Biomedical subjects

L Ross-Field

Publications and source records attributed to L Ross-Field.

3 recordsLinked to original sources

PubMed1990

Insulin protects cognitive function in experimental stroke.

There is evidence from in vitro systems that the extent of neuronal loss in acute central nervous system ischaemia can be reduced by manoeuvres which restrict availability of glucose to the ischaemic area. Experiments were designed to test whether hypoglycaemia induced with insulin is associated with improved behavioural outcome in a recovery model of stroke. Rats learned a maze task as a test of working memory, believed to be subserved by the hippocampus, and then had a period of cerebral ischaemia, followed by reperfusion. After an interval of 14 days they were tested on the same maze, where lesioned animals had very significant (p less than 0.0001) impairment of working memory, whereas lesioned and treated (2.0 u/kg-1 insulin, minimum single plasma glucose value: 3.1 mmol/l-1) animals were indistinguishable from control animals. It is concluded that a striking degree of protection can be obtained with levels of mild hypoglycaemia which may be acceptable and practicable for use in humans.

Animals↗

PubMed1987

Neuropsychological development of cognitive abilities: a new research strategy and some preliminary evidence for a sexual orientation model.

The organizing action that prenatal sex hormones exert on the brain has been implicated in the aetiology of sex differences in cognitive abilities and cerebral asymmetries. Prenatal sex hormones are known to determine neuroendocrine responses and subsequent adult sexual behaviour in nonhuman animals and these hormones may also influence human sexual orientation. To unify these observations, we elaborate a sexual orientation model of neuropsychological development which predicts that sex differences in neuroendocrine responses, cerebral asymmetries, and cognitive abilities are related to sexual orientation rather than to sex per se. A common problem in the study of sex differences is that biological and sociocultural explanations are confounded. The sexual orientation model suggests a new research strategy, the comparison of homosexual and heterosexual groups, for which explanations in terms of sociocultural factors would be more difficult to sustain. The available evidence supports the model: In terms of a neuroendocrine response, cerebral asymmetry, and cognitive abilities, homosexual males resemble heterosexual females rather than heterosexual males. Our conclusions lead to questions that further research in this area should address, and to a consideration of problems which such research may have to face.

Cognition↗

PubMed1986

Sexual orientation and visuo-spatial ability.

On the basis of a literature review it was concluded that sex differences in cognitive ability and the etiology of male homosexuality may have a common biological base, leading to the prediction that in terms of cognitive ability homosexual males (HmM) would resemble heterosexual females (HtF) rather than heterosexual males (HtM). This prediction was investigated using visuo-spatial tasks on which males are known to perform better than females. In Experiment 1 HtM performed better on a water level task than HmM and HtF whose performances did not differ significantly. A different version of the water level task and the Vincent Mechanical Diagrams Test were used in Experiment 2; on both tasks the HtM performed better than the HmM and the HtF whose performance did not differ significantly. The results are interpreted as support for a common biological determinant of cognitive ability and male sexual orientation.

Adult↗