Multistable Perception

2021 ◽  
Author(s):  
Alexander Pastukhov
Keyword(s):  
Subjective Experience ◽  
Predictive Coding ◽  
Relative Strength ◽  
Perceptual Decision Making ◽  
Behavioral Correlates ◽  
Conflicting Evidence ◽  
Multistable Perception ◽  
Initial Perception ◽  
High Level ◽  
History Presentation

Multistable perception is produced by stimuli that are consistent with two or more different comparably likely perceptual interpretations. After the initial perception is resolved in favor of one of the interpretations, continued viewing leads to fluctuating subjective experience, as perception spontaneously switches between alternative states. Multistable perception occurs for different modalities, including visual, auditory, tactile, olfactory perception and proprioception, and various conflicting sensory representations, such as eye dominance, depth, motion, or meaning. Despite large differences, multistable stimuli produce quantitatively similar perceptual experience with stereotypical distribution of durations of dominance phases, similar dependence on the absolute and relative strength of competing perceptual interpretations, prior perceptual history, presentation method, attention, and volitional control, and so on. Taken together, this shows that multistable perception reflects the action of general canonical perceptual mechanisms whose purpose is to resolve the conflicting evidence and ensure a single dominant perception that can be used for action. Thus, it informs us about mechanisms of perceptual decision making, including the importance of feedback mechanisms in resolving perceptual ambiguity and the role of parietal and frontal regions in facilitating changes in perception. Multistable perception provides useful constraints for models, inspiring a plethora of models of perception that combine neurally plausible mechanisms, such as neural adaptation and inhibition, or are based on the idea of predictive coding. The sensitive nature of multistable perception makes a valuable experimental tool that can reveal even minor differences due to low- or high-level influences, including genetic or clinical cases. As such, it is an important tool in studying neural and behavioral correlates of consciousness as it dissociates perception from the stimulus.

Subjective factors affecting gun shooting accuracy among employees of internal affairs agencies in process of learning

2020 ◽  
Vol 2020 (4) ◽  
pp. 198-206
Author(s):  
Anton Rozhkov ◽  
Anton Popov ◽  
Vitaliy Balahonskiy
Keyword(s):  
Subjective Experience ◽  
Statistical Significance ◽  
Self Regulation ◽  
Sensorimotor Coordination ◽  
Factors Affecting ◽  
Intelligent Behavior ◽  
Experience Of Stress ◽  
Firing Line ◽  
High Level ◽  
In Fire

The article is devoted to the study of subjective factors affecting shooting accuracy of law enforcement officers. The empirical study identified some subjective factors reducing gun shooting accuracy and effectiveness among law enforcers. These characteristics include sensorimotor coordination and subjective experience of stress during the shooting process. Scientific analysis made it possible to determine statistical significance of the influence of these factors on the accuracy of shooting. To increase the effectiveness of shooting among officers with a low index of sensorimotor coordination, the authors suggest using exercises aimed at cultivating sensorimotor coordination in fire training classes. While working with employees being under a high level of subjectively experienced stress, more attention should be paid to training techniques to overcome stress and form intelligent behavior in extreme situations. The authors also draw readers’ attention to factors increasing the effectiveness of shooting: officers’ ability to determine the subjective level of stress, their knowledge of emotional self-regulation techniques, knowledge of the sequence of their actions in the firing line.

scholarly journals MemCat: A new category-based image set quantified on memorability

2019 ◽  
Author(s):  
Lore Goetschalckx ◽  
Johan Wagemans
Keyword(s):  
Neural Networks ◽  
Memory Task ◽  
Semantic Category ◽  
Source Image ◽  
Behavioral Correlates ◽  
Semantic Categories ◽  
Visual Hierarchy ◽  
Image Set ◽  
High Level ◽  
Repeat Detection

This is a preprint. Please find the published, peer reviewed version of the paper here: https://peerj.com/articles/8169/. Images differ in their memorability in consistent ways across observers. What makes an image memorable is not fully understood to date. Most of the current insight is in terms of high-level semantic aspects, related to the content. However, research still shows consistent differences within semantic categories, suggesting a role for factors at other levels of processing in the visual hierarchy. To aid investigations into this role as well as contributions to the understanding of image memorability more generally, we present MemCat. MemCat is a category-based image set, consisting of 10K images representing five broader, memorability-relevant categories (animal, food, landscape, sports, and vehicle) and further divided into subcategories (e.g., bear). They were sampled from existing source image sets that offer bounding box annotations or more detailed segmentation masks. We collected memorability scores for all 10K images, each score based on the responses of on average 99 participants in a repeat-detection memory task. Replicating previous research, the collected memorability scores show high levels of consistency across observers. Currently, MemCat is the second largest memorability image set and the largest offering a category-based structure. MemCat can be used to study the factors underlying the variability in image memorability, including the variability within semantic categories. In addition, it offers a new benchmark dataset for the automatic prediction of memorability scores (e.g., with convolutional neural networks). Finally, MemCat allows to study neural and behavioral correlates of memorability while controlling for semantic category.

scholarly journals Field (In)dependence Flexibility Following a Virtual Immersion Is Associated With Cybersickness and Sense of Presence

2021 ◽  
Vol 2 ◽  
Author(s):  
A. Maneuvrier ◽  
L. M. Decker ◽  
P. Renaud ◽  
G. Ceyte ◽  
H. Ceyte
Keyword(s):  
Visual Cues ◽  
Subjective Experience ◽  
A Posteriori ◽  
Future Studies ◽  
Sense Of Presence ◽  
Before And After ◽  
High Level ◽  
Shed Light ◽  
Rod And Frame Test ◽  
Rod And Frame

Field dependence–independence (FDI) is a psychological construct determining an individual’s approach of the perception–cognition coupling. In virtual reality (VR) context, several studies suggest that an individual’s perceptive style is susceptible to shift toward a more FI mode through down-weighting of conflicting visual cues. The present study proposes to investigate the potential flexible nature of FDI following a virtual immersion and to assess if this flexibility might be associated with the subjective experience of VR. 86 participants explored a real-world–like virtual environment for approximately 10 min. FDI levels were measured before and after the VR exposure using the rod-and-frame test. Their subjective experience of VR was measured a posteriori (cybersickness and sense of presence) and used in order to build two experimental groups via a cluster analysis. The results showed that only participants with a poor subjective experience of VR (i.e., a low level of sense of presence associated with a high level of cybersickness) significantly shifted to a more FI mode, which is discussed as a sensory re-weighting mechanism. Pragmatical applications are discussed, and future studies are outlined, based on the conclusion that FDI might be more flexible than we thought, which could shed light on the psychophysiology of VR.

Change readiness as fluid trajectories: a longitudinal multiple-case study

2018 ◽  
Vol 31 (5) ◽  
pp. 1153-1175 ◽  
Author(s):  
Florian Hemme ◽  
Matthew T. Bowers ◽  
Janice S. Todd
Keyword(s):  
Public Service ◽  
Resistance To Change ◽  
Multiple Case Study ◽  
Relative Strength ◽  
Change Readiness ◽  
Content Type ◽  
External Stakeholder ◽  
Multiple Case ◽  
High Level

Purpose The purpose of this paper is to analyze change process perceptions of public service employees and document how change readiness belief salience fluctuates and evolves throughout the implementation of a major organizational restructuring effort. Design/methodology/approach This research is a longitudinal multiple-case study of a major transformation initiative in a large North American public recreation organization. Over the course of 15 months, the authors conducted four rounds of personal interviews with 19 participants (65 interviews in total, each lasting 25–45 min). Additionally, the authors analyzed internal e-mail correspondence, memos, and meeting agendas, as well as external stakeholder communication. Finally, the primary researcher spent a significant amount of time collecting field notes while shadowing high-level managers and employees and attending meetings. Findings Overall, the authors documented a clear hierarchy of change readiness dimensions. The relative strength and temporal persistence of these dimensions can be traced back to various public organizing particularities. Moreover, the authors found that an initial focus on some readiness dimensions facilitated subsequent sensemaking processes whereas others hindered such engagement with the change project. Research limitations/implications This research is the first to empirically document temporal fluidity of change readiness dimensions and salience. Moreover, it offers a rare in-depth look at a changing public service organization. Practical implications This research helps change agents in developing tailored change messages and to better understand potential sources of frustration and resistance to change efforts. Originality/value No similar efforts exist to document the underlying dynamism of evolving change readiness perceptions.

Effects of Blade Count Ratio on Aerodynamic Forcing and Mode Excitability

2015 ◽  
Author(s):  
Jing Li ◽  
Robert E. Kielb
Keyword(s):  
Harmonic Balance ◽  
Harmonic Balance Method ◽  
Relative Strength ◽  
Turbine Stage ◽  
Blade Loading ◽  
Count Ratio ◽  
Generalized Force ◽  
Pitch Ratio ◽  
Unsteady Loading ◽  
High Level

The effects of blade count ratio (BCR) on both the steady and unsteady blade loading and the sensitivity of generalized force to a change in mode shape (mode excitability) are studied numerically on two 2D configurations: a subsonic research compressor stage and a turbine stage with supersonic exit. Using the Harmonic Balance method, only a single passage is modeled to represent the actual blade count in a row at a high level of computational efficiency. BCR variation is achieved by scaling the downstream airfoils with a fixed chord-to-pitch ratio, thus preserving the steady-state aerodynamics. It is found that the interaction among potential-, wake-, and shock-related excitations, and the relative strength of harmonic contents are dependent on BCR, resulting in a non-monotonic correlation between unsteady loading and BCR in the downstream row. It is also found that the mode excitability can be sensitive to BCR variation in both up- and downstream rows in some cases. To the best of authors’ knowledge, this is the first work on BCR study involving supersonic flow and a discussion of mode excitability patterns.

scholarly journals United we sense, divided we fail: context-driven perception of ambiguous visual stimuli

2012 ◽  
Vol 367 (1591) ◽  
pp. 932-941 ◽  
Author(s):  
P. C. Klink ◽  
R. J. A. van Wezel ◽  
R. van Ee
Keyword(s):  
Contextual Information ◽  
Visual Stimuli ◽  
Sensory Information ◽  
Contextual Influences ◽  
Perceptual Decision Making ◽  
Response Characteristics ◽  
Conflicting Evidence ◽  
Neuronal Mechanisms ◽  
Neuronal Representation ◽  
The Brain

Ambiguous visual stimuli provide the brain with sensory information that contains conflicting evidence for multiple mutually exclusive interpretations. Two distinct aspects of the phenomenological experience associated with viewing ambiguous visual stimuli are the apparent stability of perception whenever one perceptual interpretation is dominant, and the instability of perception that causes perceptual dominance to alternate between perceptual interpretations upon extended viewing. This review summarizes several ways in which contextual information can help the brain resolve visual ambiguities and construct temporarily stable perceptual experiences. Temporal context through prior stimulation or internal brain states brought about by feedback from higher cortical processing levels may alter the response characteristics of specific neurons involved in rivalry resolution. Furthermore, spatial or crossmodal context may strengthen the neuronal representation of one of the possible perceptual interpretations and consequently bias the rivalry process towards it. We suggest that contextual influences on perceptual choices with ambiguous visual stimuli can be highly informative about the neuronal mechanisms of context-driven inference in the general processes of perceptual decision-making.

scholarly journals Strength, Jump Heights and Physical Characteristics of Young Male Basketball Players by Their Positions

2019 ◽  
Vol 7 (3S) ◽  
pp. 17
Author(s):  
Niyazi Sıdkı Adıgüzel
Keyword(s):  
Young Male ◽  
Knee Extension ◽  
Relative Strength ◽  
Basketball Players ◽  
Squat Jump ◽  
Absolute Strength ◽  
Significant Difference ◽  
Strength Tests ◽  
Angular Velocities ◽  
High Level

The aim of the study is to compare isokinetic leg strengths and jump performances of basketball players playing at different positions. A total of 34 basketball players (guards (n=13), forwards (n=13) and centers (n=7)) from 17 teams of Turkish Basketball Development League participated in the study. The isokinetic strength tests were performed for the dominant limb at two different angular speeds (60°s-1 and 180°s-1) and the extensor and flexor peak torques (EPT and FPT) were recorded. The strengths produced according to weight were taken as relative EPT and FPT. Jump tests were performed in three categories: free jump, 120° squat jump and active jump. Multivariate variance analysis (ANOVA) was used to compare players' scores in strength and jump tests by their positions. In the comparison of the positions, the guards were shorter and slimmer than the forwards and centers (p <0.05), and they were found to have less BMI values than the centers. The absolute strength values obtained with knee extension peak torques for both angular velocities were higher in the centers than the guards (p <0.05). There was no statistically significant difference in the relative strength values. Moreover, no statistically significant difference was found between the groups for other parameters and all jump parameters (p> 0.05). Consequently, it can be stated that there are physical differences among high-level young basketball players by their positions and absolute quadriceps strengths of the centers may be higher than of the guards.

scholarly journals Deep Gated Hebbian Predictive Coding Accounts for Emergence of Complex Neural Response Properties Along the Visual Cortical Hierarchy

2021 ◽  
Vol 15 ◽  
Author(s):  
Shirin Dora ◽  
Sander M. Bohte ◽  
Cyriel M. A. Pennartz
Keyword(s):  
Network Architecture ◽  
Hebbian Learning ◽  
Predictive Coding ◽  
Learning Rule ◽  
Neuronal Populations ◽  
Hebbian Learning Rule ◽  
Cortical Hierarchy ◽  
Latent Representations ◽  
High Level ◽  
Visual Cortical

Predictive coding provides a computational paradigm for modeling perceptual processing as the construction of representations accounting for causes of sensory inputs. Here, we developed a scalable, deep network architecture for predictive coding that is trained using a gated Hebbian learning rule and mimics the feedforward and feedback connectivity of the cortex. After training on image datasets, the models formed latent representations in higher areas that allowed reconstruction of the original images. We analyzed low- and high-level properties such as orientation selectivity, object selectivity and sparseness of neuronal populations in the model. As reported experimentally, image selectivity increased systematically across ascending areas in the model hierarchy. Depending on the strength of regularization factors, sparseness also increased from lower to higher areas. The results suggest a rationale as to why experimental results on sparseness across the cortical hierarchy have been inconsistent. Finally, representations for different object classes became more distinguishable from lower to higher areas. Thus, deep neural networks trained using a gated Hebbian formulation of predictive coding can reproduce several properties associated with neuronal responses along the visual cortical hierarchy.

scholarly journals How did that individual make that perceptual decision?

2018 ◽  
Vol 41 ◽  
Author(s):  
David A. Booth
Keyword(s):  
Decision Making ◽  
Social Context ◽  
Perceptual Decision Making ◽  
Mental Processes ◽  
Perceptual Decision ◽  
Amount Of Information ◽  
Mechanistic Theory ◽  
High Level

AbstractSuboptimality of decision making needs no explanation. High-level accounts of suboptimality in diverse tasks cannot add up to a mechanistic theory of perceptual decision making. Mental processes operate on the contents of information brought by the experimenter and the participant to the task, not on the amount of information in the stimuli without regard to physical and social context.

scholarly journals Predictive Coding of Novel versus Familiar Stimuli in the Primary Visual Cortex

2017 ◽  
Author(s):  
Jan Homann ◽  
Sue Ann Koay ◽  
Alistair M. Glidden ◽  
David W. Tank ◽  
Michael J. Berry
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Predictive Coding ◽  
Stimulus Sequence ◽  
Layer 2 ◽  
Elevated Activity ◽  
Stimulus Identity ◽  
High Level ◽  
Familiar Stimuli ◽  
Sustained Responses

AbstractTo explore theories of predictive coding, we presented mice with repeated sequences of images with novel images sparsely substituted. Under these conditions, mice could be rapidly trained to lick in response to a novel image, demonstrating a high level of performance on the first day of testing. Using 2-photon calcium imaging to record from layer 2/3 neurons in the primary visual cortex, we found that novel images evoked excess activity in the majority of neurons. When a new stimulus sequence was repeatedly presented, a majority of neurons had similarly elevated activity for the first few presentations, which then decayed to almost zero activity. The decay time of these transient responses was not fixed, but instead scaled with the length of the stimulus sequence. However, at the same time, we also found a small fraction of the neurons within the population (∼2%) that continued to respond strongly and periodically to the repeated stimulus. Decoding analysis demonstrated that both the transient and sustained responses encoded information about stimulus identity. We conclude that the layer 2/3 population uses a two-channel predictive code: a dense transient code for novel stimuli and a sparse sustained code for familiar stimuli. These results extend and unify existing theories about the nature of predictive neural codes.

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