Speed of word retrieval in postconcussion syndrome.

Speed of information processing in persons with postconcussion syndrome (PCS) was examined using word fluency tasks. Twenty patients with PCS and twenty controls matched for age, gender, and occupation were given two word fluency tasks, and the speed of word generation was measured. Response latencies were analyzed to determine whether slowed retrieval or degradation of words in semantic memory was responsible for problems with word retrieval after traumatic brain injury. The PCS group recalled fewer words, had significantly longer interresponse times, and took significantly longer to generate their first word than the controls. There was no evidence that either structure loss or slowness in word retrieval from semantic memory could account for the word fluency deficits. Rather, the findings suggest that the primary cause of word retrieval difficulties in patients with PCS is a generalized slowness of cognitive processing.

The effects of distraction on prospective remembering following traumatic brain injury assessed in a simulated naturalistic environment.

The aim of this investigation was to assess deficits in prospective remembering following chronic traumatic brain injuries (TBI), under conditions of high and low distraction. We constructed a virtual shopping precinct from photographs, sounds, and video segments linked together. The street was divided into halves, a low distraction zone and a high distraction zone (with increased visual and auditory noise). Twenty persons with TBI (7 severe, 7 very severe, 6 extremely severe) and 20 matched controls completed ongoing and prospective memory tasks while "walking" along the street. In the ongoing task, participants were given ten errands to complete with a checklist accessible at any time. The prospective component required responding to three targets that appeared repeatedly. As predicted, the TBI group performed both the ongoing and the prospective components of the street task poorly compared with the controls and was more affected by distractions. The results suggest that the real-life deficits in memory skills reported by persons with TBI may become more apparent when remembering engages executive processes and that computer simulations can be used to construct sensitive measures of practical memory abilities.

Threats to group value, domain-specific self-esteem and intergroup discrimination amongst minimal and national groups.

The research reported in this investigation sought to examine the self-esteem hypothesis (SEH) using measures of domain-specific and public collective self-esteem (CSE). Two studies were conducted. Each tested both propositions of the SEH. The first study revealed that minimal group members (a) experienced an increase in that domain of self-esteem judged to be relatively more important to the in-group, following the display of in-group favouritism and (b) that minimal group members with low public CSE (and who thus believed that the in-group was negatively evaluated by the out-group) showed enhanced levels of in-group favouritism. The second study, which utilized the members of real social categories (i.e. New Zealanders and Australians) and negative outcome allocations (i.e. white noise) revealed identical findings. The theoretical implications of these results are discussed.