ALTERATIONS IN HEART-RATE AND PUPILLARY RESPONSE IN PERSONS WITH ORGANIC-SOLVENT EXPOSURE

Cardiac and pupillary reactivity were examined in 25 persons with a hi story of exposure to organic solvents and 19 nonexposed controls durin g performance of a counting and a choice reaction task, The solvent-ex posed group demonstrated an atypical pattern of responding across task s. While control subjects showed a decline in heart rate across the tw o conditions (e.g., habituation), exposed persons had an increase in h eart rate. Initial pupil diameter was similar for both groups, but onl y the control subjects exhibited habituation across the two tasks, In the exposed group, higher heart rate was not associated with higher le vels of self-reported anxiety, Anticipatory cardiac deceleration prece ding unpredictable events was significantly less in the exposed group, but there were no significant group differences on poststimulus accel eration, The results suggest that persons with solvent exposure have a deficiency in the allocation of attention (reduced anticipatory decel eration and decreased pupillary dilation). It is further suggested tha t difficulty in the allocation of attention produces an increase in to nic sympathetic levels when confronted with a cognitively challenging task. In this experiment, in which the choice reaction task was purpos ely presented last, and was apparently more challenging for exposed pe rsons, a failure to exhibit autonomic habituation over the course of t he session characterized the solvent-exposed group.