Biomedical subjects

Sidney J Segalowitz

Publications and source records attributed to Sidney J Segalowitz.

2 recordsLinked to original sources

PubMed2002

Error negativity and response control.

Error trials are associated with faster responses than correct trials in simple discrimination tasks suggesting that errors result from impulsive responding. We investigated the relationship between error negativity (Ne/ERN), an event-related potential associated with error detection, and two behavioral indices of response control: response time (RT) differences between incorrect and correct trials (an index of impulsivity) and percentage of errors. Response-locked ERPs were collected from 17 young adults during a visual flanker task. Consistent with previous findings, participants were significantly faster on error trials. However, participants who exhibited larger Ne/ERN peak amplitudes had significantly smaller RT differences, suggesting a more controlled response strategy. Furthermore, Ne/ERN latencies were positively associated with percentage of errors. These findings are consistent with the view that the Ne/ERN reflects the activity of a monitoring system that is closely linked to remedial systems responsible for individual differences in response control or impulsive behavior.

Adult↗

PubMed2002

Altered electrodermal response to facial expression after closed head injury.

UNLABELLED: The objective was to determine whether diffuse damage to orbital and ventromedial regions of the prefrontal cortex usually associated with moderate-to-severe closed head injury (CHI) would affect the ability to perceive and respond to socially relevant information. METHODS: Participants with CHI and age-matched non-injured controls were presented with faces that varied with respect to emotional expression while electrodermal activity (EDA) was monitored. Cognitive and general adaptive functioning was also assessed. RESULTS: CHI was associated with a failure to increase EDA in response to negative facial expressions and with reduced ability to identify negative expressions, especially fear. The groups differed on other signs of orbital/medial prefrontal damage such as anosmia and in general social adaptability and awareness-of-deficit as measured by the Brock Adaptive Functioning Questionnaire. CONCLUSIONS: CHI affected the ability to identify and respond to negative facial expression. Addressing these deficits may enhance rehabilitative efforts within the social domain.

Adult↗