Relationship between reaction time,
mental processing speed and motor
speed in individuals
with mild to moderate brain injury
Kenneth NK FONG1, PhD, Marko KL CHAN2, BSc, Peggie PK NG2,
MSc
1Department
of Rehabilitation Sciences, Hong Kong Polytechnic
University
2Occupational
Therapy Department, Kowloon Hospital, Hospital
Authority
Hong Kong SAR, China
Introduction
Background
1. Slowness of reaction time and processing speed
were common difficulties for persons with brain
injury.
2. Study support trade off between accuracy and
time in tasks of people with brain injury.
(Geldmacher & Hills,1997)
3. Lack of study to investigate the relationship
between reaction time, mental processing speed
and motor speed of the people with brain
injury.
Background
„
„
„
„
„
Why Occupational Therapist concern?
Common problem of brain injury
Processing speed affect the skills acquisition.
(Brigman & Cherry, 2002 )
Relationship between work/instrumental
Activities of Daily Living and processing
speed.
=> Diff. to sustain in job and resume life role.
Aims of Study
1.
2.
3.
To investigate the relationship between three
domains(mental processing speed, motor speed, and
reaction time) in patients with Brain Injury of mild
to moderate severity and compare with the normal
subjects.
To compare the performance in these three domains
between patients with Brain Injury and healthy
adults.
To refine the assessment tools in different aspects
Method
„
20 out-patients (mean age = 35.6, male/ female
= 4:1) with mild to moderate brain injury
admitted consecutively into Cognitive training
Center of the brain injury (Occupational
Therapy Department) of Kowloon Hospital
were recruited.
„
16 of them were diagnosed as traumatic head
injury while 4 of them had other brain injury
diagnoses with similar features.
Method
„
„
„
„
„
Inclusion criteria:
post-onset of brain injury ≥ 6 months and in
Rancho’s level ≥ 7
ability to follow and understand instructions
no visual or auditory impairment
at least one functional hand (must be the best
or dominant hand) and ability to use “mouse”
in computer operation.
Method
„
„
20 healthy subjects (mean age 38.8, male/
female = 1:1) with closely matched age and
educational level were selected for the purpose
of comparison.
All subjects were evaluated by 3 selected
measures for domains, namely reaction time,
motor speed, and mental processing speed, at a
single time point.
Definition:
„
„
„
Reaction time (反應時間): Time duration for
production of response to stimuli (Incoccia et al.,
2004)
Mental Processing Speed (訊息處理機能速度):
Time duration to process the mental tasks.
Motor Speed (動作速度): Time duration to
execute the movement (Ma & Trombly, 2004)
Assessment
Outcome Measures
Mental Processing
Speed
Motor Speed
Captain’s Log
Captain’s Log
(Trail Sequence B) - (Finger Tapping)
Time & accuracy
Captain’s Log
(Stimulus Reaction
Inhibition)
Lafayette
(Movement Time)
Valpar 7 - rate of
work & accuracy
Minnesota Manual
Dexterity Test
(Placing Test)
Reaction Time
Captain’s Log
(Stimulus Reaction
Time)
Lafayette
(Reaction Time)
Bruininks-Oseretsky
Test (Subtest 6)
Mental Processing Speed
Captain’s Log (Trail Sequence B)
„
„
„
„
Beginner mode
Target order: Off
Task time: 1 - 6 minutes
Outcomes:
„ Average Reaction
Time × No. of Correct
Responses
„ Incorrect Responses
Mental Processing Speed
Valpar 7
„
„
Dominant & best hand
Outcomes:
„ Total time (Rate of
work)
„ Number of errors
Motor Speed
Lafayette (Movement Timer)
„
„
„
„
Time from leaving 1st
switch to touching 2nd
switch
3 distances between 2
switches (14, 26, 38cm)
10 trials
Outcomes:
„
Average moving time
Operation of Lafayette instrument
1 = 54cm
2 = 42cm
3 = 14cm
Initiate
cue
Reaction
time
Stimulus
selector
Moving
time
Cue delay
Stimulus
Distance
travel
Reaction Time
Lafayette (Reaction Timer)
„
„
„
„
Same physical layout
as in test of moving
time
Time from stimuli
appears to off 1st switch
10 Trials
Outcomes:
„ Average reaction
time
Result
Results(1)
1.
2.
3.
4.
5.
No significant differences were found in age &
education between two groups.
Significant differences were noted between two
groups in scores of below items:
Reaction time: Reaction Timer (p = 0.000),
Stimulus Field (p = 0.003)
Mental Processing speed: Trail Making (p =
0.000), Stimulus Inhibition (p = 0.001), V7 Rate of
work (p = 0.000)
Motor Speed: Movement Timer (p = 0.001),
Minnesota Placing Test ( p = 0.000)
Results(2):
„
„
„
Age mental processing speed, reaction time, and
motor speed ˊhealthy group × patient group.
Nil significant differences between healthy subjects
and patients with brain injury in accuracy on
complex tasks such as V7. However, the speed is
lower than the healthy people.
Also, errors in V7 were detected with faster
responses in movement timer and reaction timer
ˊ patient group × healthy group.
Results (3):
„
Mental processing speed with the
reaction time and motor speed
ˊhealthy group × patient group.
„
Trail speed only shows significant
relationship with the Valpar 7 but it is not
significantly correlate with its error.
Discussion (1)
„
The results substantiated the presence of
reduced mental processing speed, motor speed
and reaction time separately in patients with
mild to moderate grade brain injury than an
age-and education-matched comparison group
(healthy people).
Discussion(2)
„
Age was correlated to mental processing speed,
reaction time, and motor speed in the healthy
group but not noted in the patient group.
„
Age was not the key factor of the prediction of
performance .
Discussion(3)
„
Nil differences between healthy subjects and patients with
brain injury in accuracy on complex tasks but the speed is
lower.
„
Patients tended to sacrifice speed of performance to
maintain accuracy in the tasks that demanded regulation
and programming.
This trade-off phenomenon suggested that both accuracy
and the time required to perform the task should be
evaluated simultaneously.
„
Discussion(4)
„
„
Less correlation was noted in the
significant correlations among different
measures for patients with TBI than for
the healthy subjects.
Need for separate clinical examination
and training in various aspects of
subjects.
Discussion(5)
„
Trail Speed was not significantly correlated
with the error noted.
„
May be due to:
Fair manipulation of ‘mouse’.
Reduce sensitivity of ‘mouse’.
Limitation of using computer => affect the result
during comparison.
„
„
„
Future Direction
„
„
„
Study on different sensory aspect: Auditory
processing is slower than visual processing
(Madigan,2000)
Study on the training protocol of the
processing speed.
Study on the generalization to the tasks.
Conclusion:
„
„
„
Lack of relationship among mental
processing speed, motor speed, and
reaction time in patients with mild to
moderate grade of Brain Injury.
Marked reduction in the above components
of the brain injury patients.
More comprehensive training and
assessments protocols are indicated.
Mental Processing Speed
Captain’s Log
(Stimulus Reaction Inhibition)
„
„
„
„
„
„
„
Dominant & best hand
Advanced
8 seconds response time
3 seconds inhibition time
Distraction stimuli: Off
Auditory stimuli: Off
Outcomes:
„
„
„
Average reaction time
Inhibition errors
Response & non-response
errors
Motor Speed
Captain’s Log (Finger Tapping)
„
„
„
„
Dominant & best hand
10 seconds trial
10 seconds rest
Outcomes:
„ No. of trials
„ Average tapping rate
per second
Motor Speed
Minnesota Manual Dexterity Test
(Placing Test)
„
„
„
„
Dominant & best hand
Begin on right
Pick up the bottom disk and
insert it into the top hole of
the board in some column,
then pick up the next disk in
the column and so on.
Outcomes:
„ Total time of 1 trial
Reaction Time
Captain’s Log (Stimulus Reaction Time)
„
„
„
„
„
„
Dominant & best hand
Beginner
Distraction stimuli: Off
Auditory stimuli: Off
Task time: 1 minute
Outcomes
„ No. correct responses
„ Average reaction time
„ Response & nonresponse errors
Reaction Time
Bruininks-Oseretsky Test
(Response Speed)
„
„
„
Trials: 2 practice
7 recorded
Outcomes:
„
The medium score
among 7 scores is
the point score
Limitation
„
„
Small sample size
Fair internal consistency within the
assessments in the same aspect