Cognitive Neuroscience (1b) Flashcards
(10 cards)
Outline a brief history of cognitive neuroscience
- Behaviourism 50s/60s - initially believed this was the only way to understand behaviour, no interest in the mind
- mind perceived as a ‘black box’ - Cognitive Science 70s/80s - development of the computer, new metaphor = brain as an INFO PROCESSOR
- didn’t have the tools yet to look into the brain - Cognitive Neuropsychology 80s/90s - revolution of brain scanning techniques (trying to find these ‘modules)
- Cognitive Neuroscience 1990s–>
- further revolutions to measure FUNCTION (eg. fMRI) - allowed research to happen while ppl completed tasks
What is computerised cognitive testing
Measures REACTION TIMES and/or ACCURACY in different conditions
Relies on SUBTRACTION LOGIC - if you have 2 conditions that differ by a single process, the difference in RT/acc between the two conditions should reflect the operation of that process
HOWEVER: think - what else could be impacting that condition, are there difference? how well are we controlling it?
What is neuropsychology
Inferring the function of brain regions from the pattern of deficit when damaged
- originally: used double dissociation logic
- more recent studies use lesion mapping and large samples
- allows causal statements about brain-behaviour relationships
- problem: brain regions are LARGE (hard to be precise)
What is fMRI
Visualising functional brain activity during task or rest
–> measures BOLD (blood oxygen dependent signal) - which is a PROXY for neural activity
(doesn’t actually measure neural activity)
+: high spatial resolution
-: low temporal resolution
What is EEG
Recording the electrical (neuronal) signals from the scalp
–> has VERY fine temporal resolution
- but very poor SPATIAL resolution
What is TMS
Magnetic field generator placed on surface of head
- produces electrical currents in the brain region under the coil via electromagnetic induction
- idea is to produce a ‘virtual lesion’ in the brain
- delivers a ‘pulse’ time-locked to a specific part of a task that the subject performs, possible to investigate the effects of LOCALISED NEURONAL DISRUPTION
+ high temporal precision
+ can make inferences about whether brain regions are involved in certain processes
- limited to brain regions near the scalp (cannot look at subcortical structures
What are (monkey) single unit recordings
Monkey - usually macaque is training on a computerised task
Then anaesthetised, skull opened, and an electrode inserted into the brain
On awakening: monkey performs the trained task with the neural activity recorded
+ Has EXCELLENT temporal and spatial resolution - recording directly from neurons
- Arguably unethical, translation to humans can be tenuous
What are activation vs deactivation techniques
Activation: fmRI, PET
- Purpose: Measure brain activity while a person is doing a task.
- How they work: Detect changes in blood flow or metabolic activity (which indicates neural activation).
- Type of Evidence: Correlational – show which brain areas are active but cannot confirm that these areas are necessary for the behavior.
- Example: fMRI shows that the prefrontal cortex is active during a memory task, but this does not prove that the prefrontal cortex is essential for memory.
Deactivation: TMS, Neuropsychology (lesion study)
- Purpose: Temporarily disrupt or permanently study loss of brain function to see how behavior changes.
- Type of Evidence: Causal – if disabling or damaging an area disrupts a behavior, that area is likely necessary for that behavior.
- Example: Using TMS on the motor cortex makes it harder for a person to move their hand, proving this area is essential for motor control.
What three questions does cognitive neuroscience help us answer?
- Functional Localisation
- It’s a TWO STEP PROCESS
i. Cognitive Ontology - deciding on the basic ‘building blocks’ of cognition
ii. Mapping building blocks to brain regions - Mechanics
- How do these mental modules work and how are they implemented in terms of brain circuitry - Connectivity
- How different brain regions interact, what processes occur and pathways are created
What are some assumptions of cognitive neuroscience
Can we reduce all mental phenomena to physical brain processes - the search for the ‘mind’ within the brain
Cognitive neuroscience DOESN’T REQUIRE you to accept that complex phenomena can be reduced to individual neurons
Cognitive neuroscience suggests that there is an intermediate level of description at the level of neuronal systems
–> But systems don’t necessarily have to be mapped to discrete brain regions
