Further investigation on the mnemonic effect of gestures: Their meaning matters

Three experiments are reported that examine the nature of knowledge underlying performance in the invariant learning task. Previous research (Bright & Burton, 1994; McGeorge & Burton, 1990) has supported an account of performance based on the implicit abstraction and application of a rule pertaining to the invariant feature. In contrast, we found effects in both the digit and clock invariant tasks that are difficult to explain solely in terms of subjects acquiring the experimenters' rule. In all three experiments, manipulation of test item properties that are independent of the invariant feature led to a detriment in performance that is not predicted by an account based on the experimenters' rules. Furthermore, the use of an on-line measure of awareness (confidence ratings) provided some evidence that performance is mediated by low confidence explicit knowledge.