scholarly journals A Quantitative Explanation of Responses to Disparity-Defined Edges in Macaque V2

2009 ◽  
Vol 101 (2) ◽  
pp. 701-713 ◽  
Author(s):  
C. E. Bredfeldt ◽  
J. C. A. Read ◽  
B. G. Cumming
Keyword(s):  
Visual Cues ◽  
Binocular Disparity ◽  
Extended Model ◽  
Scene Segmentation ◽  
Simple Consequence ◽  
Complex Stimuli ◽  
Response Enhancement ◽  
The Individual ◽  
Convergence Model ◽  
Quantitative Explanation

Previous experiments have shown that V2 neurons respond to complex stimuli such as cyclopean edges (edges defined purely by binocular disparity), angles, and motion borders. It is currently unknown whether these responses are a simple consequence of converging inputs from a prior stage of processing (V1). Alternatively, they may identify edges in a way that is invariant across a range of visual cues defining the edge, in which case they could provide a neuronal substrate for scene segmentation. Here, we examine the ability of a simple feedforward model that combines two V1-like inputs to describe the responses of V2 neurons to cyclopean edges. A linear feedforward model was able to qualitatively reproduce the major patterns of response enhancement for cyclopean edges seen in V2. However, quantitative fitting revealed that this model usually predicts response suppression by some edge configurations and such suppression was rarely seen in the data. This problem was resolved by introducing a squaring nonlinearity at the output of the individual inputs prior to combination. The extended model produced extremely good fits to most of our data. We conclude that the responses of V2 neurons to complex stimuli such as cyclopean edges can be adequately explained by a simple convergence model and do not necessarily represent the development of sophisticated mechanisms that signal scene segmentation, although they probably constitute a step toward this goal.

Supplier Selection by Extended TOPSIS to Obtain the Ideal Compromise Solution in Group Decision Making

2017 ◽  
Vol 4 (3) ◽  
pp. 71-85
Author(s):  
Mohammad Azadfallah
Keyword(s):  
Decision Making ◽  
Group Decision Making ◽  
Supplier Selection ◽  
Group Decision ◽  
Intuitionistic Fuzzy Set ◽  
Individual Preference ◽  
Multiple Criteria Decision Making ◽  
Extended Model ◽  
The Individual ◽  
Collective Preference

In the current literature, there are several studies, which the supplier selection is typically a Multi Criteria Group Decision Making problem. Several solutions for the above problem are proposed (from simple approaches; like, Borda, Condorcet, etc., to complex ones; like, Multiple Criteria Decision Making model combined with intuitionistic fuzzy set, etc.). To solve this problem, different method (particularly, extended TOPSIS method) are proposed in this paper. Firstly, we have used TOPSIS to find the individual preference ordering, then, we have used the extended version of this method to find the collective preference orderings. In addition, this model is capable of considering the expert weights. Finally, the proposed approach is compared with an existed approach (i.e., TOPSIS and Borda's function). Compared results show the advantage of our extended model over previous one.

scholarly journals Perceptual grouping constrains inhibition in time-based visual selection

2019 ◽  
Vol 82 (2) ◽  
pp. 500-517 ◽  
Author(s):  
Zorana Zupan ◽  
Derrick G. Watson
Keyword(s):  
Perceptual Grouping ◽  
Visual Selection ◽  
Selection Task ◽  
Selection Experiment ◽  
Preview Benefit ◽  
Capacity Limits ◽  
Complex Stimuli ◽  
Selective Processing ◽  
The Individual ◽  
Task Irrelevant

AbstractIn time-based visual selection, task-irrelevant, old stimuli can be inhibited in order to allow the selective processing of new stimuli that appear at a later point in time (the preview benefit; Watson & Humphreys, 1997). The current study investigated if illusory and non-illusory perceptual groups influence the ability to inhibit old and prioritize new stimuli in time-based visual selection. Experiment 1 showed that with Kanizsa-type illusory stimuli, a preview benefit occurred only when displays contained a small number of items. Experiment 2 demonstrated that a set of Kanizsa-type illusory stimuli could be selectively searched amongst a set of non-illusory distractors with no additional preview benefit obtained by separating the two sets of stimuli in time. Experiment 3 showed that, similarly to Experiment 1, non-illusory perceptual groups also produced a preview benefit only for a small number of number of distractors. Experiment 4 demonstrated that local changes to perceptually grouped old items eliminated the preview benefit. The results indicate that the preview benefit is reduced in capacity when applied to complex stimuli that require perceptual grouping, regardless of whether the grouped elements elicit illusory contours. Further, inhibition is applied at the level of grouped objects, rather than to the individual elements making up those groups. The findings are discussed in terms of capacity limits in the inhibition of old distractor stimuli when they consist of perceptual groups, the attentional requirements of forming perceptual groups and the mechanisms and efficiency of time-based visual selection.

Saliency Priority of Individual Bottom-Up Attributes in Designing Visual Attention Models

2018 ◽  
Vol 10 (4) ◽  
pp. 1-18 ◽  
Author(s):  
Jila Hosseinkhani ◽  
Chris Joslin
Keyword(s):  
Visual Attention ◽  
Cognitive Bias ◽  
Visual Cues ◽  
Human Subjects ◽  
Saliency Detection ◽  
Visual Saliency ◽  
Human Cognition ◽  
Ranking System ◽  
Bottom Up ◽  
The Individual

A key factor in designing saliency detection algorithms for videos is to understand how different visual cues affect the human perceptual and visual system. To this end, this article investigated the bottom-up features including color, texture, and motion in video sequences for a one-by-one scenario to provide a ranking system stating the most dominant circumstances for each feature. In this work, it is considered the individual features and various visual saliency attributes investigated under conditions in which the authors had no cognitive bias. Human cognition refers to a systematic pattern of perceptual and rational judgments and decision-making actions. First, this paper modeled the test data as 2D videos in a virtual environment to avoid any cognitive bias. Then, this paper performed an experiment using human subjects to determine which colors, textures, motion directions, and motion speeds attract human attention more. The proposed benchmark ranking system of salient visual attention stimuli was achieved using an eye tracking procedure.

Predicting multisensory enhancement in neuronal responses

2012 ◽  
Vol 25 (0) ◽  
pp. 3
Author(s):  
Benjamin A. Rowland
Keyword(s):  
Alternative Hypothesis ◽  
Initial Response ◽  
Neuronal Responses ◽  
Experimental Conditions ◽  
Sensory Modalities ◽  
Response Enhancement ◽  
Multisensory Enhancement ◽  
Response Profiles ◽  
The Individual ◽  
Statistical Noise

The most dramatic physiological example of multisensory integration is response enhancement, where the integration of concordant signals across multiple sensory modalities leads to a larger and more reliable response. In the model system of the superior colliculus, the largest enhancements (often greater than the predicted sum) are observed when the individual signals being combined are weak. This principle conforms to expectations based on signal detection theory, and also as expected, enhancement is not uniform throughout any response. Typically it is greatest near its onset, when the unisensory inputs are at their weakest (Initial Response Enhancement, see Rowland et al., 2007; Rowland and Stein, 2008). Despite the general accuracy of this heuristic, however, there is a substantial amount of variance in the degree of observed enhancement at all levels of responsiveness. This observation appears to violate standard Bayesian predictions that are based on overall response magnitude. Aside from statistical noise, a possible explanation is that individual neurons in the dataset are calibrated to different ‘computational modes’. An alternative hypothesis is that the amount of enhancement is influenced greatly by response properties other than magnitude, specifically, the temporal profile of the response. The present analysis advances the latter hypothesis. We present a mechanistic framework that explains these findings and extends the standard Bayesian approach to generate an accurate prediction for the multisensory response profile given known unisensory response profiles. These predictions offer a ‘null hypothesis’ that can be used to quantify the circumstances and timing of anomalies in the integrative processes in different experimental conditions; for example, when it is developing under different conditions, or when it is disrupted by experimental or surgical intervention at any stage of life.

scholarly journals Neural dynamics of cue reliability in perceptual decisions

2019 ◽  
Author(s):  
Giovanni Mancuso ◽  
Gijs Plomp
Keyword(s):  
Visual Cues ◽  
Brain Activity ◽  
Temporal Cortex ◽  
Behavioral Performance ◽  
Shape Information ◽  
Behavioral Predictors ◽  
Cue Reliability ◽  
Behavioral Sensitivity ◽  
The Individual ◽  
Visual Shape

To extract meaningful information from scenes, the visual system must combine local cues that can vary greatly in their degree of reliability. Here, we asked whether cue reliability mostly affects visual or decision-related processes, using visual evoked potentials (VEPs) and a model-based approach to identify when and where stimulus-evoked brain activity reflects cue reliability. Participants performed a shape discrimination task on Gaborized ellipses while we parametrically, and independently, varied the reliability of contour or surface cues. We modelled the expected behavioral performance as a linear function of cue reliability and established at what latencies and electrodes VEP activity reflected behavioral sensitivity to cue reliability. We found that VEPs were linearly related to the individual behavioral predictors at around 400 ms post-stimulus, at electrodes over parietal and lateral temporal cortex. The observed cue reliability effects were similar for variations in contour and surface cues. Notably, effects of cue reliability were absent at earlier latencies where visual shape information is typically reported, and also in data time-locked to the behavioral response, suggesting the effects are not decision-related. These results indicate that reliability of visual cues is reflected in late distributed perceptual processes.

Perceptions of Standard and Nonstandard Language Varieties: The Influence of Ethnicity and Heritage Language Experience

2016 ◽  
Vol 13 (1) ◽  
pp. 55-79
Author(s):  
Maria Elena Gutiérrez ◽  
Mark Amengual
Keyword(s):  
Visual Cues ◽  
Heritage Language ◽  
American English ◽  
Language Experience ◽  
Standard American English ◽  
Language Varieties ◽  
Language Variety ◽  
Accented English ◽  
The Individual ◽  
Chicano English

The present study examines perceptions of standard and nonstandard varieties of English and the roles of perceived speaker ethnicity and heritage language experience. In this study, 24 English monolinguals and 24 English-Spanish heritage language bilinguals were asked to evaluate three speech samples representing native Standard American English, Chicano English, and non-native Spanish-accented English, each paired with one of three photographs of an individual reflecting idealized “Hispanic” or “non-Hispanic” ethnic identities. Both the language variety heard and the ethnic identity visually associated with a given speaker were found to influence listeners’ perceptions of the individual. While this study supports previous findings that visual cues lead to discrimination in language perception, it also indicates that language experience may mitigate this effect.

scholarly journals Adaptation to heading direction dissociates the roles of human MST and V6 in the processing of optic flow

2012 ◽  
Vol 108 (3) ◽  
pp. 794-801 ◽  
Author(s):  
Velia Cardin ◽  
Lara Hemsworth ◽  
Andrew T. Smith
Keyword(s):  
Optic Flow ◽  
Visual Cues ◽  
Brain Regions ◽  
Control Area ◽  
Attention Capture ◽  
Local Motion ◽  
Heading Direction ◽  
The Individual ◽  
Visual Cortical ◽  
Self Motion

The extraction of optic flow cues is fundamental for successful locomotion. During forward motion, the focus of expansion (FoE), in conjunction with knowledge of eye position, indicates the direction in which the individual is heading. Therefore, it is expected that cortical brain regions that are involved in the estimation of heading will be sensitive to this feature. To characterize cortical sensitivity to the location of the FoE or, more generally, the center of flow (CoF) during visually simulated self-motion, we carried out a functional MRI (fMRI) adaptation experiment in several human visual cortical areas that are thought to be sensitive to optic flow parameters, namely, V3A, V6, MT/V5, and MST. In each trial, two optic flow patterns were sequentially presented, with the CoF located in either the same or different positions. With an adaptation design, an area sensitive to heading direction should respond more strongly to a pair of stimuli with different CoFs than to stimuli with the same CoF. Our results show such release from adaptation in areas MT/V5 and MST, and to a lesser extent V3A, suggesting the involvement of these areas in the processing of heading direction. The effect could not be explained either by differences in local motion or by attention capture. It was not observed to a significant extent in area V6 or in control area V1. The different patterns of responses observed in MST and V6, areas that are both involved in the processing of egomotion in macaques and humans, suggest distinct roles in the processing of visual cues for self-motion.

Health and self-control: promoting unconscious healthy food choices inside the store

2020 ◽  
Vol 48 (3) ◽  
pp. 229-243
Author(s):  
Benedetta Grandi ◽  
Maria Grazia Cardinali ◽  
Silvia Bellini
Keyword(s):  
Healthy Eating ◽  
Visual Cues ◽  
Need For Cognition ◽  
Self Control ◽  
Content Type ◽  
Specific Category ◽  
The Individual ◽  
High Level ◽  
Cognitive Behaviours

PurposeThe wide literature about healthy behaviours posits that a high level of self-control is required in order to make healthy choices. This work intends to demonstrate that retailers, through the management of in-store marketing levers, can influence shopping behaviour, no matter which is the individual tendency to engage in cognitive behaviours. For this specific purpose, we have considered participants' “Need for Cognition” as a proxy of self-control.Design/methodology/approachWith reference to a specific category (cookies), we created a new display based on benefits (healthy eating) rather than products' attributes. A pre-test was conducted before the main experiment in order to assess the potential ability of the new nutritional display to help customers selecting healthier products, by testing participants' awareness and comprehension of the stimuli proposed. Then, an online between-subjects experiment was conducted by simulating the shoppers' expedition in the cookies' aisle inside a store with the aim to demonstrate that healthy choices can be also made on impulse.FindingsOur findings showed that when both communication and visual cues are provided, people low in need for cognition (NFC) are more willing to select healthy products from the shelf, compared with people high in NFC.Originality/valueWhile there is a wide literature explaining the mechanisms supporting healthy choices, fewer are the contributions about the role of retailers in promoting healthy eating through in-store marketing levers. More important, there is no contribution about how to promote health among people with low level of self-control.

scholarly journals Winning or not losing? The impact of non-pain goal focus on attentional bias to learned pain signals

2018 ◽  
Vol 18 (4) ◽  
pp. 675-686 ◽  
Author(s):  
Martien G.S. Schrooten ◽  
Stefaan Van Damme ◽  
Geert Crombez ◽  
Hanne Kindermans ◽  
Johan W.S. Vlaeyen
Keyword(s):  
Attentional Bias ◽  
Visual Cues ◽  
Goal Pursuit ◽  
Naming Task ◽  
Positive Outcome ◽  
Control Group ◽  
Significant Group ◽  
Spatial Cueing ◽  
The Individual ◽  
The Impact

Abstract Background and aims Insights into the nature of cognitive bias, including attentional bias to threat signals, are considered pivotal to understanding (chronic) pain and related distress. It has been put forward that attention to pain-related threat is normally dynamic and relates to the motivational state of the individual. In this experiment we aimed (i) to replicate the finding that attentional bias for pain signals in healthy participants can be reduced when a non-pain goal is pursued, and (ii) to extend this finding by taking into account the outcome focus of the non-pain goal. We hypothesised that the reduction in attentional bias for pain signals by concurrent non-pain goal pursuit would be stronger with non-pain prevention goals than with promotion goals. Methods Healthy university students performed an attentional bias task (i.e. spatial cueing task) containing visual cues that signalled the possible occurrence of a painful stimulus (electrocutaneous stimulus at tolerance level) or its absence, in combination with a non-pain goal task (i.e. digit naming task). The non-pain goal was either related to acquiring a positive outcome (gaining money depending on digit-naming performance; promotion goal group, n=31) or related to avoiding a negative outcome (losing money; prevention goal group, n=31). A standard attentional bias task served as the control condition (control group, n=31). Results Spatial cueing effects were larger for pain cues than for no-pain cues, indicating attentional bias for pain signals. The pattern of results suggests that this effect was indeed reduced in the goal groups as compared to the control group, but there was no significant group difference. Conclusions We found no statistically-significant evidence for the impact of non-pain goal pursuit or outcome focus on pain-related attentional bias. At best, there were indications of a reduced attentional bias for pain signals with non-pain goal pursuit that was either promotion- or prevention focused. Implications These data add to the small but growing body of literature on the assumed relevance of motivational context in explaining variations in attentional bias. The results trigger new questions on the nature and assessment of pain-related attentional bias, and more specifically attentional bias for fear-conditioned pain signals (versus safety signals), from a motivational perspective.

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