OPM(A): Using the Perceive, Recall, Plan and Perform System to assess cognitive deficits in traumatic brain impairment: A case study

Kerrie Fry, Leanne O'Brien

This paper is derived from a presentation at the OT Australia, AAOT 19th National Conference. Perth, 1997, May.

Kerrie Fry, BAppSc(OT), is an occupational therapist at the Brain Injury Unit, Westmead Hospital, Westmead, NSW.

Leanne O'Brien, BAppSc(OT), is an occupational therapist at Mount Wilga Private Hospital, Hornsby, NSW.

INTRODUCTION

Occupational therapy intervention in the Brain Injury Unit at Westmead Hospital varies according to the client's individual needs and level of recovery. The role of occupational therapy includes monitoring of post traumatic amnesia (PTA) status, upper limb orthotic prescription and fabrication, seating modification, upper limb assessment and retraining, home assessment and equipment prescription as well as assessment and retraining in self maintenance. Our main focus is assessing and assisting a persons ability to perform self maintenance, domestic and community tasks and routines relative to their previous and expected occupational roles. As part of this focus, we assess how a person's physical and cognitive component deficits impact on performance.

ASSESSMENT OPTIONS

In assessing functional cognition, we need to obtain a baseline of performance which will enable us to determine client centred goals and guide intervention. Further assessment is then required to determine the effectiveness of our intervention. Various standardised and formal observational assessments exist, however, we have found that they generally have limitations in general application to clients with traumatic brain impairment. Although standardised assessments are objective, measure change and have a clear administration procedure, we have found that they assess clients under contrived, rather than real world conditions. There are often barriers to test format, for example, post traumatic amnesia status. They are costly and some require intensive training for use. They are limited to the tasks set for assessment and the results cannot always be generalised to a person's ability to carry out individual, everyday occupational performance tasks and routines. Observations of performance relate to function, are contextually relevant and are less culturally biased. However, these observations are subjective and require a good understanding of the neurological deficits that affect performance in order to make decisions regarding appropriate intervention.

THE PERCEIVE, RECALL, PLAN AND PERFORM (PRPP) SYSTEM

The Perceive, Recall, Plan and Perform , or PRPP System of Task Analysis (Chapparo & Ranka, 1996), is an assessment tool that is based on task analysis methodology. It simultaneously enables observation of task performance, contextual influences and the client's component abilities. With training, it provides a structured way of assessing a person's cognitive abilities in any occupational performance task and guides subsequent intervention.

It is composed of a two stage analysis. Stage One analysis uses a behavioural task analysis to determine steps of a task or routine to be assessed. Through observation, errors of performance can be identified. For example, a client may miss a step of a task or inappropriately sequence a task. From this information, measurable occupational performance goals can be set and re-evaluated following intervention. Stage Two analysis focuses of cognitive component behaviours required for performance. For example, attending to the task, or recognising objects needed for the task. Both Stage One and Stage Two analysis assist in determining the type of intervention required. This may include structuring of the task environment, or provision of verbal cues or physical assistance.

Figure 4: The PRPP System (Model) showing Quadrants, Subcategories and Descriptors (Chapparo & Ranka, 1996)

STAGE TWO ANALYSIS

Stage Two analysis is divided into four areas of cognitive processing. These are identified as central quadrants in the PRPP Model (Chapparo & Ranka, 1996) (See Figure 1). The first quadrant is the Perceive Quadrant. Processes outlined in this quadrant have to do with perceiving sensory information and forming sensory pictures of ourselves and the task or routine environment. The second quadrant, Recall, involves processing to allow comparison of these perceptions of ourselves, the environment and objects with previously stored information. problem solve and make decisions about performance. The third quadrant, Plan, is where we use the sensory and stored information to problem solve and make decisions about performance. The fourth quadrant involves processes that prompt us to carry out and monitor actions required for performance. Each of these quadrants are interrelated and difficulties a person may have in one quadrant may influence their performance in another. For example, if a person is unable to generate an idea for a plan of action, problems will seen in the Plan quadrant, and also in the Perform quadrant.

In this assessment, errors in cognition in each quadrant are identified as actual, observable behaviours and are listed in the model (See Figure 1). This method of identifying cognitive problems in everyday function moves occupational therapy assessment away from the more traditional modes of naming and framing cognitive and perceptual disorders as diagnoses, such as 'agnosia' and 'apraxia'. Instead, assessment is focussed on observable behaviours that are assumed to reflect cognitive processing. The link between assessment and intervention is therefore direct. For example, instead of identifying that a client has 'apraxia', a therapist is able to identify and describe the specific behaviours , related to motor planning, that are missing in the performance of everyday tasks as follows: 'The client is unable to identify obstacles that impede successful performance; he has difficulty choosing the correct tools for the task and does not sequence and calibrate movements required for performance'. In this instance, the direction for intervention is clear. Therapy is geared towards relearning the specific processing behaviours that are problematic within the context of occupational performance.

CASE STUDY: JEFF

A case study of Jeff, will be used to illustrate how this system of tasks analysis can be used to direct intervention.

Jeff was 26 when, as a pedestrian, he was involved in a motor vehicle accident in January. The injuries sustained included a closed head injury, dislocated left elbow and a degloving injury to his left foot. A CT Scan of his brain revealed bilateral subdural haematomas. He was admitted to Westmead Hospital Brain Injury Rehabilitation Unit in February. He had generalised increased tone in his right upper limb.

In consultation with Jeff, it was decided that independence in upper body dressing was an important self maintenance skill for him.

PRPP Task Analysis: Stage One

A Stage One Behavioural Task Analysis of upper body dressing involved 13 steps. Jeff's performance was scored on each step of the task as either correct or incorrect, based on observable errors of accuracy, timing, omission or inappropriate repetition. A score out of 13 was calculated. This score was then converted to a percentage to assist with goal setting. The steps Jeff required either verbal prompting or physical assistance to complete were:

Jeff was able to complete the rest of the task independently. A score of 9/13, or 70% was obtained for this analysis.

Following completion of Stage One Analysis, the first short term goal was established for Jeff.

'In one week Jeff will complete 11/13 steps (85%) of upper body dressing independently.'

Application of data from this stage of analysis was used to determine the general direction of systematic instruction to be used during intervention. Jeff was capable of completing the last steps of the task, therefore a backward chaining instructional technique was introduced (Donelly, 1994). It was therefore expected that independence in steps 4 and 5 - placing his arms into the shirt and through the sleeves would be achieved.

PRPP Analysis: Stage Two

Once an appropriate functional goal was established, the cognitive deficits contributing to Jeff's inability to performance this tasks were determined. A Stage Two analysis was performed using the PRPP model and descriptors to identify the missing behaviours within each area of processing. From this data, further instructional techniques could be developed to suit Jeff's processing abilities.

Perceive

In the Perceive Quadrant (See Figure 1), Jeff had problems with image formation and discrimination. The particular behaviours that were missing were identified as follows.

Jeff was not noticing or monitoring what his right arm was doing when unsuccessfully placing is through the sleeve and was having difficulty locating and discriminating between different parts of the T-shirt. He was also unable to match his body parts to the appropriate parts of the T-shirt. For example, Jeff attempted to place his left arm through the neck hole.

These missing behaviours directed intervention in relation to cues and prompts used during instruction. Jeff required continual verbal prompting to look at and locate his right arm. Once the T-shirt was placed on his lap, then was instructed to locate the various elements of the shirt - the top and bottom, the sleeves and the neck hole and the match them to his body parts. For example, he was verbally prompted to 'locate the sleeve your left arm goes into'. 'Locate the hole your head fits through'.

Deficits in this quadrant result from the dysfunction of sensory systems. Intervention addressing the missing behaviours in the Perceive Quadrant therefore involves the provision of sensory cues with words such as look, locate and match.

Recall

In the Recall Quadrant, Jeff had problems recalling the task scheme where he had to contextualise to time. For example, our internal clock usually tells us to complete such a task within 30 seconds, or 60 seconds. However, Jeff was unaware of the appropriate timing and was slow even completing the steps that he had achieved independence.This missing behaviour was addressed through timing task performance and reducing the expected time of performance, once task mastery had been achieved.

Jeff's processing in the Recall Quadrant revealed strengths, indicating that with practice, he would likely remember the strategies learned.

Plan

The majority of Jeff's missing behaviours appeared in the Plan Quadrant. During performance of the task, his plan of action faded and he was unable to ideate and new goal for action. That is, he was unable to deal with problems that arose and change his actions in response to the task requirements. For example, when unsuccessfully attempting to place his arm and head through the same hole. This, in turn, affected the sequencing of his task performance with a lack of smooth transitions from one step of the task to another. Jeff had difficulty evaluating his performance. For example, he did not question or analyse his performance to ensure body parts such as this arm or head were in the correct place.

The missing behaviours were used to direct his intervention further. Jeff was assisted to ideate his plan of action by using question prompts. Before starting any action, he was asked 'what are the steps you need to complete to put on a T-Shirt?' When his plan of action faded during task completion, he required constant questioning to redefine his goal. For example, 'Which step comes next?' When problems arose, Jeff required verbal prompting to question his incorrect actions and identify specific constraints so that he could create a new or modified plan of action. For example, he was asked 'is your arm in the right place?' 'Which hole should it be placed through?'

Deficits in the Plan Quadrant result from dysfunction in a person's ability to analyse incoming information, generate new ideas and evaluate consequences. Intervention addressing the missing behaviours in this quadrant therefore involves assisting the clients to question and analyse their task performance.

Perform

In the Perform Quadrant, Jeff had a problem coordinating smooth movements in his right upper limb. The performance of the task did not flow as a result of this and the associated deficits already outlined in other quadrants. A combination of these deficits affected the timing of his task performance

The problematic behaviours in this quadrant directed intervention as follows. Smooth and controlled movements of Jeff's right upper limb were facilitated using Proprioceptive Neuromuscular Facilitation (PNF) techniques during task performance. The problems of flow and timing were specifically addressed once Jeff had achieved mastery of all steps of the task.

Deficits in the Perform Quadrant result from dysfunction in the motor response required to achieve purposeful goal directed action. Therefore intervention addressing the problematic behaviours in the Perform Quadrant involves the provision of physical guidance to carry out action required for task performance.

OUTCOME

After one week, our goal was reevaluated using the Stage One Analysis. Jeff had successfully achieved his goal. That is, he was able to complete steps 4 to 13 of the upper body dressing independently. Assistance continued to be provided for steps 2 and 3 and a new short term goal was set.

'In one week, Jeff will be independent in upper body dressing (T-shirt).'

Using this Stage Two analysis, of the PRPP System, the missing behaviours preventing John from achieving his goal were identified in the Plan Quadrant.

At the start of the task, Jeff was unable to arrange his T-shirt in an organised manner. Therefore, Jeff needed to learn to organise his T-shirt at the beginning of the task. This involved teaching him an organising preparatory strategy for putting on clothes. For example, using the questioning style to prompt processing of motor planning, he was asked 'Is the tag at the top?', to ensure that the shirt was not back to front.

Our goal was again reevaluated. After one week Jeff had achieved mastery of the task, but was unable to complete the task in a functional time frame. The goal for Jeff's dressing then became:

'In 1 month, Jeff will complete upper body dressing of a T-shirt within 30 seconds'

As described in the Recall Quadrant analysis, Jeff was unable to contextualise time. He needed to relearn the appropriate time frame for this task in relation to other tasks in his normal daily routines. Intervention then became focussed on task fluency. This involved timing Jeff's performance and instructing him to complete the task within a specified time, previously determined in consultation with him.

Jeff's goal was achieved within 3 weeks.

CONCLUSION

In the Brain Injury Rehabilitation setting at Westmead Hospital, the role of the occupational therapist includes establishing and achieving objective occupational performance goals, in conjunction with the clients, their families and the team. Due to the severity of the clients' diffuse cognitive deficits, an assessment is needed that is sensitive to small changes in functional abilities. In addition to this, assessment and training in occupational performance tasks and routines has to occur in real life environments to encourage generalisation of skills learned. Finally, in our setting, an assessment is required that is not limited to a set list of predetermined tasks, but can be used with clients who have a range of abilities and who will return to a range of social and cultural contexts.

The case study presented in this paper, illustrates how the use of the PRPP System of Task Analysis (Chapparo & Ranka, 1996) assists us to make more objective observations of task and routine performance. We have demonstrated how the information derived from this instrument can be used to establish measurable, client centered goals for intervention. Using the behavioural descriptors within this system, we have shown how specific, appropriate intervention can be developed to efficiently meet stated goals.

REFERENCES

Chapparo, C.J., & Ranka, J. (1996). The Perceive, Recall, Plan & Perform System of Task Analysis. OT Australia AAOT-NSW, Continuing Education Workshop. Sydney, February.

Donelly, M (1994) Systematic instruction: Study guide. Graduate Certificate in Applied Science (Occupational Therapy in Neurology). (Available from the School of Occupational Therapy, The University of Sydney, Lidcombe, NSW, 2141).