Endocrine Abstracts

Studies show men and women differ in their aptitude towards different cognitive tests, which may be attributable to hormonal differences. It has also been postulated that oestrogen has disease-assuaging properties in some mental illness. The aim of this study was to assess the Cambridge Neuropsychological Test Automated Battery (CANTAB) as a tool for measuring cognitive differences between the sexes.

A total of 43 volunteers, 20 women and 22 men, aged between 18 and 35 were recruited. Ethical approval was obtained and all participants gave informed written consent. Exclusion criteria included a history of mental illness, head injury, excessive drug use and pregnancy. Each participant was examined using five CANTAB tests designed to evaluate spatial recognition memory, rule learning, attention, planning and motor control. Results were collated and entered into SPSS for analysis.

A highly significant correlation (p<0.01) was found between gender and performance of the Intra-Extra Dimensional Set Shifting (IED) task. This is a working memory task that evaluates both rule acquisition and attentional shifting. Women consistently performed better than men on the IED, an observation not accounted for by analysis of additional variables. None of the other tasks produced correlations that reached statistical significance.

The IED is based upon the Wisconsin Card Sorting Test (WCST) which has been shown to be sensitive to gender differences in both healthy and mentally ill populations. The results of this study suggest that like the WCST the IED is a hormone sensitive task. Oestrogen may have beneficial effects on rule acquisition and attention. Favourable task performance might be associated with an increase in female sex hormones. This investigation is being extended to study the influence of fluctuations in gonadal steroids throughout the menstrual cycle in both healthy women and those with a diagnosis of schizophrenia.