handy for washing your clothes. | Terrible | ||
I may have upset a few people. What's a good way of dealing with an angry mob? | Hunter | Set a trap beforehand. | Excellent |
Get yourself the homeground advantage. | Good | ||
Get help. | Neutral | ||
Rig explosive traps around you. | Bad | ||
Take the fight to them. | Terrible | ||
I met this really weird guy in Karamja the other day, he kept talking to me about this plant as though it were alive. Weird. However he did introduce me to these bizarre little creatures and a way of hunting them to make potions. I thought it could be useful. Any tips? | Herblore | Make sure your farming skill is up to scratch. | Excellent |
Look out for the rare breeds of jadinko. | Excellent | ||
Make juju hunter flasks. | Good | ||
Bring hunter potions. | Good | ||
Set up lots of the traps. | Neutral | ||
Wear camouflage. | Neutral | ||
Use normal box traps. | Bad | ||
Use deadfall traps. | Bad | ||
Cut off bits of the vine to snare them. | Terrible | ||
That guy's crazy. Just trap the things with fire. | Terrible | ||
I might be overreaching a bit with this adventure. See I've heard that there might be a secret dungeon in Morytania, one created by a powerful necromancer and - well - that means there might be dark secrets to uncover. So... I'm going to investigate. Any advice that will help me get back alive? | Slayer | Necromancy seems to have nasty side effects. Be careful. | Excellent |
Don't go alone. | Excellent | ||
Bring equipment that's good against undead. | Good | ||
Keep teleport runes handy. | Good | ||
Note what you find in a journal. | Neutral | ||
Don't let zombies bite you. | Neutral | ||
Drink any potions you find. | Bad | ||
Go in secret, so no one can betray you. | Bad | ||
If a zombie bites you, bite back. | Terrible | ||
If you find anything, cast the biggest spell you can. | Terrible | ||
I think I've got a lot better at being stealthy, so I am going to test my skills. I have decided to sneak into the vampyre city and steal something from there. Any suggestions? | Thieving | Look for a vampyre resistance group. | Excellent |
Find a good disguise. | Excellent | ||
Have a quick escape plan. | Good | ||
Vampyres are hard to fool. | Good | ||
Reconsider. Vampyres are deadly. | Neutral | ||
Create a distraction. | Neutral | ||
Keep to the shadows. | Bad | ||
Stick to the high ground. | Bad | ||
It's dark, so bring a light source. | Terrible | ||
Mark yourself with blood. They won't investigate you. | Terrible | ||
I want to bind an elemental to serve me. Any ideas? | Runecrafting | Leave that to the Wizards' Tower. | Excellent |
Try and bargain with one, rather than bind it. | Good | ||
Use the opposite element to control one. | Neutral | ||
Force one into submission with violence. | Bad | ||
Invoke demonic magic. | Terrible | ||
I want to cross terrain faster. What animals are safe to ride? | Summoning | None that I know of. | Excellent |
I guess unicorns, if you can tame them. | Good | ||
I'd stick to going on foot. | Neutral | ||
Bears. | Bad | ||
Fire elementals. | Terrible | ||
I want to focus on sword fighting. Any pointers? | Attack | Treat the sword as an extension of your arm. | Excellent |
Remember - the sword can do more than just stab. | Good | ||
Keep the pointy end away from you. | Neutral | ||
Throw it at your enemy. | Bad | ||
Juggle with them to scare your foe. | Terrible | ||
I want to train an animal to help me. What would you recommend? | Summoning | Dogs are loyal and have great noses. | Excellent |
Birds have a great range of travel. | Good | ||
Ferrets can fit through small gaps. | Neutral | ||
Cats are cute. | Bad | ||
Bears are cuddly and friendly. | Terrible | ||
I was... erm... working on opening doors that, strictly speaking, I don't have the keys for. Can I pick your brain? | Thieving | Get some good quality lockpicks. | Excellent |
Locate alternative entrances. | Good | ||
Make sure the place is empty first. | Neutral | ||
Just kick the door down. | Bad | ||
Stand outside and shout 'fire!' | Terrible | ||
I was trying to disarm someone at range, but it's tricky. What do I do? | Ranged | Aim for their arm rather than their hand. | Excellent |
Use a crossbow for greater accuracy. | Good | ||
Try throwing daggers. | Neutral | ||
Use a cannon. | Bad | ||
Aim for their head. That'll disarm them. | Terrible | ||
I was wondering how I fight a pirate with a hook. | Attack | Keep your distance. | Excellent |
Carefully - treat the hook as a weapon. | Good | ||
Disarm him quickly. | Neutral | ||
Put a cork on the hook. | Bad | ||
Ignore it. focus on their main weapon. | Terrible | ||
I was wondering what the best weapon was for cutting through dense undergrowth. | Woodcutting | A strong machete. | Excellent |
A sharp sword. | Good | ||
A good knife. | Neutral | ||
A bladed whip. | Bad | ||
A warhammer. | Terrible | ||
I'll need to travel through cave networks. Any advice? | Firemaking | Get a mining helmet. | Excellent |
Speak to the dwarves for suggestions. | Good | ||
Bring rope. Lots of rope. | Neutral | ||
Oil yourself so you can slip through tight spaces. | Bad | ||
Dive straight in. | Terrible | ||
I'm trying to enchant my sword with runes, but it doesn't seem to work. ...? | Runecrafting | Enchanting doesn't work that way. | Excellent |
You'll need an enchantment spell. | Good | ||
Go to the Wizards' Tower for help. | Neutral | ||
Make a sword out of rune essence. | Bad | ||
Eat rune essence so you're in tune with your sword. | Terrible | ||
I'm worried about insects. Any ideas of how to protect against them? | Hunter | Insects don't like smoke. | Excellent |
When in a tent, cover the gaps with netting. | Good | ||
Avoid walking near hives. | Neutral | ||
Ignore them. You need to toughen up. | Bad | ||
Coat yourself in honey. | Terrible | ||
I've been formally challenged to my first duel. Please help! | Slayer | Scope out the arena first. | Excellent |
Research your opponent. | Good | ||
Check your weapons first. | Neutral | ||
Sabotage their weapon beforehand. | Bad | ||
Don't turn up. | Terrible | ||
I've discovered an ancient temple filled with the undead. How do I kill them? | Slayer | Bring a group. | Excellent |
Arm yourself with powerful weapons. | Good | ||
Bring food to heal. | Neutral | ||
Undead are weak. Just charge in. | Bad | ||
Use the Bones to Peaches spell on the skeletons. | Terrible | ||
I've found a waterfall I need to scale down. What's the best thing to do? | Agility | Find a path nearby. | Excellent |
Scale the cliffside, not the fall. | Good | ||
Tie a rope to the top to control your descent. | Neutral | ||
Test a raft first. | Bad | ||
Close your eyes and hope. | Terrible | ||
I've heard rumours of a haunted house. Any thoughts on how I should investigate? | Find out why the ghosts are haunting it. | Excellent | |
Talk to an exorcist first. | Good | ||
Bring salt. | Neutral | ||
Go alone. You'll draw less attention. | Bad | ||
Stab the ghosts. | Terrible | ||
I've noticed several restless ghosts wandering around Gielinor and I want to help. I've decided I will become an exorcist, setting these spirits free. Erm... don't suppose you have any idea how I do that? | Prayer | Father Urhney is a skilled exorcist. He can help. | Excellent |
Try to find out what's keeping the spirits trapped. | Excellent | ||
An amulet of ghostspeak would be useful. | Good | ||
Give them a proper burial. | Good | ||
Salt and holy water. | Neutral | ||
Get a priest to help. | Neutral | ||
Just ignore them. | Bad | ||
Destroy them with magic. | Bad | ||
Give them to a demon. | Terrible | ||
Bind them to serve you. | Terrible | ||
Oh dear. I'm hoping to adventure in Lumbridge, but I'm a little concerned about how to deal with the goblin population. Any pointers? A great adventurer like you must know something! | Ranged | Distract them with something shiny first. | Excellent |
Try attacking from a distance. They tend to be melee-based. | Excellent | ||
Goblins are fairly weak. Just be brave. | Good | ||
Strike quickly, before they can strike you. | Good | ||
A quick strike to the stomach often works. | Neutral | ||
Make yourself seem intimidating. | Neutral | ||
Work on counter-attacks, not attacks. | Bad | ||
Throw rocks at them. | Bad | ||
They're harmless. Just punch them. | Terrible | ||
Just remember to mock Bandos. | Terrible | ||
Oh, good Guthix! I-I-I was attacked by... by ROCKS! ROCKS! They just seemed to move of their own accord and went for me. I fought them off, but it was close. I have been told that they're called 'rock crabs'. Do you have advice about them? | Slayer | Fighting rock crabs is good combat training. | Excellent |
Their rock forms can be identified, if you're observant. | Excellent | ||
Pickaxes are good against them. | Good | ||
They have a strong defence. Be careful. | Good | ||
Use a dwarf multicannon. | Neutral | ||
Take care not to get too injured. | Neutral | ||
Disguise yourself as a rock. | Bad | ||
Just run away screaming. | Bad | ||
They spit fire! | Terrible | ||
They're highly poisonous. FLEE, MEG! | Terrible | ||
Oh, I discovered a terrible thing on my travels to Morytania. There are people who are not what they seem. One moment they are normal humans, but the next they become huge snarling creatures. I need to know how to deal with them. Any suggestions? | Slayer | I hear there is a magic weapon that will help. | Excellent |
Attack from a distance. | Excellent | ||
Try diplomacy first. | Good | ||
Bring food. They can hit hard. | Good | ||
They're scary, but mortal. | Neutral | ||
Try and kill them before they change. | Neutral | ||
Stamp on their tail. | Bad | ||
Swat them on the nose. | Bad | ||
Poke them repeatedly; they can't fight if angry. | Terrible | ||
Insult their fur. | Terrible | ||
Oh, it's awful - those poor people in Morytania, forced to live under the yoke of cruel vampyre masters. I'm going to save as many as I can. I'll slay me some vampyres. Ahh... any idea how I would do that? | Slayer | Vampyres don't like silver. | Excellent |
I hear you need a potion to defeat them. | Excellent | ||
Be careful. Vampyres are very dangerous. | Good | ||
You'll need a special weapon to defeat them. | Good | ||
Stake them. | Neutral | ||
I think holy water is effective. | Neutral | ||
Drag them into sunlight. | Bad | ||
Coat your sword in garlic first. | Bad | ||
Just stab them. | Terrible | ||
Fight them bare-handed. | Terrible | ||
Oh, while I've got you - I was planning on seeing if I could use a bow and arrow as a sort of grappling hook thing. What do you think? | Ranged | You'd be better off using a crossbow | Excellent |
Arrows aren't generally good at holding weight. | Good | ||
Use the arrows as footholds instead. | Neutral | ||
Aim the arrow at a downward angle. | Bad | ||
Use flaming arrows, so they melt into the surface a bit. | Terrible | ||
Okay, so a friend of mine told me he's heard rumours of a powerful flail that was wielded by one of Saradomin's generals way back in the God Wars. I'm going to go and quest for it. Do you have any suggestions on where to start? | Dungeoneering | Be careful. A weapon like that will be guarded. | Excellent |
Be sure you can trust your friend. | Excellent | ||
Saradomin's followers may know something. | Good | ||
Ask around. Rumours are occasionally based on truth. | Good | ||
Look in ancient ruins. | Neutral | ||
It's just a rumour. | Neutral | ||
Leave it to me. I'll find it eventually. | Bad | ||
It's clearly a lie, Meg. Why bother looking? | Bad | ||
Keep buying flails until you get the right one. | Terrible | ||
Never liked flails. Too easy to hit yourself. | Terrible | ||
Okay, so I have a problem. Um. I set up a series of magical traps and... locked myself out of my own house. Any suggestions? | Thieving | Study them carefully. It'll come back to you. | Excellent |
Work backwards. | Good | ||
Set them off remotely. | Neutral | ||
Just charge through. | Bad | ||
Move house. | Terrible | ||
Okay, so I heard that I can hunt swamp lizards and use them to breathe fire on my enemies. That sounds really useful. Any ideas on how to catch them? | Hunter | Watch out for ghasts. | Excellent |
Look for trees that aren't rotten. | Excellent | ||
Don't wear anything flammable. | Good | ||
Set several traps to be sure. | Good | ||
Wear camouflage. | Neutral | ||
Be very quiet to avoid spooking them. | Neutral | ||
Box traps might work. | Bad | ||
Deadfall traps are good for them. | Bad | ||
Stamp on them. | Terrible | ||
Douse yourself in oil first. | Terrible | ||
Okay, so I wanted to improve my connection to the divine powers and I thought Lumbridge would be a good place to start. Any suggestions? | Prayer | Ask Father Aereck about a ghost for a good reward. | Excellent |
The Salvation auras can be useful. | Excellent | ||
Imps drop ashes that you can scatter. | Good | ||
There are lots of goblins to get bones from. | Good | ||
Just buy a bunch of bones from the Grand Exchange. | Neutral | ||
Sit in on local sermons. | Neutral | ||
Just keep praying. You'll improve it that way. | Bad | ||
Duel random people to show your devotion to the gods. | Bad | ||
Ignore Lumbridge and go straight to the frost dragons. | Terrible | ||
Greater demons drop some nice ashes. You can defeat them, right? | Terrible | ||
Okay, so I was speaking to this wise old adventurer in the Poison Arrow pub the other day - scary place and he told me the tale of El Piskay the Demon Fish of the River Lum. So I am going to catch it! Although I'm not so good with water... or fish... or fishing rods... Any advice? | Fishing | I think you should start smaller, Meg. | Excellent |
Why not get some help on this one? | Excellent | ||
I'm not sure that fish is real, Meg. | Good | ||
Be calm and don't panic. | Good | ||
Make sure the rod is secure. | Neutral | ||
Find out what the right bait is first. | Neutral | ||
If you fire several harpoons at once, you won't miss. | Bad | ||
Buy the adventurer a drink and bring him along. | Bad | ||
Wrestle it into submission. You'll be legendary! | Terrible | ||
Dam up the river so it can't escape! | Terrible | ||
Okay, so I went to Lumbridge and I noticed the vast wealth difference between the Duke and his subjects and I just thought 'why?'. I mean, it's not like he needs ALL of that wealth. So, I am going to break into the castle and steal from his treasury to give it to the poor locals. Erm... any idea how I would go about doing that? | Thieving | You might want to have a chat with the Thieves' Guild. | Excellent |
The castle's fairly open. Scope it out first. | Excellent | ||
A disguise is always a good idea. | Good | ||
Take the wealth in small batches over time. | Good | ||
Plan carefully. | Neutral | ||
Go at night, when it's easier to stay unseen. | Neutral | ||
Enlist the goblins for help. | Bad | ||
Dig under the tower from the swamp. | Bad | ||
No subtlety. Attack directly - show them who's boss! | Terrible | ||
Borrow a cannon and lay siege to the castle as a distraction. | Terrible | ||
Okay, so I'm planning on crossing over White Wolf Mountain, but there are... well, there are wolves there! I don't want to be eaten. Can you help me at all? I really need advice. | Ranged | Take them out from a distance. | Excellent |
Run past them and bring food. | Excellent | ||
Collect their bones for summoning. | Good | ||
Wear strong armour to reduce the danger. | Good | ||
You could just teleport past it. | Neutral | ||
Travel in a group. | Neutral | ||
Go at night, for stealth. | Bad | ||
Dig through the mountain. | Bad | ||
Remember - wolves always work alone. | Terrible | ||
Cover yourself in blood first. That scares them. | Terrible | ||
Okay, so I'm taking myself on an adventure to the dangerous town of Lumbridge and I heard about this technique called runecrafting. It sounds like a useful skill to have and so I have made it my mission to investigate! Erm... any ideas what it is and where I should look? | Runecrafting | Find the Wizard's Tower. They can help. | Excellent |
Ask the wizards about the Runespan. | Excellent | ||
Get yourself a wicked hood. | Good | ||
Goblins sometimes drop talismans when slain. Worth a look. | Good | ||
You'll need some essence first. | Neutral | ||
The air altar can be found east of the River Lum. | Neutral | ||
Runecrafting is lame. Magic is for sissies. | Bad | ||
Fletching is more useful. | Bad | ||
Find runes, then just paint the symbols on rocks. | Terrible | ||
Crush runes up and use the dust. | Terrible | ||
Okay, so I've been tasked with a dangerous undertaking: the... erm... assassination of a dangerous foe. I have to kill... THE FERRET OF DOOM! A big, burly Fremennik warrior named Thok told me about it. Any hints or tips? | Dungeoneering | I think you should let Thok overcome his own fears. | Excellent |
I think its natural enemy is the heim crab. | Excellent | ||
Set a trap for it. | Good | ||
I suspect it's not as scary as he claims. | Good | ||
Sneak up on it from behind. | Neutral | ||
Use stealth; stick to the shadows. | Neutral | ||
Collapse the dungeon on it. | Bad | ||
Go alone; just be quick. | Bad | ||
Just tell Thok that he's a big coward. | Terrible | ||
Wait it out. Ferrets don't live that long. | Terrible | ||
Okay, so I've decided I need to pitch my fighting skills against scarier opponents than chickens. I've decided to test my swordsmanship against the Black Knights. Of course, I would like to come back alive from this, so I wondered if you had any tips. | Magic | They're weak against magic. | Excellent |
Bring a White Knight as assistance. | Excellent | ||
Keep your nerves steady. | Good | ||
You can heal at the Monastery. | Good | ||
Make sure you're wearing good armour. | Neutral | ||
Bring food to heal. | Neutral | ||
Wear black armour to infiltrate them. | Bad | ||
Bring a Black Knight as assistance. | Bad | ||
Dress in white armour so they don't suspect you. | Terrible | ||
Use ranged weapons. They're weak against those. | Terrible | ||
Okay, so I've heard rumours of an ancient temple hidden in the Kharazi jungle somewhere. I've decided to investigate to see if I can be the first to uncover it. Don't suppose you have any pointers do you? | Woodcutting | Bring a machete. The jungle is thick. | Excellent |
Might want to find someone who's been there before. | Excellent | ||
Mark where you've been so you can get back. | Good | ||
Arm yourself. The locals might not be friendly. | Good | ||
Remember that it's just a rumour, Meg. | Neutral | ||
Climb a tree to get a better view of the area. | Neutral | ||
If attacked, wave your swords around while screaming. | Bad | ||
Flies can be a great source of nutrition. | Bad | ||
Ask a monkey. | Terrible | ||
Tame a deathwing and survey the area from above. | Terrible | ||
Okay, well, thing is... I was hoping to catch something in Lumbridge. Something horrible; something terrifying beyond words. I was hoping to catch... shrimp. Don't laugh - they're horrible things! Slimy and icky... Any tips on how to catch them effectively? | Fishing | Just remember that they're harmless. | Excellent |
Use a small fishing net and grab the shrimp quickly. | Excellent | ||
Cook them immediately so they don't freak you out. | Good | ||
Wear gloves so you don't have to feel them. | Good | ||
Just look for the right fishing spots. | Neutral | ||
Get a net and shove it in the water. | Neutral | ||
Get a fishing rod and be patient. | Bad | ||
Just buy them from the Grand Exchange. | Bad | ||
Harpoon the shrimp, they'll know who's boss. | Terrible | ||
Stick your head in and catch them with your teeth. | Terrible | ||
So I've been wanting to work on my fletching skills, but I just can't get enough feathers. The shops won't sell them to me after that nasty incident at the archery competition. It was the wind, I'm sure of it! Anyway, I've discovered these birds that have amazing blue feathers so, how do I catch them? | Hunter | Set up several traps and be patient. | Excellent |
Watch for favoured flight patterns. | Excellent | ||
Disguise the traps as best you can. | Good | ||
Consider putting seeds on the trap. | Good | ||
Not really my area of expertise. | Neutral | ||
Wear camouflage. | Neutral | ||
Shoot them down with an arrow. | Bad | ||
Sing at them. Birds love song. | Bad | ||
Just whack the birds with a whip. | Terrible | ||
Set fire to the trees so they can only land on your trap. | Terrible | ||
So, I've been wondering about those little red things... imps, I think they're called. There were a few in Lumbridge and I was going to try my hand at catching one. Got any pointers? | Hunter | Try baiting the traps with beads. | Excellent |
Watch out for their teleports. | Excellent | ||
Be quiet and keep still. You don't want to spook them. | Good | ||
Make sure you're using the right trap. | Good | ||
Dress as a Zamorakian monk so they don't suspect you. | Neutral | ||
You'll need to use a magic box. | Neutral | ||
Shoot at them first. | Bad | ||
Throw beads at them to confuse them. | Bad | ||
Use a simple box trap. They're cheaper. | Terrible | ||
Use holy water on them. They hate it. | Terrible | ||
So, I've discovered that between me and my target is an army of the undead. What do I do? | Slayer | Whittle them down with cannonfire. | Excellent |
Don't panic. Undead are slow and stupid. | Good | ||
Blast them with magic. | Neutral | ||
Sneak past them. | Bad | ||
Fight them with fists - they're weak to fists. | Terrible | ||
So I've heard about this powerful demonic force and I wondered if you had any idea how to stop it. | Prayer | Most demons can be banished. Find the ritual. | Excellent |
Look for a binding spell. | Good | ||
Be strong in your faith. | Neutral | ||
Stabbing it normally works. | Bad | ||
Make a bargain with it. Should be fine. | Terrible | ||
So I've realised that I can make a little bit of money from polar kebbit fur. I figured I can't get tracking wrong. Except it turns out I can. I was stuck under that log for hours! Don't suppose you have any advice? | Hunter | Wear polar camouflage. | Excellent |
Stock up on hunter potions. | Excellent | ||
Keep quiet. They're easily spooked. | Good | ||
Just keep focused and prepare to lose a few. | Good | ||
Wear white clothes to blend in. | Neutral | ||
Stand upwind so they can't smell you. | Neutral | ||
Blast the burrows with Earth Bolt spells. | Bad | ||
Block up all the exits with snow. | Bad | ||
Smoke them out with fire. | Terrible | ||
Shout loudly to scare them. | Terrible | ||
So, I decided I need to improve my mystical knowledge and I said to myself, 'Meg, what better way to do so than to have a nice chat with a demon? Of course, they're big and scary and might try to devour my soul... Still, no pain no gain. Got any advice? | Prayer | Demons lie, Meg. Don't trust them. | Excellent |
Make sure you have a powerful wizard with you. | Excellent | ||
Whatever you do, don't agree to anything. | Good | ||
Be careful. | Good | ||
Make sure it's bound properly. | Neutral | ||
I think you should reconsider. | Neutral | ||
Summon it in a church. | Bad | ||
Make sure you summon it in a place of power. | Bad | ||
Don't bother with any sort of binding circle. | Terrible | ||
Offer it your soul for information. | Terrible | ||
So I had this plan to sneak into Varrock castle - you know, for all the treasure... But I'm a little concerned at what I should do if I get caught. Any tips? | Thieving | Trick the guard. | Excellent |
Fake illness, then escape. | Excellent | ||
Dig a tunnel with a spoon. | Good | ||
Hide under the bed. | Good | ||
Just don't get caught. | Neutral | ||
Remember that it's just a rumour, Meg. | Neutral | ||
Knock the guard out. | Bad | ||
Kill the guard. | Bad | ||
Kill everyone you meet. | Terrible | ||
Set fire to the castle. | Terrible | ||
So, I have decided that I need to get in touch with my spiritual side. I'm heading into Lumbridge to learn the secrets of the Saradominist church there. You know, the one by the graveyard. Any advice? | Prayer | Father Aereck is a good man to talk to. | Excellent |
Talk to Xenia in the nearby graveyard. She is an experienced adventurer. | Excellent | ||
Kill some goblins and bury their bones. | Good | ||
Be quiet and polite. It is a place of worship, after all. | Good | ||
Be sure to go in disguise. | Neutral | ||
It's just a church, Meg. You can just go inside. | Neutral | ||
Go find Father Urhney instead. He loves company. | Bad | ||
Break in through the northern window. | Bad | ||
It's secretly a Zamorakian temple. | Terrible | ||
Be careful - Father Aereck is clearly a Mahjarrat. | Terrible | ||
So I have heard the stories of flesh-eating fish, in the heart of Karamja, that will strip the flesh from your bones in seconds. I'm going to catch me some. Any suggestions? | Fishing | Use a long rod. | Excellent |
Don't go in the water. | Excellent | ||
Set a trap using meat and a net. | Good | ||
Find a way to trap them. | Good | ||
Wear sturdy armour. | Neutral | ||
Use meat as bait. | Neutral | ||
Use fish as bait. | Bad | ||
Use fruit as bait. | Bad | ||
Wade in and catch them close up. | Terrible | ||
Dive in and catch them with your teeth. | Terrible | ||
So I may have... accidentally made a pact with a demon. How do I get out of it? | Prayer | Find a loophole in the contract. | Excellent |
Bind the demon to your service. | Good | ||
Destroy the demon. | Neutral | ||
You can't. | Bad | ||
Bargain with other demons. | Terrible | ||
So, I want to prove that I have what it takes to be an adventurer - you know, to get the job done. I realised that I'm going to need to get my hands dirty and show off my thieving skills. So I figured, what better way than to infiltrate the Thieves' Guild in Lumbridge? What do you think? Any suggestions? | Thieving | I've heard it's near a furnace. | Excellent |
Get on Darren Lightfinger's good side first. | Excellent | ||
Accept any 'job' offers the guild offers you. | Good | ||
Consider the art of disguise. | Good | ||
Steal from stalls to get some practice. | Neutral | ||
Practice pickpocketing on H.A.M members. They deserve it. | Neutral | ||
Remember - don't touch the handkerchiefs. | Bad | ||
Ask the guards about where to find them. | Bad | ||
Remember to shout at people before you rob them. | Terrible | ||
The secret to stealth is to drink a lot of alcohol first. | Terrible | ||
So, I was planning on making a canoe and sailing to some of the wilder places downriver. Tell me, what's the best wood to use? | Woodcutting | Just use one of the trees at the canoe station. | Excellent |
Try oak - sturdy, and not too expensive. | Good | ||
A tree's a tree. | Neutral | ||
Cursed magic trees, for extra speed. | Bad | ||
Bloodwood trees. You can get to those, right? | Terrible | ||
So I was talking to an adventurer friend of mine. Well, 'friend' might be a strong term... 'Adventurer I met once' might be more accurate. Anyway, they were telling me about how useful rune essence is and I realised I could make a tidy profit if I just found another supply of it. Any idea where I might find one? | Runecrafting | Very special circumstances create rune essence. Look for those. | Excellent |
Honestly, it's unlikely you'll find one. | Excellent | ||
Rune essence absorbs magic. Look for weird side effects. | Good | ||
Look for high concentrations of magic. | Good | ||
Maybe the Wizards' Tower can help. | Neutral | ||
I'd consider a more fruitful quest. | Neutral | ||
Just take control of an existing mine. | Bad | ||
Give up, Meg. | Bad | ||
Just keep saying different words in the teleport spell. | Terrible | ||
Randomly teleport around the world. | Terrible | ||
So. Okay. So, don't judge me on this, but I've been having a few problems dealing with the... erm... Well, the chickens. I can't seem to defeat the chickens in Lumbridge. I don't suppose you have any advice do you? | Slayer | Sneak up on them from behind. | Excellent |
Draw a line in front of their beaks to hypnotise them. | Excellent | ||
Try not to show fear | Good | ||
Strike quickly. It gets it over with faster. | Good | ||
Just stab them. | Neutral | ||
Throw a rock at them first. | Neutral | ||
Make loud noises to scare them. | Bad | ||
Chase them around to tire them out. | Bad | ||
Use fire to trap them. | Terrible | ||
Summon the Evil Chicken. He'll take care of them. | Terrible | ||
Well I was planning on seeing if I could catch me a baby squirrel pet. I heard there were a couple of them around Lumbridge somewhere and I wanted to try my luck. Any advice? | Make sure you're good enough at summoning to keep one. | Excellent | |
A squirrel is for life, not just for a whim. | Excellent | ||
Nuts. I don't really need to say more. | Good | ||
Be careful. They can scratch. | Good | ||
Make sure your trap is secure. | Neutral | ||
Be patient and use more than one trap. | Neutral | ||
Try to catch one with a hawk. | Bad | ||
Scare them into submission first. | Bad | ||
Deadfall traps work better than nets. | Terrible | ||
Pitfall traps are the best way. | Terrible | ||
Well, I've been planning an expedition into the heart of the Lumbridge swamps, as a friend of mine told me that he's found a cavern full of something called a 'rune golem'. It only cost me 1000 gold - a bargain! Do you have any tips on how to deal with a rune golem? | Dungeoneering | Tread carefully. It might be a trap. | Excellent |
It's never wise to pay money up-front like that. | Excellent | ||
You need to find better friends. | Good | ||
I think your 'friend' may have tricked you. | Good | ||
Bring a light source. | Neutral | ||
Scout out the area first. | Neutral | ||
Use fire. Golems hate fire. | Bad | ||
You're an idiot, Meg. | Bad | ||
Fold up your shopping list and put it into the golem's head. | Terrible | ||
I'll tell you for 1000 gold... | Terrible | ||
What's the best armour to wear while exploring? | Defence | Something durable, which still allows freedom of movement. | Excellent |
Something that provides all-round protection. | Good | ||
Something comfortable. | Neutral | ||
A full suit of chainmail. | Bad | ||
A full suit of heavy plate. | Terrible | ||
What's the best food to hunt for in the wild? | Fishing | Fish are generally easy to come by. | Excellent |
Rabbits are tasty and easy to catch. | Good | ||
Fruits and berries. | Neutral | ||
Rats are numerous. | Bad | ||
Crocodiles. | Terrible | ||
What's the best way to take out a sorcerer? | Ranged | Use a powerful bow to take him out from range. | Excellent |
Take him out from the shadows. | Good | ||
Use a ranged weapon. | Neutral | ||
Fight Fire Bolts with Fire bolts. | Bad | ||
Run up and punch him in the face . | Terrible | ||
Which of the gods is the right one to follow? | Prayer | Only you can answer that. | Excellent |
Why follow just one god? | Good | ||
Don't follow any. | Neutral | ||
Depends on what your favourite colour is. | Bad | ||
Defy all of the gods, openly. | Terrible |
Dialogue
This article on an NPC has an associated dialogue page. Click here for a transcript of possible conversations with this NPC. |
Trivia
- The fourth option when speaking to her is 'Shut up Meg.', which is a reference to the reoccurring line in the American animated sitcom Family Guy. Choosing this option does not have any effect on your standing with Meg.
- One of her descriptions also references Family Guy by stating that for the first four years of her life, her parents thought that she was a house cat, similar to Peter sending a letter to Meg stating such.
- Meg's question about travelling across terrain faster could be a reference that players often request a 'riding skill' or 'mounts'. So far no mount or riding system exists in RuneScape.
- When Meg asks about the best way to steal money due to the Duke being rich, while his subjects are poor, is most likely a Robin Hood reference.
- The options for Meg traversing a waterfall from bad-good are a reference to the Waterfall Quest where you take a raft, before using a rope to descend the cliff.
- The riding crop she holds in her hand is a possible reference to Indiana Jones.
- The question about the rare lobsters in Morytania that are deep obsidian black is a reference to the 'Rare' Black lobsters scam, where players would attempt to sell burnt lobsters for lots of money. One of the answers for the question references the cutting gem scam.
- The question on the El Piskay Demon fish of Lumbridge River could be a word twist on El Fishy as pisc- is the latin root for fish, as well as Elpis, the Greek spirit of hope.
- The answer 'Dig a tunnel with a spoon' is a reference to the June 1962 Alcatraz escape, where three prisoners escaped Alcatraz by digging a hole through the cell wall with steel spoons.
- The answer stating 'Poke her with spoons. Witches hate spoons.' in the question about stealing a Morytanian witch's book of spells is a reference to the popular internet meme about female dogs liking leaves.
- The question of how to handle a rare shark that walks on land, and the answers 'They'll probably use sound to track prey' and 'Keep above ground', may be a possible reference to the 1990 film Tremors.
- Meg's name and examine text during Mega May are references to crime novelist Agatha Christie.
- During the Mega May event, she was replaced by Seasinger Jemi for her usual weekly adventurer role where she asks questions to the player, though her voiced dialogue still said Meg.
- The answer 'Run up and punch him in the face.' is likely a reference to a Japanese Anime called 'A Certain Magical Index', where the main premise of the show is the protagonist running up and punching magicians in the face to defeat them.
Meg's cases | |
---|---|
NPCs |
|
Enemies | |
Items | |
Rewards | |
Related |
Kindred Spirits | |||||
---|---|---|---|---|---|
Part 4 of the Sliske quest series | |||||
NPCs |
| ||||
Enemies | |||||
Items |
| ||||
Rewards | |||||
Music | |||||
Miscellaneous |
Player-owned port | ||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ||||||||||||||||||||
| ||||||||||||||||||||
| ||||||||||||||||||||
| ||||||||||||||||||||
|
New Varrock | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
NPCs |
| ||||||||||||
Items |
| ||||||||||||
Shops | |||||||||||||
Music | |||||||||||||
Related |
Distractions and Diversions | |
---|---|
Once daily | |
Twice daily | |
Weekly | |
Monthly | |
Other | |
Distraction and Diversions locations (Lite) |
Magnetoencephalography | |
---|---|
Medical diagnostics | |
MeSH | D015225 |
Magnetoencephalography (MEG) is a functional neuroimaging technique for mapping brain activity by recording magnetic fields produced by electrical currents occurring naturally in the brain, using very sensitive magnetometers. Arrays of SQUIDs (superconducting quantum interference devices) are currently the most common magnetometer, while the SERF (spin exchange relaxation-free) magnetometer is being investigated for future machines.[1][2] Applications of MEG include basic research into perceptual and cognitive brain processes, localizing regions affected by pathology before surgical removal, determining the function of various parts of the brain, and neurofeedback. This can be applied in a clinical setting to find locations of abnormalities as well as in an experimental setting to simply measure brain activity.[3]
- 3Magnetic shielding
- 4Source localization
- 5Use in the field
- 6Comparison with related techniques
History[edit]
MEG signals were first measured by University of Illinois physicist David Cohen in 1968,[4] before the availability of the SQUID, using a copper induction coil as the detector. To reduce the magnetic background noise, the measurements were made in a magnetically shielded room. The coil detector was barely sensitive enough, resulting in poor, noisy MEG measurements that were difficult to use. Later, Cohen built a much better shielded room at MIT, and used one of the first SQUID detectors, just developed by James E. Zimmerman, a researcher at Ford Motor Company,[5] to again measure MEG signals.[6] This time the signals were almost as clear as those of EEG. This stimulated the interest of physicists who had been looking for uses of SQUIDs. Subsequent to this, various types of spontaneous and evoked MEGs began to be measured.
At first, a single SQUID detector was used to successively measure the magnetic field at a number of points around the subject's head. This was cumbersome, and, in the 1980s, MEG manufacturers began to arrange multiple sensors into arrays to cover a larger area of the head. Present-day MEG arrays are set in a helmet-shaped vacuum flask that typically contain 300 sensors, covering most of the head. In this way, MEGs of a subject or patient can now be accumulated rapidly and efficiently.
Recent developments attempt to increase portability of MEG scanners by using spin exchange relaxation-free (SERF) magnetometers. SERF magnetometers are relatively small, as they do not require bulky cooling systems to operate. At the same time, they feature sensitivity equivalent to that of SQUIDs. In 2012, it was demonstrated that MEG could work with a chip-scale atomic magnetometer (CSAM, type of SERF).[7] More recently, in 2017, researchers built a working prototype that uses SERF magnetometers installed into portable individually 3D-printed helmets[2], which they noted in interviews could be replaced with something easier to use in future, such as a bike helmet.
The basis of the MEG signal[edit]
Synchronized neuronal currents induce weak magnetic fields. The brain's magnetic field, measuring at 10 femtotesla (fT) for cortical activity and 103 fT for the human alpha rhythm, is considerably smaller than the ambient magnetic noise in an urban environment, which is on the order of 108 fT or 0.1 µT. The essential problem of biomagnetism is, thus, the weakness of the signal relative to the sensitivity of the detectors, and to the competing environmental noise.
The MEG (and EEG) signals derive from the net effect of ionic currents flowing in the dendrites of neurons during synaptic transmission. In accordance with Maxwell's equations, any electrical current will produce a magnetic field, and it is this field that is measured. The net currents can be thought of as current dipoles[citation needed], i.e. currents with a position, orientation, and magnitude, but no spatial extent[dubious]. According to the right-hand rule, a current dipole gives rise to a magnetic field that points around the axis of its vector component.
To generate a signal that is detectable, approximately 50,000 active neurons are needed.[8] Since current dipoles must have similar orientations to generate magnetic fields that reinforce each other, it is often the layer of pyramidal cells, which are situated perpendicular to the cortical surface, that gives rise to measurable magnetic fields. Bundles of these neurons that are orientated tangentially to the scalp surface project measurable portions of their magnetic fields outside of the head, and these bundles are typically located in the sulci. Researchers are experimenting with various signal processing methods in the search for methods that detect deep brain (i.e., non-cortical) signal, but no clinically useful method is currently available.
It is worth noting that action potentials do not usually produce an observable field, mainly because the currents associated with action potentials flow in opposite directions and the magnetic fields cancel out. However, action fields have been measured from peripheral nerves.
Magnetic shielding[edit]
Meg And Dia Monster Dubstep
Since the magnetic signals emitted by the brain are on the order of a few femtoteslas, shielding from external magnetic signals, including the Earth's magnetic field, is necessary. Appropriate magnetic shielding can be obtained by constructing rooms made of aluminium and mu-metal for reducing high-frequency and low-frequency noise, respectively.
Meg Donnelly
Magnetically shielded room (MSR)[edit]
A magnetically shielded room (MSR) model consists of three nested main layers. Each of these layers is made of a pure aluminium layer plus a high-permeability ferromagnetic layer, similar in composition to molybdenum permalloy. The ferromagnetic layer is supplied as 1 mm sheets, while the innermost layer is composed of four sheets in close contact, and the outer two layers are composed of three sheets each. Magnetic continuity is maintained by overlay strips. Insulating washers are used in the screw assemblies to ensure that each main layer is electrically isolated. This helps eliminate radio frequency radiation, which would degrade SQUID performance. Electrical continuity of the aluminium is also maintained by aluminium overlay strips to ensure ACeddy current shielding, which is important at frequencies greater than 1 Hz. The junctions of the inner layer are often electroplated with silver or gold to improve conductivity of the aluminium layers.[9]
Active shielding system[edit]
Active systems are designed for three-dimensional noise cancellation. To implement an active system, low-noise fluxgate magnetometers are mounted at the center of each surface and oriented orthogonally to it. This negatively feeds a DC amplifier through a low-pass network with a slow falloff to minimize positive feedback and oscillation. Built into the system are shaking and degaussing wires. Shaking wires increase the magnetic permeability, while the permanent degaussing wires are applied to all surfaces of the inner main layer to degauss the surfaces.[4] Moreover, noise cancellation algorithms can reduce both low-frequency and high-frequency noise. Modern systems have a noise floor of around 2–3 fT/Hz0.5 above 1 Hz.
Source localization[edit]
The inverse problem[edit]
The challenge posed by MEG is to determine the location of electric activity within the brain from the induced magnetic fields outside the head. Problems such as this, where model parameters (the location of the activity) have to be estimated from measured data (the SQUID signals) are referred to as inverse problems (in contrast to forward problems[10] where the model parameters (e.g. source location) are known and the data (e.g. the field at a given distance) is to be estimated.) The primary difficulty is that the inverse problem does not have a unique solution (i.e., there are infinite possible 'correct' answers), and the problem of defining the 'best' solution is itself the subject of intensive research.[11] Possible solutions can be derived using models involving prior knowledge of brain activity.
The source models can be either over-determined or under-determined. An over-determined model may consist of a few point-like sources ('equivalent dipoles'), whose locations are then estimated from the data. Under-determined models may be used in cases where many different distributed areas are activated ('distributed source solutions'): there are infinitely many possible current distributions explaining the measurement results, but the most likely is selected. Localization algorithms make use of given source and head models to find a likely location for an underlying focal field generator.
One type of localization algorithm for overdetermined models operates by expectation-maximization: the system is initialized with a first guess. A loop is started, in which a forward model is used to simulate the magnetic field that would result from the current guess. The guess is adjusted to reduce the discrepancy between the simulated field and the measured field. This process is iterated until convergence.
Another common technique is beamforming, wherein a theoretical model of the magnetic field produced by a given current dipole is used as a prior, along with second-order statistics of the data in the form of a covariance matrix, to calculate a linear weighting of the sensor array (the beamformer) via the Backus-Gilbert inverse. This is also known as a linearly constrained minimum variance (LCMV) beamformer. When the beamformer is applied to the data, it produces an estimate of the power in a 'virtual channel' at the source location.
The extent to which the constraint-free MEG inverse problem is ill-posed cannot be overemphasized. If one's goal is to estimate the current density within the human brain with say a 5mm resolution then it is well established that the vast majority of the information needed to perform a unique inversion must come not from the magnetic field measurement but rather from the constraints applied to the problem. Furthermore, even when a unique inversion is possible in the presence of such constraints said inversion can be unstable. These conclusions are easily deduced from published works.[12]
Magnetic source imaging[edit]
The source locations can be combined with magnetic resonance imaging (MRI) images to create magnetic source images (MSI). The two sets of data are combined by measuring the location of a common set of fiducial points marked during MRI with lipid markers and marked during MEG with electrified coils of wire that give off magnetic fields. The locations of the fiducial points in each data set are then used to define a common coordinate system so that superimposing the functional MEG data onto the structural MRI data ('coregistration') is possible.
A criticism of the use of this technique in clinical practice is that it produces colored areas with definite boundaries superimposed upon an MRI scan: the untrained viewer may not realize that the colors do not represent a physiological certainty, because of the relatively low spatial resolution of MEG, but rather a probability cloud derived from statistical processes. However, when the magnetic source image corroborates other data, it can be of clinical utility.
Dipole model source localization[edit]
A widely accepted source-modeling technique for MEG involves calculating a set of equivalent current dipoles (ECDs), which assumes the underlying neuronal sources to be focal. This dipole fitting procedure is non-linear and over-determined, since the number of unknown dipole parameters is smaller than the number of MEG measurements.[13] Automated multiple dipole model algorithms such as multiple signal classification (MUSIC) and MSST (MultiStart Spatial and Temporal) modeling are applied to the analysis of MEG responses. The limitations of dipole models for characterizing neuronal responses are (1) difficulties in localizing extended sources with ECDs, (2) problems with accurately estimating the total number of dipoles in advance, and (3) dependency on dipole location, especially depth in the brain.
Distributed source models[edit]
Unlike multiple-dipole modeling, distributed source models divide the source space into a grid containing a large number of dipoles. The inverse problem is to obtain the dipole moments for the grid nodes.[14] As the number of unknown dipole moments is much greater than the number of MEG sensors, the inverse solution is highly underdetermined, so additional constraints are needed to reduce ambiguity of the solution. The primary advantage of this approach is that no prior specification of the source model is necessary. However, the resulting distributions may be difficult to interpret, because they only reflect a 'blurred' (or even distorted) image of the true neuronal source distribution. The matter is complicated by the fact that spatial resolution depends strongly on several parameters such as brain area, depth, orientation, number of sensors etc.[15]
Independent component analysis (ICA)[edit]
Independent component analysis (ICA) is another signal processing solution that separates different signals that are statistically independent in time. It is primarily used to remove artifacts such as blinking, eye muscle movement, facial muscle artifacts, cardiac artifacts, etc. from MEG and EEG signals that may be contaminated with outside noise.[16] However, ICA has poor resolution of highly correlated brain sources.
Use in the field[edit]
In research, MEG's primary use is the measurement of time courses of activity. MEG can resolve events with a precision of 10 milliseconds or faster, while functional MRI (fMRI), which depends on changes in blood flow, can at best resolve events with a precision of several hundred milliseconds. MEG also accurately pinpoints sources in primary auditory, somatosensory, and motor areas. For creating functional maps of human cortex during more complex cognitive tasks, MEG is most often combined with fMRI, as the methods complement each other. Neuronal (MEG) and hemodynamic (fMRI) data do not necessarily agree, in spite of the tight relationship between local field potentials (LFP) and blood oxygenation level-dependent (BOLD) signals. MEG and BOLD signals may originate from the same source (though the BOLD signals are filtered through the hemodynamic response).
MEG is also being used to better localize responses in the brain. The openness of the MEG setup allows external auditory and visual stimuli to be easily introduced. Some movement by the subject is also possible as long as it does not jar the subject's head. The responses in the brain before, during, and after the introduction of such stimuli/movement can then be mapped with greater spatial resolution than was previously possible with EEG.[17] Psychologists are also taking advantage of MEG neuroimaging to better understand relationships between brain function and behavior. For example, a number of studies have been done comparing the MEG responses of patients with psychological troubles to control patients. There has been great success isolating unique responses in patients with schizophrenia, such as auditory gating deficits to human voices.[18] MEG is also being used to correlate standard psychological responses, such as the emotional dependence of language comprehension.[19]
Recent studies have reported successful classification of patients with multiple sclerosis, Alzheimer's disease, schizophrenia, Sjögren's syndrome, chronic alcoholism, facial pain and thalamocortical dysrhythmias. MEG can be used to distinguish these patients from healthy control subjects, suggesting a future role of MEG in diagnostics.[20][21]
Focal epilepsy[edit]
The clinical uses of MEG are in detecting and localizing pathological activity in patients with epilepsy, and in localizing eloquent cortex for surgical planning in patients with brain tumors or intractable epilepsy. The goal of epilepsy surgery is to remove the epileptogenic tissue while sparing healthy brain areas.[22] Knowing the exact position of essential brain regions (such as the primary motor cortex and primary sensory cortex, visual cortex, and areas involved in speech production and comprehension) helps to avoid surgically induced neurological deficits. Direct cortical stimulation and somatosensory evoked potentials recorded on ECoG are considered the gold standard for localizing essential brain regions. These procedures can be performed either intraoperatively or from chronically indwelling subdural grid electrodes. Both are invasive.
Noninvasive MEG localizations of the central sulcus obtained from somatosensory evoked magnetic fields show strong agreement with these invasive recordings.[23][24][25] MEG studies assist in clarification of the functional organization of primary somatosensory cortex and to delineate the spatial extent of hand somatosensory cortex by stimulation of the individual digits. This agreement between invasive localization of cortical tissue and MEG recordings shows the effectiveness of MEG analysis and indicates that MEG may substitute invasive procedures in the future.
Fetal[edit]
MEG has been used to study cognitive processes such as vision, audition, and language processing in fetuses and newborns.[26]
Comparison with related techniques[edit]
MEG has been in development since the 1960s but has been greatly aided by recent advances in computing algorithms and hardware, and promises improved spatial resolution coupled with extremely high temporal resolution (better than 1 ms). Since the MEG signal is a direct measure of neuronal activity, its temporal resolution is comparable with that of intracranial electrodes.
MEG complements other brain activity measurement techniques such as electroencephalography (EEG), positron emission tomography (PET), and fMRI. Its strengths consist in independence of head geometry compared to EEG (unless ferromagneticimplants are present), non-invasiveness, use of no ionizing radiation, as opposed to PET and high temporal resolution as opposed to fMRI.
MEG in comparison to EEG[edit]
Although EEG and MEG signals originate from the same neurophysiological processes, there are important differences.[27] Magnetic fields are less distorted than electric fields by the skull and scalp, which results in a better spatial resolution of the MEG. Whereas scalp EEG is sensitive to both tangential and radial components of a current source in a spherical volume conductor, MEG detects only its tangential components. Scalp EEG can, therefore, detect activity both in the sulci and at the top of the cortical gyri, whereas MEG is most sensitive to activity originating in sulci. EEG is, therefore, sensitive to activity in more brain areas, but activity that is visible in MEG can also be localized with more accuracy.
Scalp EEG is sensitive to extracellular volume currents produced by postsynaptic potentials. MEG detects intracellular currents associated primarily with these synaptic potentials because the field components generated by volume currents tend to cancel out in a spherical volume conductor[28] The decay of magnetic fields as a function of distance is more pronounced than for electric fields. Therefore, MEG is more sensitive to superficial cortical activity, which makes it useful for the study of neocortical epilepsy. Finally, MEG is reference-free, while scalp EEG relies on a reference that, when active, makes interpretation of the data difficult.
See also[edit]
References[edit]
- ^Hämäläinen M, Hari R, Ilmoniemi RJ, Knuutila J, Lounasmaa OV (1993). 'Magnetoencephalography—theory, instrumentation, and applications to noninvasive studies of the working human brain'(PDF). Reviews of Modern Physics. 65 (2): 413–497. Bibcode:1993RvMP...65..413H. doi:10.1103/RevModPhys.65.413. ISSN0034-6861.
- ^ abBoto, Elena; Holmes, Niall; Leggett, James; Roberts, Gillian; Shah, Vishal; Meyer, Sofie S.; Muñoz, Leonardo Duque; Mullinger, Karen J.; Tierney, Tim M. (March 2018). 'Moving magnetoencephalography towards real-world applications with a wearable system'. Nature. 555 (7698): 657–661. Bibcode:2018Natur.555..657B. doi:10.1038/nature26147. ISSN1476-4687. PMC6063354. PMID29562238.
- ^Carlson NR (2013). Physiology of Behavior. Upper Saddle River, NJ: Pearson Education Inc. pp. 152–153. ISBN978-0-205-23939-9.
- ^ abCohen D (August 1968). 'Magnetoencephalography: evidence of magnetic fields produced by alpha-rhythm currents'. Science. 161 (3843): 784–6. Bibcode:1968Sci...161..784C. doi:10.1126/science.161.3843.784. PMID5663803.
- ^Zimmerman JE, Theine P, Harding JT (1970). 'Design and operation of stable rf-biased superconducting point-contact quantum devices, etc'. Journal of Applied Physics. 41 (4): 1572–1580. doi:10.1063/1.1659074.
- ^Cohen D (February 1972). 'Magnetoencephalography: detection of the brain's electrical activity with a superconducting magnetometer'(PDF). Science. 175 (4022): 664–6. Bibcode:1972Sci...175..664C. doi:10.1126/science.175.4022.664. PMID5009769.
- ^Sander TH, Preusser J, Mhaskar R, Kitching J, Trahms L, Knappe S (May 2012). 'Magnetoencephalography with a chip-scale atomic magnetometer'. Biomedical Optics Express. 3 (5): 981–90. doi:10.1364/BOE.3.000981. PMC3342203. PMID22567591.
- ^Okada Y (1983). 'Neurogenesis of evoked magnetic fields'. In Williamson SH, Romani GL, Kaufman L, Modena I (eds.). Biomagnetism: an Interdisciplinary Approach. New York: Plenum Press. pp. 399–408. ISBN978-1-4757-1785-3.
- ^Cohen D, Schläpfer U, Ahlfors S, Hämäläinen M, Halgren E. 'New Six-Layer Magnetically-Shielded Room for MEG'. Charlestown, Massachusetts: Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital.Missing or empty
|url=
(help) - ^Tanzer IO (2006). Numerical Modeling in Electro- and Magnetoencephalography (Ph.D. thesis). Finland: Helsinki University of Technology.
- ^Hauk O, Wakeman DG, Henson R (February 2011). 'Comparison of noise-normalized minimum norm estimates for MEG analysis using multiple resolution metrics'. NeuroImage. 54 (3): 1966–74. doi:10.1016/j.neuroimage.2010.09.053. PMC3018574. PMID20884360.
- ^Sheltraw D, Coutsias E (2003). 'Invertibility of current density from near-field electromagnetic data'(PDF). Journal of Applied Physics. 94 (8): 5307–5315. Bibcode:2003JAP....94.5307S. doi:10.1063/1.1611262.
- ^Huang MX, Dale AM, Song T, Halgren E, Harrington DL, Podgorny I, Canive JM, Lewis S, Lee RR (July 2006). 'Vector-based spatial-temporal minimum L1-norm solution for MEG'. NeuroImage. 31 (3): 1025–37. doi:10.1016/j.neuroimage.2006.01.029. PMID16542857.
- ^Hämäläinen MS, Ilmoniemi RJ (January 1994). 'Interpreting magnetic fields of the brain: minimum norm estimates'. Medical & Biological Engineering & Computing. 32 (1): 35–42. doi:10.1007/BF02512476. PMID8182960.
- ^Molins A, Stufflebeam SM, Brown EN, Hämäläinen MS (September 2008). 'Quantification of the benefit from integrating MEG and EEG data in minimum l2-norm estimation'. NeuroImage. 42 (3): 1069–77. doi:10.1016/j.neuroimage.2008.05.064. PMID18602485.
- ^Jung TP, Makeig S, Westerfield M, Townsend J, Courchesne E, Sejnowski TJ (October 2000). 'Removal of eye activity artifacts from visual event-related potentials in normal and clinical subjects'(PDF). Clinical Neurophysiology. 111 (10): 1745–58. CiteSeerX10.1.1.164.9941. doi:10.1016/S1388-2457(00)00386-2. PMID11018488.
- ^Cui R, Cunnington R, Beisteiner R, Deecke L (2012). 'Effects of force-load on cortical activity preceding voluntary finger movement'. Neurology, Psychiatry and Brain Research. 18 (3): 97–104. doi:10.1016/j.npbr.2012.03.001.
- ^Hirano Y, Hirano S, Maekawa T, Obayashi C, Oribe N, Monji A, Kasai K, Kanba S, Onitsuka T (March 2010). 'Auditory gating deficit to human voices in schizophrenia: a MEG study'. Schizophrenia Research. 117 (1): 61–7. doi:10.1016/j.schres.2009.09.003. PMID19783406.
- ^Ihara A, Wei Q, Matani A, Fujimaki N, Yagura H, Nogai T, Umehara H, Murata T (January 2012). 'Language comprehension dependent on emotional context: a magnetoencephalography study'. Neuroscience Research. 72 (1): 50–8. doi:10.1016/j.neures.2011.09.011. PMID22001763.
- ^Georgopoulos AP, Karageorgiou E, Leuthold AC, Lewis SM, Lynch JK, Alonso AA, Aslam Z, Carpenter AF, Georgopoulos A, Hemmy LS, Koutlas IG, Langheim FJ, McCarten JR, McPherson SE, Pardo JV, Pardo PJ, Parry GJ, Rottunda SJ, Segal BM, Sponheim SR, Stanwyck JJ, Stephane M, Westermeyer JJ (December 2007). 'Synchronous neural interactions assessed by magnetoencephalography: a functional biomarker for brain disorders'. Journal of Neural Engineering. 4 (4): 349–55. Bibcode:2007JNEng...4..349G. doi:10.1088/1741-2560/4/4/001. hdl:10161/12446. PMID18057502.
- ^Montez T, Poil SS, Jones BF, Manshanden I, Verbunt JP, van Dijk BW, Brussaard AB, van Ooyen A, Stam CJ, Scheltens P, Linkenkaer-Hansen K (February 2009). 'Altered temporal correlations in parietal alpha and prefrontal theta oscillations in early-stage Alzheimer disease'. Proceedings of the National Academy of Sciences of the United States of America. 106 (5): 1614–9. Bibcode:2009PNAS..106.1614M. doi:10.1073/pnas.0811699106. PMC2635782. PMID19164579.
- ^Luders HO (1992). Epilepsy Surgery. New York Raven Press.
- ^Sutherling WW, Crandall PH, Darcey TM, Becker DP, Levesque MF, Barth DS (November 1988). 'The magnetic and electric fields agree with intracranial localizations of somatosensory cortex'. Neurology. 38 (11): 1705–14. doi:10.1212/WNL.38.11.1705. PMID3185905.
- ^Rowley HA, Roberts TP (November 1995). 'Functional localization by magnetoencephalography'. Neuroimaging Clinics of North America. 5 (4): 695–710. PMID8564291.
- ^Gallen CC, Hirschkoff EC, Buchanan DS (May 1995). 'Magnetoencephalography and magnetic source imaging. Capabilities and limitations'. Neuroimaging Clinics of North America. 5 (2): 227–49. PMID7640886.
- ^Sheridan CJ, Matuz T, Draganova R, Eswaran H, Preissl H (2010). 'Fetal Magnetoencephalography - Achievements and Challenges in the Study of Prenatal and Early Postnatal Brain Responses: A Review'. Infant and Child Development. 19 (1): 80–93. doi:10.1002/icd.657. PMC2830651. PMID20209112.
- ^Cohen D, Cuffin BN (July 1983). 'Demonstration of useful differences between magnetoencephalogram and electroencephalogram'. Electroencephalography and Clinical Neurophysiology. 56 (1): 38–51. doi:10.1016/0013-4694(83)90005-6. PMID6190632.
- ^Barth DS, Sutherling W, Beatty J (March 1986). 'Intracellular currents of interictal penicillin spikes: evidence from neuromagnetic mapping'. Brain Research. 368 (1): 36–48. doi:10.1016/0006-8993(86)91040-1. PMID3955364.
Further reading[edit]
- Baillet S, Mosher JC, Leahy RM (November 2001). 'Electromagnetic Brain Mapping'. IEEE Signal Processing Magazine. 18 (6): 14–30. Bibcode:2001ISPM...18...14B. doi:10.1109/79.962275.
- Cohen D (2004). 'Boston and the history of biomagnetism'. Neurology and Clinical Neurophysiology. 30 (1).
- Cohen D, Halgren E (2004). 'Magnetoencephalography'. In Adelman G, Smith B (eds.). Encyclopedia of Neuroscience. Elsevier.
- Hämäläinen M, Hari R, Ilmoniemi R, Knuutila J, Lounasmaa OV (1993). 'Magnetoencephalography – theory, instrumentation, and applications to noninvasive studies of signal processing in the human brain'(PDF). Reviews of Modern Physics. 65 (2): 413–497. doi:10.1103/revmodphys.65.413.
- Hansen PC, Kringelbach ML, Salmelin R (2010). MEG: An Introduction to Methods. New York: Oxford University Press Inc.
- Murakami S, Okada Y (September 2006). 'Contributions of principal neocortical neurons to magnetoencephalography and electroencephalography signals'. The Journal of Physiology. 575 (Pt 3): 925–36. doi:10.1113/jphysiol.2006.105379. PMC1995687. PMID16613883.
- Suk J, Ribary U, Cappell J, Yamamoto T, Llinás R (March 1991). 'Anatomical localization revealed by MEG recordings of the human somatosensory system'. Electroencephalography and Clinical Neurophysiology. 78 (3): 185–96. doi:10.1016/0013-4694(91)90032-y. PMID1707790.
- Tanzer OI (2006). Numerical Modeling in Electro- and Magnetoencephalography (Ph.D. thesis). Finland: Helsinki University of Technology.