Neuropsychological correlates of alogia and affective flattening in schizophrenia

We examined whether two negative symptoms, alogia and affective flattening, were more strongly associated with dysfunction of certain brain regions than with others in a sample of 27 schizophrenic subjects. Neuropsychological tests were used to measure the integrity of functioning of different brain regions. Functioning of left and right frontal regions was assessed by word fluency and design fluency, respectively, and functioning of the left temporo-hippocampal region was assessed by Hebb's digit-sequences recall test. Measures of alogia and affective flattening were obtained using the Scale for the Assessment of Negative Symptoms. The results indicated that more severe levels of these negative symptoms were associated with poorer performance on the fluency tests. These relationships were fairly specific as indicated in two ways: (1) only certain neuropsychological measures were associated with negative symptoms; and (2) poor performance on fluency tests was not associated with all psychiatric symptoms. In addition, affective flattening, but not alogia, appeared to be associated with lateralized dysfunction.