Absence of Face-specific Cortical Activity in the Complete Absence of Awareness: Converging Evidence from Functional Magnetic Resonance Imaging and Event-related Potentials

In this study, we explored the neural correlates of perceptual awareness during a masked face detection task. To assess awareness more precisely than in previous studies, participants employed a 4-point scale to rate subjective visibility. An event-related fMRI and a high-density ERP study were carried out. Imaging data showed that conscious face detection was linked to activation of fusiform and occipital face areas. Frontal and parietal regions, including the pre-SMA, inferior frontal sulcus, anterior insula/frontal operculum, and intraparietal sulcus, also responded strongly when faces were consciously perceived. In contrast, no brain area showed face-selective activity when participants reported no impression of a face. ERP results showed that conscious face detection was associated with enhanced N170 and also with the presence of a second negativity around 300 msec and a slow positivity around 415 msec. Again, face-related activity was absent when faces were not consciously perceived. We suggest that, under conditions of backward masking, ventral stream and fronto-parietal regions show similar, strong links of face-related activity to conscious perception and stress the importance of a detailed assessment of awareness to examine activity related to unseen stimulus events.

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Neural Correlates of Subjective Awareness and Unconscious Processing: An ERP Study

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2009.21064 ◽

2009 ◽

Vol 21 (7) ◽

pp. 1435-1446 ◽

Cited By ~ 83

Author(s):

Dominique Lamy ◽

Moti Salti ◽

Yair Bar-Haim

Keyword(s):

Event Related Potentials ◽

Neural Correlates ◽

Choice Response ◽

Backward Masking ◽

Unconscious Perception ◽

Behavioral Measures ◽

Subjective Awareness ◽

Related Potentials ◽

Physically Identical ◽

P3 Component

The aim of the present study was to dissociate the ERP (Event Related Potentials) correlates of subjective awareness from those of unconscious perception. In a backward masking paradigm, participants first produced a forced-choice response to the location of a liminal target presented for an individually calibrated duration, and then reported on their subjective awareness of the target's presence. We recorded (Event-Related Potentials) ERPs and compared the ERP waves when observers reported being aware vs. unaware of the target but localized it correctly, thereby isolating the neural correlates of subjective awareness while controlling for differences in objective performance. In addition, we compared the ERPs when participants were subjectively unaware of the target's presence and localized it correctly versus incorrectly, thereby isolating the neural correlates of unconscious perception. All conditions involved stimuli that were physically identical and were presented for the same duration. Both behavioral measures were associated with modulation of the amplitude of the P3 component of the ERP. Importantly, this modulation was widely spread across all scalp locations for subjective awareness, but was restricted to the parietal electrodes for unconscious perception. These results indicate that liminal stimuli that do not affect performance undergo considerable processing and that subjective awareness is associated with a late wave of activation with widely distributed topography.

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The Neuronal Correlate of Bidirectional Synesthesia: A Combined Event-related Potential and Functional Magnetic Resonance Imaging Study

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2007.19.12.2050 ◽

2007 ◽

Vol 19 (12) ◽

pp. 2050-2059 ◽

Cited By ~ 59

Author(s):

Roi Cohen Kadosh ◽

Kathrin Cohen Kadosh ◽

Avishai Henik

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Functional Magnetic Resonance Imaging ◽

Event Related Potentials ◽

Event Related Potential ◽

Imaging Data ◽

Functional Magnetic Resonance ◽

Resonance Imaging ◽

Neuronal Correlate ◽

Related Potentials

The neuronal correlate of a rare explicit bidirectional synesthesia was investigated with numerical and physical size comparison tasks using both functional magnetic resonance imaging and event-related potentials. Interestingly, although participant I.S. exhibited similar congruity effects for both tasks at the behavioral level, subsequent analyses of the imaging data revealed that different brain areas were recruited for each task, and in different time windows. The results support: (1) the genuineness of bidirectional synesthesia at the neuronal level, (2) the possibility that discrepancy in the neuronal correlates of synesthesia between previous studies might be task-related, and (3) the possibility that synesthesia might not be a unitary phenomenon.

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Behavioral and Electrophysiologic Evidence of Auditory Processing Disorder: A Twin Study

Journal of the American Academy of Audiology ◽

10.1055/s-0040-1716007 ◽

2002 ◽

Vol 13 (08) ◽

pp. 438-460 ◽

Cited By ~ 1

Author(s):

James Jerger ◽

Linda Thibodeau ◽

Jeffrey Martin ◽

Jyutika Mehta ◽

Gail Tillman ◽

...

Keyword(s):

Standardized Tests ◽

Auditory Processing ◽

Event Related Potentials ◽

Auditory Processing Disorder ◽

Auditory Information ◽

Gap Detection ◽

Backward Masking ◽

Behavioral Measures ◽

Normal Limits ◽

Related Potentials

We administered a battery of both behavioral and electrophysiologic measures to a pair of fraternal twin girls, one of whom exhibited symptoms consistent with an auditory processing disorder. Both twins were within normal limits on standardized tests of cognitive and language skills. Basic audiometric measures, as well as behavioral tests of simultaneous masking, backward masking, gap detection, and frequency-sweep discrimination, showed little difference between the twins. Significant differences, however, were evident on event-related potentials (ERPs) in response to both within-channel and across-channel gap detection tasks. Substantial differences were also noted for ERPs to both linguistic and nonlinguistic targets in dichotic listening paradigms. The pattern of electrophysiologic results was consistent with a deficit in the efficiency of interhemispheric transfer of auditory information. A possible reason for the greater effectiveness of electrophysiologic over behavioral measures is discussed.

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The Organization of Brain Activations in Number Comparison: Event-Related Potentials and the Additive-Factors Method

Journal of Cognitive Neuroscience ◽

10.1162/jocn.1996.8.1.47 ◽

1996 ◽

Vol 8 (1) ◽

pp. 47-68 ◽

Cited By ~ 274

Author(s):

Stanislas Dehaene

Keyword(s):

Cognitive Task ◽

Reaction Times ◽

Event Related Potentials ◽

Normal Subjects ◽

Imaging Data ◽

Comparison Task ◽

Cerebral Lateralization ◽

Magnitude Comparison ◽

Number Comparison ◽

Related Potentials

Measuring reaction times (RTs) using the additive-factors method provides information about the sequence of processing stages in a cognitive task. Here, I describe how the simultaneous recording of event-related potentials (ERPs) in the same task can provide complementary information that cannot be obtained using RTs alone. Most notably, ERP data can reveal the absolute activation time and the coarse brain localization of processing stages. RTs and ERPs can also be used to cross-validate a serial-stage model. These notions were applied to a study of the temporal unfolding of brain activations in a number comparison task. ERPs were recorded from 64 scalp electrodes while normal subjects classified numbers as larger or smaller than 5. Specific scalp signatures and timing data were obtained for stages of word and digit identification, magnitude comparison, response programming, and error capture and correction. The observed localizations were compatible with previous neuropsychological and brain imaging data and provided new insights into the cerebral lateralization and timing of number processing.

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A Temporal Dissociation of Subliminal versus Supraliminal Fear Perception: An Event-related Potential Study

Journal of Cognitive Neuroscience ◽

10.1162/089892904322926809 ◽

2004 ◽

Vol 16 (3) ◽

pp. 479-486 ◽

Cited By ~ 146

Author(s):

Belinda J. Liddell ◽

Leanne M. Williams ◽

Jennifer Rathjen ◽

Howard Shevrin ◽

Evian Gordon

Keyword(s):

Event Related Potentials ◽

Neural Mechanism ◽

Event Related Potential ◽

Neural Mechanisms ◽

Backward Masking ◽

Emotional Processes ◽

Detailed Evaluation ◽

Related Potentials ◽

Excitatory Component ◽

Temporal Model

Current theories of emotion suggest that threat-related stimuli are first processed via an automatically engaged neural mechanism, which occurs outside conscious awareness. This mechanism operates in conjunction with a slower and more comprehensive process that allows a detailed evaluation of the potentially harmful stimulus (LeDoux, 1998). We drew on the Halgren and Marinkovic (1995) model to examine these processes using event-related potentials (ERPs) within a backward masking paradigm. Stimuli used were faces with fear and neutral (as baseline control) expressions, presented above (supraliminal) and below (subliminal) the threshold for conscious detection. ERP data revealed a double dissociation for the supraliminal versus subliminal perception of fear. In the subliminal condition, responses to the perception of fear stimuli were enhanced relative to neutral for the N2 “excitatory” component, which is thought to represent orienting and automatic aspects of face processing. By contrast, supraliminal perception of fear was associated with relatively enhanced responses for the late P3 “inhibitory” component, implicated in the integration of emotional processes. These findings provide evidence in support of Halgren and Marinkovic's temporal model of emotion processing, and indicate that the neural mechanisms for appraising signals of threat may be initiated, not only automatically, but also without the need for conscious detection of these signals.

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Functional Changes in Brain Activity Using Hypnosis: A Systematic Review

Brain Sciences ◽

10.3390/brainsci12010108 ◽

2022 ◽

Vol 12 (1) ◽

pp. 108

Author(s):

Thomas Gerhard Wolf ◽

Karin Anna Faerber ◽

Christian Rummel ◽

Ulrike Halsband ◽

Guglielmo Campus

Keyword(s):

Systematic Review ◽

Imaging Techniques ◽

Brain Activity ◽

Brain Area ◽

Event Related Potentials ◽

Anxiety Reduction ◽

Anterior Cingulate ◽

Cross Sectional ◽

Functional Changes ◽

Related Potentials

Hypnosis has proven a powerful method in indications such as pain control and anxiety reduction. As recently discussed, it has been yielding increased attention from medical/dental perspectives. This systematic review (PROSPERO-registration-ID-CRD42021259187) aimed to critically evaluate and discuss functional changes in brain activity using hypnosis by means of different imaging techniques. Randomized controlled trials, cohort, comparative, cross-sectional, evaluation and validation studies from three databases—Cochrane, Embase and Medline via PubMed from January 1979 to August 2021—were reviewed using an ad hoc prepared search string and following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. A total of 10404 articles were identified, 1194 duplicates were removed and 9190 papers were discarded after consulting article titles/abstracts. Ultimately, 20 papers were assessed for eligibility, and 20 papers were included after a hand search (ntotal = 40). Despite a broad heterogenicity of included studies, evidence of functional changes in brain activity using hypnosis was identified. Electromyography (EMG) startle amplitudes result in greater activity in the frontal brain area; amplitudes using Somatosensory Event-Related Potentials (SERPs) showed similar results. Electroencephalography (EEG) oscillations of θ activity are positively associated with response to hypnosis. EEG results showed greater amplitudes for highly hypnotizable subjects over the left hemisphere. Less activity during hypnosis was observed in the insula and anterior cingulate cortex (ACC).

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Cognitive Brain Potentials and their Application

The British Journal of Psychiatry ◽

10.1192/s0007125000291897 ◽

1990 ◽

Vol 157 (S9) ◽

pp. 96-101 ◽

Cited By ~ 50

Author(s):

D. H. R. Blackwood ◽

W. J. Muir

Keyword(s):

Electrical Activity ◽

Event Related Potentials ◽

Imaging Data ◽

Brain Potentials ◽

Averaging Methods ◽

Non Invasive ◽

Disease States ◽

Related Potentials ◽

Recording Conditions ◽

The Brain

Computerised averaging methods have made it possible to extract and identify the electrical activity accompanying specific activities of the brain, including certain psychological processes, from the random background signals in electroencephalography (EEG). Event-related potentials (ERPs) and the way these change under various recording conditions are a powerful, non-invasive and relatively simple means of relating psychopathology to underlying physiology, and by comparing ERPs with imaging data it should be possible to compare electrical activity with changes in brain structure and blood flow in different disease states.

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Graded Visual Consciousness During the Attentional Blink

10.1101/2021.01.15.426792 ◽

2021 ◽

Author(s):

Anna Eiserbeck ◽

Alexander Enge ◽

Milena Rabovsky ◽

Rasha Abdel Rahman

Keyword(s):

Attentional Blink ◽

Visual Awareness ◽

Event Related Potentials ◽

Event Related Potential ◽

Experimental Paradigm ◽

Perceptual Awareness ◽

Accuracy Measure ◽

Related Potentials ◽

Visual Consciousness ◽

Present Event

One of the ongoing debates about visual consciousness is whether it can be considered as an all-or-none or a graded phenomenon. This may depend on the experimental paradigm and the task used to investigate this question. The present event-related potential study (N = 32) focuses on the attentional blink paradigm for which so far only little and mixed evidence is available. Detection of T2 face targets during the attentional blink was assessed via an objective accuracy measure (reporting the faces’ gender), subjective visibility on a perceptual awareness scale (PAS) as well as event-related potentials time-locked to T2 onset (components P1, N1, N2, and P3). The behavioral results indicate a graded rather than an all-or-none pattern of visual awareness. Corresponding graded differences in the N1, N2, and P3 components were observed for the comparison of visibility levels. These findings suggest that conscious perception during the attentional blink can occur in a graded fashion.

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Associations Between Brain and Behavioral Processing of Facial Expressions of Emotion and Sensory Reactivity in Young Children

10.31234/osf.io/kfjec ◽

2021 ◽

Author(s):

Chris L. Porter ◽

Courtney A. Evans Stout ◽

Peter Joseph Reschke ◽

Larry J Nelson ◽

Daniel C. Hyde

Keyword(s):

Individual Differences ◽

Young Children ◽

Facial Expressions ◽

Event Related Potentials ◽

Two Dimensions ◽

Perceptual Awareness ◽

Sensory Reactivity ◽

Fearful Faces ◽

Facial Expressions Of Emotion ◽

Related Potentials

The ability to decode and accurately identify information from facial emotions may advantage young children socially. This capacity to decode emotional information may likewise be influenced by individual differences in children’s temperament. This study investigated whether sensory reactivity and perceptual awareness, two dimensions of temperament, as well as children’s ability to accurately label emotions relates to the neural processing of emotional content in faces. Event related potentials (ERPs) of 4 to 6 year-old children (N = 119) were elicited from static displays of anger, happy, fearful, sad, and neutral emotion faces. Children, as a group, exhibited differential early (N290) and mid-latency (P400) event-related potentials (ERPs) in response to facial expressions of emotion. Individual differences in children’s sensory reactivity were associated with enhanced P400 amplitudes to neutral, sad, and fearful faces. In a separate task, children were asked to provide an emotional label for the same images. Interestingly, children less accurately labeled the same neutral, sad, and fearful faces, suggesting that, contrary to previous work showing enhanced attentional processing to threatening cues (i.e., fear), children higher in sensory reactivity may deploy more attentional resources when decoding ambiguous emotional cues.

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