scholarly journals Distinct Contributions of Nonpredictive and Predictive Peripheral Cues to Visual Conscious Perception: an MEG study

2020 ◽  
Author(s):  
Alfredo Spagna ◽  
Dimitri J. Bayle ◽  
Zaira Romeo ◽  
Lydia Yahia-Cherif ◽  
Ana B. Chica ◽  
...  
Keyword(s):  
Visual Perception ◽  
Left Hemisphere ◽  
Visual Cues ◽  
Brain Activity ◽  
Conscious Perception ◽  
Spatial Cues ◽  
Temporoparietal Junction ◽  
Parietal Lobes ◽  
The Right ◽  
Near Threshold

AbstractDo we need attention to become aware of an external event? We used magnetoencephalography (MEG) in human participants to assess the effects of nonpredictive and predictive supra-threshold peripheral visual cues on the conscious perception of near-threshold Gabor patches. Both nonpredictive and predictive valid cues increased the number of detected targets, and shifted the response criterion towards a more liberal decision. Predictive cues unexpectedly induced a greater sensitivity (d’) for invalid trials than for valid trials. With nonpredictive cues, seen targets were associated with right-lateralized frontoparietal feed-forward and feedback sweeps. For seen targets there was increased connectivity among visual regions, and between these areas and the inferior parietal lobes and the anterior insular cortices (AIC), bilaterally. Valid predictive cues interacted with conscious target detection, with greater activation of areas mostly located in the left hemisphere, especially in the frontoparietal network and temporoparietal junction, and induced an increased connectivity between the right AIC and areas of the visual ventral stream in the seen condition only. Thus, neural activity induced by nonpredictive and predictive spatial cues can enhance conscious visual perception through distinct mechanisms, mostly relying on frontoparietal activity in the right or left hemisphere, respectively. Connectivity involving the AIC participates in shaping the interaction between attention and conscious visual perception.Significance StatementDo we need to pay attention to external objects in order to become aware of them? Characterizing the spatiotemporal dynamics of attentional effects on visual perception is critical to understand how humans process information coming from relevant aspects of their environment. Participants detected near-threshold visual targets preceded by supra-threshold spatial cues with varying degrees of predictivity, while their brain activity was recorded using magnetoencephalography. Results demonstrated that spatial cues, especially when predictive, biased participants’ conscious perception through an early recruitment of frontoparietal regions. This work highlights an interactive pattern between spatial attention and consciousness, as shown by the effects of attention-related regions on visual sensory cortices bilaterally, consistent with the hypothesis that attention is a pathway to conscious perception.

Emotional Reactivity to Visual Content as Revealed by ERP Component Clustering

2015 ◽  
Vol 29 (4) ◽  
pp. 135-146 ◽  
Author(s):  
Miroslaw Wyczesany ◽  
Szczepan J. Grzybowski ◽  
Jan Kaiser
Keyword(s):  
Emotional Reactivity ◽  
Brain Activity ◽  
Affective State ◽  
Occipital Lobe ◽  
Stimulus Onset ◽  
Emotional States ◽  
Neural Basis ◽  
Temporoparietal Junction ◽  
The Right ◽  
The Impact

Abstract. In the study, the neural basis of emotional reactivity was investigated. Reactivity was operationalized as the impact of emotional pictures on the self-reported ongoing affective state. It was used to divide the subjects into high- and low-responders groups. Independent sources of brain activity were identified, localized with the DIPFIT method, and clustered across subjects to analyse the visual evoked potentials to affective pictures. Four of the identified clusters revealed effects of reactivity. The earliest two started about 120 ms from the stimulus onset and were located in the occipital lobe and the right temporoparietal junction. Another two with a latency of 200 ms were found in the orbitofrontal and the right dorsolateral cortices. Additionally, differences in pre-stimulus alpha level over the visual cortex were observed between the groups. The attentional modulation of perceptual processes is proposed as an early source of emotional reactivity, which forms an automatic mechanism of affective control. The role of top-down processes in affective appraisal and, finally, the experience of ongoing emotional states is also discussed.

scholarly journals Subjective visual perception: from local processing to emergent phenomena of brain activity

2014 ◽  
Vol 369 (1641) ◽  
pp. 20130534 ◽  
Author(s):  
Theofanis I. Panagiotaropoulos ◽  
Vishal Kapoor ◽  
Nikos K. Logothetis
Keyword(s):  
Visual Perception ◽  
Visual Stimulation ◽  
Brain Activity ◽  
Sensory Information ◽  
Brain Regions ◽  
Intrinsic Activity ◽  
Subjective Perception ◽  
Conscious Perception ◽  
Perceptual Awareness ◽  
Sensory Stimuli

The combination of electrophysiological recordings with ambiguous visual stimulation made possible the detection of neurons that represent the content of subjective visual perception and perceptual suppression in multiple cortical and subcortical brain regions. These neuronal populations, commonly referred to as the neural correlates of consciousness , are more likely to be found in the temporal and prefrontal cortices as well as the pulvinar, indicating that the content of perceptual awareness is represented with higher fidelity in higher-order association areas of the cortical and thalamic hierarchy, reflecting the outcome of competitive interactions between conflicting sensory information resolved in earlier stages. However, despite the significant insights into conscious perception gained through monitoring the activities of single neurons and small, local populations, the immense functional complexity of the brain arising from correlations in the activity of its constituent parts suggests that local, microscopic activity could only partially reveal the mechanisms involved in perceptual awareness. Rather, the dynamics of functional connectivity patterns on a mesoscopic and macroscopic level could be critical for conscious perception. Understanding these emergent spatio-temporal patterns could be informative not only for the stability of subjective perception but also for spontaneous perceptual transitions suggested to depend either on the dynamics of antagonistic ensembles or on global intrinsic activity fluctuations that may act upon explicit neural representations of sensory stimuli and induce perceptual reorganization. Here, we review the most recent results from local activity recordings and discuss the potential role of effective, correlated interactions during perceptual awareness.

scholarly journals Comparing the structure and function of social-cognition-related brain areas in bisexual, heterosexual, and homosexual women and men

2021 ◽  
Author(s):  
Victoria Klimaj ◽  
Adam Safron ◽  
David Sylva ◽  
A.M. Rosenthal ◽  
Meng Li ◽  
...  
Keyword(s):  
Social Cognition ◽  
Large Scale ◽  
Brain Activity ◽  
Gray Matter Volume ◽  
Sex And Gender ◽  
Social Environments ◽  
Men And Women ◽  
Temporoparietal Junction ◽  
Mixed Support ◽  
The Right

A small number of studies have examined neuroanatomical differences between heterosexual and homosexual men and women. These studies have yielded mixed support for the hypothesis that homosexual individuals possess sex-atypical neural anatomy. However, in addition to differing along dimensions of sex-typicality, non-heterosexual individuals’ brains may be different in other ways, potentially as a result of differences in experience. One way in which sexual minorities may differ from others is in their social experiences. Bisexual individuals in particular may occupy unique social niches and experience complex social environments as a result of sexual and romantic interactions with both men and women, and potentially also in terms of having a less-widely-recognized sexual identity than heterosexual and homosexual individuals. Based on this idea, we hypothesized that bisexual individuals may show increased gray matter volume and activity in two social-cognition-related areas of the brain: the right temporoparietal junction (rTPJ) and the dorsomedial prefrontal cortex (dmPFC). Contrary to our hypotheses, neither brain structure nor brain activity in the rTPJ and dmPFC were significantly greater in bisexual individuals than in heterosexual and homosexual individuals. Instead, we found larger rTPJ volumes in heterosexual women than in homosexual women. We also found larger relative volumes in the dmPFC in women than in men, consistent with a recent large-scale study of sex differences, and potentially indicative of sex and gender differences in social cognition.

scholarly journals EEG and fMRI Correlates of Insight: A Pilot Study

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 330
Author(s):  
Gennady G. Knyazev ◽  
Vadim L. Ushakov ◽  
Vyacheslav A. Orlov ◽  
Denis G. Malakhov ◽  
Sergey I. Kartashov ◽  
...  
Keyword(s):  
Problem Solving ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Brain Activity ◽  
Fmri Data ◽  
Eeg Data ◽  
Analytical Step ◽  
Remote Association ◽  
The Right ◽  
Increased Activity

Insight is described as the sudden solution of a problem and is contrasted with an analytical, step-by-step approach. Traditionally, insight is thought to be associated with activity of the right hemisphere, whereas analytical solutions are thought to be associated with activity of the left hemisphere. However, empirical evidence as to the localization of insight-related brain activity is mixed and inconclusive. Some studies seem to confirm the traditional view, whereas others do not. Moreover, results of EEG and fMRI studies frequently contradict each other. In this study, EEG and fMRI data were recorded while subjects performed the remote association test and for each solved problem were asked to report whether the solution was reached analytically or insightfully. The data were analyzed in a 16-second fragment preceding the subject’s response. Source localization techniques were used in the analysis of EEG data. Based on EEG data, insightful as compared to analytical problem solving was accompanied by high-frequency synchronization in semantic cortical areas of the left hemisphere 10–12 s before the subject’s response. Based on fMRI data, however, insightful solutions were accompanied by increased activity in frontal and temporal regions of the right hemisphere. The results are interpreted in terms of different cognitive processes involved in insightful problem solving, which could be differently reflected in EEG and fMRI data.

scholarly journals Fronto-parietal Organization for Response Times in Inhibition of Return: The FORTIOR Model

2017 ◽  
Author(s):  
Tal Seidel Malkinson ◽  
Paolo Bartolomeo
Keyword(s):  
Left Hemisphere ◽  
Inhibition Of Return ◽  
Right Hemisphere ◽  
Functional Organization ◽  
Response Times ◽  
Visual Fields ◽  
Response Threshold ◽  
Manual Response ◽  
Temporoparietal Junction ◽  
The Right

Inhibition of Return (IOR) refers to a slowing of response times (RTs) for visual stimuli repeated at the same spatial location, as compared to stimuli occurring at novel locations. The functional mechanisms and the neural bases of this phenomenon remain debated. Here we present FORTIOR, a model of the cortical control of visual IOR in the human brain. The model is based on known facts about the anatomical and functional organization of fronto-parietal attention networks, and accounts for a broad range of behavioral findings in healthy participants and brain-damaged patients. FORTIOR does that by combining four principles of asymmetry: a) Asymmetry in the networks topography, whereby the temporoparietal junction (TPJ) and ventrolateral prefrontal cortex (vlPFC) nodes are lateralized to the right hemisphere, causing higher activation levels in the right intraparietal sulcus (IPS) and frontal eye field (FEF) nodes. b) Asymmetry in inter-hemispheric connectivity, in which inter-hemispheric connections from left hemisphere IPS to right hemisphere IPS and from left hemisphere FEF to right hemisphere FEF are weaker than in the opposite direction. c) Asymmetry of visual inputs, stipulating that the FEF receives direct visual input coming from the ipsilateral visual cortex, while the right TPJ and vlPFC and IPS nodes receive input from both the contralateral and the ipsilateral visual fields. d) Asymmetry in the response modality, with a higher response threshold for the manual response system than that required to trigger a saccadic response. This asymmetry results in saccadic IOR being more robust to interference than manual IOR. FORTIOR accounts for spatial asymmetries in the occurrence of IOR after brain damage and after non-invasive transcranial magnetic stimulation on parietal and frontal regions. It also provides a framework to understand dissociations between manual and saccadic IOR, and makes testable predictions for future experiments to assess its validity.

The Role of the Right Superior Parietal Lobule in Processing Visual Context for the Establishment of the Egocentric Reference Frame

2014 ◽  
Vol 26 (10) ◽  
pp. 2201-2209 ◽  
Author(s):  
Benjamin D. Lester ◽  
Paul Dassonville
Keyword(s):  
Reference Frame ◽  
Visual Cues ◽  
Right Hemisphere ◽  
Superior Parietal Lobule ◽  
Spatial Cues ◽  
Tilt Illusion ◽  
Egocentric Reference Frame ◽  
Parietal Lobule ◽  
The Right ◽  
Rod And Frame

Visual cues contribute to the creation of an observer's egocentric reference frame, within which the locations and orientations of objects can be judged. However, these cues can also be misleading. In the rod-and-frame illusion, for example, a large tilted frame distorts the observer's sense of vertical, causing an enclosed rod to appear tilted in the opposite direction. To determine the brain region responsible for processing these spatial cues, we used TMS to suppress neural activity in the superior parietal lobule of healthy observers. Stimulation of the right hemisphere, but not the left, caused a significant reduction in rod-and-frame susceptibility. In contrast, a tilt illusion caused by a mechanism that does not involve a distortion of the observer's egocentric reference frame was unaffected. These results demonstrate that the right superior parietal lobule is actively involved in processing the contextual cues that contribute to our perception of egocentric space.

scholarly journals Psychic Tonus, Body Schema and the Parietal Lobes: A Multiple Lesion Case Analysis

2007 ◽  
Vol 18 (2) ◽  
pp. 65-80 ◽  
Author(s):  
C. M. J. Braun ◽  
S. Desjardins ◽  
S. Gaudelet ◽  
A. Guimond
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Hemispheric Specialization ◽  
Body Schema ◽  
The Body ◽  
Parietal Lobes ◽  
Hemisphere Lesion ◽  
The Right ◽  
Internal Experience ◽  
And Behavior

The psychic tonus model (Braun and colleagues, 1999, 2002, 2003, 2006) states that the left hemisphere is a “booster” of internal experience and behavior in general, and that the right hemisphere is a “dampener”. Twenty-five patients with a “positive” extreme disturbance of body schema (somatoparaphrenia) and 37 patients with a “negative” disturbance of body schema (autotopagnosia or Gerstmann’s syndrome), all following a unilateral parietal lesion, were found in the literature and were analyzed to test predictions from Braun’s “psychic tonus” model. As expected, patients with a positive syndrome had a right hemisphere lesion significantly more frequently, and those with a negative syndrome had a left hemisphere lesion significantly more frequently. Thus the psychic tonus model of hemispheric specialization, previously supported with regard to psychomotor baseline, libido, talkativeness, memory, auditory and visual perceptual tonus, now incorporates the tonus of representation of the body (body schema) in the parietal lobes.

scholarly journals When differences matter: rTMS/fMRI reveals how differences in dispositional empathy translate to distinct neural underpinnings of self-other distinction in empathy

2019 ◽  
Author(s):  
Henryk Bukowski ◽  
Martin Tik ◽  
Giorgia Silani ◽  
Christian Ruff ◽  
Christian Windischberger ◽  
...  
Keyword(s):  
Individual Differences ◽  
Brain Stimulation ◽  
Brain Activity ◽  
Control Site ◽  
Temporoparietal Junction ◽  
Empathic Understanding ◽  
Affect And Cognition ◽  
Neural Underpinnings ◽  
The Right ◽  
Dispositional Empathy

Self-other distinction is crucial for empathy, since it prevents the confusion of self-experienced emotions with those of others. We aimed to extend our understanding of the neurocognitive mechanisms of self-other distinction. Thirty-one female participants underwent continuous theta burst transcranial magnetic stimulation (cTBS) targeting the right supramarginal gyrus (rSMG), a sub-region of the temporoparietal junction previously shown to be involved in self-other distinction, and the vertex, a cortical control site. Right after stimulation they completed a visuo-tactile empathy task in an MRI scanner. Self-other distinction was assessed by differences in emotion judgments, and brain activity between conditions differing in the requirement for self-other distinction. Effects of brain stimulation on self-other distinction depended on individual differences in dispositional empathic understanding: cTBS of rSMG, compared to vertex, enhanced self-other distinction in participants with lower dispositional empathic understanding, but diminished it in participants with higher empathic understanding. On the neural level, this inverse relationship between empathic disposition and self-other distinction performance was linked to a reduction of cTBS-induced rSMG activity in persons with lower dispositional empathy, and an increase in those with lower dispositional empathy. These opposite cTBS impacts were also associated with two anatomically and functionally distinct networks. These findings open up novel perspectives on the causal role of rSMG in self-other distinction and empathy. They also suggest that considering individual differences may yield novel insights into how brain stimulation affects higher-level affect and cognition, and its neural correlates.

Visual Perception of Optic Flow in the Left and in the Right Visual Hemifield

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 234-234
Author(s):  
O V Levashov ◽  
H Levashova
Keyword(s):  
Visual Perception ◽  
Left Hemisphere ◽  
Optic Flow ◽  
Computational Models ◽  
Right Hemisphere ◽  
Target Position ◽  
Experimental Session ◽  
Visual Hemifield ◽  
The Subject ◽  
The Right

Recently we have found right visual hemifield (HF) superiority in detection of local texture optic flow discontinuity (H O Levashova and O V Levashov, 1996 Perception25 Supplement, 128). In the present work we investigated a possible difference between hemifields in the perception of global optic flow. The stimulus consisted of two large texture fields which moved across the screen to the left and to the right from a central vertical line. It gave the illusion of motion through an infinite corridor with high walls. The left or the right wall could be curvilinear (convex) while the other one was flat. In order to make the task more difficult the central vertical meridian of the screen was occluded by a black mask with a width of 5 deg. The task of the subject was to detect the curvilinear wall and press the ‘left’ or the ‘right’ key in accordance with target position. When the target was absent (in some presentations both the walls were flat) or when the subject could not detect it he/she had to press the third key. The distance from the screen was 57 cm. One experimental session consisted of 100 – 150 trials. All subjects showed a superiority of the right hemifield (the difference was significant, p<0.05). The observed right-hemifield superiority in the detection of large texture flow could suggest that the left hemisphere has a certain dominance in visual perception of optic flow. This is in agreement with the hypothesis that the left hemisphere is more ‘phasic’ and the right hemisphere is more ‘tonic’ [O V Levashov, 1989 Computational Models of Sensory Systems (Moscow: VINITI) (in Russian)].

scholarly journals Visual Puzzles, Figure Weights, and Cancellation: Some Preliminary Hypotheses on the Functional and Neural Substrates of These Three New WAIS-IV Subtests

2011 ◽  
Vol 2011 ◽  
pp. 1-19 ◽  
Author(s):  
Simon M. McCrea ◽  
Thomas P. Robinson
Keyword(s):  
Visual Search ◽  
Numerical Magnitude ◽  
Adult Intelligence Scale ◽  
Temporoparietal Junction ◽  
Wechsler Adult Intelligence Scale ◽  
Search Tasks ◽  
Parietal Lobes ◽  
Neuropsychological Tasks ◽  
Wechsler Adult Intelligence ◽  
The Right

In this study, five consecutive patients with focal strokes and/or cortical excisions were examined with the Wechsler Adult Intelligence Scale and Wechsler Memory Scale—Fourth Editions along with a comprehensive battery of other neuropsychological tasks. All five of the lesions were large and typically involved frontal, temporal, and/or parietal lobes and were lateralized to one hemisphere. The clinical case method was used to determine the cognitive neuropsychological correlates of mental rotation (Visual Puzzles), Piagetian balance beam (Figure Weights), and visual search (Cancellation) tasks. The pattern of results on Visual Puzzles and Figure Weights suggested that both subtests involve predominately right frontoparietal networks involved in visual working memory. It appeared that Visual Puzzles could also critically rely on the integrity of the left temporoparietal junction. The left temporoparietal junction could be involved in temporal ordering and integration of local elements into a nonverbal gestalt. In contrast, the Figure Weights task appears to critically involve the right temporoparietal junction involved in numerical magnitude estimation. Cancellation was sensitive to left frontotemporal lesions and not right posterior parietal lesions typical of other visual search tasks. In addition, the Cancellation subtest was sensitive to verbal search strategies and perhaps object-based attention demands, thereby constituting a unique task in comparison with previous visual search tasks.

Sign in / Sign up

Export Citation Format

Share Document