A number of ways of taxonomizing human learning have been proposed. We examine the evidence for one such proposal, namely, that there exist independent explicit and implicit learning systems. This combines two further distinctions, between learning that takes place with versus without concurrent awareness, and between learning that involves the encoding of instances versus the induction of abstract rules or hypotheses. Implicit learning is assumed to involve unconscious rule learning. We examine the evidence for implicit learning derived from subliminal learning, (...) conditioning, artificial grammar learning, instrumental learning, and reaction times in sequence learning. We conclude that unconscious learning has not been satisfactorily established in any of these areas. The assumption that learning in some of these tasks is predominantly based on rule abstraction is questionable. When subjects cannot report the “implicitly learned” rules that govern stimulus selection, this is often because their knowledge consists of instances or fragments of the training stimuli rather than rules. In contrast to the distinction between conscious and unconscious learning, the distinction between instance and rule learning is a sound and meaningful way of taxonomizing human learning. We discuss various computational models of these two forms of learning. (shrink)

Evaluative learning refers to the change in the affective evaluation of a previously neutral stimulus that occurs after the stimulus has been associated with a second, positive or negative, affective stimulus . Four experiments are reported in which the AS was presented very briefly. Significant evaluative learning was observed in participants who did not notice the presentation of the affective stimuli or could not discriminate between the briefly presented positive and negative ASi when asked to do so . In two (...) other experiments , no significant learning effect was obtained. A meta-analysis performed on the present and previously reported results gave evidence for a small, though statistically reliable evaluative learning effect when ASi are presented “subliminally.” This finding supports the hypothesis that evaluative associations can be learned implicitly. (shrink)

We are reviewing and summarizing evidence for the processes of acquisition of information outside of conscious awareness (processing information about covariations, nonconscious indirect and interactive inferences, self-perpetuation of procedural knowledge). A considerable amount of data indicates that as compared to consciously controlled cognition, the nonconscious information-acquisition processes are not only much faster but also structurally more sophisticated in the sense that they are capable of efficient processing of multidimensional and interactive relations between variables. Those mechanisms of nonconscious acquisition of information (...) provide a major channel for the development of procedural knowledge which is indispensable for such important aspects of cognitive functioning as encoding and interpretation of stimuli and the triggering emotional reactions. (shrink)