Caracterización de la prensa escrita como instancia comunicativa

To what extent can it be inferred that performance on the Predicaments test predicts real-life problem-solving behaviour? Experimental tests might potentially underestimate, or indeed overestimate, the extent o f everyday difficulties shown by people with brain lesions. Underestimation on the basis o f laboratory performance

may stem from factors such as the structuring cues provided by tests compared to the lack o f clear structure in everyday life, and the provision o f all the relevant information together, which is often not available in real life. The Predicaments test attempted to avoid these issues by using open-ended problem situations and minimising the use o f questions and prompts. Overestimation o f real-life problems might result because people have difficulties in imagining the situations in reality, or are less motivated by a personal need to resolve the problems. The problem situations in the Predicaments test were hypothetical, and were solved verbally rather than carried out in real life. However, several factors suggested their relevance for everyday behaviour. Their ecological validity was thought to be high since they were based on real-life situations that most people might encounter either personally or through others, and the video versions were presented in real time. Moreover, the anterior group, who showed the greatest level o f impairment, were also characterised by real-life difficulties such as disinhibited behaviour. It therefore seems plausible that impairment both in generating and selecting appropriate problem solutions as demonstrated on the Predicaments test is likely to reflect potential difficulties in dealing with real-life problem situations, although this cannot be established beyond doubt. Nevertheless, the development o f tests such as this appear to offer an intermediate step in the assessment o f real-life problems compared to conventional abstract tasks or lengthy observation of everyday behaviour.

The DEX questionnaire was included to give an indication o f everyday life behaviour, and the lack o f significant group differences on the DEX questionnaire was surprising. Selection o f patients for the study was based on the presence o f a circumscribed brain lesion involving (or not involving) the frontal cortex, rather than on behavioural criteria. However, disinhibited or other inappropriate behaviour during testing revealed significant abnormalities in some although not all o f the anterior participants, and clinical information available for some o f them confirmed that this was also an issue in everyday life. Another important factor may be the way that the DEX rating scale was interpreted by individuals, and possible group differences in this. The range o f behaviour used for comparison for the normal

participants was probably narrower than for the lesion participants, who may have had considerably greater experience o f behavioural problems associated with brain injury, whether in themselves or others. Moreover, ratings made by patients and by relatives on different scales have previously been reported to underestimate the extent o f problem behaviour, as assessed by professionals (e.g. Fordyce & Roueche 1986). Ratings from professionals would probably have provided a more accurate assessment, especially if the same individuals rated all the participants. Additional information available for two cases in the present study lent some support to this, since both received low DEX ratings, but were known to have severe problems in everyday behaviour. Further information about everyday problem-solving performance could be gained in future work by asking patients and relatives to describe any specific real-life difficulties encountered in a range o f common situations.

7.1.4.6 Summary

In summary, the findings showed that participants with anterior brain lesions were impaired in aspects o f real-life-type problem-solving performance, as predicted in Hypothesis 1, and that impairment was more extensive for participants with left­ sided lesions. Participants with posterior lesions also showed impairments on the Predicaments test, although these were less marked than those in the anterior group, as predicted in Hypothesis 2. The pattern o f results suggests that brain damage may disrupt ability both to generate solutions and to select socially appropriate and effective practical solutions. Contrary to the prediction in Hypothesis 3, the anterior and posterior groups did not differ from each other on the measures in the executive battery. It was speculated that a range o f non-executive processes might be relevant to performance on these tasks, in addition to executive skills. The findings suggest that the Predicaments test is more sensitive to the deficits shown by participants with anterior lesions than many abstract, standardised measures. However, as predicted in Hypothesis 4, there were significant correlations between some o f the executive measures and the Predicaments measures. A range o f factors potentially contributed to the impairments shown by the anterior group, including deficits in executive function, poorer judgm ent o f interpersonal issues, adequate application of

prior knowledge to guide performance, and disrupted emotional processes. The study described in Part B goes on to detail the adaptation o f this measure, with the intention o f providing a test that is both more sensitive to the deficits shown by participants with frontal lobe lesions, and is more user-friendly.

7.2 PART B

7.2.1 INTRODUCTION

The findings reported above showed that multiple dimensions o f problem-solving could be assessed using the Predicaments task. However, the measure was time- consuming to administer and score, and there were no differences in performance according to mode o f presentation. Therefore, it was decided to develop a shorter form o f the test, which could be presented solely on video in order to retain ecological validity, or alternatively, could be presented as stories for ease o f testing in any setting. This section describes the development o f a shorter, sharper version o f the Predicaments test using eight o f the original sixteen items. The purpose was to create a measure that was more sensitive to the effects o f anterior lesions, but with a smaller number o f scenarios. The intention was to administer this shorter measure to other groups o f participants with postulated frontal lobe involvement, and compare the profiles seen with those o f participants with structural frontal lobe lesions. For this purpose, only the performance o f the anterior group relative to the control group was considered pertinent. Therefore, eight scenarios were selected as described below. Analyses were performed in order to ensure that the lower power did not reduce the sensitivity. In addition, in order to allow for easier comparison of the profile o f results with other groups with potential frontal lobe dysfunction, analyses were also carried out for the measures in the executive battery comparing the anterior and control groups.

7.2.1.1 Hypotheses

1) It was hypothesised that the anterior group would remain impaired on the shorter Predicaments measure relative to the control group.

2) It was hypothesised that for the measures in the executive battery that significantly differentiated the lesion and control groups in Part A, the anterior group would differ significantly from the control group when the posterior participants were not included.

7.2.2 METHOD