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Reingold, E. M. (1992).  Conscious versus unconscious processes:  Are 
	they qualitatively different?  Behavioral and Brain Sciences 15, 218-219.

Commentary; The target article can be found here

Conscious versus unconscious processes: Are they qualitatively different?

Eyal M. Reingold

Can conscious and unconscious processes be distinguished empirically? No amount of precision in measurement is in itself sufficient. Equal emphasis on methodological rigor, and conceptual clarity, is necessary for genuine progress. Methodologically, the study of the unconscious involves illusive and fragile phenomena, difficult to replicate findings, and inconsistent, and sometimes inadequate measurement criteria (see Eriksen, 1960; Holender, 1986; Merikle, 1982; Reingold & Merikle, 1988, 1990). Conceptually, definitional and terminological chaos, and implicit assumptions that are rarely acknowledged, fuel the often futile controversy between "believers" and "nonbelievers" in the unconscious (see Dunn & Kirsner, 1988, 1989; Erdelyi, 1985, 1986; Lockhart, 1989; Reingold & Merikle, 1988, 1990; Richardson-Klavehn & Bjork, 1988). Not surprisingly, these difficulties have prompted practical researchers to stay clear of the conscious/unconscious distinction (Searle, 1991), while related phenomena have been investigated under a variety of different dichotomies (e.g., attended/unattended, intentional/incidental, explicit/implicit, overt/covert, controlled/automatic, etc.). Yet the terms consciousness and awareness still seem to preserve best the historical link among related ideas; moreover their very ambiguity is an accurate reflection, and a constant reminder of the vagueness of theoretical constructs and their relation to empirical work in this area.

It is precisely in this context that Dennett & Kinsbourne (D & K) make a truly unique contribution. They not only expose brilliantly an important confusion between the temporal properties of the process of representing and the temporal content of the representations themselves, but they also provide powerful metaphors that may help one avoid sliding back into this ingrained confusion.

An inadvertent consequence, however, of D & K's very compelling case against attempts to time the emergence of consciousness and against the Cartesian notion of a transition between the unconscious and the conscious realms, may be an underestimation of the importance of the conscious/unconscious distinction. Although one can agree with the authors' portrayal of the graceful interplay between conscious and unconscious processes, and its temporal indeterminacy, this should not prevent us from trying to explore and explain the qualitative differences between these processes. This line of work would complement D & K's arguments; their very effective critique of nonquestions should be coupled with alternative questions. It is precisely because consciousness cannot be temporally or spatially localized in the brain that identifying qualitative differences between conscious and unconscious processes is crucial for the conscious/unconscious distinction. Indeed, the method of establishing such differences (e.g., Cheesman & Merikle, 1986; Dixon, 1971, 1981; Jacoby & Whitehouse, 1989; Jacoby, et al., 1989; Merikle & Reingold, 1990, 1991; Shevrin & Dickman, 1980) may provide the ultimate test for the value of the conscious/unconscious distinction. More specifically, if the difference between conscious versus unconscious processing is quantitative, rather than qualitative, then the merit of agonizing over this distinction becomes highly questionable (see Cheesman & Merikle, 1986). Perhaps in their response, D & K can specify where they stand on this issue.

On a more general level, Libet's work (see Libet, 1985, 1987. 1989), reconsidered by D & K, is an example of the dissociation paradigm for the study of the unconscious (see Erdelyi, 1985, 1986). Briefly, this requires two indices of processing, one which reflects information available to consciousness, and another which reflects information available irrespective of consciousness. As elaborated elsewhere (Reingold & Merikle, 1988, 1990), when consciousness is defined in terms of subjective report or claimed awareness, as in Libet's research, the dissociation paradigm yields ample evidence for unconscious processing. However, there is no general consensus as to the adequacy of such a definition. In fact, no operational definition of conscious awareness can be justified solely on an a priori basis; each requires convergent empirical evidence to establish its validity. Thus, the qualitative differences approach may help validate any proposed index of consciousness.


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