Lateralized interference in finger tapping: assessment of block design activities.

Dual task procedures were used to evaluate lateralized processing of block design solutions. Right-handed college students tapped a micro-key alone vs tapped while solving block design problems. Lateralized interference, implicating right-hemisphere processing, was observed when subjects manually completed block designs with their non-tapping band. When manual block manipulation was not required and subjects solved designs mentally, a different laterality pattern suggesting left-hand facilitation in conjunction with right-hand interference in tapping performance was observed. Only the facilitation effect, however, was reliably different from zero.