Learning objectives understand the nature of response time reaction time and movement time understand the role of working memory in choice reaction time break reaction time down into its component parts ID: 561491
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Slide1
REACTION TIMESlide2
Learning objectives
understand the nature of response time, reaction time and movement time
understand
the role of working memory in choice reaction time
break
reaction time down into its component parts
understand
the nature of the Hick-Hyman Law
understand
the role and effect of probability on choice reaction time
understand
the nature of the psychological refractory
period
be aware of some of the factors affecting reaction timeSlide3
Response time
Response time
is the time from the
introduction of a stimulus to the completion of the action required to deal with the
problem
It is made up of
reaction time plus movement time
Reaction time
is
the
time from the
presentation of a stimulus to the beginning of an overt response
Movement time
is
the
time taken to
carry out the motor aspects of the performanceSlide4
Response time
STIMULUS
END OF RESPONSE
RESPONSE TIME
BEGINNING OF RESPONSE
REACTION TIME
MOVEMENT TIMESlide5
Reaction time subdivisions
Reception time
Time for information to pass from peripheral senses to sensory cortices
Opto-motor integration time
, which consists of
stimulus identification
stimulus evaluationmotor preparation (preparing the movement to be undertaken)
Motor outflow timeTransmission of information from the premotor cortex to the musclesOpto-motor integration time is responsible for almost all inter- and intraindividual differences Slide6
Inter- and intraindividual differences
Simple reaction time
(one stimulus and one predetermined response) is faster than
choice reaction time
(
several stimuli and a different response for each
stimulus)With simple RT, stimulus evaluation and motor preparation can take place before stimulus presentationHick-Hyman Law
As the number of stimulus-response couplings are doubled, RT is increasedIf RT is plotted against the log of the stimulus-response couplings there is a linear increaseEach time RT increases by about 150 msSlide7
Probability and reaction time
If a stimulus is likely to occur 90% or 80% of the time it is reacted to faster than when it is likely to occur 50% of the time
Possible reasons:
We focus on most likely stimulus (Alain
and
Proteau
, 1980) We prepare most likely response (Dillon
et al., 1989) Slide8
Psychological refractory period
When 2 stimuli are presented close together RT to
S2
is
slower
than normal RT
The brain can only deal with 1 stimulus at a timeS2 only begins to be processed during movement time to
S1Slide9
S2
S1
R1
R2
PRP
S1
stimulus 1
S2 stimulus 2
R1
response 1
R2
response 2
PRP
psychological refractory period
If
S2
is presented <50 ms after
S1
the two stimuli can be treated as one.
Practice can
not
eliminate
PRP
but can lessen the effect .Slide10
Stimulus and response factors
Stimulus strength
stronger stimuli elicit quicker RT
Stimulus familiarity
we react faster to stimuli with which we are familiar
Sensory modality
auditory stimuli elicit the fastest reaction times
visual – slowed by time taken to transduce light waves to nerve impulses (electric)tactile - depends on where the stimulus is appliedPsychological setSensory set (focusing on stimulus identification and evaluation) is faster than motor set (focusing on motor preparation)Slide11
Foreperiods
Foreperiod
is the time from the warning signal to the presentation of the stimulus (set then bang in a 100 m race)
Constant
foreperiods result in very
fast
RTShort foreperiods result in slow
RTperson has little time to prepare a responseLong foreperiods result in slow RTindividual can not maintain attention and/or physical readinessSlide12
Response complexity
The
more complex
the response the
slower
the RT
Motor preparation takes longer
Stimulus illuminated
When the participant sees that the yellow sign is illuminated, he/she must move their finger from the red button directly to the black (Task 1) or to the black button via the green buttons (Task 2). RT is measured from the
illumination of the yellow sign to the lifting of the finger from the red button
. RT will be longer for Task 2,
even though that initial part is the same in Tasks 1 and 2
.Slide13
Response compatibility
If the
stimulus and response are compatible, RT is faster than when they are incompatible
Compatible situation. The blue sign is illuminated, therefore the person has to press the blue button which is on the same side as the blue sign.
Non-compatible situation. Again the blue sign is illuminated, therefore the person has to press the blue button but it is on the opposite side to the blue button. RT will be slower than in the compatible situation.Slide14
Development and reaction time
RT improves steadily from birth to about 17 years
It plateaus
until about 20 years
Then begins to deteriorate
a slow deterioration and nonlinear in
natureincreases post-50 years are probably due to decreases in brain blood flow and cell loss particularly in the prefrontal cortex
reception times can be affected by decline of the senses