Theories and measures of consciousness develop together q Anil

Persaud, McLeod, and Cowey (2007b) dispute my claim that ‘‘post-decision wagering [PDW] cannot supply a direct behavioral measure of consciousness’’ (Seth, 2007), in which a ‘‘direct measure’’ is one that transparently reflects its target property, as a ruler directly measures length. Here I defend this claim and argue in favour of a virtuous circularity among measures, theories, and data. Behavioral measures of consciousness come in two flavours, subjective and objective. Subjective measures leverage introspective capabilities, for example by a person verbally reporting the content of her conscious experience or expressing her level of confidence in a previous decision or discrimination. Introspection always involves metacognition because introspective reports consist of judgments about mental states. Therefore, subjective measures are always indirect and can be vulnerable to many biases (e.g., reluctance to report uncertain experiences). Also, because metacognitive conscious content assumes primary (sensory) consciousness but not vice versa, subjective measures risk incorrectly rejecting the presence of sensory consciousness based on the absence of metacognition. Objective measures do not require introspection and instead use some other behavior, for example forcedchoice decision accuracy, as a proxy. Although objective measures need not involve metacognition they are also always indirect, for two reasons. First, they still require a response criterion, for example whether to push a button or not. Second, they may not measure consciousness at all because many behavioral proxies— forced-choice decision accuracy being a good example—are capable of being learned unconsciously. So the simple reason why PDW cannot supply a direct measure of consciousness is that no behavioral measure, subjective or objective, is up to the job. Indeed, the fact that consciousness is ontologically subjective precludes direct behavioral access to conscious content. This does not however mandate pessimism: A science of consciousness is made possible in the first place by adopting epistemologically objective attitudes towards ontologically subjective phenomena (Searle, 1992). Importantly, both subjective and objective measures are epistemologically objective because both produce data that can be shared publicly. Persaud et al. raise two other issues in support of PDW being a direct measure: its intuitiveness for subjects, and evidence that it doesn’t affect the conscious states that it supposedly measures, at least not as much as some subjective measures do. However, both conscious and unconscious behaviors can be intuitive and indeed the phenomenology of intuition is often associated with unconscious knowledge (Dienes & Scott, 2005). And having a measure of X that doesn’t affect X is a prerequisite for a good measure of X, one which may be necessary but is by no means sufficient for establishing directness.