Left turning (swivel) in manic patients.

Nineteen bipolar inpatients in manic episodes and 19 normal control subjects were tested on a two-button task which required turning (swiveling) 180 degrees to collect coin-reinforcers. Significantly more right-handed (8/16) manic patients turned left (consistently 16 times to collect reinforcement) than right-handed normal controls (1/15), most of whom turned consistently right 16 times. Right-handed manic patients were also significantly slower with both hands on a motor sequencing task (Pin Test) than the normal controls. Left hemi-spatial preference may be linked to asymmetric striatal dopaminergic activity common to all psychoses.