Biomedical subjects

S P Verney

Publications and source records attributed to S P Verney.

3 recordsLinked to original sources

PubMed2001

Pupillary responses and processing resources on the visual backward masking task.

Task-evoked pupillary responses were recorded during a visual backward masking task as an index of resource allocation. Increased pupillary dilation indicates increased allocation of processing resources to the task. Consistent with numerous studies, detection accuracy increased with longer interstimulus intervals and approximated no-mask accuracy in the 300-ms condition. Pupillary dilation responses were significantly greater during task performance (cognitive load) than during a passive stimulus viewing condition (no-load) and were significantly greater in the 300-ms condition than the no-mask condition. Consistent with models of early visual information processing, the results suggest that the mask demanded extra processing resources when it followed the target by more than 100 ms. Pupillography methods may be useful in evaluating the contribution and timing of resource-demanding processes during early visual information processing.

Adult↗

PubMed1996

Span of apprehension deficits in older outpatients with schizophrenia.

Performance on the span of apprehension task, a well-studied information processing task in schizophrenia research, was examined in 11 schizophrenia patients and 11 normal comparison participants, all over the age of 45 years. Subjects detected "T' and "F' targets in briefly-flashed arrays of 1, 6, and 12 letters on the span task. Consistent with previously reported findings in younger schizophrenia patients, the older patients detected significantly fewer targets in the larger (12-letter), but not smaller (1-, or 6-letter), arrays. The older schizophrenia patients also showed significantly slower reaction times in all array-size conditions. Neither age of onset nor duration of illness was significantly correlated with span task performance. The characteristic span of apprehension task deficit found in the older schizophrenia patients suggests that late-life schizophrenia shares a common cognitive impairment with childhood and young adulthood schizophrenia, and provides supportive evidence for a possible stable vulnerability trait deficit in schizophrenia that is independent of age of onset and duration of illness.

Age Factors↗

PubMed1996

Unconscious mood-congruent memory bias in depression.

The purpose of this study was to investigate an unconscious or implicit mood-congruent memory (MCM) bias in clinical depression. Many studies have shown an explicit memory bias, but no study has yet found an implicit MCM bias in clinical depression. The authors compared depressed and control group participants on a conceptually driven implicit memory test. After studying words of positive, neutral, and negative affective valences, participants produced free associations to various cues. Implicit memory or priming was demonstrated by the production of more studied than unstudied words to the association cues. Depressed participants showed more priming of negative words, whereas controls showed more priming of positive words, thus supporting the MCM pattern. Also, no implicit memory deficit was found in depressed participants. These findings are discussed in the context of several prominent theories of cognition and depression.

Adolescent↗