PSY2002 SEMESTER 1 - WEEK 8 Flashcards
compare cognitive control, and EF
top-down mental process, constrating to stimulus driven bottom-up processes
require effort
give examples of core cognitive processes
WM, IC, flexibility
name higher order cognitions
object permanence, self-recognition, mental time travel, theory of mind, tool use/causal reasoning
what real-life act can EF impact
addiction, OCD, depression, jobs, ADHD, relationships, crime, QoL, treatment adherence, maths/reading ability
whys inhibition important in psychology
describes behaviour, decision making, cognitive processes
measures of inhibitory control used in research and relate to clinical and dev psychology, neuroscience AI and robotics
what is associative inhibition
original term used instead of inhibitory control
umbrella term for proactive and retroactive inhibition in context of learning and memory
what is behavioural inhibition, name 3 example
stopping actions
1. deferred gratification
2. response inhibition
3. reversal learning (inflexibility, compulsivity)- discrimination reversal, rule-reversal, wisconsin tasks
name example for response inhibitino
not answering phone when driving
name 3 type of response inhibition
action restraint/withholding
action postponing (waiting)
action cancellation (stopping)
what is cognitive inhibition?
stopping mental process (memory, thoughts, perceptions, emotions)
cognitive inhibition is difficult to quantify or study. what can be done instead
control of movement is similar to controlling ideas, so study principles/mechanisms of cognitive inhibition via studying inhibiting motor response
override planned/already initiated actions, behavioural tasks
what was Freud’s view for inhibitive control
problematic (defined as expression of restriction of ego-function having different cause, linking to concept of anxiety) but earlier Freudian concepts similar to lack of excitation
what does lesioning PFC do with inhibition
demonstrate interference of delayed response task, perseveration
frontal lobe damage also shows disinhibition
define response perseveration, where is it located?
inability to shift from 1 response to another linked to damage of prefrontal-caudate-subthalamic-hippocampal system
define drive disinhibition, where is it located?
related to motivational/emotional processes and associated with prefrontal-hypothalamic-amygdaloid complex
what other brain areas are implicated in inhibition
basal ganglia, hippocampus, cerebellum, brainstem reticular formation
what does stimulation of PFC during go/nogo task cause
reduced activity in PFC motor cortex and resopnse suppression
what is the current view regarding EF coactivity
requires each other and so combination of attention, inhibition, flexibility, allows complex behaviour
what is relationship between inhibition and impulsivity
impulsivity a result of deficient inhibitory process, links to addiction, ADHD, mania, psychiatric disorder
how can inhibition be studied in a lab, but issues of doing this
using response inhibition (however may only correspond to some types of impulsivity, not all impulsivity)
translational potential of animal studies into response inhibition
outline distributions for reaction times
large varibility in reaction time even if simple stimulus-response actions
can be more prepared to respond to certain stimuli (ie, know that green means go)
summarise model of reaction time
from time 0s, each runner described as linear function of form: y=ax
y is runner current position (“activation of process”)
a is speed of runner (process’ slope)
x is time
in reaction times model, what is needed when defining fast/slow reaction times
speed of each runner (slope of each line)
goal line (threshold)
what are model parameters?
slope and thresholds
can be chosen to fit behavioural data given from ppt
for each process, we can determine time when it crossed threshold (follow line up, until hit threshold) = model reaction time
Hanes studied reaction time variability of neurophysiological basis in monkeys, what did he do
stimulus of dot in circle, shifts to outside circle, monkey eyes saccade
record frontal eye field of monkey performing reaction time task
Hanes studied reaction time variability of neurophysiological basis in monkeys, what did he find
neuron increases firing rates before saccade and neurons in frontal cortex indicate that reaction times vary due to rate variability in slope of underlying process
process race toward threshold
outline go, nogo task
ppt needs to respond to some stimuli but not others
measure reaction times and number of correct go/nogo trial
outline stop-signal task
go/stop trial mixed randomly so cannot predict (otherwise response doesn’t need to be inhibited)
different types of stimulus, response, trial types can be used
key parameter = stop-signal delay time (shorter ssd makes stopping easier)
what is measured in stop-signals task
reaction time for go trials and failed stop trials
number of correct/error trials
inhibition functions
stop-signal reaction time
what is an issue of waiting strategy in stop-signal task
if wait, never clap, then 100% success rates
what does stop-signal-reaction-time measure
all 3 components of stopping= signal detection, action selection, inhibition
used to describe how well individual can inhibit response
used in researching neurological/psychiatric condition
summarise the race model of stopping
a race between go, stop processes
process reaching threshold first determines our behaviour
go win= response happens (failure to stop)
stop win= no response happens (successful stop)
give strengths of the race model
mathematically relates signal-respond reaction time, no-stop signal reaction time, inhibition functions, allows estimations of SSRT
written using generic finish time distribution meaning is generalisable to any subject population
give limitations of race model
generalisable as doesn’t specify underlying processes meaning only describes (not explain) reactive control
explain why race model is general
describes both behaviour and underlying cognitive, neurobiological processes and can be applied to different animals and different types of stopping (hand, fingers, leg movement)
and different types of stop-signal tasks (stimuli, task structure)
how can race model be used to model inhibition functions
identify cognitive and neural mechanisms,
compared with patient populations or used in conjunction with imaging (fMRI, EEG)
what is extended race model
includes choice in go process and potential for choice in stop process
what is interactive race model
go process link to movement-related neurons and stop process link to fixation neurons in frontal eye-lid (controls eye movements)
accounts for behaviour, firing rates recorded from movement and fixation neurons in monkeys on counteramdning tasks
in cortical-basal ganglia model (race model), what happens on go, stop-signal trials
go: saccadic responses generated from frontal eye fields and superior colliculus
stop-signal: response inhibited via hyperdirect pathway
allow basis of understanding interaction between brain structure in response inhibition and other task that are constrained by physiology, behaviour and computation
summarise selective stopping tasks
ppt has to do discrimination before stopping, but found that when ppts successfully stop, have longer signal-respond RT than no-stop-signal RT due to low selection demand in simple stopping tasks
stop-rate parameter depend on discriminability, intensity, modality of stop signal that can be interpreted as capacity limitations
define proactive inhibition
ability to adjust behaviour in anticipation of potentially having to inhibit response
“being prepared to stop”
visible as the change in go reaction time
in trials, when is proactive inhibition made
beginning of block or on trial-by-trial basis, suggests flexible cognitive system that adjust itself quickly in response to context info
how can proactive inhibition be measured via stop-signal tasks (implicit and explicit methods)
manipulate degree of proactive inhibition exerted by ppts by providing info on probability of stop-signal
explicit: provide specific cue indicating possibility of stop-signal occuring, trial by-trial/block
implicit: vary probability across blocks
define trial
single presentation of stimulus-response sequence
define block
consists of several trials, typically having specific parameters
eg; reward probability, trial types
define session
consists of one or more blocks, different sessions then separated by longer time intervals (hour/days)
how does proactive inhibition manifest in stop-go blocks
change in average reaction time in go trial between 2 block
summarise how we measure proactive inhibition in go trial/block
- collect all reaction times from go trials in block 1
- average them = mean reaction time for block 1
- do same for block 2
- proactive inhibition score = mean reaction time for block 2 - mean RT for block 1
what is proactive adjustment hypothesis
proactive inhibition involves adjustments of response threshold
how can proactive adjustment hypothesis be tested
present cue indicating if signal relevant for next trial
found increasing response threshold increases finishing time of go process but decreases both probability of incorrect go response on no-stop-signal trials and probability of response on stop-signal trials
summarise research results for stop-signal tasks comparing stop-signal reaction times in PD vs control
tested on and off L-DOPA
longer SSRT in patient >control, but no signif diff between on/off L-DOPA
what is stop-signal response time like in alcohol, methamphetamines, cocaine
longer SSRT> control groups
