Action Preperation Flashcards
Reaction time
Interval between stimulus and initiation of muscle response (movement)
E.g. time between gun goes off and first initiation of movement
2 reaction time components
- Premotor time
- Motor time
Pre-motor time
Indicates perceptual and cognitive decision making activity (neural aspect)
- before any muscle activity
Motor time
Time between electromyography activity and the movement we see
Info processing model of premotor activities
Perception (stimulus identification) -> cognition (response selection) ->action planning (response programming)
What does response time include
Reaction time and movement time
Movement time
Interval of time between start and end of movement
What are RT and MT
Independent measures
Fast reaction does not mean fast movement in many situations
When does muscle activity occur
During motor time and movement time
How do we know how much time we spend in each phase
Donders subtractive method
Donders subtractive method
Measure duration of each stage of info processing using 3 different conditions and 4 stages in RT paradigm
4 parts of RT
Cue to move, start of muscle activity, movement start, movement end
3 conditions of Donders subtractive method
- Simple RT (task a)
- Choice RT (task b)
- Discrimination RT (task c)
Simple RT
One signal, one response
E.g. stop sign
Choice RT
More than one signal, each with own response
E.g. traffic light
Discrimination RT
More than one signal, one response
Go or no go
4 stages in RT paradigm of Donders subtractive method
- Stimulus detection
- Stimulus recognition
- Response selection
- Response programming
Stimulus detection
Determining if sitmulus has occurred
Stimulus recognition
Identify what stimulus it was
Response selection
Choosing correct response
Response programming
Generating motor commands to make movement happen
What does stimulus detection and stimulus identification of the Donders subtractive method line up with in the info processing model
Perception
What does response selection line up to in info processing model
Cognition
What does response programming from Donders subtractive method line up with in info processing model
Action planning
What parts of Donders subtractive method are used in choice RT
Stimulus detection - stimulus recognition - response selection - response program
What parts of Donders subtractive method are used in go or no go
Stimulus detection - stimulus recognition - response program
What parts of Donders subtractive method are used in simple RT
Stimulus detection - response program
Which type of RT has more chance of error
Discrimination
6 situation and task characteristics that affect reaction time
- # of choices
- Predictability of choices
- Probability of pre cue correctness
- Stimulus-response compatibility
- Regulatory of foreperiod
- Order of stimulus presentation
Hicks law
Number of choices
RT will increase as number of choices increases
What is number of choices interested in
Process time from input to output
Increasing number of choices influences what
Decisions making -> increases response selection stage of info processing -> increase in RT
Each time number of choices doubles what happens
RT increases by nearly an equal amount
To decrease reaction time in hicks law
Want to decrease amount of choices
When can hicks law not be applied
When some of the choices can be predicted with precues
What is precuing technique
Involves presenting a precue before the signal to move
what does precue provide info about
Some, none, ore all the options defining the desired response
As predictability of one of the possible choices increases
Reaction time decreases
As number of pre-cued dimensions increase
RT decreased
What is the benefit of precue info
The participant only need to prepare non precued dimensions - decreased RT
What must happen to gain benefits from the precue
Need to maintain focus
Probability of precue correctness
If there is higher probability of a particular choice occurring, the performer will likely prepare that movement choice in advance of reaction stimulus
What is the cost-benefit trade-off of probability of precue correctness
Cost= slower RT if bias is incorrect
Benefit= faster RT if bias is correct
Stimulus-response compatibility
RT improves with the compatibility between the sitmulus and the response
RT increases if stimulus suggests one type of response but required response is different
Left light means left button and right light means right button
Spatially compatible
Left light means press left side and right light press on right side
Effector compatible
Left light means right button and right light means left button
Spatially incompatible
Left light triggers right hand and right light triggers left hand
Effector incompatible
If left light means right button but arms crossed and pressed with left finger
Effector compatible
Location is spatially compatible if
Signal on right side of screen corresponds to key location on right side of the keyboard
Effector is compatible if
Signal on left side of screen corresponds to key press with left hand
Which incompatibility has greatest effect on RT
Spatially incompatibility
Strop test
RT increases (and numbers of errors) when the sitmulus (meaning of word) is not compatible with required response (colour of text)
What do we process faster: meaning of word or appearance of font
Meaning of word
What is most affected by strop effect
Response selection/cognition
What other factors affect stroop test
Number of stimulus response alternatives, S-R compatibility and amount of practice
Foreperiod
Time between warning signal and a “go” signal
Effect of fore period length on RT
If foreperiod constant, simple RT decreases
- performer can anticipate timing
What can we attribute the shorter RT associate with constant fore periods to
Anticipation of the performer
Difference between foreperiod and precue
Foreperiod- no info just a warning period
Precue- info about direction, or about task, etc.
Order of stimulus presented
Situation that require person to respond to a signal with an action then respond to another signal with a different action
Ie. bball defence: offence fakes right then moves left
RT will be slower for defensive players second movement than first
What causes RT to seconds movement to be slower than first
Psychological refractory period
Reflects a distinct limitation in action prep process
Why is there a psychological refractory period
Response 2 cannot be selected until first movement is initiated
When can PRP be eliminated
If stimulus 2 occurs after response 1
2 characteristics of the performer affecting reaction time
- Level of alertness
- Where attention is directed
Alertness of performer influences
-time they take to prepare a required action
- quality of action itself
Two types of performance situation where alertness important
RT task- short length but needs response quickly and accurately
Long term maintenance of alertness- respond fast and accurate but signals are infrequent and irregular
What sort of tasks is alertness important for
Immediate and longer term tasks
Immediate tasks (RT tasks)
Optimal length between warning signal and “go” signal
1-4 seconds for simple RT tasks
If go signal too soon after warning signal then RT increases
If go signal too later after warning signal then RT increases
“Vigilance” tasks (long term )
Longer term maintenance for irregular, infrequent stimuli
Increase time between signals= increas RT and errors
Negatively affected by sleep deprivation
2 important components when reacting as fast as possible to signal
- RT
- Movement time
What to focus when reacting
Can focus
on signal itself (sensory set)
On movement required (motor set)
What focus shortened prep time
Focusing on signal (sensory set)
Decreased prep time decreased RT
