The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform
Howard Shevrin - One of the best experts on this subject based on the ideXlab platform.
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Subliminal affect valence words change conscious mood potency but not valence is this evidence for unconscious valence affect
Brain Sciences, 2012Co-Authors: Howard Shevrin, Jaak Panksepp, Linda A W Brakel, Michael SnodgrassAbstract:Whether or not affect can be unconscious remains controversial. Research claiming to demonstrate unconscious affect fails to establish clearly unconscious stimulus conditions. The few investigations that have established unconscious conditions fail to rule out conscious affect changes. We report two studies in which unconscious stimulus conditions were met and conscious mood changes measured. The Subliminal Stimuli were positive and negative affect words presented at the objective detection threshold; conscious mood changes were measured with standard manikin valence, potency, and arousal scales. We found and replicated that unconscious emotional Stimuli produced conscious mood changes on the potency scale but not on the valence scale. Were positive and negative affects aroused unconsciously, but reflected consciously in potency changes? Or were the valence words unconscious cognitive causes of conscious mood changes being activated without unconscious affect? A thought experiment is offered as a way to resolve this dilemma.
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Event-related markers of unconscious processes.
International Journal of Psychophysiology, 2001Co-Authors: Howard ShevrinAbstract:A series of studies is reviewed strongly suggesting that event-related potentials (ERPs) may provide markers for unconscious processes. In one study it was shown that, although smaller in amplitude by a least a factor of four, ERPs to Subliminal Stimuli have a similar component structure to ERPs to supraliminal Stimuli. In another study, it was shown that an oddball P300 could be obtained for Subliminal Stimuli. In two additional studies, it was shown that aversive conditioning could be established unconsciously. The implications for our understanding of the role of unconscious processes in phobias and post-traumatic stress disorders are discussed, as well as more general implications for memory formation.
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event related brain potentials differentiate positive and negative mood adjectives during both supraliminal and Subliminal visual processing
International Journal of Psychophysiology, 2001Co-Authors: Edward M. Bernat, Scott C. Bunce, Howard ShevrinAbstract:This experiment provides brain event-related potential (ERP) evidence for differential processing of visually presented pleasant and unpleasant affectively valent words (mood adjectives) for both supraliminal (40 ms) and Subliminal (unmasked, 1 ms) stimulus durations. Unpleasant words elicited a more positive amplitude than pleasant words in both durations. ERP components (P1, N1, P2, P3, and a late positive potential; LP) were measured at six electrode sites (F3, F4, P3, P4, CzPz, Oz). ERPs to Subliminal Stimuli demonstrated differences between pleasant and unpleasant words in the left hemisphere across all measured components. Supraliminal processing showed similar differences in the left hemisphere for early components (P1 and N1), but bilateral differences for late components (P3 and LP). Activity in the P2 time window was associated with the divergence between supraliminal and Subliminal affective responses. Implications for the study of affect and consciousness are discussed.
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Subliminal visual oddball Stimuli evoke a P300 component
Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, 2001Co-Authors: Edward M. Bernat, Howard Shevrin, Michael SnodgrassAbstract:Abstract Objective : To provide evidence that a P300 component can be elicited by Subliminal Stimuli in an oddball paradigm. Methods : The words LEFT and RIGHT were presented in a frequent-rare ratio (80–20%), counterbalanced between subjects. Stimuli were presented at the objective detection threshold ( d ′=0, via unmasked 1 ms presentations), a stringent measure for detecting any conscious perception. Results : A significantly larger amplitude component was found for rare vs. frequent stimulus presentations across electrodes Fz, Cz, and Pz using both a broad 200–900 ms window ( F (1,27)=5.75, P η 2 =0.18; one-tailed), and a more narrow 400–760 ms window defined using principal component analysis ( F (1,27)=10.10, P η 2 =0.27; one-tailed). No significant component latency effects were found. An analysis of the conscious perception index ( d ′) and the oddball effect (rare-frequent amplitude difference) revealed a negative relationship, further supporting the contention that conscious perception does not account for the finding, and suggesting that any conscious stimulus detection may inhibit this Subliminal effect. Conclusions : Results provide evidence that an endogenous component can be elicited by undetectable Subliminal Stimuli in an oddball paradigm. Implications are discussed for comparing conscious and unconscious information processing, unconscious learning, and the measurement of ERPs to Subliminal Stimuli.
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Further evidence for unconscious learning: preliminary support for the conditioning of facial EMG to Subliminal Stimuli.
Journal of psychiatric research, 1999Co-Authors: Scott C. Bunce, Edward M. Bernat, Philip S. Wong, Howard ShevrinAbstract:Abstract This study investigated the predictive validity of facial electromyograms (EMGs) in a Subliminal conditioning paradigm. Two schematic faces (pleasant; CS− and unpleasant; CS+), were presented to eight right-handed males during supraliminal pre- and postconditioning phases. Subliminal conditioning consisted of 36 energy-masked presentations of each face pairing the CS+ with an aversive shock 800 ms poststimulus. A forced-choice recognition task established that the energy mask effectively precluded conscious recognition of Stimuli. For the obicularis oculi and corrugator EMGs, significant face × condition interactions were found at 20–100 ms and 400–792 ms poststimulus. The results demonstrate the existence of an expressive motoric response related to affect operating in response to a learned but unconscious event. Subjects were not aware of a contingency between the CS+ and the US, suggesting emotional contingencies can be unconsciously acquired.
Niko A Busch - One of the best experts on this subject based on the ideXlab platform.
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decreased visual detection during Subliminal stimulation
Journal of Vision, 2014Co-Authors: Isabelle Bareither, Niko A Busch, Arno VillringerAbstract:: What is the perceptual fate of invisible Stimuli-are they processed at all and does their processing have consequences for the perception of other Stimuli? As has been shown previously in the somatosensory system, even Stimuli that are too weak to be consciously detected can influence our perception: Subliminal stimulation impairs perception of near-threshold Stimuli and causes a functional deactivation in the somatosensory cortex. In a recent study, we showed that Subliminal visual Stimuli lead to similar responses, indicated by an increase in alpha-band power as measured with electroencephalography (EEG). In the current study, we investigated whether a behavioral inhibitory mechanism also exists within the visual system. We tested the detection of peripheral visual target Stimuli under three different conditions: Target Stimuli were presented alone or embedded in a concurrent train of Subliminal Stimuli either at the same location as the target or in the opposite hemifield. Subliminal Stimuli were invisible due to their low contrast, not due to a masking procedure. We demonstrate that target detection was impaired by the Subliminal Stimuli, but only when they were presented at the same location as the target. This finding indicates that Subliminal, low-intensity Stimuli induce a similar inhibitory effect in the visual system as has been observed in the somatosensory system. In line with previous reports, we propose that the function underlying this effect is the inhibition of spurious noise by the visual system.
A Cotugno - One of the best experts on this subject based on the ideXlab platform.
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conscious and intentional access to unconscious decision making module in ambiguous visual perception
International Work-Conference on Artificial and Natural Neural Networks, 1999Co-Authors: C Taddeiferretti, Carlo Musio, Silvia Santillo, A CotugnoAbstract:Increasingly higher levels of information processing contribute to the highest level of visual perception, that of object recognition. An unconscious decision-making event arising at the end of an unconscious inference process acts upon the already processed visual information resolving the ambiguity inherent to such information. In the case of multistable reversible patterns, the ambiguity is never resolved and the perception alternates among different interpretations of the visual information. The perception alternance model is used here to investigate the possibility to access into the decision-making module by means of mental activities applied in a downward direction. A will effort modifies the time patterning of the perception alternance. The will effect is higher if the decision-making mechanism is resetted also by the application of Subliminal Stimuli.
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IWANN (1) - Conscious and Intentional Access to Unconscious Decision-Making Module in Ambiguous Visual Perception
Lecture Notes in Computer Science, 1999Co-Authors: C. Taddei-ferretti, Carlo Musio, Silvia Santillo, A CotugnoAbstract:Increasingly higher levels of information processing contribute to the highest level of visual perception, that of object recognition. An unconscious decision-making event arising at the end of an unconscious inference process acts upon the already processed visual information resolving the ambiguity inherent to such information. In the case of multistable reversible patterns, the ambiguity is never resolved and the perception alternates among different interpretations of the visual information. The perception alternance model is used here to investigate the possibility to access into the decision-making module by means of mental activities applied in a downward direction. A will effort modifies the time patterning of the perception alternance. The will effect is higher if the decision-making mechanism is resetted also by the application of Subliminal Stimuli.
Isabelle Bareither - One of the best experts on this subject based on the ideXlab platform.
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decreased visual detection during Subliminal stimulation
Journal of Vision, 2014Co-Authors: Isabelle Bareither, Niko A Busch, Arno VillringerAbstract:: What is the perceptual fate of invisible Stimuli-are they processed at all and does their processing have consequences for the perception of other Stimuli? As has been shown previously in the somatosensory system, even Stimuli that are too weak to be consciously detected can influence our perception: Subliminal stimulation impairs perception of near-threshold Stimuli and causes a functional deactivation in the somatosensory cortex. In a recent study, we showed that Subliminal visual Stimuli lead to similar responses, indicated by an increase in alpha-band power as measured with electroencephalography (EEG). In the current study, we investigated whether a behavioral inhibitory mechanism also exists within the visual system. We tested the detection of peripheral visual target Stimuli under three different conditions: Target Stimuli were presented alone or embedded in a concurrent train of Subliminal Stimuli either at the same location as the target or in the opposite hemifield. Subliminal Stimuli were invisible due to their low contrast, not due to a masking procedure. We demonstrate that target detection was impaired by the Subliminal Stimuli, but only when they were presented at the same location as the target. This finding indicates that Subliminal, low-intensity Stimuli induce a similar inhibitory effect in the visual system as has been observed in the somatosensory system. In line with previous reports, we propose that the function underlying this effect is the inhibition of spurious noise by the visual system.
Carlo Musio - One of the best experts on this subject based on the ideXlab platform.
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conscious and intentional access to unconscious decision making module in ambiguous visual perception
International Work-Conference on Artificial and Natural Neural Networks, 1999Co-Authors: C Taddeiferretti, Carlo Musio, Silvia Santillo, A CotugnoAbstract:Increasingly higher levels of information processing contribute to the highest level of visual perception, that of object recognition. An unconscious decision-making event arising at the end of an unconscious inference process acts upon the already processed visual information resolving the ambiguity inherent to such information. In the case of multistable reversible patterns, the ambiguity is never resolved and the perception alternates among different interpretations of the visual information. The perception alternance model is used here to investigate the possibility to access into the decision-making module by means of mental activities applied in a downward direction. A will effort modifies the time patterning of the perception alternance. The will effect is higher if the decision-making mechanism is resetted also by the application of Subliminal Stimuli.
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IWANN (1) - Conscious and Intentional Access to Unconscious Decision-Making Module in Ambiguous Visual Perception
Lecture Notes in Computer Science, 1999Co-Authors: C. Taddei-ferretti, Carlo Musio, Silvia Santillo, A CotugnoAbstract:Increasingly higher levels of information processing contribute to the highest level of visual perception, that of object recognition. An unconscious decision-making event arising at the end of an unconscious inference process acts upon the already processed visual information resolving the ambiguity inherent to such information. In the case of multistable reversible patterns, the ambiguity is never resolved and the perception alternates among different interpretations of the visual information. The perception alternance model is used here to investigate the possibility to access into the decision-making module by means of mental activities applied in a downward direction. A will effort modifies the time patterning of the perception alternance. The will effect is higher if the decision-making mechanism is resetted also by the application of Subliminal Stimuli.
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explan a programming language for complex visual Stimuli presentation
International Journal of Bio-medical Computing, 1994Co-Authors: Romano Colucci, Carlo Musio, C TaddeiferrettiAbstract:Visual cognition research requires the flexible use of structured spatial patterns, characterized by various space and time parameters, which may be administered as visual Stimuli. Dealing with this kind of study, we developed a specialpurpose programming language and implemented a compiler to build executable programs. The language allows the presentation of Stimuli, their space coordinates, persistency values, sequence, kinematic parameters, space-time proximity with other visual Stimuli, determination of their modification according to external interaction, generation of Subliminal Stimuli, monitoring of different subject reactions, automatic reporting of stimulus presentation, and reaction monitoring. Such a language has been successfully utilized in a visual perception research.
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EXPLAN — a programming language for complex visual Stimuli presentation
International journal of bio-medical computing, 1994Co-Authors: Romano Colucci, Carlo Musio, C. Taddei-ferrettiAbstract:Visual cognition research requires the flexible use of structured spatial patterns, characterized by various space and time parameters, which may be administered as visual Stimuli. Dealing with this kind of study, we developed a special-purpose programming language and implemented a compiler to build executable programs. The language allows the presentation of Stimuli, their space coordinates, persistency values, sequence, kinematic parameters, space-time proximity with other visual Stimuli, determination of their modification according to external interaction, generation of Subliminal Stimuli, monitoring of different subject reactions, automatic reporting of stimulus presentation, and reaction monitoring. Such a language has been successfully utilized in a visual perception research.
