The Effects of Task Demand and Knowledge of Results on Operator Engagement and Vigilance Performance Moderation with a Biocybernetic System

The present study examined whether a biocybernetic system could moderate performance in a vigilance task. The system manipulated critical signal (CS) amplitude based on cybernetic feedback contingencies. Under negative feedback, CS amplitude increased when the index fell below a predetermined level and decreased when the index rose above that level The opposite occurred under positive feedback. The system was expected to initiate more amplitude changes under negative feedback to regulate engagement. Performance feedback (Knowledge of Results; KR) was also provided and was expected to improve performance by motivating participants to pay closer attention to the task. Forty participants performed a 40-min vigilance task. A 2 Feedback (negative and positive) x 2 Knowledge of Results (KR and yoked) x 3 Critical Signal (CS) Amplitude (small, medium, large) x 4 Monitoring Period (10-min periods) mixed factorial design was implemented. The results showed that the biocybernetic system did not moderate vigilance performance. Participants in both feedback conditions detected fewer signals over the course of the session. Response times to hits (RTH) also decreased with time on task. KR did seem to increase engagement and some aspects of performance. However, the KR results must be interpreted with caution; examination of raw data files revealed that the system failed to present KR to all missed signals. Future research is needed to investigate viability of a biocybernetic system for maintaining performance on extended tasks requiring few overt responses.