The association between eye-tracking dysfunctions and thought disorder in psychosis

The relationship between the presence of smooth-pursuit eye-movement dysfunctions and degree of thought disorder was assessed in four groups: schizophrenics, manics, atypical psychotic patients, and normal persons. A positive relationship, constant for all groups, was found to be significant but low. Impaired eye tracking accounted for 4.22% of the total variance of thought disorder. Diagnosis accounted for over 10% of the thought-disorder variance. Although there is a tendency for those persons with poor eye tracking to have higher amounts of thought disorder than those with unimpaired eye tracking, all psychotic patients, regardless of diagnostic class, tended to have thought disorder scores in the pathological range, as measured by the Thought Disorder Index. Although the data may be viewed as supporting similar hypothetical processes that underlie pursuit dysfunctions and thought disorder, the greater likelihood exists that the coupling of thought disorder and eye-tracking dysfunctions may be explained differently in the schizophrenia and in the major affective disorders.