The Error-Related Negativity: Evidence for a Neural Mechanism for Error-Related Processing

158 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1992.The analysis of response-locked event-related potential (ERP) waveforms from several experiments points to the existence of a neural system involved in processing information associated with errors in choice reaction time tasks. The experiments included a sentence verification task, a Sternberg memory search task, and two letter discrimination tasks. In all these experiments, a negative-going deflection (the error-related negativity, or ERN) in the event-related brain potential began around the time of error onset and peaked about 100 msec later. It ranged in amplitude from 3 to 10 microvolts, was bilaterally symmetrical, and had a scalp distribution maximal at central and frontal electrode sites. The ERN was not evident on correct trials.I examined the hypothesis that the ERN manifests a process involved in error detection and compensation. The ERN was larger in conditions where accuracy was emphasized than where it was not, consistent with the view that the processing manifested by the ERN occurs to the extent that errors are task-relevant. The relationship between the ERN and measures of performance on the error trial suggested that the ERN may manifest a process related to compensating for errors as they occur: erroneous responses were less forceful than correct responses, and less forceful error responses were associated with larger ERNs. Finally, sequential analyses performed using a single trial measure derived from a stepwise discriminant analysis revealed that responses on trials following errors that elicit large error-related negativities were slower than following small error-related negativities. This result is consistent with a relationship between the ERN and a process involved in reducing the probability of future errors. These data point to the existence of a neural mechanism for error-related processing and are consistent with the hypothesis that the ERN manifests information processing activity related to the detection of and compensation for errors.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD