methods of cognitive neuroscience Flashcards
how might we define a mental representation
anything that means something to an individual
explain Posner’s letter matching task
the subject responds “same” when both letters are either vowels or consonants and “different” when they are from different categories.
what were the findings of Posner’s original matching task
Found reaction times varied for different conditions - fastest reaction time when identical - slowest when different categories
how did Posner argue letter processing worked
identity representations activated first, phonetic second and categorisations last
How did Posner change his task for the second version
Stimulus onset asynchrony - an interval separates the presentation of the two letters
explain the memory comparison task
Subject shown a set of one two or four letters, asked to memorise and then shown a singular letter and have to indicate if it is a part of the memory set
what were the findings of Posner’s second matching task
Found as the interval increases, the difference in reaction time between conditions shortened
usual findings of memory comparison tasks
reaction time increases with set size
where are single cell recordings used
humans
animals
treating epilepsy
visual and audio tasks
describe the method of single cell recordings
Microelectrode inserted into brain tissue and action potentials recorded, ideally of a single neuron (usually extracellular)
Various sensory stimuli presented and neuronal activity is monitored
advantages of single cell recording
good spatial resolution
good temporal resolution
disadvantages of single cell recording
samples only small section of neuronal system
causes of brain damage
- Trauma
- Stroke
- Tumours
- Neurodegenerative diseases
- Infectious disorders
Functional neurosurgery
what is an EEG
Electrodes attached to the head to measure electrical activity in the brain
what is an ERP
Event related potential
-electrodes placed directly onto brain and response to specific event measured
what are the origins of functional neurosurgery
lobotomy - used to treat insanity
define functional neurosurgery
Altering the activity of a brain area by either using ablation (removing), electrical or pharmacological methods to establish overall more normal patient function.
what may functional neurosurgery be use for
Movement disorders
Psychiatric disorders
Chronic pain
Epilepsy
Tumours
what is a single dissociation
Patient group shows impairment on one task and not on the other
what is a double dissociation
One patient shows impairment on one task
Second patient shows impairment on another task
what type of dissociation provides better evidence for selective impairment
double
what is an issue with using correlations
only shows a relationship, cannot establish causation
what are optogenetics
using light to manipulate neuronal activity
what is TMS
transcranial magnetic stimulation
what does TMS do
Low level currents that result in action potentials under the anodes
what is an fMRI
functional magnetic resonance imaging
what does fMRI measure
BOLD levels
what are BOLD levels
Blood oxygen level dependent - depletion of oxygen from the activated cells
