Cognitive and psychomotor function in hypoglycemia: response error patterns and retest reliability.

Hypoglycemia has been shown to impair cognitive and psychomotor function, but it has been unclear which measures are most reliable and sensitive for detecting these effects. In a single-blind repeated measures design, healthy young adults (N=17, 8 male, mean age 27 years) performed three PC-based cognitive and psychomotor function tests: a paced auditory serial addition task (PASAT), an adaptive five-choice reaction time test (CRTT), and a manual tracking test on two occasions 4 weeks apart. In each session, a hyperinsulinemic clamp method was used during a normoglycemic (plasma glucose: 4.7 mmol/l) baseline testing period, followed in one session by a normoglycemic target testing period, and in the other session by a hypoglycemic (2.7 mmol/l) target testing period. All cognitive and psychomotor function measures showed high test-retest reliability (r ranging from.69 to.95) and sensitivity to hypoglycemia (P<.01). A new finding is that on the PASAT, hypoglycemia appears to differentially increase the rate of omission errors more than it increases false responses. Data on PASAT reaction time (RT) are also presented.