Visual Gnosis and Face Perception

2012 ◽  
Vol 3 (4) ◽  
pp. 11-20
Author(s):  
Shozo Tobimatsu
Keyword(s):  
Spatial Frequency ◽  
Facial Expressions ◽  
Face Perception ◽  
Time Windows ◽  
High Spatial Frequency ◽  
Early Time ◽  
Event Related Potentials ◽  
Temporal Region ◽  
The Face ◽  
Related Potentials

There are two major parallel pathways in humans: the parvocellular (P) and magnocellular (M) pathways. The former has excellent spatial resolution with color selectivity, while the latter shows excellent temporal resolution with high contrast sensitivity. Visual stimuli should be tailored to answer specific clinical and/or research questions. This chapter examines the neural mechanisms of face perception using event-related potentials (ERPs). Face stimuli of different spatial frequencies were used to investigate how low-spatial-frequency (LSF) and high-spatial-frequency (HSF) components of the face contribute to the identification and recognition of the face and facial expressions. The P100 component in the occipital area (Oz), the N170 in the posterior temporal region (T5/T6) and late components peaking at 270-390 ms (T5/T6) were analyzed. LSF enhanced P100, while N170 was augmented by HSF irrespective of facial expressions. This suggested that LSF is important for global processing of facial expressions, whereas HSF handles featural processing. There were significant amplitude differences between positive and negative LSF facial expressions in the early time windows of 270-310 ms. Subsequently, the amplitudes among negative HSF facial expressions differed significantly in the later time windows of 330–390 ms. Discrimination between positive and negative facial expressions precedes discrimination among different negative expressions in a sequential manner based on parallel visual channels. Interestingly, patients with schizophrenia showed decreased spatial frequency sensitivities for face processing. Taken together, the spatially filtered face images are useful for exploring face perception and recognition.

Visual Gnosis and Face Perception

2011 ◽  
pp. 55-64
Author(s):  
Shozo Tobimatsu
Keyword(s):  
Spatial Frequency ◽  
Facial Expressions ◽  
Face Perception ◽  
Time Windows ◽  
High Spatial Frequency ◽  
Early Time ◽  
Event Related Potentials ◽  
Temporal Region ◽  
The Face ◽  
Face Stimuli

There are two major parallel pathways in humans: the parvocellular (P) and magnocellular (M) pathways. The former has excellent spatial resolution with color selectivity, while the latter shows excellent temporal resolution with high contrast sensitivity. Visual stimuli should be tailored to answer specific clinical and/or research questions. This chapter examines the neural mechanisms of face perception using event-related potentials (ERPs). Face stimuli of different spatial frequencies were used to investigate how low-spatial-frequency (LSF) and high-spatial-frequency (HSF) components of the face contribute to the identification and recognition of the face and facial expressions. The P100 component in the occipital area (Oz), the N170 in the posterior temporal region (T5/T6) and late components peaking at 270-390 ms (T5/T6) were analyzed. LSF enhanced P100, while N170 was augmented by HSF irrespective of facial expressions. This suggested that LSF is important for global processing of facial expressions, whereas HSF handles featural processing. There were significant amplitude differences between positive and negative LSF facial expressions in the early time windows of 270-310 ms. Subsequently, the amplitudes among negative HSF facial expressions differed significantly in the later time windows of 330–390 ms. Discrimination between positive and negative facial expressions precedes discrimination among different negative expressions in a sequential manner based on parallel visual channels. Interestingly, patients with schizophrenia showed decreased spatial frequency sensitivities for face processing. Taken together, the spatially filtered face images are useful for exploring face perception and recognition.

scholarly journals Electrophysiological Studies of Face Perception in Humans

1996 ◽  
Vol 8 (6) ◽  
pp. 551-565 ◽  
Author(s):  
Shlomo Bentin ◽  
Truett Allison ◽  
Aina Puce ◽  
Erik Perez ◽  
Gregory McCarthy
Keyword(s):  
Face Perception ◽  
Event Related Potentials ◽  
Neural Mechanism ◽  
Differential Sensitivity ◽  
Temporal Region ◽  
Electrophysiological Studies ◽  
The Face ◽  
Related Potentials ◽  
The Right ◽  
Human Faces

Event-related potentials (ERPs) associated with face perception were recorded with scalp electrodes from normal volunteers. Subjects performed a visual target detection task in which they mentally counted the number of occurrences of pictorial stimuli from a designated category such as butterflies. In separate experiments, target stimuli were embedded within a series of other stimuli including unfamiliar human faces and isolated face components, inverted faces, distorted faces, animal faces, and other nonface stimuli. Human faces evoked a negative potential at 172 msec (N170), which was absent from the ERPs elicited by other animate and inanimate nonface stimuli. N170 was largest over the posterior temporal scalp and was larger over the right than the left hemisphere. N170 was delayed when faces were presented upside-down, but its amplitude did not change. When presented in isolation, eyes elicited an N170 that was significantly larger than that elicited by whole faces, while noses and lips elicited small negative ERPs about 50 msec later than N170. Distorted human faces, in which the locations of inner face components were altered, elicited an N170 similar in amplitude to that elicited by normal faces. However, faces of animals, human hands, cars, and items of furniture did not evoke N170. N170 may reflect the operation of a neural mechanism tuned to detect (as opposed to identify) human faces, similar to the “structural encoder” suggested by Bruce and Young (1986). A similar function has been proposed for the face-selective N200 ERP recorded from the middle fusiform and posterior inferior temporal gyri using subdural electrodes in humans (Allison, McCarthy, Nobre, Puce, & Belger, 1994c). However, the differential sensitivity of N170 to eyes in isolation suggests that N170 may reflect the activation of an eye-sensitive region of cortex. The voltage distribution of N170 over the scalp is consistent with a neural generator located in the occipitotemporal sulcus lateral to the fusiform/inferior temporal region that generates N200.

scholarly journals Anorexia nervosa and body dysmorphic disorder are associated with abnormalities in processing visual information

2015 ◽  
Vol 45 (10) ◽  
pp. 2111-2122 ◽  
Author(s):  
W. Li ◽  
T. M. Lai ◽  
C. Bohon ◽  
S. K. Loo ◽  
D. McCurdy ◽  
...  
Keyword(s):  
Anorexia Nervosa ◽  
Spatial Frequency ◽  
Visual Processing ◽  
Visual Information ◽  
Body Dysmorphic Disorder ◽  
High Spatial Frequency ◽  
Event Related Potentials ◽  
Visual Stream ◽  
N170 Component ◽  
Related Potentials

BackgroundAnorexia nervosa (AN) and body dysmorphic disorder (BDD) are characterized by distorted body image and are frequently co-morbid with each other, although their relationship remains little studied. While there is evidence of abnormalities in visual and visuospatial processing in both disorders, no study has directly compared the two. We used two complementary modalities – event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI) – to test for abnormal activity associated with early visual signaling.MethodWe acquired fMRI and ERP data in separate sessions from 15 unmedicated individuals in each of three groups (weight-restored AN, BDD, and healthy controls) while they viewed images of faces and houses of different spatial frequencies. We used joint independent component analyses to compare activity in visual systems.ResultsAN and BDD groups demonstrated similar hypoactivity in early secondary visual processing regions and the dorsal visual stream when viewing low spatial frequency faces, linked to the N170 component, as well as in early secondary visual processing regions when viewing low spatial frequency houses, linked to the P100 component. Additionally, the BDD group exhibited hyperactivity in fusiform cortex when viewing high spatial frequency houses, linked to the N170 component. Greater activity in this component was associated with lower attractiveness ratings of faces.ConclusionsResults provide preliminary evidence of similar abnormal spatiotemporal activation in AN and BDD for configural/holistic information for appearance- and non-appearance-related stimuli. This suggests a common phenotype of abnormal early visual system functioning, which may contribute to perceptual distortions.

scholarly journals Let’s Talk About Each Other: Neural Responses to Dissenting Personality Evaluations Based on Real Dyadic Interactions

2021 ◽  
pp. 095679762199519
Author(s):  
Sebastian Schindler ◽  
Anne Höhner ◽  
Robert Moeck ◽  
Maximilian Bruchmann ◽  
Thomas Straube
Keyword(s):  
Time Windows ◽  
Early Time ◽  
Event Related Potentials ◽  
Late Time ◽  
Dyadic Interactions ◽  
Neural Responses ◽  
Time Points ◽  
Evaluative Feedback ◽  
Early Posterior Negativity ◽  
Related Potentials

Dyadic interactions are associated with the exchange of personality-related messages, which can be congruent or incongruent with one’s self-view. In the current preregistered study ( N = 52), we investigated event-related potentials (ERPs) toward real social evaluations in order to uncover the neural mechanisms underlying the processing of congruent and incongruent evaluative feedback. Participants interacted first, and then during an electroencephalogram (EEG) session, they received evaluations from their interaction partner that were either congruent or incongruent with their own ratings. Findings show potentiated processing of self-related incongruent negative evaluations at early time points (N1) followed by increased processing of both incongruent negative and positive evaluations at midlatency time windows (early posterior negativity) and a prioritized processing of self-related incongruent positive evaluations at late time points (feedback-related P3, late positive potential). These findings reveal that, after real social interactions, evaluative feedback about oneself that violates one’s self-view modulates all processing stages with an early negativity and a late positivity bias.

scholarly journals The Effects of Dynamic and Static Emotional Facial Expressions of Humans and Their Avatars on the EEG: An ERP and ERD/ERS Study

2021 ◽  
Vol 15 ◽  
Author(s):  
Teresa Sollfrank ◽  
Oona Kohnen ◽  
Peter Hilfiker ◽  
Lorena C. Kegel ◽  
Hennric Jokeit ◽  
...  
Keyword(s):  
Facial Expressions ◽  
Event Related Potentials ◽  
Emotional Facial Expressions ◽  
Emotional Faces ◽  
Dynamic Facial Expressions ◽  
The Face ◽  
Related Potentials ◽  
Face Stimuli ◽  
Human Faces ◽  
Healthy Participants

This study aimed to examine whether the cortical processing of emotional faces is modulated by the computerization of face stimuli (”avatars”) in a group of 25 healthy participants. Subjects were passively viewing 128 static and dynamic facial expressions of female and male actors and their respective avatars in neutral or fearful conditions. Event-related potentials (ERPs), as well as alpha and theta event-related synchronization and desynchronization (ERD/ERS), were derived from the EEG that was recorded during the task. All ERP features, except for the very early N100, differed in their response to avatar and actor faces. Whereas the N170 showed differences only for the neutral avatar condition, later potentials (N300 and LPP) differed in both emotional conditions (neutral and fear) and the presented agents (actor and avatar). In addition, we found that the avatar faces elicited significantly stronger reactions than the actor face for theta and alpha oscillations. Especially theta EEG frequencies responded specifically to visual emotional stimulation and were revealed to be sensitive to the emotional content of the face, whereas alpha frequency was modulated by all the stimulus types. We can conclude that the computerized avatar faces affect both, ERP components and ERD/ERS and evoke neural effects that are different from the ones elicited by real faces. This was true, although the avatars were replicas of the human faces and contained similar characteristics in their expression.

scholarly journals Emotional Processing Impairments in Apathetic Patients with Parkinson’s Disease: An ERP Study in Early Time Windows

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Wei Wei ◽  
Jianghai Ruan ◽  
Xiaodong Duan ◽  
Hua Luo
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Emotional Processing ◽  
Right Hemisphere ◽  
Digit Span ◽  
Time Windows ◽  
Early Time ◽  
Event Related Potentials ◽  
Related Potentials ◽  
The Right

We investigated emotional processing in apathetic patients with Parkinson’s disease (PD) by observing components of event-related potentials (ERPs) in early time windows. Forty PD patients and 21 healthy controls (HCs) were enrolled. The Starkstein Apathy Scale (SAS) was used to divide the PD patients into apathetic and nonapathetic groups. Cognitive function was evaluated by the forward and backward Digit Span tests, Trail Making Test (TMT), and Word Fluency Test. The participants were required to recognize positive, neutral, and negative emotional faces and engage in an emotion categorization task while EEG was recorded. The time to completion for the TMT (Part A and Part B) from highest to lowest was in the order of apathetic group > nonapathetic group > HC group. Compared with the nonapathetic and HC groups, in the apathetic group, P100 amplitudes were smaller for positive expressions in the right hemisphere and latencies were longer for positive expressions in the left hemisphere, while latencies were longer for neutral expressions bilaterally. Compared with the nonapathetic group, in the apathetic group, N170 amplitudes were attenuated and latencies were delayed for neutral and negative expressions in the right hemisphere. A trend towards larger N170 amplitudes in the right hemisphere than in the left was observed in the nonapathetic and HC groups, but this difference was not significant in the apathetic group. In the apathetic group, bilateral P100 amplitudes elicited by negative expressions were negatively correlated with SAS scores, and SAS scores were positively correlated with Part B of the TMT. N170 amplitudes elicited by negative expressions in the right hemisphere were negatively correlated with SAS in the apathetic group and with Part B of TMT in both PD groups. Our findings suggested that emotional processing was impaired in apathetic PD patients and that the right hemisphere was more sensitive to reflecting this impairment in the early time windows of ERPs.

scholarly journals In context: emotional intent and temporal immediacy of contextual descriptions modulate affective ERP components to facial expressions

2020 ◽  
Vol 15 (5) ◽  
pp. 551-560
Author(s):  
Katharina M Rischer ◽  
Mattias Savallampi ◽  
Anushka Akwaththage ◽  
Nicole Salinas Thunell ◽  
Carl Lindersson ◽  
...  
Keyword(s):  
Facial Expressions ◽  
Face Perception ◽  
Emotional Reactivity ◽  
Contextual Information ◽  
Event Related Potentials ◽  
Verbal Description ◽  
Facial Stimuli ◽  
Late Event ◽  
Related Potentials ◽  
Valence And Arousal

Abstract In this study, we explored how contextual information about threat dynamics affected the electrophysiological correlates of face perception. Forty-six healthy native Swedish speakers read verbal descriptions signaling an immediate vs delayed intent to escalate or deescalate an interpersonal conflict. Each verbal description was followed by a face with an angry or neutral expression, for which participants rated valence and arousal. Affective ratings confirmed that the emotional intent expressed in the descriptions modulated emotional reactivity to the facial stimuli in the expected direction. The electrophysiological data showed that compared to neutral faces, angry faces resulted in enhanced early and late event-related potentials (VPP, P300 and LPP). Additionally, emotional intent and temporal immediacy modulated the VPP and P300 similarly across angry and neutral faces, suggesting that they influence early face perception independently of facial affect. By contrast, the LPP amplitude to faces revealed an interaction between facial expression and emotional intent. Deescalating descriptions eliminated the LPP differences between angry and neutral faces. Together, our results suggest that information about a person’s intentions modulates the processing of facial expressions.

scholarly journals Hemispheric Asymmetry in Visual Processing: An Erp Study on Spatial Frequency Gratings

2021 ◽  
Author(s):  
Alice Mado Proverbio ◽  
and Alberto Zani
Keyword(s):  
Spatial Frequency ◽  
Visual Processing ◽  
Visual Information ◽  
Hemispheric Asymmetry ◽  
High Spatial Frequency ◽  
Event Related Potentials ◽  
Repeated Measure ◽  
Sensory Response ◽  
Visual Responses ◽  
Related Potentials

A hemispheric asymmetry is known for the processing of global vs. local visual information. In this study, we investigated the existence of a hemispheric asymmetry for visual processing of low vs. high spatial frequency gratings. Event-related potentials were recorded in a group of healthy right-handed volunteers from 30 scalp sites. Six types of stimuli (1.5, 3 and 6 c/deg gratings) were randomly flashed 180 times in the left and right upper hemi-fields. Stimulus duration was 80 ms and ISI ranged between 850-1000 ms. Participants had to pay attention and respond to targets based on their spatial frequency and location, or to passively look at the stimuli. C1 and P1 visual responses, as well as a later Selection negativity and a P300 components of ERPs were quantified and subjected to repeated-measure ANOVAs. Overall, performance was faster for the RVF, thus suggesting a left hemispheric advantage for attentional selection of local elements. Similarly, the analysis of mean area amplitude of C1 (60-110 ms) sensory response showed a stronger attentional effect (F+L+ vs. F-L+) at left occipital areas, thus suggesting the sensory nature of this hemispheric asymmetry.

scholarly journals Hemispheric Asymmetry in Visual Processing: An ERP Study on Spatial Frequency Gratings

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 180
Author(s):  
Alice Mado Proverbio ◽  
Alberto Zani
Keyword(s):  
Spatial Frequency ◽  
Visual Processing ◽  
Hemispheric Asymmetry ◽  
High Spatial Frequency ◽  
Event Related Potentials ◽  
Repeated Measure ◽  
Right Visual Field ◽  
Sensory Response ◽  
Visual Responses ◽  
Related Potentials

A hemispheric asymmetry for the processing of global versus local visual information is known. In this study, we investigated the existence of a hemispheric asymmetry for the visual processing of low versus high spatial frequency gratings. The event-related potentials were recorded in a group of healthy right-handed volunteers from 30 scalp sites. Six types of stimuli (1.5, 3 and 6 c/deg gratings) were randomly flashed 180 times in the left and right upper hemifields. The stimulus duration was 80 ms, and the interstimulus interval (ISI) ranged between 850 and 1000 ms. Participants paid attention and responded to targets based on their spatial frequency and location. The C1 and P1 visual responses, as well as a later selection negativity and a P300 component of event-related potentials (ERPs), were quantified and subjected to repeated-measure analyses of variance (ANOVAs). Overall, the performance was faster for the right visual field (RVF), thus suggesting a left hemispheric advantage for the attentional selection of local elements. Similarly, the analysis of the mean area amplitude of the C1 (60–110 ms) sensory response showed a stronger attentional effect (F+L+ vs. F−L+) at the left occipital areas, thus suggesting the sensory nature of this hemispheric asymmetry.

scholarly journals Charged With a Crime: The Neuronal Signature of Processing Negatively Evaluated Faces Under Different Attentional Conditions

2021 ◽  
pp. 095679762199666
Author(s):  
Sebastian Schindler ◽  
Maximilian Bruchmann ◽  
Claudia Krasowski ◽  
Robert Moeck ◽  
Thomas Straube
Keyword(s):  
Event Related Potentials ◽  
Emotional Information ◽  
Early Posterior Negativity ◽  
Information Studies ◽  
The Face ◽  
Related Potentials ◽  
Feature Based ◽  
Human Faces ◽  
Emotional Knowledge ◽  
Late Stages

Our brains rapidly respond to human faces and can differentiate between many identities, retrieving rich semantic emotional-knowledge information. Studies provide a mixed picture of how such information affects event-related potentials (ERPs). We systematically examined the effect of feature-based attention on ERP modulations to briefly presented faces of individuals associated with a crime. The tasks required participants ( N = 40 adults) to discriminate the orientation of lines overlaid onto the face, the age of the face, or emotional information associated with the face. Negative faces amplified the N170 ERP component during all tasks, whereas the early posterior negativity (EPN) and late positive potential (LPP) components were increased only when the emotional information was attended to. These findings suggest that during early configural analyses (N170), evaluative information potentiates face processing regardless of feature-based attention. During intermediate, only partially resource-dependent, processing stages (EPN) and late stages of elaborate stimulus processing (LPP), attention to the acquired emotional information is necessary for amplified processing of negatively evaluated faces.

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