scholarly journals Effect of spatiotemporally changing environment on serial dependence in ensemble representations

2021 ◽  
Author(s):  
Sangkyu Son ◽  
Joonyeol Lee ◽  
Oh-Sang Kwon ◽  
Yee Joon Kim
Keyword(s):  
Visual Information ◽  
Temporal Integration ◽  
Real Life ◽  
Task Demands ◽  
Strong Impact ◽  
Serial Dependence ◽  
Environmental Statistics ◽  
Observer Model ◽  
Differential Pattern ◽  
Repulsion Effect

The recent visual past has a strong impact on our current perception. Recent studies of serial dependence in perception show that low-level adaptation repels our current perception away from previous stimuli whereas post-perceptual decision attracts perceptual report toward the immediate past. In their studies, these repulsive and attractive biases were observed with different task demands perturbing ongoing sequential process. Therefore, it is unclear whether the opposite biases arise naturally in navigating complex real-life environments. Here we only manipulated the environmental statistics to characterize how serially dependent perceptual decisions unfold in spatiotemporally changing visual environments. During sequential mean orientation adjustment task on the array of Gabor patches, we found that the repulsion effect dominated only when ensemble variance increased across consecutive trials whereas the attraction effect prevailed when ensemble variance decreased or remained the same. The observed attractive bias by high-to-low-variance stimuli and repulsive bias by low-to-high-variance stimuli were reinforced by the repeated exposure to the low and the high ensemble variance, respectively. Further, this variance-dependent differential pattern of serial dependence in ensemble representation remained the same regardless of whether observers had a prior knowledge of environmental statistics or not. We used a Bayesian observer model constrained by visual adaptation to provide a unifying account of both attractive and repulsive bias in perception. Our results establish that the temporal integration and segregation of visual information is flexibly adjusted through variance adaptation.

scholarly journals A Bayesian and efficient observer model explains concurrent attractive and repulsive history biases in visual perception

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Matthias Fritsche ◽  
Eelke Spaak ◽  
Floris P de Lange
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Temporal Pattern ◽  
Visual Experience ◽  
Ideal Observer ◽  
Serial Dependence ◽  
Short Term ◽  
The Past ◽  
Observer Model

Human perceptual decisions can be repelled away from (repulsive adaptation) or attracted towards recent visual experience (attractive serial dependence). It is currently unclear whether and how these repulsive and attractive biases interact during visual processing and what computational principles underlie these history dependencies. Here we disentangle repulsive and attractive biases by exploring their respective timescales. We find that perceptual decisions are concurrently attracted towards the short-term perceptual history and repelled from stimuli experienced up to minutes into the past. The temporal pattern of short-term attraction and long-term repulsion cannot be captured by an ideal Bayesian observer model alone. Instead, it is well captured by an ideal observer model with efficient encoding and Bayesian decoding of visual information in a slowly changing environment. Concurrent attractive and repulsive history biases in perceptual decisions may thus be the consequence of the need for visual processing to simultaneously satisfy constraints of efficiency and stability.

scholarly journals A Bayesian and efficient observer model explains concurrent attractive and repulsive history biases in visual perception

2020 ◽  
Author(s):  
Matthias Fritsche ◽  
Eelke Spaak ◽  
Floris P. de Lange
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Temporal Pattern ◽  
Visual Experience ◽  
Ideal Observer ◽  
Serial Dependence ◽  
Short Term ◽  
The Past ◽  
Observer Model

AbstractPerceptual decisions can be repelled away from (repulsive adaptation) or attracted towards recent visual experience (attractive serial dependence). It is currently unclear whether and how these repulsive and attractive biases interact during visual processing and what computational principles may underlie these history dependencies. In the current study, we disentangle repulsive and attractive biases by exploring the respective timescales over which current visual processing is influenced by previous experience. Across four experiments, we find that perceptual decisions about stimulus orientation are concurrently attracted towards the short-term perceptual history and repelled from stimuli experienced up to minutes into the past. We show that the temporal pattern of short-term attraction and long-term repulsion cannot be captured by an ideal Bayesian observer model alone. Instead, it is well captured by an ideal observer model with efficient encoding and Bayesian decoding of visual information in a slowly changing environment. Concurrent attractive and repulsive history biases in perceptual decisions may thus be the consequence of the need for visual processing to simultaneously satisfy constraints of both efficiency and stability.

scholarly journals ECOCAPTURE@HOME: Protocol for the Remote Assessment of Apathy and Its Everyday-Life Consequences

2021 ◽  
Vol 18 (15) ◽  
pp. 7824
Author(s):  
Valérie Godefroy ◽  
Richard Levy ◽  
Arabella Bouzigues ◽  
Armelle Rametti-Lacroux ◽  
Raffaella Migliaccio ◽  
...  
Keyword(s):  
Everyday Life ◽  
New Technologies ◽  
Electrodermal Activity ◽  
Real Life ◽  
Smartphone Application ◽  
Measurement Model ◽  
Strong Impact ◽  
Active Data ◽  
Personalised Treatment

Apathy, a common neuropsychiatric symptom associated with dementia, has a strong impact on patients’ and caregivers’ quality of life. However, it is still poorly understood and hard to define. The main objective of the ECOCAPTURE programme is to define a behavioural signature of apathy using an ecological approach. Within this program, ECOCAPTURE@HOME is an observational study which aims to validate a method based on new technologies for the remote monitoring of apathy in real life. For this study, we plan to recruit 60 couples: 20 patient-caregiver dyads in which patients suffer from behavioral variant Fronto-Temporal Dementia, 20 patient-caregiver dyads in which patients suffer from Alzheimer Disease and 20 healthy control couples. These dyads will be followed for 28 consecutive days via multi-sensor bracelets collecting passive data (acceleration, electrodermal activity, blood volume pulse). Active data will also be collected by questionnaires on a smartphone application. Using a pool of metrics extracted from these passive and active data, we will validate a measurement model for three behavioural markers of apathy (i.e., daytime activity, quality of sleep, and emotional arousal). The final purpose is to facilitate the follow-up and precise diagnosis of apathy, towards a personalised treatment of this condition within everyday life.

A homogenously weighted moving average scheme for observations under the effect of serial dependence and measurement inaccuracy

2021 ◽  
Vol 12 (4) ◽  
pp. 401-414 ◽  
Author(s):  
Maonatlala Thanwane ◽  
Sandile C. Shongwe ◽  
Muhammad Aslam ◽  
Jean-Claude Malela-Majika ◽  
Mohammed Albassam
Keyword(s):  
Measurement Errors ◽  
Moving Average ◽  
Length Distribution ◽  
Real Life ◽  
Sampling Strategy ◽  
Serial Dependence ◽  
Statistical Efficiency ◽  
Average Scheme ◽  
Run Length Distribution ◽  
Weighted Moving Average

The combined effect of serial dependency and measurement errors is known to negatively affect the statistical efficiency of any monitoring scheme. However, for the recently proposed homogenously weighted moving average (HWMA) scheme, the research that exists concerns independent and identically distributed observations and measurement errors only. Thus, in this paper, the HWMA scheme for monitoring the process mean under the effect of within-sample serial dependence with measurement errors is proposed for both constant and linearly increasing measurement system variance. Monte Carlo simulation is used to evaluate the run-length distribution of the proposed HWMA scheme. A mixed-s&m sampling strategy is incorporated to the HWMA scheme to reduce the negative effect of serial dependence and measurement errors and its performance is compared to the existing Shewhart scheme. An example is given to illustrate how to implement the proposed HWMA scheme for use in real-life applications.

scholarly journals The Effect of Irrelevant Environmental Noise on the Performance of Visual-to-Auditory Sensory Substitution Devices Used by Blind Adults

2019 ◽  
Vol 32 (2) ◽  
pp. 87-109 ◽  
Author(s):  
Galit Buchs ◽  
Benedetta Heimler ◽  
Amir Amedi
Keyword(s):  
Background Noise ◽  
Visual Information ◽  
Real Life ◽  
Sensory Substitution ◽  
Auditory Modality ◽  
Auditory Information ◽  
Visual Rehabilitation ◽  
Actual Use ◽  
Significant Performance ◽  
Audio Information

Abstract Visual-to-auditory Sensory Substitution Devices (SSDs) are a family of non-invasive devices for visual rehabilitation aiming at conveying whole-scene visual information through the intact auditory modality. Although proven effective in lab environments, the use of SSDs has yet to be systematically tested in real-life situations. To start filling this gap, in the present work we tested the ability of expert SSD users to filter out irrelevant background noise while focusing on the relevant audio information. Specifically, nine blind expert users of the EyeMusic visual-to-auditory SSD performed a series of identification tasks via SSDs (i.e., shape, color, and conjunction of the two features). Their performance was compared in two separate conditions: silent baseline, and with irrelevant background sounds from real-life situations, using the same stimuli in a pseudo-random balanced design. Although the participants described the background noise as disturbing, no significant performance differences emerged between the two conditions (i.e., noisy; silent) for any of the tasks. In the conjunction task (shape and color) we found a non-significant trend for a disturbing effect of the background noise on performance. These findings suggest that visual-to-auditory SSDs can indeed be successfully used in noisy environments and that users can still focus on relevant auditory information while inhibiting irrelevant sounds. Our findings take a step towards the actual use of SSDs in real-life situations while potentially impacting rehabilitation of sensory deprived individuals.

scholarly journals Spatiotemporal Characteristics of 360-Degree Basic Attention

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yuki Harada ◽  
Junji Ohyama
Keyword(s):  
Visual Information ◽  
Response Times ◽  
Real Life ◽  
Temporal Variations ◽  
Virtual Reality Technology ◽  
Spatiotemporal Characteristics ◽  
Age Related ◽  
Gaze Patterns ◽  
Position Data ◽  
Measured Response

Abstract The spatiotemporal characteristics of basic attention are important for understanding attending behaviours in real-life situations, and they are useful for evaluating the accessibility of visual information. However, although people are encircled by their 360-degree surroundings in real life, no study has addressed the general characteristics of attention to 360-degree surroundings. Here, we conducted an experiment using virtual reality technology to examine the spatiotemporal characteristics of attention in a highly controlled basic visual context consisting of a 360-degree surrounding. We measured response times and gaze patterns during the 360-degree search task and examined the spatial distribution of attention and its temporal variations in a 360-degree environment based on the participants’ physical position. Data were collected from both younger adults and older adults to consider age-related differences. The results showed the fundamental spatiotemporal characteristics of 360-degree attention, which can be used as basic criteria to analyse the structure of exogenous effects on attention in complex 360-degree surroundings in real-life situations. For practical purposes, we created spherical criteria maps of 360-degree attention, which are useful for estimating attending behaviours to 360-degree environmental information or for evaluating visual information design in living environments, workspaces, or other real-life contexts.

scholarly journals Influence of Planning in Oral Teaching Methods

2019 ◽  
Vol 8 (7) ◽  
pp. 56
Author(s):  
Elena Vladimirovna Litvinenko ◽  
Liliia Saimovna Sirazova ◽  
Jamil Eftim Toptsi
Keyword(s):  
Teaching Methods ◽  
Visual Information ◽  
Planning Process ◽  
Qualitative Content Analysis ◽  
Strong Impact ◽  
Planning Time ◽  
Research Article ◽  
The Impact ◽  
Positive Effect ◽  
Oral Teaching

The mixed methods study presented in this paper investigates the influence of planning in oral teaching methods.. This research article presented examines the impact of planned and unplanned conditions on three different variables in the context of oral teaching methods: fluency, vocabulary complexity, and accuracy. As a research tool two narrative tasks were used which required the participant construct linguistic forms based on visual information, requiring the use of the participant’s imagination. With the help of qualitative content analysis, the most common ‘pattern-finding’ moves were described from the collected data in detail. In order to compare data from unplanned and planned conditions, three analyses were conducted with the help of three software tools: D-tool, P-lex, and Coh-Metrix. The results showed that pre-task planning time had a positive effect on lexical sophistication and accuracy. However, fluency under unplanned conditions was greater than under planned conditions, suggesting that the planning process does not produce a strong impact on fluency. According to most of the participants, they paid close attention to the logical order of the pictures, organization of ideas, and the coherence of their utterance while using their individual planning time.

Assessing audiovisual saliency and visual-information content in the articulation of consonants and vowels on audiovisual temporal perception

2012 ◽  
Vol 25 (0) ◽  
pp. 29
Author(s):  
Argiro Vatakis ◽  
Charles Spence
Keyword(s):  
Visual Information ◽  
Temporal Order ◽  
Temporal Integration ◽  
Visual Speech ◽  
Auditory Signal ◽  
Audiovisual Speech Perception ◽  
Speech Stream ◽  
Point Of Subjective Simultaneity ◽  
Speech Token ◽  
Manner Of Articulation

Research has revealed different temporal integration windows between and within different speech-tokens. The limited speech-tokens tested to date has not allowed for the proper evaluation of whether such differences are task or stimulus driven? We conducted a series of experiments to investigate how the physical differences associated with speech articulation affect the temporal aspects of audiovisual speech perception. Videos of consonants and vowels uttered by three speakers were presented. Participants made temporal order judgments (TOJs) regarding which speech-stream had been presented first. The sensitivity of participants’ TOJs and the point of subjective simultaneity (PSS) were analyzed as a function of the place, manner of articulation, and voicing for consonants, and the height/backness of the tongue and lip-roundedness for vowels. The results demonstrated that for the case of place of articulation/roundedness, participants were more sensitive to the temporal order of highly-salient speech-signals with smaller visual-leads at the PSS. This was not the case when the manner of articulation/height was evaluated. These findings suggest that the visual-speech signal provides substantial cues to the auditory-signal that modulate the relative processing times required for the perception of the speech-stream. A subsequent experiment explored how the presentation of different sources of visual-information modulated such findings. Videos of three consonants were presented under natural and point-light (PL) viewing conditions revealing parts, or the whole, face. Preliminary analysis revealed no differences in TOJ accuracy under different viewing conditions. However, the PSS data revealed significant differences in viewing conditions depending on the speech token uttered (e.g., larger visual-leads for PL-lip/teeth/tongue-only views).

Remote Diagnosis in Dynamic Task Environments

1996 ◽  
Vol 40 (4) ◽  
pp. 218-222 ◽  
Author(s):  
Y. Xiao ◽  
C. F. Mackenzie
Keyword(s):  
Visual Information ◽  
Information Overload ◽  
Real Life ◽  
Remote Diagnosis ◽  
Range Restriction ◽  
Dynamic Task ◽  
Telecommunication Systems ◽  
The Status ◽  
Remote Sites ◽  
Task Environments

Increasingly telecommunication systems have become an integral part of many professions. However, little empirical data and guidelines exist for designing telecommunication systems to facilitate decision makers in cooperative efforts in dynamic task environments. A preliminary experiment was conducted in which the subjects (all experienced in the domain concerned) were presented with video-tapes of previously recorded real-life trauma patient resuscitation. The experiment examined the subjects' ability to understand the status of the patient and resuscitation efforts shown in the video. The experiment was to simulate remote diagnosis tasks in which experts provide consultation through video linkage. The subjects were found to have a number of difficulties in achieving a full understanding. Hypotheses about the reasons that could explain these difficulties are proposed and they include (1) background noise, viewing range restriction, and insecure viewing access to remote sites (2) visual information overload due to the multiple action threads at remote sites (3) lack of adequate dynamic mental models of remote events and activities (4) lack of context information.

scholarly journals Optimization of Visual Information Presentation for Visual Prosthesis

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Fei Guo ◽  
Yuan Yang ◽  
Yong Gao
Keyword(s):  
Object Recognition ◽  
Edge Detection ◽  
Visual Information ◽  
Dynamic Range ◽  
Real Life ◽  
Visual Prosthesis ◽  
Prosthetic Implants ◽  
Processing Strategies ◽  
Background Clutter ◽  
Low Dynamic Range

Visual prosthesis applying electrical stimulation to restore visual function for the blind has promising prospects. However, due to the low resolution, limited visual field, and the low dynamic range of the visual perception, huge loss of information occurred when presenting daily scenes. The ability of object recognition in real-life scenarios is severely restricted for prosthetic users. To overcome the limitations, optimizing the visual information in the simulated prosthetic vision has been the focus of research. This paper proposes two image processing strategies based on a salient object detection technique. The two processing strategies enable the prosthetic implants to focus on the object of interest and suppress the background clutter. Psychophysical experiments show that techniques such as foreground zooming with background clutter removal and foreground edge detection with background reduction have positive impacts on the task of object recognition in simulated prosthetic vision. By using edge detection and zooming technique, the two processing strategies significantly improve the recognition accuracy of objects. We can conclude that the visual prosthesis using our proposed strategy can assist the blind to improve their ability to recognize objects. The results will provide effective solutions for the further development of visual prosthesis.

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