No abstract

I examine the phenomenon of implicit learning, the process by which knowledge about the ralegoverned complexities of the stimulus environment is acquired independently of conscious attempts to do so. Our research with the two, seemingly disparate experimental paradigms of synthetic grammar learning and probability learning is reviewed and integrated with other approaches to the general problem of unconscious cognition. The conclusions reached are as follows: (a) Implicit learning produces a tacit knowledge base that is abstract and representative of the structure of the environment; (b) such knowledge is optimally acquired independently of conscious efforts to learn; and (c) it can be used implicitly to solve problems and make accurate decisions about novel stimulus circumstances. Various epistemological issues and related prob-1 lems such as intuition, neuroclinical disorders of learning and memory, and the relationship of evolutionary processes to cognitive science are also discussed.Special thanks go to Rhianon Allen, Ruth Hernstadt, Paul Lewicki, and Robert McCauley for suggestions, insights, and gentle criticisms (which I probably should have paid more attention to).

for suggestions, insights, and gentle criticisms (which I probably should have paid more attention to).

The effect of instructional set on implicit learning of a synthetic language was explored. Specifically, the neutral, implicit instructions used in previous studies were compared with explicit instructions which directed subjects to search for the complex rules that determined letter orderings. The subjects given the explicit instructions were poorer at memorizing exemplars from the language, learned less about the underlying structure, and tended to invent nonrepresentational rules. The results have strong implications for a theory of implicit learning which stresses a nonconscious abstraction system that operates when the stimulus environment exhibits exceedingly complex structure, and subjects are not actively trying to break the code.