Auditory processing speed and signal detection in schizophrenia.

Examined 2 differing explanations of schizophrenic processing deficit, J. Chapman and A. McGhie's (1962) and A. J. Yates's (see PA, Vol 41:10769). 32 18-46 yr old schizophrenics, classified on the acute-chronic and paranoid-nonparanoid dimensions, and 8 17-45 yr old neurotics were tested on 2 dichotic listening tasks. One task gave reaction time measures of processing speed at 3 rates of stimulus presentation; the other assessed stimulus detection and channel selectivity using theory of signal detection methods. Results support Yates and indicate that schizophrenics can attend successfully to 1 of 2 competing channels. Neither reduced sensory sensitivity nor response bias appeared to affect the performance of any group of Ss. Slowness of processing was a deficit characteristic of chronic, particularly nonparanoid, schizophrenics, although the factors responsible for this slowness remain a matter for empirical investigation. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Speed of perceptual functioning in chronic nonparanoid schizophrenics: Partial replication and extension.

Results of a partial replication of a study by A. J. Yates and P. Korboot (see record 1971-06730-001), with 3 groups of 10 chronic nonparanoid schizophrenics, paranoid schizophrenics, and psychotic depressives as Ss, confirm the finding of the extreme slowness of functioning in chronic nonparanoid schizophrenics. The finding was extended by showing that this group was also significantly slower than chronic psychotic depressives when inspection time was measured uncontaminated by verbal response time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)