Linkage of a normal personality trait to the color-blindness gene: preliminary evidence

Does food recognition depend on color?

Color is considered important in food perception, but its role in food-specific visual mechanisms is unclear. We explore this question in North American adults. We build on work revealing contributions from domain-general and domain-specific abilities in food recognition and a negative correlation between the domain-specific component and food neophobia (FN, aversion to novel food). In Study 1, participants performed two food-recognition tests, one in color and one in grayscale. Removing color reduced performance, but food recognition was predicted by domain-general and -specific abilities, and FN negatively correlated with food recognition. In Study 2, we removed color from both food tests. Food recognition was still predicted by domain-general and food-specific abilities, but with a relation between food-specific ability and FN. In Study 3, color-blind men reported lower FN than men with normal color perception. These results suggest two separate food-specific recognition mechanisms, only one of which is dependent on color.

Molecular Genetics of Mental Disorders with Particular Reference to Affective Disorders

The present article reviews the recent molecular genetic findings in affective disorders. Results of linkage and association studies are discussed in regard to the main limitations of these approaches in psychiatric disorders. On the whole, linkage and association studies contributed to the localisation of some potential vulnerability genes for Bipolar affective disorder on chromosomes 18, 5, 11, 4, 21 and X. The hypothesis of anticipation in affective disorders is also considered in light of interesting results with trinucleotide repeat mutations.

TPQ in euthymic manic-depressive patients

Researchers using various psychological measures and instruments have concluded that the personality of remitted bipolars and normal controls are essentially similar. We recently suggested that specific personality traits might be genetic markers for manic-depressive illness. The Tridimensional Personality Questionnaire (TPQ) is a personality questionnaire with heritable subscales and hypothesized anchoring in neurochemistry. We studied the personality of euthymic bipolar manic depressive patients using the TPQ. Subjects were volunteers from the out-patient Lithium Clinic. TPQs were individually administered to 50 euthymic bipolar patients. Persistence is significantly reduced, and harm avoidance and reward dependence significantly increased, compared with U.S. norms. These traits may be part of the genetic diathesis for manic-depressive illness.