Lectures Flashcards
Where are the external electrodes placed during an EEG and why?
(1+2): The brain electrode comparisons are made with the electrodes on the mastoid because it serves as a relatively neutral reference point.
(3+4): eyes are magnets; positively charged in the front and negatively towards the back. Therefore this sensor records eye movement and no brain activity, so then the eye activity (noise) can be subtracted from the brain activity. This is necessary because EEG recordings also pick up EMG (electromuscular) signals (incl. heart palpitations)
What is an EEG?
Electroencephalograms measure the difference in electrical potential (V) of pyramidal neurons between two points
What are alpha waves?
10 Hz signal that is produced under a state of awakeness and relaxation
what are beta waves indicative of?
movement and active thinking
what are gamma waves indicative of?
coordination between neurons
what are delta waves indicative of?
deep sleep
what are theta waves indicative of?
relaxed or meditative state
What do frequency filters do?
bypass noise in EEG and get cleaner signals
name the 3 types of frequency filters and what each filters out
Low-pass filter: keeps waves that are below a defined threshold
High-pass filter: keeps waves that are above a defined threshold
Bandpass filter: keeps waves that are within a defined range
What is an ERP?
the average of waves from different locations
Why do we perform baseline corrections when examining ERPs?
because there is neural activity between stimulus presentations that set signals above or below 0. These corrections are done to make more accurate comparisons between ERPs
What is the P300?
an ERP elicited during decision making, thought to reflect processes involved in stimulus evaluation or categorisation
what is the N400?
an ERP indicating semantic processing → relatedness correlates to the strength of the N400 potential
What is the N150?
indicates basic visual processing → fires maximally when the letters, font, and letter size are the same
What is the N250?
indicates orthographic processing, i.e., how (dis)similar words are based on their letters. This applies to entirely different letters, but not to differences between the same uppercase and lowercase letter
What is the P325?
indicates lexical processing, i.e., whether a word actually exists and is identifiable by the reader or not. Other factors such as font or letter size don’t influence this potential
What is MEG? How does it differ from EEG?
Records tiny magnetic fields that are generated within the brain, instead of the differences in electrical potential. These magnetic fields are much less distorted by brain tissue compared to EEG recordings
What is depicted here?
the ventral processing stream
This MEG data depicts the N400 potential. Why is the potential high for words AND pseudowords?
Because our brain is trying to analyse whether the pseudowords are real or not and thus whether they hold any semantic meaning
EEG measures the difference in electrical potential between…
one or more electrodes on the scalp and one or more electrodes placed on a neutral reference location
EEG records signals from..
brain signals, eye & muscle movement, heart beats, & any nearby electromagnetic activity
What is the timeline of word processing (hint: order of 4 ERPs and what they process)
N150: only identifies exactly identical words
N250: identifies identical words regardless of leterring
P325: indentifies existing vs. non-existing words
N400: identifies synonyms
What are text-based inferences?
inferences connecting information within the text
what are knowledge-based inferences?
inferences connecting information from the text to prior knowledge
What are the 3 levels of reading comprehension according to the Construction-Integration Model (Kintsch)?
Surface level: understanding basic text
Text base level: understand meaning and connect information in the text
Situation model: understand text and can connect it to prior knowledge
What does the simple view of reading (Hoover & Gough) state?
Comprehension is based on text decoding (reading words quickly and accurately) and language comprehension
In lower school grades ____ is easier than ____ .
In higher grades, ____ .
listening comprehension
reading comprehension
the reverse applies
A study examined the difference in reading comprehension for text and video in children, What did they find?
There was no overall difference between modalities
What are the pros and cons of testing reading comprehension using open-ended questions?
Pro: can ask questions targeting specific information and connections
Con: questions may impact comprehension after reading
What are the pros and cons of testing reading comprehension using free recall tasks?
Pro: does not influence comprehension after reading
Con: depends heavily on memory and what individuals choose to share
Con: not very practical
What are the pros and cons of testing reading comprehension using closed tasks?
Pro: objective and easy to make and administer
Con: only tests comprehension at the sentence level
What is the benefit of testing reading comprehension using sentence verification tasks?
it tests comprehension at the surface level and the text base
What is strategy instruction and what is it used for?
it is a method to improve reading comprehension by using strategies to read and practise with literature. However, it is not very motivating and using strategies shouldn’t be a goal of its own
What is inference instruction and what is it used for?
it is a method to improve reading comprehension by looking for keywords to infer what situation is being described, or using graphic organisers (visual help) to answer knowledge-based inferences
Pragmatics study ____, while semantics pertain to ____
utterances
sentences
What are pragmatics?
language in context
What do we need to know to decode utterance meaning?
the speaker’s intentions
Describe the two types of face-threatening acts
Positive face: you want to be liked and approved by others
Negative face: you don’t want to be restrained by others
what is redressive action?
when one is polite to minimise threat to the listener’s positive or negative face
What are the criticisms of Speech Act Theory (Searle, 1969)?
- It is centred around the speaker
- There are more variables that are involved in face-threat calculation
- It views politeness as being inherently strategic
- It doesn’t take impoliteness into account
What are the 4 components of a complaint?
- Subject of complaint (i.e., the complainable)
- Subjective negative evaluation
- Target person/organisation responsible for the problem
- Wish for compensation
implicit complaints contain none of the above
What does the Communication as Transfer Theory state (Shannon)?
We communicate by transferring an idea. There are 2 participants (sender & receiver) and a message is encoded, sent, and decoded
the theory is too simplistic and doesn’t consider the importance of context
What are the 3 levels of meaning?
Grice (1957) believed that comprehension needs an intention recognition system, whereby the speaker and listener are rational cooperative people. What did he mean with his cooperative principle?
“Make your contribution such as is required, at the stage at which it occurs, by the accepted purpose of the talk exchange in which you are engaged”
ToM research was used to explain why autistic people had communication deficits, but newer research points towards new findings. What do those support?
Communication requires conceptual allignment: it is not coding and decoding, but it involves jointly building a common conceptual space in which signals are a means to seek and provide evidence for mutual understanding.
