Unconscious processes, by whatever name they may be known , are invariably operationalized by the dissociation paradigm, any situation involving the dissociation between two indicators , one of availability and the other, of accessibility , such that, ε>α. Subliminal perception has been traditionally defined by a special case of the dissociation paradigm in which availability exceeds accessibility when accessibility is null . Construct validity issues bedevil all dissociation paradigms since it is not clear what might constitute appropriate indicators (...) that, moreover, are pure and exhaustive. Semantic and theoretic drifts in the recent literature—e.g., the confusion of different versions of the dissociation paradigm, the equation of conscious–unconscious with direct–indirect tests, and the foisting of the criterion of qualitative differences—have tended to undermine emerging theoretic parsimony. On the other hand, a crucial factor has been left out of theory development: time. Both ε and α can rise and fall over time, often asynchronously, and so dissociations may wax and wane and, even, reverse over time. Some laboratory evidence suggests that accessibility measures , as they approach chance, may actually dip below chance . If so, d′=0 , could be an averaging artifact of positive and negative d′s. Conscious accessibility is not either–or but more or less, and variable over time. (shrink)

Subliminal perception (SP) is today considered a well-supported theory stating that perception can occur without conscious awareness and have a significant impact on later behaviour and thought. In this article, we first present and discuss different approaches to the study of SP. In doing this, we claim that most approaches are based on a dichotomic measure of awareness. Drawing upon recent advances and discussions in the study of introspection and phenomenological psychology, we argue for both the possibility (...) and necessity of using an elaborated measure of subjective states. In the second part of the article, we present findings where these considerations are implemented in an empirical study. The results and implications are discussed in detail, both with reference to SP, and in relation to the more general problem of using elaborate introspective reports as data in relation to studies of cognition. (shrink)

Graham Bird; XIV*—Subliminal Perception, Proceedings of the Aristotelian Society, Volume 73, Issue 1, 1 June 1973, Pages 217–232, https://doi.org/10.1093/aristo.

We addressed the questions whether stimuli presented below the threshold of verbal awareness are nevertheless perceived and whether there are perceptual differences between the two cerebral hemispheres. Pictures of line drawn objects and animals were subliminally presented to each visual half-field for subsequent identification in a form as fragmented as possible. The performance of 40 healthy subjects was compared to that of 63 controls. Whereas identification performance after blank presentation in the experimental group did not differ from that of controls, (...) identification in a significantly more fragmented form was achieved after the presentation of the complete picture. This effect, however, occurred only after subliminal stimulation in the left visual field, i.e., of the right hemisphere. Our results show that pictures presented below the threshold of verbal awareness can be perceived, and that only the right hemisphere can perceive them and make use of the perception. It remains an open question whether this kind of hemispheric specialization represents a right hemisphere dominance for subliminal perception or reflects an inability of the left hemisphere to access and behaviorally use unaware percepts via fragmented picture identification, for which a right hemisphere advantage is known. (shrink)

Graham Bird; XIV*—Subliminal Perception, Proceedings of the Aristotelian Society, Volume 73, Issue 1, 1 June 1973, Pages 217–232, https://doi.org/10.1093/aristo.

In a masked priming experimental paradigm, we studied a possible subliminal perception effect on a semantic selection task. To gauge the degree to which subjects solved the SST consciously, they subsequently reported their level of confidence of having made a correct response. This was done on each trial, and the subjects used individually constructed category rating scales to do so, in order to achieve a more sensitive measurement of which trials were influenced by conscious processes. During the construction (...) of these individual rating scales, subjects verbally reported their experiences after each trial. The present study failed to find evidence of performance above chance level when subjects themselves reported to be at chance level. In fact, performance closely covaried with subjects' confidence ratings. About half of the subjects reported they would sometimes experience a 'feeling of knowing' the correct response to the SST, despite being unaware of the specific identity of the prime. From this, we observe the methodological point that in order to demonstrate subliminal perception in a masked priming paradigm with a semantic selection task it is not enough to demonstrate a lack of conscious visual perception of the prime, since a vague, yet conscious, FOK experience can be used by subjects to solve the task. (shrink)

Previous studies making use of indirect processing measures have shown that perceptual grouping can occur outside the focus of attention. However, no previous study has examined the possibility of subliminal processing of perceptual grouping. The present work steps forward in the study of perceptual organization, reporting direct evidence of subliminal processing of Gestalt patterns. In two masked priming experiments, Gestalt patterns grouped by proximity or similarity that induced either a horizontal or vertical global orientation of the stimuli were (...) presented as masked primes and followed by visible targets that could be congruent or incongruent with the orientation of the primes. The results showed a reliable priming effect in the complete absence of prime awareness for both proximity and similarity grouping principles. These findings suggest that a phenomenal report of the Gestalt pattern is not mandatory to observe an effect on the response based on the global properties of Gestalt stimuli. (shrink)

Eighty-four undergraduate male subjects were tachistoscopically exposed either to an experimental message designed to arouse anxiety , or to a neutral control message , at 4 ms or 200 ms durations. Electrodermal responses were recorded before, during and after exposure to the critical messages. Three measures of awareness of 4 ms stimuli were used; recall, recognition and discrimination. No evidence of stimulus awareness was found on any of these measures. Only subjects exposed to the experimental message at 4 ms durations (...) showed a significant increase in EDR from pre-exposure to message exposure period. These results support Silverman's hypothesis that drive-related stimuli must be presented subliminally in order to produce significant effects on behavior, and are consistent with Bornstein's hypothesis that stimulus awareness inhibits responding to drive- and affect-related stimuli. (shrink)

“Source monitoring” theory is applied to the turn-of-the-century argument that, whenever binocularly fused patterns are self-consciously apperceived, both eyes' monocular sensations are consciously perceived. According to monitoring theory's refinement of the argument, binocularly apperceived patterns are accompanied by selfconsciousness that one is perceiving patterns , whereas monocular sensations are accompanied by no self-consciousness of their source. In the current test of this refined argument, 32 subjects were monocularly presented with 6 letters of the alphabet, while binocularly fusing 6 different letters, (...) and were subsequently required to discriminate these 12 letters from 6 other letters that they had visually imaged. Consistent with monitoring theory, the results of experimental testing suggest that binocularly fused letters are neurally monitored as “peripheral,” self-consciously experienced as “perceived,” and subsequently remembered as not “imaged.” The results further suggest that, during such binocular apperception, monocular data are not totally unconscious-like computer data-but are consciously experienced as “sourceless” sensations that are memorially confused with visually imaged sensations. (shrink)

Amidst the many brain events evoked by a visual stimulus, which are specifically associated with conscious perception, and which merely reflect non-conscious processing? Several recent neuroimaging studies have contrasted conscious and non-conscious visual processing, but their results appear inconsistent. Some support a correlation of conscious perception with early occipital events, others with late parieto-frontal activity. Here we attempt to make sense of those dissenting results. On the basis of a minimal neuro-computational model, the global neuronal workspace hypothesis, we (...) propose a taxonomy which distinguishes between vigilance and access to conscious report, as well as between subliminal, preconscious and conscious processing. We suggest that these distinctions map onto different neural mechanisms, and that conscious perception is systematically associated with a sudden surge of parieto-frontal activity causing top-down amplification. (shrink)

Research on perception without awareness has provoked strong emotional responses from individuals within and outside the scientific community, due in part to the perceived potential for abuse of subliminal techniques. In this paper, four basic issues regarding the use of subliminal techniques for propaganda purposes are discussed: whether exposure to subliminal stimuli can produce significant, predictable changes in affect, cognition and behavior; whether these effects are robust and powerful enough to make the use of subliminal (...) techniques for propaganda purposes feasible; whether the effects of subliminal stimulation are stable over time; and whether subliminal influences can be resisted by unwilling subjects. Research suggests that exposure to simple drive-or affect-related subliminal stimuli can produce ecologically significant, temporally stable changes in attitudes and behavior, and therefore may have potential for use as propaganda tools. Implications of these findings for our understanding of the mechanisms underlying subliminal perception are discussed. Technical problems which would need to be addressed before subliminal propaganda techniques could be employed are also discussed. Ethical issues raised by the use of covert attitude and behavior manipulation techniques are addressed. (shrink)

Research has shown repeatedly that attention influences implicit learning effects. In a similar vein, interoceptive awareness might be involved in unaware fear conditioning: The fact that the CS is repeatedly presented in the context of aversive bodily experiences might facilitate the development of conditioned responding. We investigated the role of interoceptive attention in a subliminal conditioning paradigm. Conditioning was embedded in a spatial cueing task with subliminally presented cues that were followed by a masking stimulus. Response times to the (...) targets that were either validly or invalidly predicted by the cues served as index of conditioning. Interoceptive attention was manipulated between-subjects. Half the participants completed a heartbeat detection task before conditioning. This task tunes attention to one’s own bodily signals. We found that conditioned responding was facilitated in this latter group of participants. These results are in line with the hypothesis that a rise interoceptive attention enhances unaware conditioned responding. (shrink)

In his analysis of subliminal perception research, Erdelyi documented two important phenomena: subchance perception and temporal variability in stimulus availability and accessibility. This Commentary addresses three issues raised by Erdelyi's review: the importance of distinguishing “micro” from “macro” temporal shifts; the need to analyze perception without awareness data at the level of the individual as well as the group; and parallels between the dissociations associated with neuroclinical phenomena and those observed in patients with certain forms of (...) personality pathology. Continued integration of laboratory findings with in vivo observations of clinical syndromes will yield a more cohesive and heuristic approach to the study of implicit mental states. (shrink)

Los estudios recientes sobre Hobbes han puesto una gran atención en el uso de las imágenes. Permanece, sin embargo, una objeción seria y factible: se podría argumentar que Hobbes no relaciona su producción de imágenes, ni a su política, ni a su teoría de la percepción y que, por tanto, no tenemos razón para creer que sus imágenes son una aplicación de esta doctrina. El propósito de este trabajo es mostrar que Hobbes de hecho sí vincula — de un modo (...) implícito — la construcción de imágenes y su teoría psicológica al orden político. Primero, el artículo reconstruye la teoría hobbesiana de la percepción y sus implicaciones. Segundo, se muestra que el Leviathan establece encubiertamente el vínculo entre la teoría de las imágenes y las imágenes políticas, incluyendo, por consiguiente, las creadas por el propio Hobbes. Tercero, se muestra que el Leviatán de Hobbes rara vez descubre su rol como dispositivo para ver, para hacer que el lector vea imágenes que él considera necesarias. Finalmente, se discuten las consecuencias de este descubrimiento para nuestra comprensión de Hobbes y de la visualidad y las imágenes en el pensamiento político. (shrink)

According to recent evidence, neurophysiological processes coupled to pain are closely related to the mechanisms of consciousness. This evidence is in accordance with findings that changes in states of consciousness during hypnosis or traumatic dissociation strongly affect conscious perception and experience of pain, and markedly influence brain functions. Past research indicates that painful experience may induce dissociated state and information about the experience may be stored or processed unconsciously. Reported findings suggest common neurophysiological mechanisms of pain and dissociation and (...) point to a hypothesis of dissociation as a defense mechanism against psychological and physical pain that substantially influences functions of consciousness. The hypothesis is also supported by findings that information can be represented in the mind/brain without the subject’s awareness. The findings of unconsciously present information suggest possible binding between conscious contents and self-functions that constitute self-representational dimensions of consciousness. The self-representation means that certain inner states of own body are interpreted as mental and somatic identity, while other bodily signals, currently not accessible to the dominant interpreter’s access are dissociated and may be defined as subliminal self-representations. In conclusion, the neurophysiological aspects of consciousness and its integrative role in the therapy of painful traumatic memories are discussed. (shrink)

This landmark volume brings together the work of the world's leading researchers in sublimated perception. This compilation marks a fundamental shift in the current study of subliminal effects: No longer in question is the notion that perception without awareness occurs. Now, the emphasis is on elucidating the parameters of subliminal effects and understanding the conditions under which stimuli perceived without awareness significantly influence affect, cognition, and behavior. PERCEPTION WITHOUT AWARENESS firmly establishes subliminal perception (...) within the mainstream of psychological science. Well represented here are the two main research branches that have emerged: One directly investigates the nature of subliminal effects; the other uses subliminal techniques as tools for investigating psychological phenomena such as hypnosis, dreaming, repression, social judgment and inference, psychopathology, and symptom formation. Broadly grouped into three main sections, the contributed chapters explore * The cognitive perspective--including implicit memory and implicit perception, the measurement of unconscious perceptual processes, and methods for revealing unconscious processes * The clinical perspective--exploring the cognitive and dynamic aspects of subliminal perception, memory, and consciousness; direct recovery of subliminal stimuli; and validation of subliminal psychodynamic activation * The social perspective--discussing subliminal mere-exposure effects, affect and social perception, and the role of subliminality in social psychology Timely and thought-provoking, PERCEPTION WITHOUT AWARENESS is sure to be of enormous interest to all psychoanalytic clinicians and scholars, as well as cognitive, clinical, and social psychologists whose work touches upon issues relating to psychopathology, perception, cognition, and memory. (shrink)

Reingold and MerikleÕs (1988, 1990) critique of the classic dissociation paradigm identified several issues as inherent problems that severely undermine the utility of this paradigm. Erdelyi (2004) extending his prior analysis (Erdelyi, 1985, 1986) points out several additional factors that may complicate the interpretation of empirically obtained dissociations. The goal of the present manuscript is to further discuss some of these commonly neglected interpretive difficulties. Ó 2003 Elsevier Inc. All rights reserved.

In a recent article, [Sergent, C. & Dehaene, S. . Is consciousness a gradual phenomenon? Evidence for an all-or-none bifurcation during the attentional blink, Psychological Science, 15, 720–729] claim to give experimental support to the thesis that there is a clear transition between conscious and unconscious perception. This idea is opposed to theoretical arguments that we should think of conscious perception as a continuum of clarity, with e.g., fringe conscious states [Mangan, B. . Sensation’s ghost—the non-sensory “fringe” of (...) consciousness, Psyche, 7, 18]. In the experimental study described in this article, we find support for this opposite notion that we should have a parsimonious account of conscious perception. Our reported finding relates to the hypothesis that there is more than one perceptual threshold [Merikle, P.M., Smilek, D. & Eastwood, J.D. . Perception without awareness: perspectives from cognitive psychology, Cognition, 79, 115–134], but goes further to argue that there are different “levels” of conscious perception. (shrink)

This study renews the classical concept of subliminal perception by investigating the impact of subliminal flicker from fluorescent lighting on affect and cognitive performance. It was predicted that low compared to high frequency lighting would evoke larger changes in affective states and also impair cognitive performance. Subjects reported high rather than low frequency lighting to be more pleasant, which, in turn, enhanced their problem solving performance. This suggests that sensory processing can take place outside of conscious awareness (...) resulting in conscious emotional consequences; indicating a role of affect in subliminal/implicit perception, and that positive affect may facilitate cognitive task performance. (shrink)

There is growing interest in the effect of sound on visual motion perception. One model involves the illusion created when two identical objects moving towards each other on a two-dimensional visual display can be seen to either bounce off or stream through each other. Previous studies show that the large bias normally seen toward the streaming percept can be modulated by the presentation of an auditory event at the moment of coincidence. However, no reports to date provide sufficient evidence (...) to indicate whether the sound bounce-inducing effect is due to a perceptual binding process or merely to an explicit inference resulting from the transient auditory stimulus resembling a physical collision of two objects. In the present study, we used a novel experimental design in which a subliminal sound was presented either 150 ms before, at, or 150 ms after the moment of coincidence of two disks moving towards each other. The results showed that there was an increased perception of bouncing when the subliminal sound was presented at or 150 ms after the moment of coincidence compared to when no sound was presented. These findings provide the first empirical demonstration that activation of the human auditory system without reaching consciousness affects the perception of an ambiguous visual motion display. (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)