Psychophysiological studies of a geographically defined population.

In the Berlevag project attemps have been made at using psycho-physiological and cognitive measures as indexes of psychiatric morbidity.--With skin conductance response, psychotics and neurotics showed signs of autonomic inhibition compared with conduct disorders and normal controls. All groups except psychotics showed cognitive effects in conditioning. No differences between the groups could be established for stereotype indexes, but the Berlevag sample appeared to have unusual high stereotypy indexes. With word associations the patient groups were markedly different from controls, with most deviations in psychotics and least deviations in conduct disorders.--A comparison of word associations in samples of the Oslo and the Berlevag populations suggested that the associative network was very similar in the two populations. There are differences with regard to verbal fluency, response types and reaction times.--It is unresolved whether these differences measure psychiatric morbidity or reflect a culture-dependent character of the word association test.