Time error in tactile size judgment after penetrating brain injury.

Abstract

Size estimation as a function of interpolated time between presentation of identical stimuli to affected hand, normal hand or with bilateral presentation (standard to one hand, variable to the other) was determined for human subjects with central or peripheral nerve injury, and with and without sensory involvement of the hand. Interpolated time intervals ranged from 0.1 sec. to 5 sec. For all groups and conditions the time error was negative, and did not change as a function of time interval for the bilateral condition. However, for either affected or unaffected hand alone, the longer intervals produced more negative time errors. Only one difference between groups divided as to cortical area of injury was observed. The frontal lobe injury group had a significant time error for the bilateral condition but not for either unilateral condition. It is suggested that this difference in the frontal lobe group "may reflect the interference with neural processes similar to those involved in the delayed response performance of frontal monkeys.".