1
Q
types of brain damage
A
- trauma
- strokes
- tumors
- infectious diseases
- epilepsy
2
Q
define single dissociation with an example
A
- occurs when patient shows selective impairment in one cognitive task while performing normally on another task
- single dissociation needs: 2 groups e.g patient and control as well as 2 tasks ti determine ifn deficit is specific to function or general impairment
3
Q
limitations of single dissociation
A
- don’t definitively prove that 2 functions are independent as impaired task could’ve just been more difficult or required more concentration
- solve using double dissociation
4
Q
define double dissociation
A
- when a third group is added to draw a comparison e.g add a different brain deficit group as well
- patients just need to be better at one task than the other compared to other groups
- rules out possibility that one task is just ‘harder’
5
Q
limitations of patient/lesion studies
A
- assumes that mental processes occur in isolation from other mental processes
- lesion size and location vary so hard to find similar group of patients
- connections between areas not considered
- individual differences
- no experimental contrail over lesion location
6
Q
benefits of patient studies
A
- shows which areas are necessary for particular cognitive function through DD
- shows cognitive, emotional and social consequences of deficit
- cost and time effective
- can reveal new insights about brain function without experimental design
7
Q
describe the basis if fMRI
A
- uses Blood Oxygen Level Dependent response where levels of oxyhaemoglobin change, increased oxyhaemoglobin = active brain area
8
Q
what is cognitive subtraction
A
measure brain activity by subtracting brain activity/ reaction time of a control task from an experimental task
9
Q
name and describe the 4 major thinkers of neural theory
A
- Helmhotz- measured speed of action potentials proving signal was electrical and physical
- Golgi- invented method of staining neurons with silver nitrate
- Cajal- used Golgi method to produce detailed drswings of neural assemblies and discovered synapse and functional polarity of neurons
- Hebb- 1st comprehensive theory of how brain activity produces complex phenomena,introduced cell assemblies as elements of cognition
10
Q
name the 3 main neuroglia
A
- Astrocytes- supply nutrients, structural support, clean up and are chemical protection for neurons
- Oligodendrocytes- from processes which produce myelin sheath
- Schwann cells- wrap neurons and provides guide to support regeneration of axons of damaged neurons
11
Q
define membrane potential and ion exchange
A
- resting potential -70mv= polarized
- membrane potential maintained by sodium-potassium pump- to keep -70mv sodium must be higher outside so pump puts 3 na out of cell for every 2 potassium pumped in
- when excitation reached na channels open= more na in cell increasing potential, then k opens closing n causing repolarization
12
Q
define Excitatory PSP
A
- when NT’s like glutamate cause na channels to open resulting in increase in na causing depolarisation moving neuron closer to firing threshold
13
Q
define inhibitory PSP
A
- when NT’s like GABA cause k channels to open letting k leave, or Cl opens allowing Cl to enter causing hyperpolarisation decreasing membrane potential moving neuron away from firing threshold
14
Q
glutamate
A
- excitatory- increases membrane potential
- activates several types of receptors-AMPA + NMDA
- when binds to AMPA it allows sodium to enter cell causing EPSP
- critical messenger for long term potentiation
15
Q
GABA
A
- inhibitory- decreases membrane potential
- prevents excessive excitation
- GABAa controls Cl , GABAb controls K channels
16
Q
dopamine
A
- effect of DA can be excitatory, inhibitory or modulators(long lasting) depending on type of receptor
- dopaminergic mesolimbic reward system
17
Q
define agonists
A
- facilitates postsynaptic effects
18
Q
define antagonists
A
- inhibit postsynaptic effects
19
Q
define the 4 points for mechanisms of drug action
A
- serve as precursors- L-DOPA for DA’
- stimulate or block post-synaptic receptors-nicotine
- block reuptake- cocaine
- inactivate enzymes or prevent NT storage
20
Q
addiction and reinforcement
A
addiction driven by reinforcement of behaviour linked to dopamine release in Nucleus Accumbens
21
Q
define positive reinforcement
A
- presentation of appetitive stimulus like euphoria
22
Q
define negative reinforcement
A
removal of aversive stimulus like anxiety
23
Q
explain how cocaine works
A
- agonist
- blocks reuptake of DA
- long term use leads to reduced DA receptors in basal ganglia
24
Q
explain how alcohol works
A
- binds to receptors for acetylcholine, sert, GABA and glutamate
- is a glutamate antagonist that interferes with learning and memory
- addictive properties due to reinforcement
25
what are the 2 main forms of learning
* classical conditioning- association between 2 stimuli and an automatic response
* operant conditioning- association between a learned response and a stimulus strengthened by reinforcement
26
define Hebb's rule
* cells that fire together, wire together
* if a synapse is repeatedly active while post synaptic neuron is firing, that synapse is strenghtened
27
define long term potentiation
based on Hebb's rule
process through which experience changes the connectivity of neurons in a network, imprinting a record of learning as memory
28
define role of the NMDA receptor in learning and LTP
* depolarisation moves Mg that is blocking NMDA receptor allowing Ca to enter
* entering of Ca triggers insertion of more AMPA receptors and increases presynaptic glutamate release creating stronger synaptic connection
29
role of hippocampus in memory
* it isn't necessary for STM
* isn't storage sight for LTM
* critical for consolidation of short term declarative memories into long term storage
30
what is attention
* the preferential selection of a subset of that info
* involves both voluntary/controlled processes and reflexive processes
31
selective attending -Broadbent's model
* relevant inputs selected thorugh top down processes at an early stage of processing
32
early vs late selection in attention
* early-affects perceptual analysis-processes info from select locations
* late- affects higher level stages-decisions,semantic memory encoding
33
define voluntary/reflexive orienting
* voluntary evoked by central symbolic cues-slow
* reflexive evoked by peripheral non symbolic cues-fast
34
what are the 3 ways that attention selects info for preferential processing
* spatial location-increased activation in sensory areas regarded to space
* item attributes- activation increased in brain region for processing attended characteristics
* objects- increased activation in area that processes objects
35
what are the 3 attentional networks in the brain
* alerting-> maintaining high state of sensitivity to incoming stimuli
* orienting-> attending to source of sensory signal
* executive-> directs attention according to an individuals goals
36
name the 5 ways to study attention
1. Posner's cueing paradigm
2. visual search tasks
3. object based attention
4. stimulus onset asynchronies
5. ERP's fMRI
37
define executive functions
* give organisation and order to actions and behaviour
* includes representing and maintaining goals, planning for future and initiating behaviour
38
what are the 4 subregions of PFC
* dorsolateral
* ventrolateral
* anterior pole
* ventromedial
39
name the 3 characteristics of PFC anatomy
* late phylogenesis
* late ontogenesis
* highly interconnected with virtually all brain areas
40
what are the tasks to measure executive control
* Wisconsin card sorting task
* digit span
* stroop task
* flanker task
41
name the fissures that separate and connect the hemispheres
* separated by sagittal fissure
* connected by commissures corpus callosum, and anterior commissure
42
how to test hemispheres for auditory input
* auditory input strongest to contralateral hemisphere
* test hemispheric differences with dichotic listening
43
how to test hemisphere for visual input
* visual input contralateral(opp side)
* test each hemisphere using lateralised visual presentation
44
how to test hemispheres with fMRI
* reveals lateralisation of main brain regions involved in cognitive processes
* activity in 2 hemispheres can be compared and differences plotted on lateralisation map
45
define disconnection syndrome from split brain
* split brain prevents spread of seizure activity but creates disconnection syndrome where each H is disconnected and doesn't have access to thoughts,memories of the other
46
define functional asymmetry in terms of language abilities
* when there is unilateral brain damage causing an aphasia it suggests that language centres are predominantly LH
47
define Cartesian dualism
* mind and body are separate realms
* body is an earthen machine, mind is essential to our breing in a way that body isn't
48
define monism
* more modern approach
* the mind is the brain
49
what are the 6 points of consciousness
* awakeness vs asleep
* general alertness
* focal attention
* reflective state
* self awareness
* qualia- subjective experience
50
what are the 3 ways to approach consciousness
* operationalised- can it be defined and observed objectivEly
* implementation- can we find ways to implement it in artificial network
* adaptivity- is there an evolutionary function
51
what is the global neuronal workspace theory
* processing a stimulus may reach consciousness only if it is integrated into a large scale system of cortical activity
526
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