Attention in schizophrenia: An analysis of selectivity in the functional visual field.

Presents a visual–spatial approach to the study of attention dysfunction. The hypotheses of broadened and narrowed attention were tested by comparing peripheral visual discrimination of 10 acute schizophrenic and 11 chronic schizophrenic inpatients and 16 normal Ss (hospital staff) within 2 regions of the functional visual field. Pairs of visual stimuli were presented at 4 display angles. Measures of response accuracy, response latency, and latency of eye movement of peripheral stimuli were obtained. Results indicate that acute schizophrenics generally discriminated peripheral signals more accurately than chronic schizophrenics or normals. Normals discriminated signals more accurately than chronic schizophrenics. Results suggest the differential use of selective strategies. Limitations in the use of peripheral information among chronic schizophrenics implies a reduction in the amount of information transmitted in a selective act and a reduction in the economy of selective activities. In contrast to normals, acute schizophrenics utilized more efficient selective strategies over a greater spatial area, implying greater transmission of information within discrete selective acts. Results also indicate that schizophrenics initiated eye movements earlier than normals and that response latency was greater for acute schizophrenics than for normals. Results are interpreted as providing partial support for P. H. Venable's (1964) theory of input dysfunction. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of inversion-induced conflict on field dependence.

Verbal reports of loss of control and surrender to powerful visual changes, experienced during inversion of the visual world in previous studies, suggest changes in field dependence. In the present study with 40 undergraduates, field dependence (rod-and-frame test vertical was tested under conditions of inversion and noninversion. Significantly greater field dependence was observed for Ss exposed to complete inversion rotation of the rod-and-frame configuration in the experimental period than for Ss exposed to rotation without inversion, partial rod-and-frame inversion rotation, or inversion rotation without a frame. The change in field dependence was not significantly affected by 10 min of active experience with inversion, and no significant aftereffects were observed. Results are interpreted in terms of the effect of conflict on perceptual-cognitive decentering. Implications for perceptual adaptation and personality theory are discussed. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes of auditory word discrimination induced by inversion of the visual field.

Examined auditory discrimination in normal hospital staff members during induced visual conflict. Discrimination of words accompanied by background noise was measured at 6 speech-signal-noise intensity levels during preexperimental (normal vision), experimental (inverted vision), and postexperimental (normal vision) periods. A control condition (no inverted vision) served as a check for the possible effects of practice or fatigue. Significant losses of word discrimination occurred only in the inverted vision condition. Discrimination losses occurred at all intensity levels in which speech was accompanied by noise, prior to walking in the inverted vision condition, following a walking period, and after removal of inversion eyepieces. Results are attributed to a process of visually induced conflict in which Ss were unable to decenter the altered contents of vision. Affinities between reports of induced alterations of experience and pathological alterations of experience are discussed. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)