The interocular suppression technique termed continuous flash suppression (CFS) has become an immensely popular tool for investigating visual processing outside of awareness. The emerging picture from studies using CFS is that extensive processing of a visual stimulus, including its semantic and affective content, occurs despite suppression from awareness of that stimulus by CFS. However, the current implementation of CFS in many studies examining processing outside of awareness has several drawbacks that may be improved upon for future studies using CFS. In (...) this paper, we address some of those shortcomings, particularly ones that affect the assessment of unawareness during CFS, and ones to do with the use of ‘visible’ conditions that are often included as a comparison to a CFS condition. We also discuss potential biases in stimulus processing as a result of spatial attention and feature-selective suppression. We suggest practical guidelines that minimize the effects of those limitations in using CFS to study visual processing outside of awareness. (shrink)

COMMENTARY ON: LaBerge, D. "Attention, Awareness, and the Triangular Circuit". Consciousness and Cognition, 6, 149-181.

This reply to five continuing commentaries on my 1991 target article on “Is human information processing conscious” focuses on six related issues: 1) whether focal attentive processing replaces consciousness as a causal agent in third-person viewable human information processing, 2)whether consciousness can be dissociated from human information processing, 3) continuing disputes about definitions of "consciousness" and about what constitutes a “conscious process” , 4) how observer-relativity in psychology relates (and does not relate) to relativity in physics, 5) whether the first-person (...) viewable causal efficacy of consciousness counts as ‘real’ causal efficacy and 6) a clarification of the sense in which first- and third-person causal accounts of mental processing are complementary and mutually irreducible. (shrink)

Jeannerod's target article describes support, through empirical and neurological findings, for the intriguing idea of motor imagery, a form of representation hypothesized to have levels of functional equivalence with motor preparation, while being consciously accessible. Jeannerod suggests that the subjectively accessible content of motor imagery allows it to be distinguished from motor preparation, which is unconscious. Motor imagery is distinguished from visual imagery in terms of content. Motor images are kinesthetic in nature; they are parametrized by variables such as force (...) and time and they are potentially governed by kinematic rules. Jeannerod acknowledges, however, that motor and visual imagery may not easily be separated, because actions take place in a spatial environment. I agree; in fact, I suggest here that visualization may generally be concomitant with, and may even subjectively dominate, motor imagery. (shrink)

We have learned that the issues we raised are very difficult to think about clearly, and what "works" for one thinker falls flat for another, and leads yet another astray. So it is particularly useful to get these re-expressions of points we have tried to make. Both commentaries help by proposing further details for the Multiple Drafts Model, and asking good questions. They either directly clarify, or force us to clarify, our own account. They also both demonstrate how hard it (...) is for even sympathetic commentators always to avoid the very habits of thought the Multiple Drafts Model was designed to combat. While acknowledging and expanding on their positive contributions, we must sound a few relatively minor alarms. (shrink)

Block seems to propose untested answers to empirical questions. Whether consciousness is a “mongrel problem,” rather than a single core fact with many facets, is an empirical issue. Likewise, the intimate relationship between personal consciousness and global access functions cannot be decided pretheoretically. This point is demonstrated by the reader's private experience of foveal versus parafoveal vision, and for conscious versus unconscious representation of the many meanings of common words.

When is choice affected by subliminal messages? This question has fascinated scientists and lay people alike, but it is only recently that reliable empirical data began to emerge. In the current paper we bridge the literature on implicit motivation and that on subliminal persuasion. We suggest that motivation in general, and implicit motivation more specifically, plays an important role in subliminal persuasion: It sensitizes us to subliminal cues. To examine this hypothesis we developed a new paradigm that allows powerful tests (...) of subliminal influences as well as stringent assessments of subliminality. The results of two experiments suggest that implicit motivation can enhance the effects of subliminal priming on choice. (shrink)

Consciousness can be measured in various ways, but different measures often yield different conclusions about the extent to which awareness relates to performance. Here, we compare five different subjective measures of awareness in the context of an artificial grammar learning task. Participants expressed their subjective awareness of rules using one of five different scales: confidence ratings , post-decision wagering , feeling of warmth , rule awareness , and continuous scale . All scales were equally sensitive to conscious knowledge. PDW, however, (...) was affected by risk aversion, and both RAS and SDS applied different minimal criteria for rule awareness. CR seems to capture the largest range of consciousness, but failed to indicate unconscious knowledge with the guessing criterion. We close by discussing the theoretical implications of scale sensitivity and propose that CR’s unique features enable a finer assessment of subjective states of awareness. (shrink)

Our visual systems account for stimulus context in brightness perception, but whether such adjustments occur for stimuli that we are unaware of has not been established. We therefore assessed whether stimulus context influences brightness processing by measuring unconscious priming with metacontrast masking. When a middle-gray disk was presented on a darker background, such that it could be consciously perceived as brighter via simultaneous brightness contrast , reaction times were significantly faster to a bright annulus than to a dark annulus. We (...) further show that context-dependent brightness priming does not correlate with visibility using an objective measure of awareness and that context-dependent, but not context-independent brightness priming, occurs equally strongly for stimuli below or above the subjective threshold for awareness . These results suggest that SBC occurs at early levels of visual input and is not influenced by conscious perception. (shrink)

Consciousness is now a hot topic in both philosophy and the cognitive sciences, yet there is much controversy over how to measure it. First, it is not clear whether biased subjective reports should be taken as adequate for measuring consciousness, or if more objective measures are required. Ways to benefit from the advantages of both these measures in the form of ‘Type 2’ metacognitive measures are under development, but face criticism. Research into neurophysiological measures of consciousness is potentially very valuable, (...) but often hindered by its dependence on behavioural measures that are themselves controversial. Newer informational measures are theoretically interesting, but as yet not easily applicable, while other measures of consciousness are designed for application in clinical cases . Although much optimism accompanies research into measures of consciousness, the controversies and methodological problems reviewed here suggest that making progress in this area may be more difficult than is often acknowledged. (shrink)