A psychological investigation into the relationship between hemispheric functioning and specific written language difficulties (dyslexia), using pharmaceutical intervention techniques

This thesis attempts a psychological investigation of hemispheric functioning in developmental dyslexia. Previous work using neuropsychological methods with developmental dyslexics is reviewed ,and original work is presented both of a conventional psychometric nature and also utilising a new means of intervention. At the inception of inquiry into dyslexia, comparisons were drawn between developmental dyslexia and acquired alexia, promoting a model of brain damage as the common cause. Subsequent investigators found developmental dyslexics to be neurologically intact, and so an alternative hypothesis was offered, namely that language is abnormally localized (not in the left hemisphere). Research in the last decade, using the advanced techniques of modern neuropsychology, has indicated that developmental dyslexics are probably left hemisphere dominant for language. The development of a new type of pharmaceutical prep~ration (that appears to have a left hemisphere effect) offers an oppertunity to test the experimental hypothesis. This hypothesis propounds that most dyslexics are left hemisphere language dominant, but some of these language related operations are dysfunctioning. The methods utilised are those of psychological assessment of cognitive function, both in a traditional psychometric situation, and with a new form of intervention (Piracetam). The information resulting from intervention will be judged on its therapeutic validity and contribution to the understanding of hemispheric functioning in dyslexics. The experimental studies using conventional psychometric evaluation revealed a dyslexic profile of poor sequencing and name coding ability, with adequate spatial and verbal reasoning skills. Neuropsychological information would tend to suggest that this profile was indicative of adequate right hemsiphere abilities and deficits in some left hemsiphere abilities. When an intervention agent (Piracetam) was used with young adult dyslexics there were improvements in both the rate of acquisition and conservation of verbal learning. An experimental study with dyslexic children revealed that Piracetam appeared to improve reading, writing and sequencing, but did not influence spatial abilities. This would seem to concord with other recent findings, that deve~mental dyslexics may have left hemisphere language localisation, although some of these language related abilities are dysfunctioning.

Transition from community dwelling to retirement village in older adults:cognitive functioning and psychological health outcomes

Supported living and retirement villages are becoming a significant option for older adults with impairments, with independence concerns or for forward planning in older age, but evidence as to psychological benefits for residents is sparse. This study examined the hypothesis that the multi-component advantages of moving into a supported and physically and socially accessible “extra care” independent living environment will impact on psychological and functioning measures. Using an observational longitudinal design, 161 new residents were assessed initially and three months later, in comparison to 33 older adults staying in their original homes. Initial group differences were apparent but some reduced after three months. Residents showed improvement in depression, perceived health, aspects of cognitive function, and reduced functional limitations, while controls showed increased functional limitations (worsening). Ability to recall specific autobiographical memories, known to be related to social-problem solving, depression and functioning in social relationships, predicted change in communication limitations, and cognitive change predicted changes in recreational limitations. Change in anxiety and memory predicted change in depression. Findings suggest that older adults with independent living concerns who move to an independent but supported environment can show significant benefits in psychological outcomes and reduction in perceived impact of health on functional limitations in a short period. Targets for focussed rehabilitation are indicated, but findings also validate development of untargeted general supportive environments.

An overview of psychological and neurobiological mechanisms by which early negative experiences increase risk of mood disorders

Objective: Early life experiences are associated with severe and long-lasting effects on behavioural and emotional functioning, which in turn are thought to increase the risk for unipolar depression and other disorders of affect regulation. The neurobiological and psychological mechanisms through which adverse early life experiences confer risk are poorly understood. Method: Alterations in brain structure and function in limbic and prefrontal cortical regions have been linked to early negative experiences and to mood disorders. Results: There are a number of psychological domains that may be dysfunctional in people with mood disorders, and which, if the dysfunction occurs prior to onset of mood symptoms, may signify a risk factor for depression. Cognitive dysfunction has been examined in patients with mood disorders, with some suggestion that changes in cognitive function may antedate the onset of mood symptoms, and may be exacerbated in those who experienced early negative trauma. Social cognition, including emotion comprehension, theory of mind and empathy, represent under-studied domains of psychological function that may be negatively influenced by early adverse experience. Temperament and personality factors may also leave people vulnerable to mood instability. Conclusion: This review summarizes the evidence for dysfunction in each of these domains for people with mood disorders.