EEG- Dr. Connolly Lecture

Question 1

Children diagnosed as non-verbal autistic are also associated with having…

Answer 1

Severe intellectual disabilities
(10-15% aren’t actually at the intellectual
disadvantage that the diagnosis entails)

Question 2

Locked in condition

Answer 2

your can functionally think and understand but you cannot move or demonstrate it (kind of like being awake but under anaesthesia)

Question 3

fMRI measures..

Answer 3

changes in blood flow in different brain areas

very poor temporal resolution

Question 4

MEG

Answer 4

Looks at magnetic fluxes of the brain

much better at telling where a signal originated than EEG

Question 5

EEG

Answer 5

less robust in terms of where signals come from

the ideal is to combine MEG and EEG

Question 6

ERP

Answer 6

(event related potential)
average stimulus of trials.. a signal to noise ratio (the brain insists on doing many things at once)
-the stimulus must be repeated many times in order to determine where it is amongst all the “noise”

Question 7

N400

Answer 7

semantic processing in the visual/auditory modality
“the winter was harsh this allowance”
Large N400 at unexpected semantic stimulus

Question 8

PMN

Answer 8

response to processing speech at a phonological level

Question 9

What kind of PMN

“the winter was harsh this allowance”

Answer 9

Large PMN at [a]llowance

when the [a] phoneme appears PMN occurs because you’re expecting to hear a “y” sound for “year”

Question 10

What kind of PMN / N400

“The pigs wallowed in the pen”

Answer 10

no N400 ("pen" works in the sentence)
PMN appears (expecting to hear "m" for mud)

Question 11

What kind of PMN / N400

“The gambler had a streak of bad luggage”

Answer 11

Large N400- expecting “luck”

No PMN - “L” phoneme works for luck and luggage

Question 12

PMN reflects a pre-lexical stage of processing (T/F)

Answer 12

TRUE

present in word/nonword matches in rhyming tasks

Question 13

PMN

Answer 13

response to processing speech at a phonological level

begins 200 ms after onset

Question 14

PMN reflects a pre-lexical stage of processing (T/F)

Answer 14

TRUE

present in word/nonword matches in rhyming tasks

Question 15

Test: Phoneme deletion paradigm

done to avoid N400

Answer 15

CLAP without the [k]
Correct deletion: LAP
Incorrect: CAP
Initial consonant cluster: AP
Irrelevant (control): MILK 
Able to see the difference between correct and incorrect deletion responses in the brain

Question 16

Test: Homophones reading (N400)

Answer 16

Congruent: “A dove is a sign of peace”
Foil: “we baked a cake and ate a peace”
Incongruent: “the car ran out of bawl”

Congruent and Foil had little to no N400

Question 17

Vegetative state (VS)

Answer 17

ABI (acquired brain injury) with no evidence of awareness of self or environment / inability to interact with others
no evidence of comprehension of language

Question 18

New method to test vegetative state vs. Locked-in condition

Answer 18

ERP assessment of cognitive function

looking for N400 and PMN responses in patients

Question 19

What about autism?

Answer 19

25% of kids diagnosed with autism are considered non-verbal
if they know 5 functional words or less= nonverbal
there must be something wrong with relying on behaviour based tests

Question 20

Example of new method test on autism

Answer 20

GIRL:

• substantial N400 with sentences used on adults
• also could recognize her name
• must mean she’s not truly non-verbal because she can comprehend language well

BOY

• small hint of N400 but not strong in adult sentences
• Did not understand his name
• he cannot comprehend language

Individual variation

Question 21

Example of new method test on VS patients

Answer 21

Male stabbed in head

• 3-4 weeks after adult he showed N400 (clear semantic understanding)
• 2 months later- became more robust
• determined not VS and got rehab therapy

Question 22

Neuropsychological test paired with ERP tests …

Answer 22

provide “value-added” methodology for non-verbal or non-communicative individuals
-provides better understanding of their condition