Relationship between reaction time, mental processing speed and motor speed in individuals with mild to moderate brain injury

Transcription

1 Relationship between reaction time, mental processing speed and motor speed in individuals with mild to moderate brain injury Kenneth NK FONG 1, PhD, Marko KL CHAN 2, BSc, Peggie PK NG 2, MSc 1 Department of Rehabilitation Sciences, Hong Kong Polytechnic University 2 Occupational Therapy Department, Kowloon Hospital, Hospital Authority Hong Kong SAR, China

2 Introduction

3 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.

4 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.

5 Aims of Study 1. 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. 2. To compare the performance in these three domains between patients with Brain Injury and healthy adults. 3. To refine the assessment tools in different aspects

6 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.

7 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.

8 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.

9 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)

10 Assessment

11 Outcome Measures Mental Processing Speed Captain s Log (Trail Sequence B) - Time & accuracy Captain s Log (Stimulus Reaction Inhibition) Valpar 7 - rate of work & accuracy Motor Speed Captain s Log (Finger Tapping) Lafayette (Movement Time) Minnesota Manual Dexterity Test (Placing Test) Reaction Time Captain s Log (Stimulus Reaction Time) Lafayette (Reaction Time) Bruininks-Oseretsky Test (Subtest 6)

12 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

13 Mental Processing Speed Valpar 7 Dominant & best hand Outcomes: Total time (Rate of work) Number of errors

14 Motor Speed Lafayette (Movement Timer) Time from leaving 1 st switch to touching 2 nd switch 3 distances between 2 switches (14, 26, 38cm) 10 trials Outcomes: Average moving time

15 Operation of Lafayette instrument 1 = 54cm 2 = 42cm 3 = 14cm Reaction time Initiate cue Moving time Stimulus Stimulus selector Cue delay Distance travel

16 Reaction Time Lafayette (Reaction Timer) Same physical layout as in test of moving time Time from stimuli appears to off 1 st switch 10 Trials Outcomes: Average reaction time

17 Result

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19 Results(1) 1. No significant differences were found in age & education between two groups. 2. Significant differences were noted between two groups in scores of below items: 3. Reaction time: Reaction Timer (p = 0.000), Stimulus Field (p = 0.003) 4. Mental Processing speed: Trail Making (p = 0.000), Stimulus Inhibition (p = 0.001), V7 Rate of work (p = 0.000) 5. Motor Speed: Movement Timer (p = 0.001), Minnesota Placing Test ( p = 0.000)

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22 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.

23 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.

24 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).

25 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.

26 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.

27 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.

28 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.

29 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.

30 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.

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33 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

34 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

35 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

36 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

37 Reaction Time Bruininks-Oseretsky Test (Response Speed) Trials: 2 practice 7 recorded Outcomes: The medium score among 7 scores is the point score

38 Limitation Small sample size Fair internal consistency within the assessments in the same aspect