The Objective Threshold/Strategic Model proposes that strong, qualitative inferences of unconscious perception can be made if the relationship between perceptual sensitivity and stimulus visibility is nonlinear and nonmonotonic. The model proposes a nadir in priming effects at the objective identification threshold . These predictions were tested with masked semantic priming and repetition priming of a lexical decision task. The visibility of the prime stimuli was systematically varied above and below the objective identification threshold. The obtained relationship between prime visibility and (...) priming facilitation was nonlinear, but the results failed to confirm a nadir in priming effects at the objective identification threshold. We conclude that the objective identification threshold does not necessarily indicate the point where presumably unconscious priming effects might be inhibited by conscious cognitive processes. (shrink)

Block [Block, N. . Two neural correlates of consciousness. Trends in Cognitive Science, 9, 46–52] and Snodgrass claim that a signal detection theory analysis of qualitative difference paradigms, in particular the exclusion failure paradigm, reveals cases of phenomenal consciousness without access consciousness. This claim is unwarranted on several grounds. First, partial cognitive access rather than a total lack of cognitive access can account for exclusion failure results. Second, Snodgrass’s Objective Threshold/Strategic model of perception relies on a problematic ‘enable’ approach to (...) perception that denies the possibility of intentional control of unconscious perception and any effect of following different task instructions on the presence/absence of phenomenal consciousness. Many of Block’s purported examples of phenomenal consciousness without cognitive access also rely on this problematic approach. Third, qualitative difference paradigms may index only a subset of access consciousness. Thus, qualitative difference paradigms like exclusion failure cannot be used to isolate phenomenal consciousness, any attempt to do so still faces serious methodological problems. (shrink)

While there is now general agreement that memory gives rise to both conscious and unconscious influences, there remains disagreement concerning the process architecture underlying these distinct influences. Do they arise from independent underlying systems or from systems that are interactive ? In the current paper we present a novel “inside-out” technique that can be used with the process-dissociation paradigm to arrive at more concrete conclusions concerning this central question and demonstrate this technique via a meta-analysis of currently published findings. Our (...) results suggest that the data presented in these studies vary in ways most consistent with the assumption that conscious and unconscious influences behave independently. (shrink)

We briefly presented either the letter ‘b’ or the letter ‘h’ to participants who were instructed to respond by saying the letter that was not shown. This binary version of the exclusion task avoids problems with assessing baseline completion rates. When the letters were shown for 5–10 ms participants erroneously responded with the shown letter at a rate greater than chance. They were capable of following the instructions when the letter was shown for longer . Given the chance to wager (...) low or high on their choices after short duration stimuli, participants declined to wager high even when they were correct. Taken together these results suggest that the briefly presented stimuli were processed subconsciously. (shrink)

Three experiments examined the role of response criteria in a masked semantic priming paradigm using an exclusion task. Experiment 1 used on-line prime-report and exclusion instructions in which participants were told to avoid completing a word stem with a word related to a prime flashed for 0, 38 or 212 ms. Semantic priming was significant in the items analysis, but was moderated by peoples’ ability to report the prime in the participant analysis. Prime-report thresholds in Experiment 2 were made more (...) liberal by instructing participants to guess on every trial. Prime-report increased from Experiment 1 as exclusion failures were eliminated. Experiment 3 clarified the relationship between awareness and prime identification using an on-line measure of confidence and different liberal prime report instructions. The current findings suggest that the ability to act upon and report information in a masked prime is determined by a variable response criterion, which can be manipulated as an independent variable. (shrink)

We investigated the competition between automatic and controlled processes in a word stem completion task. Prime-display duration and the prime-target interval were manipulated. On each trial a masked prime was displayed briefly, followed either immediately or after a delay by a word stem. The subjects were required to complete each stem with the first word that came to mind, to report any prime they could identify, and not to give as completion any identified prime. By the assumption that automatic processes (...) require less stimulus input and can be completed faster than consciously controlled processes we expected a stronger performance contribution from automatic processes with the shorter prime-display durations and in the immediate stems condition. The results confirmed this expectation. The findings highlight that consciously controlled processes require more time to run their course than unconscious automatic processes. (shrink)

Introspective and phenomenological methods are once again being used to support the use of subjective reports, rather than objective behavioural measures, to investigate and measure consciousness. Objective measures are often seen as useful ways of investigating the range of capacities subjects have in responding to phenomena, but are fraught with the interpretive problems of how to link behavioural capacities with consciousness. Instead, gathering subjective reports is seen as a more direct way of assessing the contents of consciousness. This article explores (...) three different ways of gathering subjective reports that have been discussed in recent literature on consciousness, including immediate retrospection (Schwitzgebel [2007]) and two types of introspective training (Overgaard et al. [2004]; Schwitzgebel [2008]). Although not an exhaustive survey of the range of introspective methods now used, the discussion below highlights a range of general methodological problems with introspective methods, many identified up to a century ago. It is argued that none of the methodological problems established in earlier criticisms of the use of subjective reports have been dealt with, yet are still valid criticisms. Given that this is not the first time proponents of introspective, subjective measures of conscious have failed to answer these criticisms, this raises the question of whether the goal of providing a measure of consciousness is a methodological muddle worth pursuing. (shrink)

Erdelyi does us all a great service by his customarily incisive discussion of the various ways in which our field tends to neglect, confuse, and misunderstand numerous critical issues in attempting to differentiate conscious from unconscious perception and memory. Although no single commentary could hope to comprehensively assess these issues, I will address Erdelyi’s three main points: How the dissociation paradigm can be used to validly infer unconscious perception; The implications of below-chance effects; and The role of time. I suggest (...) that significant progress on construct validity issues is possible; below-chance effects are part of a more general bidirectional phenomenon, very likely unconscious, and do not threaten absolute subliminality; and practice/learning effects pose potential difficulties for time-based dissociation paradigms. (shrink)

This paper argues for a position of ‘dark pessimism’ towards introspective reports playing a strong justificatory role in consciousness science, based on the application of frameworks and concepts of measurement. I first show that treating introspective reports as measurements fits well within current discussions of the reliability of introspection, and argue that introspective reports must satisfy at least a minimal definition of measurement in order to play a justificatory role in consciousness science. I then show how treating introspective reports as (...) measurements makes it possible to identify the foundational methodological problems that underlie much of the current philosophical and scientific debate about the status of introspective evidence in studying consciousness. I argue that these problems prevent introspective reports from playing a strong justificatory role and resolving long-standing debates in consciousness science, both in contemporary work and in the future. (shrink)

This paper argues for a position of ‘dark pessimism’ towards introspective reports playing a strong justificatory role in consciousness science, based on the application of frameworks and concepts of measurement. I first show that treating introspective reports as measurements fits well within current discussions of the reliability of introspection, and argue that introspective reports must satisfy at least a minimal definition of measurement in order to play a justificatory role in consciousness science. I then show how treating introspective reports as (...) measurements makes it possible to identify the foundational methodological problems that underlie much of the current philosophical and scientific debate about the status of introspective evidence in studying consciousness. I argue that these problems prevent introspective reports from playing a strong justificatory role and resolving long-standing debates in consciousness science, both in contemporary work and in the future. (shrink)