Mjpm. Verbraak et al., THE HETEROGENEITY OF SCHIZOPHRENIC INFORMATION-PROCESSING AND NEGATIVE VERSUS POSITIVE SYMPTOMS, The Journal of nervous and mental disease, 181(12), 1993, pp. 738-743
In this study, 20 schizophrenic patients were subdivided into a schizo
phrenia group with positive symptoms (N = 11) and a schizophrenia grou
p with negative symptoms (N = 9) by Andreasen's rating scales: the Sca
le for the Assessment of Negative Symptoms and the Scale for the Asses
sment of Positive Symptoms. These groups were compared with 17 normal
controls and 17 subjects with a closed head injury Indices of informat
ion processing derived from Coglab, a multiparadigmatic cognitive test
battery developed by Spaulding et al., were used for comparison. The
''negative'' schizophrenia subjects were characterized by a more perva
sive deficient information-processing capacity than the ''positive'' s
chizophrenia subjects. The deficits both groups had in common were, ho
wever, not of equal severity. The closed head injury group, who served
as an indirect control for the presumed generalized deterioration in
the negative schizophrenia group, did not compare very well to this la
tter group. The results are discussed in relation to the question of w
hether the information-processing deficiencies stem from a single caus
al process, or whether these deficiencies are independent and associat
ed with many etiological pathways.