scholarly journals Laws of concatenated perception: Vision goes for novelty, Decisions for perseverance

2017 ◽  
Author(s):  
D. Pascucci ◽  
G. Mancuso ◽  
E. Santandrea ◽  
C. Della Libera ◽  
G. Plomp ◽  
...  
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Process Model ◽  
Multilevel Modelling ◽  
Sensory Adaptation ◽  
Serial Dependence ◽  
Human Visual Perception ◽  
History Of ◽  
High Level ◽  
The Impact

AbstractEvery instant of perception depends on a cascade of brain processes calibrated to the history of sensory and decisional events. In the present work, we show that human visual perception is constantly shaped by two contrasting forces, exerted by sensory adaptation and past decisions. In a series of experiments, we used multilevel modelling and cross-validation approaches to investigate the impact of previous stimuli and responses on current errors in adjustment tasks. Our results revealed that each perceptual report is permeated by opposite biases from a hierarchy of serially dependent processes: low-level adaptation repels perception away from previous stimuli; high-level, decisional traces attract perceptual reports toward previous responses. Contrary to recent claims, we demonstrated that positive serial dependence does not result from continuity fields operating at the level of early visual processing, but arises from the inertia of decisional templates. This finding is consistent with a Two-process model of serial dependence in which the persistence of read-out weights in a decision unit compensates for sensory adaptation, leading to attractive biases in sequential responses. We propose the first unified account of serial dependence in which functionally distinct mechanisms, operating at different stages, promote the differentiation and integration of visual information over time.

scholarly journals Continuous Flash Suppression Known and Unknowns

2019 ◽  
Author(s):  
Ali Pournaghdali ◽  
Bennett L Schwartz
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Continuous Flash Suppression ◽  
Low Level ◽  
Experimental Configuration ◽  
High Level ◽  
The Impact ◽  
Nonconscious Perception

Studies utilizing continuous flash suppression (CFS) provide valuable information regarding conscious and nonconscious perception. There are, however, crucial unanswered questions regarding the mechanisms of suppression and the level of visual processing in the absence of consciousness with CFS. Research suggests that the answers to these questions depend on the experimental configuration and how we assess consciousness in these studies. The aim of this review is to evaluate the impact of different experimental configurations and the assessment of consciousness on the results of the previous CFS studies. We review studies that evaluated the influence of different experimental configuration on the depth of suppression with CFS and discuss how different assessments of consciousness may impact the results of CFS studies. Finally, we review behavioral and brain recording studies of CFS. In conclusion, previous studies provide evidence for survival of low-level visual information and complete impairment of high-level visual information under the influence of CFS. That is, studies suggest that nonconscious perception of lower-level visual information happens with CFS but there is no evidence for nonconscious highlevel recognition with CFS.

scholarly journals Informative neural representations of unseen objects during higher-order processing in human brains and deep artificial networks

2021 ◽  
Author(s):  
Ning Mei ◽  
Roberto Santana ◽  
David Soto
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Model Simulation ◽  
Conscious Experience ◽  
Neural Representation ◽  
Visual Stream ◽  
Order Processing ◽  
High Level ◽  
Unseen Objects ◽  
Human Brains

AbstractDespite advances in the neuroscience of visual consciousness over the last decades, we still lack a framework for understanding the scope of unconscious processing and how it relates to conscious experience. Previous research observed brain signatures of unconscious contents in visual cortex, but these have not been identified in a reliable manner, with low trial numbers and signal detection theoretic constraints not allowing to decisively discard conscious perception. Critically, the extent to which unconscious content is represented in high-level processing stages along the ventral visual stream and linked prefrontal areas remains unknown. Using a within-subject, high-precision, highly-sampled fMRI approach, we show that unconscious contents, even those associated with null sensitivity, can be reliably decoded from multivoxel patterns that are highly distributed along the ventral visual pathway and also involving prefrontal substrates. Notably, the neural representation in these areas generalised across conscious and unconscious visual processing states, placing constraints on prior findings that fronto-parietal substrates support the representation of conscious contents and suggesting revisions to models of consciousness such as the neuronal global workspace. We then provide a computational model simulation of visual information processing/representation in the absence of perceptual sensitivity by using feedforward convolutional neural networks trained to perform a similar visual task to the human observers. The work provides a novel framework for pinpointing the neural representation of unconscious knowledge across different task domains.

scholarly journals The Binding Ring Illusion: assimilation affects the perceived size of a circular array

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 58 ◽  
Author(s):  
J Daniel McCarthy ◽  
Colin Kupitz ◽  
Gideon P Caplovitz
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Circular Array ◽  
Multiple Sources ◽  
Spatial Frequencies ◽  
Constructive Process ◽  
Novel Variant ◽  
Assimilation Process ◽  
Circular Contour ◽  
High Level

Our perception of an object’s size arises from the integration of multiple sources of visual information including retinal size, perceived distance and its size relative to other objects in the visual field. This constructive process is revealed through a number of classic size illusions such as the Delboeuf Illusion, the Ebbinghaus Illusion and others illustrating size constancy. Here we present a novel variant of the Delbouef and Ebbinghaus size illusions that we have named the Binding Ring Illusion. The illusion is such that the perceived size of a circular array of elements is underestimated when superimposed by a circular contour – a binding ring – and overestimated when the binding ring slightly exceeds the overall size of the array. Here we characterize the stimulus conditions that lead to the illusion, and the perceptual principles that underlie it. Our findings indicate that the perceived size of an array is susceptible to the assimilation of an explicitly defined superimposed contour. Our results also indicate that the assimilation process takes place at a relatively high level in the visual processing stream, after different spatial frequencies have been integrated and global shape has been constructed. We hypothesize that the Binding Ring Illusion arises due to the fact that the size of an array of elements is not explicitly defined and therefore can be influenced (through a process of assimilation) by the presence of a superimposed object that does have an explicit size.

scholarly journals The impact of joint attention on the sound-induced flash illusions

2021 ◽  
Author(s):  
Lucas Battich ◽  
Isabelle Garzorz ◽  
Basil Wahn ◽  
Ophelia Deroy
Keyword(s):  
Joint Attention ◽  
Cognitive Processing ◽  
Visual Processing ◽  
Visual Information ◽  
Focus Of Attention ◽  
Audiovisual Integration ◽  
Gaze Following ◽  
Information Encoding ◽  
Single Flash ◽  
The Impact

AbstractHumans coordinate their focus of attention with others, either by gaze following or prior agreement. Though the effects of joint attention on perceptual and cognitive processing tend to be examined in purely visual environments, they should also show in multisensory settings. According to a prevalent hypothesis, joint attention enhances visual information encoding and processing, over and above individual attention. If two individuals jointly attend to the visual components of an audiovisual event, this should affect the weighing of visual information during multisensory integration. We tested this prediction in this preregistered study, using the well-documented sound-induced flash illusions, where the integration of an incongruent number of visual flashes and auditory beeps results in a single flash being seen as two (fission illusion) and two flashes as one (fusion illusion). Participants were asked to count flashes either alone or together, and expected to be less prone to both fission and fusion illusions when they jointly attended to the visual targets. However, illusions were as frequent when people attended to the flashes alone or with someone else, even though they responded faster during joint attention. Our results reveal the limitations of the theory that joint attention enhances visual processing as it does not affect temporal audiovisual integration.

Effect of fentanyl buccal tablet on pain-related anxiety: A 4-week open-label study among opioid-tolerant patients with chronic and breakthrough pain

2018 ◽  
Vol 7 (4) ◽  
pp. 297-308
Author(s):  
Lynn R. Webster, MD ◽  
John Messina, PharmD ◽  
Fang Xie, PhD ◽  
Srinivas Nalamachu, MD
Keyword(s):  
Breakthrough Pain ◽  
Anxiety Symptoms ◽  
Open Label ◽  
Serious Adverse Events ◽  
Fentanyl Buccal Tablet ◽  
Buccal Tablet ◽  
Titration Period ◽  
History Of ◽  
High Level ◽  
The Impact

Objective: To evaluate the effect of fentanyl buccal tablet (FBT) on pain-related anxiety in opioid-tolerant patients with chronic pain and breakthrough pain (BTP).Design: This study consisted of a screening visit, open-label titration period, and 4-week open-label treatment period.Setting: Thirty-one US study centers.Patients: Opioid-tolerant adults with chronic, persistent pain experiencing 1-4 BTP episodes per day at baseline. Two hundred eighteen patients were enrolled in this study; 180 completed the titration period; and 169 completed the treatment period.Intervention: Patients were treated with FBT (100-800 g) for BTP episodes for 4 weeks while continuing their around-the-clock opioid regimens.Main outcome measures: Change from baseline in the Pain Anxiety Symptoms Scale (PASS) total score at the final visit.Results: Based on a mean baseline PASS total score of 82.6, study patients had a high level of anxiety; 92 patients (42 percent) had a history of anxiety disorders. The change from baseline in PASS total score was not statistically significant (mean change, −1.6; p = 0.322). Numerical improvements were reported in some secondary measures (eg, Beck Depression Inventory total score [mean change, −1.1; p = 0.038]) and categorical measures (eg, Pain Flare Treatment Satisfaction, Patient Assessment of Function, and Clinician Assessment of Patient Function ratings). FBT was generally well tolerated, with no serious adverse events related to study drug.Conclusions: Four weeks of treatment with FBT did not reduce anxiety to a clinically meaningful extent, although improvement was reported in several secondary measures of functioning. Further research is needed to assess the impact of treatment for BTP on anxiety symptoms in opioid-tolerant patients with BTP.

scholarly journals The Effect of Spatial Frequency on the Visual Category Representation in the Macaque Inferior Temporal Cortex

2021 ◽  
Author(s):  
Esmaeil Farhang ◽  
Ramin Toosi ◽  
Behnam Karami ◽  
Roxana Koushki ◽  
Ehsan Rezayat ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Visual Processing ◽  
Visual Information ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Category Representation ◽  
Neural Basis ◽  
Shape Information ◽  
Category Information ◽  
The Impact

ABSTRACTTo expand our knowledge about the object recognition, it is critical to understand the role of spatial frequency (SF) in an object representation that occurs in the inferior temporal (IT) cortex at the final stage of processing the visual information across the ventral visual pathway. Object categories are being recognized hierarchically in at least three levels of abstraction: superordinate (e.g., animal), mid-level (e.g., human face), and subordinate (e.g., face identity). Psychophysical studies have shown rapid access to mid-level category information and low SF (LSF) contents. Although the hierarchical representation of categories has been shown to exist inside the IT cortex, the impact of SF on the multi-level category processing is poorly understood. To gain a deeper understanding of the neural basis of the interaction between SF and category representations at multiple levels, we examined the neural responses within the IT cortex of macaque monkeys viewing several SF-filtered objects. Each stimulus could be either intact or bandpass filtered into either the LSF (coarse shape information) or high SF (HSF) (fine shape information) bands. We found that in both High- and Low-SF contents, the advantage of mid-level representation has not been violated. This evidence suggests that mid-level category boundary maps are strongly represented in the IT cortex and remain unaffected with respect to any changes in the frequency content of stimuli. Our observations indicate the necessity of the HSF content for the superordinate category representation inside the IT cortex. In addition, our findings reveal that the representation of global category information is more dependent on the HSF than the LSF content. Furthermore, the lack of subordinate representation in both LSF and HSF filtered stimuli compared to the intact stimuli provide strong evidence that all SF contents are necessary for fine category visual processing.

scholarly journals Neural dynamics of perceptual inference and its reversal during imagery

2019 ◽  
Author(s):  
Nadine Dijkstra ◽  
Luca Ambrogioni ◽  
Marcel A.J. van Gerven
Keyword(s):  
Mental Imagery ◽  
Information Flow ◽  
Visual Processing ◽  
Visual Information ◽  
Predictive Processing ◽  
Reverse Order ◽  
Visual Hierarchy ◽  
Abstract Representations ◽  
Oscillatory Pattern ◽  
High Level

After the presentation of a visual stimulus, cortical visual processing cascades from low-level sensory features in primary visual areas to increasingly abstract representations in higher-level areas. It is often hypothesized that the reverse process underpins the human ability to generate mental images. Under this hypothesis, visual information feeds back from high-level areas as abstract representations are used to construct the sensory representation in primary visual cortices. Such reversals of information flow are also hypothesized to play a central role in later stages of perception. According to predictive processing theories, ambiguous sensory information is resolved using abstract representations coming from high-level areas through oscillatory rebounds between different levels of the visual hierarchy. However, despite the elegance of these theoretical models, to this day there is no direct experimental evidence of the reversion of visual information flow during mental imagery and perception. In the first part of this paper, we provide direct evidence in humans for a reverse order of activation of the visual hierarchy during imagery. Specifically, we show that classification machine learning models trained on brain data at different time points during the early feedforward phase of perception are reactivated in reverse order during mental imagery. In the second part of the paper, we report an 11Hz oscillatory pattern of feedforward and reversed visual processing phases during perception. Together, these results are in line with the idea that during perception, the high-level cause of sensory input is inferred through recurrent hypothesis updating, whereas during imagery, this learned forward mapping is reversed to generate sensory signals given abstract representations.

scholarly journals Violencia intrafamiliar y relaciones interpersonales en los escolares.

Ciencia Unemi ◽  
2017 ◽  
Vol 10 (22) ◽  
pp. 111-117
Author(s):  
Carmen Graciela Zambrano Villalba
Keyword(s):  
Domestic Violence ◽  
Interpersonal Relationships ◽  
Interpersonal Violence ◽  
Partner Violence ◽  
Interpersonal Relations ◽  
Reliability And Validity ◽  
Educational Institutions ◽  
History Of ◽  
High Level ◽  
The Impact

En la historia de la humanidad, la violencia ha dejado huellas de destrucción masiva quitando  la vida a millones de  personas, en  diferentes épocas, legado que genera más violencia, y las víctimas aprenden de sus agresores. El objetivo de este estudio es analizar el impacto de la violencia intrafamiliar sobre las relaciones interpersonales de niños y jóvenes escolares de las instituciones educativas de la Zona 5 de Ecuador, identificar  los factores que intervienen en la violencia intrafamiliar y establecer los diferentes modelos de comportamiento social que utilizan en sus relaciones interpersonales. La muestra estuvo comprendida por 11 053 estudiantes de 10–17 años, de séptimo año de Educación Básica media – superior,  a primero de Bachillerato. Para medir el clima familiar se utilizó el cuestionario de Moos y Moos (1981), y para las relaciones interpersonales la Escala de comunicación de padres-adolescentes de Barnes y Olson (1985), ambos, aplicados en otras investigaciones y alto nivel de confiabilidad y validez. De los resultados obtenidos, las manifestaciones más graves de violencia interpersonal es  la violencia intrafamiliar, violencia de pareja, maltrato infantil, de padres a hijos. Las diferentes formas de violencia intrafamiliar afectan a la población más vulnerable  e influye, de manera determinante, en el comportamiento de los escolares. Throughout the history of humanity, violence has left traces of mass destruction taking the lives of millions of people at different times of the world, whose legacy generates more violence, and victims learn from victimizers. The aim of this study is to analyze the impact of domestic violence on interpersonal relations of children and young students of educational institutions in Zone 5 of Ecuador, identifying the factors involved in domestic violence and establish the different models of behavior they use in their social relationships. The sample was comprised of 11 053 students aged 10 to 17 years old from seventh year of primary and secondary education. To evaluate family atmosphere, a questionnaire by Moos, R and Moos, B. (1981) was used and for interpersonal relationships, the Scale communication of parent-adolescent by Barnes and Olson (1985) was taken, both with high level of reliability and validity applied in other research. According to the results, the most serious manifestations of interpersonal violence is domestic violence, partner violence and child abuse from parents to children. The different forms of domestic violence affect the most vulnerable people and influence in most cases the schoolchildren behavior.

scholarly journals Longitudinal association between myopia and parental myopia and outdoor time among students in Wenzhou: a 2.5-year longitudinal cohort study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dandan Jiang ◽  
Haishuang Lin ◽  
Chunchun Li ◽  
Linjie Liu ◽  
Haishao Xiao ◽  
...  
Keyword(s):  
Protective Factor ◽  
First Grade ◽  
Myopia Progression ◽  
Work Activity ◽  
Longitudinal Association ◽  
History Of ◽  
High Level ◽  
Near Work ◽  
The Impact

Abstract Background To evaluate the impact of parental myopia and outdoor time on myopia among students in Wenzhou. Methods We examined 1388 primary students from first grade to third grade in Wenzhou from September 2012 to March 2015. We performed noncycloplegic refractometry on each student every six months and axial length (AL) measurements every year. At the commencement of our study, children were asked to complete a questionnaire regarding near work activity and outdoor activity, whereas parents were asked to complete a self-administered questionnaire regarding their background circumstances and their history of myopia. Results A total of 1294 students (93.2%) returned for follow-up examinations. Children with initial and final no myopia spent more time on outdoor activities than those with new onset myopia (1.92 vs. 1.81 h/d, p = 0.022), and elongation of AL in children with a high level (> 2.5 h/day) of outdoor time (0.22 ± 0.13 mm/Y) was less than those with a low level (≤ 1.5 h/day) of outdoor time (0.24 ± 0.14 mm/Y, p = 0.045). The proportion of rapid myopia progression (≤-0.5D/Y) was 16.7%, 20.2% and 31.5% among the children with no myopic parent, one myopic parent and two myopic parents, respectively (X2 = 28.076, p < 0.001), and the elongation of AL in children among different numbers of myopic parents was significantly different (p < 0.001). A high level of outdoor time was a protective factor for children with one myopic parent (HR 0.49, 95% CI 0.27–0.88; p = 0.018). Conclusions In this sample, parental myopia and outdoor time were associated with myopia in children. A high level of outdoor time was a protective factor for children with one myopic parent.

scholarly journals Temporal stability of stimulus representation increases along rodent visual cortical hierarchies

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Eugenio Piasini ◽  
Liviu Soltuzu ◽  
Paolo Muratore ◽  
Riccardo Caramellino ◽  
Kasper Vinken ◽  
...  
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Neural Coding ◽  
Temporal Stability ◽  
Receptive Fields ◽  
Ventral Stream ◽  
Dynamic Stimuli ◽  
The Stability ◽  
Visual Cortical ◽  
The Impact

AbstractCortical representations of brief, static stimuli become more invariant to identity-preserving transformations along the ventral stream. Likewise, increased invariance along the visual hierarchy should imply greater temporal persistence of temporally structured dynamic stimuli, possibly complemented by temporal broadening of neuronal receptive fields. However, such stimuli could engage adaptive and predictive processes, whose impact on neural coding dynamics is unknown. By probing the rat analog of the ventral stream with movies, we uncovered a hierarchy of temporal scales, with deeper areas encoding visual information more persistently. Furthermore, the impact of intrinsic dynamics on the stability of stimulus representations grew gradually along the hierarchy. A database of recordings from mouse showed similar trends, additionally revealing dependencies on the behavioral state. Overall, these findings show that visual representations become progressively more stable along rodent visual processing hierarchies, with an important contribution provided by intrinsic processing.

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