ON THE ABILITY TO SELF-MONITOR COGNITIVE PERFORMANCE DURING SLEEP-DEPRIVATION - A CALIBRATION STUDY

The antagonistic effects of extensive sleep deprivation (SD) on human cognitive performance are well documented. However, one aspect of huma n performance that has not been investigated with respect to its susce ptibility to SD is the 'meta-cognitive' ability to self-monitor overt performance. In the present study, 16 male subjects participated in an experiment requiring sustained cognitive work during a three day peri od. One of the cognitive tasks required the mental addition of rapidly presented numbers. On each trial, subjects reported the sum and then provided a subjective confidence rating to indicate the degree of cert ainty in their response. As expected, performance on the sequential ad dition task deteriorated with increasing fatigue and returned to basel ine following a recovery sleep. However, calibration analyses, which q uantify a number of properties of the relationship between subjective and overt performance, revealed that the correlation between confidenc e and performance (calibration), the ability to differentiate correct from incorrect judgments (resolution), and validity of subjective 'cer tainty', were all unaffected by SD. Hence, in the absence of external feedback from the environment, people have access to fairly reliable i nternal feedback about their performance during periods of sustained a nd vigilant cognitive activity.