Online research in philosophy

Dienes & Perner's target article contains numerous but unsystematic references to the implicit or explicit knowledge of the temporal context of a known state of affairs such as may constitute the content of a propositional attitude. In this commentary, the forms of cognition that, according to D&P, require only implicit knowledge of time are contrasted with those for which explicit temporal knowledge is needed. It is suggested that the explicit representation of time may have been important in human evolution and that certain developmental disorders including autism may be (partly) caused by defective ability to represent time.

Dienes & Perner argue that the explicit representation of an individual to which a property is attributed requires explicit representation of the attributed property. The reasons for this conclusion are similar to the reasons why another of their conclusions may be considered suspect: A property may be explicit without an explicit representation of an individual or the predication of the property to an individual. We question the latter conclusion and draw connections to neurophysiological and cognitive evidence.

Distinguishing explicit from implicit knowledge on the basis of the active representation of certain propositional attitudes fails to provide an explanation for dissociations in learning performance under implicit and explicit conditions. This suggests an account of implicit and explicit knowledge grounded in the presence of multiple learning mechanisms, and multiple brain systems more generally. A rough outline of a connectionist account of this kind is provided.

Dienes and Perner offer us a theory of explicit and implicit knowledge that promises to systematise a large and diverse body of research in cognitive psychology. Their advertised strategy is to unpack this distinction in terms of explicit and implicit representation. But when one digs deeper one finds the HOT theory of consciousness doing much of the work. This reduces both the plausibility and usefulness of their account. We think their strategy is broadly correct, but that consensus on the explicit/implicit knowledge distinction is still a fair way off.

The scenario used by Dienes & Perner to show that individual representation can be implicit when property representation is explicit can be adapted to show that property representation can be implicit when individual representation is explicit. So there is no hierarchy of explicitness, contrary to their claim. There is a reading of the “implicit/explicit” distinction that does appear to exhibit an asymmetry parallel to that alleged to hold between individual and property. But this is not a distinction Dienes & Perner mention, nor is it one that could be easily incorporated into their framework.

In Dienes & Perner's analysis, implicitly represented knowledge differs from explicitly represented knowledge only in the attribution of properties to specific events and to self-awareness of the knower. This commentary questions whether implicit knowledge should be thought of as being represented in the same conceptual vocabulary; rather, it may involve a quite different form of representation.

This paper distinguishes between implicit self-related information and explicit self-representation and argues that the latter is required for self-consciousness. It is further argued that self-consciousness requires an awareness of other minds and that this awareness develops over the course of an increasingly complex perspectival differentiation, during which information about self and other that is implicit in early forms of social interaction becomes redescribed into an explicit format.

Much of traditional AI exemplifies the explicit representation paradigm, and during the late 1980''s a heated debate arose between the classical and connectionist camps as to whether beliefs and rules receive an explicit or implicit representation in human cognition. In a recent paper, Kirsh (1990) questions the coherence of the fundamental distinction underlying this debate. He argues that our basic intuitions concerning explicit and implicit representations are not only confused but inconsistent. Ultimately, Kirsh proposes a new formulation of the distinction, based upon the criterion ofconstant time processing.The present paper examines Kirsh''s claims. It is argued that Kirsh fails to demonstrate that our usage of explicit and implicit is seriously confused or inconsistent. Furthermore, it is argued that Kirsh''s new formulation of the explicit-implicit distinction is excessively stringent, in that it banishes virtually all sentences of natural language from the realm of explicit representation. By contrast, the present paper proposes definitions for explicit and implicit which preserve most of our strong intuitions concerning straightforward uses of these terms. It is also argued that the distinction delineated here sustains the meaningfulness of the abovementioned debate between classicists and connectionists.

The visual system captures a unique contrast between implicit and explicit representation where the same event (location of a visible object) is coded in both ways in parallel. A method of differentiating the two representations is described using an illusion that affects only the explicit representation. Consistent with predictions, implicit information is available only from targets presently visible, but, surprisingly, a two-alternative decision does not disturb the implicit representation.