Exploring the Validity of the Perceive, Recall, Plan and Perform System of Task Analysis: Cognitive Strategy Use in Adults with Brain Injury
Nott, Melissa T., Chapparo, Christine, British Journal of Occupational Therapy
Effective information processing for occupational performance depends on a person's ability to select and apply the most efficient cognitive processing strategies in response to environmental and internal stimuli. Cognitive strategies reported to be most vulnerable in adults with brain injury include allocation of attention, planning, sequencing complex tasks and self-monitoring of performance, collectively referred to as executive functions (Radomski 2008). Measuring how these cognitive processing strategies integrate either to support or to inhibit functional performance, particularly during the acute stages of brain injury recovery, has traditionally challenged rehabilitation clinicians. Conventional measures of executive functioning have questionable ecological validity and test results may not generalise to everyday occupational performance (Manchester et al 2004, Gillen 2009). A functionally led, ecologically valid approach has been strongly advocated to link cognitive operations or strategies with directly observable behaviours, which reflect a functional goal, instruction or intention to act (Chapparo and Ranka 2005).
Cognitive assessment in the area of occupational therapy has traditionally focused on measuring discrete cognitive capacities, such as memory, attention or visual-perception, using assessments designed to simulate real-world occupational performance. For example, occupational therapists may use the Rivermead Behavioural Memory Test (Wilson et al 2003) or the Test of Everyday Attention (Bate et al 2001) to evaluate cognitive skills in isolation from daily occupations. In contrast, contemporary assessments, such as the Perceive, Recall, Plan and Perform (PRPP) System of Task Analysis (Chapparo and Ranka 1997), adopt an occupation-based perspective, evaluating how cognitive strategies are implemented during functional task performance. Therapists using the PRPP system first identify occupational performance errors (stage 1 analysis), then determine the cognitive strategy deficits resulting in performance errors (stage 2 analysis). The stage 2 cognitive task analysis evaluates the information processing strategies that underpin occupational performance. These strategies include attention and sensory perception (Perceive), memory (Recall), response planning and evaluation (Plan) and performance monitoring (Perform). These are illustrated in the central quadrants of the PRPP system's theoretical model (Chapparo and Ranka 2005, Fig. 1). In total, 34 strategies, termed descriptors, are rated on a three-point scale, indicating how effectively the person applied each cognitive strategy. Descriptors are represented in the outer layer of Fig. 1.
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The PRPP System of Task Analysis is distinct from other functional evaluations using task observation (for example, Baum and Edwards 1993) in its synthesis of information processing theory and occupational performance. It also contrasts with other ecological assessments, such as the Assessment of Motor and Process Skills (AMPS), which is designed to measure activity participation and restriction without specifically evaluating underlying impairments or capacities within the cognitive domain (Boman et al 2004).
The PRPP System of Task Analysis is an assessment that fits within the Occupational Performance Model (Australia) and provides therapists with an assessment process that measures performance at the level of body structure and function of the International Classification of Functioning, Disability and Health, and at the level of activity and participation (Stamm et al 2006). This assessment system is particularly relevant for assessing adults during acute rehabilitation following brain injury, as the assessment is observation based, is not written or language based, and the assessment context is familiar functional tasks and activities (Fry and O'Brien 2002). …