Does brain function underlie personality differences or vice versa?
by
Robin Turner
Department of Mathematics and Statistics, University of Canterbury
Coauthors: Irene L Hudson, Peter R Joyce, Philip H Butler

The relationship between regional cerebral blood flow and personality types may be an important key in the search for understanding some psychiatric disorders, such as depression. Some psychiatrists believe that personality can be explained, at least partly, in terms of differences in brain function. The study used the technique of SPECT imaging (Costa, Vascular Medicine Review, 1990, 1:179-201) in conjunction with the TCI-R personality measures (Cloninger, Current Opinion in Neurobiology, 1994, 4:266-273) on twenty normal, non-depressed, male volunteers. Statistical techniques have been used to investigate the relationship between differences in regional blood flow patterns with differences in the personality traits. Initial analysis categorised the sample into two groups according to the level of a personality trait. Image averaging and subtraction emphasised regional differences, if any, between the two groups. Statistical parametric methods (Friston, Functional Neuroimaging Technical Foundations, 1994, 79-93) were used to model the personality traits in relation to the blood flow in each image voxel. The resulting map showed areas of significant activation or otherwise. To complement the methods used above a data reduction step was used to reduce approximately 500 000 brain voxels down to a more manageable size. Resulting factors were then related to the personality domain to see if a combination of brain areas was contributing the differences in personality types. The results of these analyses will be presented and compared.

Date received: September 4, 2001