Higher cognition Flashcards
1
Q
Executive functioning
- Processes involved
- Age-related EF differences
A
Processes:
- selective attention
- working memory
- task switching
- response inhibition
Age-related differences:
- WM and processing speed decrease with age
- capacity to integrate abstract information decreases with age
2
Q
Response inhibition (EF)
- What is it?
- Tasks
A
Stopping/avoiding a thought or action - stopping automatic processes
TASKS:
- Stroop (1935) - override automatic impulse to read word and read colour instead
- Speed theory = reading arrives to decision-making faster + interferes with slower colour recognition
- Selective attention = colour recognition needs more attention - uses more EF resources so slower RT
- Peret (1974) - left prefrontal lesions –> find stroop particularly hard
- Brain correlates (Leung et al., (2000): fMRI
- activation in central/frontal/parietal cortices
- anterior cingulate + lateral prefrontal cortices particularly
- activation in central/frontal/parietal cortices
- Go/No-go tasks - press buttons for all stimuli except X - inhibit motor response
3
Q
Task switching (EF)
- tasks (2)
A
Task switch:
- 2 levels:
- task 1 (e.g. odd vs even OR consonant vs vowel)
- task 2 –> if you see a different target (e.g. different borders) switch task
Trail-making test
- Switch between 2 types of sequencing
- e.g: 1A2B3C4D etc.
- shows who has EF/EC issues
4
Q
Selective attention (EF) task
A
Flanker paradigm: respond to central target
- if surrounded by incongruent arrows (flankers), reaction time increases
- Richard et al., (2008) - flanker effects
- central notches square/round - ignore flankers either side
- if flanker on different object, no evidence of interference
- reaction time lower for congruent than incongruent
- central notches square/round - ignore flankers either side
5
Q
What guides our actions?
- 2 levels of processing
- times when one is preferable over the other
- Dysexecutive syndrome
A
Desimone & Dunean (1995):
- top-down processing:
- perceptually/hypothesis/expectation-driven processing of information
- bottom-up processing:
- perceptually-driven processing of information
Norman & Shallice (1986) - times when automatic behaviour not optimal + top-down better:
- planning and decision making
- error-correction
- technical difficulties
- overcoming habit
- danger
Dysexecutive syndrome –> affects PFC (stroke/injury/tumour)
- perserveration –> repetition of action previously performed
- distractability –> can’t block out irrelevant stimuli
- utilisation behaviour –> respond impulsively to irrelevant stimuli
- personality change –> apathy, impulsive, hypersexuality, rude
- NO DIFFERENCE in: language, motor, memory skills
6
Q
Planning and decision-making (EF):
- tasks (3)
- brain correlates
A
Tower of london task (Shallice, 1982):
- planning, sequencing and monitoring
- plan steps to move beads from initial position to end point
- most efficiently, lowest RT, lowest number of moves
- Brain correlates - left frontal lobe damage = more moves, trial + error over planning:
- Rowe et al., (2001) - activation in left dorsolateral prefrontal cortex during task
- Newman et al., (2003) - rDLPFC activity associated with other WM tasks - harder = more activation
Multiple errands task (Shallice & Burgess, 1991):
- multi-task in real life high street
- frontal lobe injury:
- fail to plan in organised/coordinated way
- fail to switch tasks
- spend too long planning one tasks so run out of time
Wisconsin Card Sorting Task (Milner, 1963):
- error correction - overcoming habitual response
- sort cards according to rules that then change unexpectedly
- shift rules used due to feedback that previous response was incorrect
- frontal lobe lesions:
- fail to shift rules + stick to previous one
- Monchi et al., (2001) - monitoring feedback associated with DLPFC activation in WCST
7
Q
Frontal lobe importance (in humans)
A
Fuster (1989) - disproportionately larger in humans - 1/3rd of cortical volume
Schoenemann et al (2005) - enlargement matched with high functional connectivity in humans
8
Q
Attention vs awareness
- relation to consciousness
- differences
A
Attention = process by which you focus awareness
- attention is a filter
- modulates awareness and perception
- need to attend to be aware
Awareness = taking conscious notice (it’s the ‘knowing’)
- being able to report the information
Conscious state = state that is available for explicit verbal report (operational definition)
- William James (1890) - attention as the gateway to consciousness + awareness
- Wundt (1912) - attention selects a subset of what is already conscious
- awareness is what we can report from a scene
9
Q
Functions of attention (3)
A
- Orienting function towards the environment
* attentional capture, orienting memory/EF/language - Partial control of the content of consciousness
* ‘not this but that’ - Maintaining alertness
* readiness AND simply not falling asleep - Focus
* visual search –> serial sequential visual search - shows top-down control of attention
10
Q
What is perception?
- what does it depend on?
A
Perception = processing stimuli to the point that it stays in memory and/or central executive can work with it
- we are only consciously aware of a small portion of what we perceive
- can automatically make use of information we’re not consciously aware of (attended or not)
- if you PERCEIVE - you are CONSCIOUSLY perceiving –> otherwise it’s just sensing
Depends on: arousal, attention, type/salience of stimuli
NB: not consciously aware of exactly how things are processed (e.g. in V1)
11
Q
Ambiguous perception and attention:
- illusions x2
A
Things we see may have properties we create –> automatic attention drives perception
- Hollow face illusion
- we KNOW it is concave (cue to visual cues) but we perceive it as convex (NB: salience)
- illusion/perception is so strong you can’t exert cognitive control over it
- attention is continuous but perception changes –> shows awareness + attention independent
- Necker cube
- conscious cognitive control can change view of cube (coming out towards or going back into page)
- attention can change awareness
12
Q
Does attention = awareness?
- neuropsychological evidence for NO
- behavioural + neurological evidence for NO
- behavioural evidence for NO
A
- Blindsight –> attention without awareness
- De Gelder et al., (2008): patient TN - bilateral lesion of striate cortex
- no conscious vision (reports blindness) BUT can navigate obstacles
- brain pathway from eyes that doesn’t require awareness - reports to motor plan + action system directly (bypassing occipital cortex via superior colliculus)
- Inattentional blindness –> awareness without attention
- fails to notice fully visible but unexpected object because attention is elsewhere
- Simons & Chabris (1999) - number of ball passes counted - miss gorilla (but processed in vision)
- Cherry (2016) - we focus on important things and rely on existing schemas to fill in the rest (economical)
- Change blindness –> attention without awareness
- fail to notice large changes in visual scene because can’t hold it in a flow of consciousness
- brief transitory event in visual field distracts attention - can’t hold scene in memory
- Reddy et al., 2006:
- single neurons in human medial temporal lobe can detect change
- neural activation correlates with awareness BUT is modulated by attention
- flickering figures - can’t overtly attent
- specific neurons capture attention shift OR awareness change - separate
- single neurons in human medial temporal lobe can detect change
13
Q
Dissociations:
- unconcious/conscious x top-down attention/no top down attention
A
Unconscious:
- top-down attention required:
- priming, visual search, adaptation, object processing
- top-down attention NOT required:
- formation of after-images
- rapid vision (<120ms)
Conscious:
- top-down attention required:
- WM, detection + discrimination of unfamiliar/unexpected stimuli
- top-down attention not required:
- pop-out visual search, iconic memory, gist
14
Q
Consciousness: forms and functions
A
Forms of consciousness: awareness of self and/or environment
- Awareness –> realise something has happened and use that information
- metacognition
- subjective awareness of mental events
- James (1890) - stream of thoughts/feelings/emotions
- capacity for mental travel (human component of cognition)
Functions of consciousness:
- monitoring mental events
- self-monitoring = metacognition
- control: EF and cognitive control
15
Q
Metacognition (form of consciousness)
- what is it?
- neuropsychological patients
A
Metacognition = ability to know our own cognitive functions and use that knowledge
- self-awareness linked to goal formation - need it to plan (i want/i need)
- Milner & Rugg (1992) - many neurologically impaired patients lack metacognitive insight that something is wrong with them
- Clive Wearing (temporal lobe damage - memory; frontal lobe damage - EF)
- constantly living in the present - no flow of consciousness for 2mins+
- metacognition with no future/past
17
Q
Models of consciousness:
- Norman & Shallice (1980)
- Baars (1989)
- Global Neuronal Workspace hypothesis (Dehaene et al., 1998)
A
Norman & Shallice (1980)
- conscious processing involved in supervisory attentional regulation by PFC
- it regulates lower-level sensorimotor chains
Baars (1989)
- lots of percepts come into central processor
- if the percepts enter global workspace - we become conscious of it
Global Neuronal Workspace Hypothesis (Dehaene et al., 1998)
- global workspace (conscious) has massive connectivity to different areas (particularly dense in PFC)
- when you have to work with objects from LTM, attention, perception, tasks –> they enter global workspace
- explains associations of consciousness with integrative cognitive processes (attention/decision-making)
18
Q
How events reach consciousness:
- Dehaene et al., (2006)
- Dehaene et al., (2012)
A
Dehaene et al., (2006):
- Subliminal processing
- feed-forward propagation
- activation propagates BUT weak + quickly dissipates
- Preconscious processing
- activation can be strong, durable and spread to specialised sensorimotor areas
- BUT: can’t reach frontoparietal regions without attention
- Conscious processing
- activation reaches frontoparietal areas
- can be held in WM and used to guide actions + made decisions
Dehaene 2012:
- brain activity in visual cortex is the same regardless of awareness (1,2,3)
- at 200/300ms - huge divergence - conscious access is a late event
- conscious –> activation in inferior frontal cortex + inferior parietal cortex
- unconscious –> activation limited to temporal lobe
- non-linear activation of frontoparietal areas - all or nothing
19
Q
Baars 2010 model
A
Combines:
- Baddeley & Hitch (1974) WM model
- Atkinson & Shiffrin (1968) multi-store model
Key points:
- Sensory systems
- receive input from receptors (energy –> neuron firing)
- sensory cortices mapped in topographical way
- Long-term stores
- range from perceptual memory to highly practiced habits
- when not activated - unconscious contents
- WM
- input to LTM (which is divided into implicit + explicit)
- explicit = conscious knowledge (semantic + episodic)
- implicit = unconscious (priming/habits/motor skills)
- inputs from primary/secondary cortices OR memory
- frontoparietal network (CE) to flexibly work with inputs
- input to LTM (which is divided into implicit + explicit)
- Attention
- attentional capture (bottom up)
- context-driven - salience/memory of stimulus = more attention paid
- top-down modulation - CE drives attention towards incoming stimuli
- to take decision/act
- attentional capture (bottom up)
- Conscious event
- when something is processed to the point that it can be used by the central executive
