Het Brein In Beeld Flashcards
What are single-cell recordings?
The measure of responsiveness of a neuron to a given stimulus (in terms of action potentials per second)
What is an EEG?
Electroencephalography: electrodes are put on the scalp to measure electrical signals generated by the brain
What is an ERP?
Event-related potential: the average amount of change in voltage at the scalp that is linked to the timing of particular cognitive events
What are multi-cell recordings?
The electrical activity (in terms of action potentials per second) of many individually recorded neurons recorded at one or more electrodes
What is a grandmother cell?
A hypothetical neuron that responds to just one particular stimulus (like the sight of one’s grandmother)
What are the three types of representation?
- Local representation: all the information about a stimulus or event is carried in one of the neurons (grandmother cell)
- Fully distributed representation: all the information about a stimulus or event is carried in all the neurons of a given population
- Sparse distributed representation: a small proportion of the neurons carry information about a stimulus or event
What is a dipole?
A pair of positive and negative electrical charges seperated by a small distance (push each other away)
What is the additive factors method and which stages does it have?
A general method for dividing reaction times into different stages.
1. Encoding the probe digit (number that needs to be remembered).
2. Comparing the probe digit with the items held in memory.
3. Deciding which response to make.
4. Responding by executing the button press.
What is N170?
An ERP component (negative potential at 170 ms) linked to perceiving facial structures (all faces, famous and not famous, and also cartoon and animal faces)
What is N250?
An ERP component larger for famous and personally familiar faces relative to unfamiliar faces.
What is associative priming?
Reaction times are faster to stimulus X after being presented to stimulus Y if X and Y have previously been associated together (if they tend to co-occur, e.g. name and face)
What are exogenous components?
Exogenous or evoked potentials are components that depend on the physical property of a stimulus (sensory, size, intensity)
What are endogenous components?
Components that depend on properties of the task (what the participant is required to do with the stimulus)
What is the inverse problem in ERP research?
The difficulty of locating the sources of electrical activity from measurements taken at the scalp (if you’re in the 15th floor of a building and put your ear to the ground, you won’t be able to tell from which floor the drill is coming from)
What is the solution to the inverse problem?
Dipole modelling: trying to solve the inverse problem by assuming how many dipoles (regions of electrical activity) contribute to the signal recorded at the scalp.
