EFFECTS OF MEMORY LOAD ON INTERHEMISPHERIC RELAY

Experimentation with unilateral and bilateral tachistoscopic stimulati on (the Dimond paradigm) increasingly suggests that interhemispheric c ooperation (bilateral advantage) occurs or increases as a function of task complexity in general and memory load in particular. However, tac histoscopic experimentation with ipsilateral and contralateral field/h and relation conditions (the Poffenberger paradigm) has failed to prov ide any conclusive supporting evidence. The present investigation comp rised a Sternberg ''high speed memory scanning'' task, modified as a g o/no-go task, and formatted into the Poffenberger paradigm. Sets of it ems to be scanned (memory load) varied in size from one to four. A hig hly significant effect of load and a significant field/hand interactio n were found, but the field/hand/load interaction did not reach signif icance. We concluded that the interhemispheric transfer time (ITT) met ric drawn from this paradigm is not reliably sensitive to increasing m emory load. However, our finding of significantly longer ITT in women than in men suggests that commissural anatomy and physiology may be se xually dimorphic.