Comparison of behavioural measures of consciousness has attracted much attention recently. In a recent article, Szczepanowski et al. conclude that confidence ratings predict accuracy better than both the perceptual awareness scale and post-decision wagering when using stimuli with emotional content . Although we find the study interesting, we disagree with the conclusion that CR is superior to PAS because of two methodological issues. First, the conclusion is not based on a formal test. We performed this test and found no evidence (...) that CR predicted accuracy better than PAS . Second, Szczepanowski et al. used the present version of PAS in a manner somewhat different from how it was originally intended, and the participants may not have been adequately instructed. We end our commentary with a set of recommendations for future studies using PAS. (shrink)

Both the multidimensional phenomenon and the polysemous notion of consciousness continue to prove resistant to consistent measurement and unambiguous definition. This is hardly surprising, given that there is no agreement even as regards the most fundamental issues they involve. One of the basic disagreements present in the continuing debate about consciousness pertains to its gradational nature. The general aim of this article is to show how consciousness might be graded and multidimensional at the same time. We therefore focus on the (...) question of what it is, exactly, that is or could be graded in cases of consciousness, and how we can measure it. Ultimately, four different gradable aspects of consciousness will be described: quality, abstractness, complexity and usefulness, which belong to four different dimensions, these being understood, respectively, as phenomenal, semantic, physiological, and functional. Consequently, consciousness may be said to vary with respect to phenomenal quality, semantic abstraction, physiological complexity, and functional usefulness. It is hoped that such a four-dimensional approach will help to clarify and justify claims about the hierarchical nature of consciousness. The approach also proves explanatorily advantageous, as it enables us not only to draw attention to certain new and important differences in respect of subjective measures of awareness and to justify how a given creature may be ranked higher in one dimension of consciousness and lower in terms of another, but also allows for innovative explanations of a variety of well-known phenomena (amongst these, the interpretations of blindsight and locked-in syndrome will be briefly outlined here). Moreover, a 4D framework makes possible many predictions and hypotheses that may be experimentally tested (We point out a few such possibilities pertaining to interdimensional dependencies). (shrink)

In this paper we argue that awareness comes in degrees, and we propose a novel multi-factor account that spans both subjective experiences and perceptual representations. At the subjective level, we argue that conscious experiences can be degraded by being fragmented, less salient, too generic, or flash-like. At the representational level, we identify corresponding features of perceptual representations—their availability for working memory, intensity, precision, and stability—and argue that the mechanisms that affect these features are what ultimately modulate the degree of awareness. (...) We conclude the paper by demonstrating why the original interpretations of certain empirical findings that apparently pose problems for our account are, in fact, flawed. (shrink)

Mental causation is a predominantly theoretical topic rather than a topic studied in the laboratory. The purpose of this paper is to outline a general approach for studying mental causation by empirical means for philosophers and scientists interested in the topic. The aim is to outline how we can infer mental causation by empirical methods given an unknown solution to the mind-body problem. The approach is based on the principles of causal inference to find causal relations among observed variables used (...) in all branches of science. With these principles, it is possible to estimate the causal effects of mental events: Make an experimental manipulation of a mental event, control confounding variables, and estimate causal effects on the outcome. The caveat is that we cannot separate the causal effects of a mental event from the physical base of the mental event, independent of whether we assume mental events can be reduced to their physical base. A challenge to estimating causal effects of mental events is that measured physical variables, such as electrophysiological potentials from the brain, might reflect processes that are part of “higher-order” phenomena, such as mental events. This means that controlling “downwards” for confounding variables is challenging. It is, however, not impossible. It also means that inferring non-mental causes of action cannot be done by measuring only physical variables alone. Keeping the mind-body problem in mind when designing experiments, it is possible to infer mental causation. (shrink)