scholarly journals The time course of salience: not entirely caused by salience

2021 ◽  
Author(s):  
Alexander Krüger ◽  
Ingrid Scharlau
Keyword(s):  
Processing Speed ◽  
Visual Processing ◽  
Time Course ◽  
Formal Theory ◽  
Attentional Selection ◽  
Experimental Designs ◽  
Processing Capacity ◽  
Visual Salience ◽  
Selection Mechanism ◽  
Scarce Resources

AbstractVisual salience is a key component of attentional selection, the process that guards the scarce resources needed for conscious recognition and perception. In previous works, we proposed a measure of visual salience based on a formal theory of visual selection. However, the strength of visual salience depends on the time course as well as local physical contrasts. Evidence from multiple experimental designs in the literature suggests that the strength of salience rises initially and declines after approximately 150 ms. The present article amends the theory-based salience measure beyond local physical contrasts to the time course of salience. It does so through a first experiment which reveals that—contrary to expectations—salience is not reduced during the first 150 ms after onset. Instead, the overall visual processing capacity is severely reduced, which corresponds to a reduced processing speed of all stimuli in the visual field. A second experiment confirms this conclusion by replicating the result. We argue that the slower stimulus processing may have been overlooked previously because the attentional selection mechanism had not yet been modeled in studies on the time course of salience.

scholarly journals Target tracking reveals the time course of visual processing with millisecond-scale precision

2020 ◽  
Author(s):  
Johannes Burge ◽  
Lawrence K. Cormack
Keyword(s):  
Target Tracking ◽  
Processing Speed ◽  
Visual Processing ◽  
Time Course ◽  
Predictive Power ◽  
Moving Objects ◽  
Analytical Techniques ◽  
Movement Dynamics ◽  
Time Required ◽  
Processing Differences

AbstractImage differences between the eyes can cause millisecond-scale interocular differences in processing speed. For moving objects, these differences can cause dramatic misperceptions of distance and 3D direction. Here, we develop a continuous target-tracking paradigm that shows these tiny differences in the speed of visual processing are preserved in the movement dynamics of the hand. Human observers continuously tracked a target stimulus with various luminance differences across the eyes as it underwent Brownian motion in the horizontal plane. We show that suitable analysis recovers the time course of the visuomotor response, and comparisons across luminance conditions reveal the temporal evolution of visual processing differences between the eyes. Additionally, using a direct within-observer comparison, we show that target tracking and traditional psychophysics provide scalar estimates of interocular delays that agree on average to within a fraction of a millisecond. Thus, target tracking accurately recovers millisecond-scale differences in processing speed while revealing the millisecond-by-millisecond time course of visual processing, all in a fraction of the time required by traditional methods. This paradigm provides the potential for new predictive power, the application of analytical techniques from computational neuroscience, and the rapid measurement of clinical and developmental populations in which traditional psychophysics might be impractical.

Computing with Self-Excitatory Cliques: A Model and an Application to Hyperacuity-Scale Computation in Visual Cortex

1999 ◽  
Vol 11 (1) ◽  
pp. 21-66 ◽  
Author(s):  
Douglas A. Miller ◽  
Steven W. Zucker
Keyword(s):  
Visual Processing ◽  
Network Architecture ◽  
Early Stage ◽  
Cortical Cell ◽  
Pyramidal Cells ◽  
Direct Calculation ◽  
Formal Theory ◽  
Cortical Cells ◽  
Cell Counts ◽  
Spatiotemporal Response

We present a model of visual computation based on tightly inter-connected cliques of pyramidal cells. It leads to a formal theory of cell assemblies, a specific relationship between correlated firing patterns and abstract functionality, and a direct calculation relating estimates of cortical cell counts to orientation hyperacuity. Our network architecture is unique in that (1) it supports a mode of computation that is both reliable and efficent; (2) the current-spike relations are modeled as an analog dynamical system in which the requisite computations can take place on the time scale required for an early stage of visual processing; and (3) the dynamics are triggered by the spatiotemporal response of cortical cells. This final point could explain why moving stimuli improve vernier sensitivity.

scholarly journals The Rapid Extraction of Gist—Early Neural Correlates of High-level Visual Processing

2012 ◽  
Vol 24 (2) ◽  
pp. 521-529 ◽  
Author(s):  
Frank Oppermann ◽  
Uwe Hassler ◽  
Jörg D. Jescheniak ◽  
Thomas Gruber
Keyword(s):  
Visual Processing ◽  
Time Course ◽  
Occipital Cortex ◽  
Stimulus Onset ◽  
Gamma Band ◽  
Oscillatory Activity ◽  
Rapid Extraction ◽  
The Right ◽  
High Level ◽  
Individual Objects

The human cognitive system is highly efficient in extracting information from our visual environment. This efficiency is based on acquired knowledge that guides our attention toward relevant events and promotes the recognition of individual objects as they appear in visual scenes. The experience-based representation of such knowledge contains not only information about the individual objects but also about relations between them, such as the typical context in which individual objects co-occur. The present EEG study aimed at exploring the availability of such relational knowledge in the time course of visual scene processing, using oscillatory evoked gamma-band responses as a neural correlate for a currently activated cortical stimulus representation. Participants decided whether two simultaneously presented objects were conceptually coherent (e.g., mouse–cheese) or not (e.g., crown–mushroom). We obtained increased evoked gamma-band responses for coherent scenes compared with incoherent scenes beginning as early as 70 msec after stimulus onset within a distributed cortical network, including the right temporal, the right frontal, and the bilateral occipital cortex. This finding provides empirical evidence for the functional importance of evoked oscillatory activity in high-level vision beyond the visual cortex and, thus, gives new insights into the functional relevance of neuronal interactions. It also indicates the very early availability of experience-based knowledge that might be regarded as a fundamental mechanism for the rapid extraction of the gist of a scene.

Visual attention in adults with attention-deficit/hyperactivity disorder before and after stimulant treatment

2018 ◽  
Vol 49 (15) ◽  
pp. 2617-2625 ◽  
Author(s):  
Ann-Marie Low ◽  
Signe Vangkilde ◽  
Julijana le Sommer ◽  
Birgitte Fagerlund ◽  
Birte Glenthøj ◽  
...  
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Visual Attention ◽  
Attention Deficit ◽  
Processing Speed ◽  
Visual Processing ◽  
Stimulant Medication ◽  
Hyperactivity Disorder ◽  
Visual Processing Speed ◽  
Adhd Symptomatology

AbstractBackgroundAttention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder which frequently persists into adulthood. The primary goal of the current study was to (a) investigate attentional functions of stimulant medication-naïve adults with ADHD, and (b) investigate the effects of 6 weeks of methylphenidate treatment on these functions.MethodsThe study was a prospective, non-randomized, non-blinded, 6-week follow-up design with 42 stimulant medication-naïve adult patients with ADHD, and 42 age and parental education-matched healthy controls. Assessments included measures of visual attention, based on Bundesen's Theory of Visual Attention (TVA), which yields five precise measures of aspects of visual attention; general psychopathology; ADHD symptoms; dyslexia screening; and estimates of IQ.ResultsAt baseline, significant differences were found between patients and controls on three attentional parameters: visual short-term memory capacity, threshold of conscious perception, and to a lesser extent visual processing speed. Secondary analyses revealed no significant correlations between TVA parameter estimates and severity of ADHD symptomatology. At follow-up, significant improvements were found specifically for visual processing speed; this improvement had a large effect size, and remained when controlling for re-test effects, IQ, and dyslexia screen performance. There were no significant correlations between changes in visual processing speed and changes in ADHD symptomatology.ConclusionsADHD in adults may be associated with deficits in three distinct aspects of visual attention. Improvements after 6 weeks of medication are seen specifically in visual processing speed, which could represent an improvement in alertness. Clinical symptoms and visual attentional deficits may represent separate aspects of ADHD in adults.

Reduced information processing speed as primum movens for cognitive decline in MS

2014 ◽  
Vol 21 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Jeroen Van Schependom ◽  
Marie B D’hooghe ◽  
Krista Cleynhens ◽  
Mieke D’hooge ◽  
Marie-Claire Haelewyck ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Information Processing ◽  
Processing Speed ◽  
Time Course ◽  
Age At Onset ◽  
Memory Task ◽  
Cognitive Domain ◽  
Information Processing Speed ◽  
Survival Curves ◽  
Cross Sectional

Background: Cognitive impairment affects half of the multiple sclerosis (MS) patient population and is an important contributor to patients’ daily activities. Most cognitive impairment studies in MS are, however, cross-sectional or/and focused on the early disease stages. Objective: We aim to assess the time course of decline of different cognitive domains. Methods: We collected neuropsychological data on 514 MS patients to construct Kaplan-Meier survival curves of the tests included in the Neuropsychological Screening Battery for MS (NSBMS) and the Symbol Digit Modalities Test (SDMT). Cox-proportional hazard models were constructed to examine the influence of MS onset type, age at onset, gender, depression and level of education on the time course, expressed as age or disease. Results: Survival curves of tests focusing on information processing speed (IPS) declined significantly faster than tests with less specific demands of IPS. Median age for pathological decline was 56.2 years (95% CI: 54.4–58.2) on the SDMT and 63.9 years (95% CI: 60–66.9) on the CLTR, a memory task. Conclusion: In conclusion, IPS is the cognitive domain not only most widely affected by MS but it is also the first cognitive deficit to emerge in MS.

scholarly journals The Four- vs. Alternative Six-Factor Structure of the French WISC-IV

2010 ◽  
Vol 69 (4) ◽  
pp. 221-232 ◽  
Author(s):  
Thierry Lecerf ◽  
Jérôme Rossier ◽  
Nicolas Favez ◽  
Isabelle Reverte ◽  
Laurence Coleaux
Keyword(s):  
Processing Speed ◽  
Visual Processing ◽  
Fluid Intelligence ◽  
Short Term Memory ◽  
Chc Theory ◽  
Confirmatory Factor Analyses ◽  
Model Based ◽  
Technical Manual ◽  
Confirmatory Factor ◽  
Perceptual Reasoning

Exploratory and confirmatory factor analyses reported in the French technical manual of the WISC-IV provides evidence supporting a structure with four indices: Verbal Comprehension (VCI), Perceptual Reasoning (PRI), Working Memory (WMI), and Processing Speed (PSI). Although the WISC-IV is more attuned to contemporary theory, it is still not in total accordance with the dominant theory: the Cattell-Horn-Carroll (CHC) theory of cognitive ability. This study was designed to determine whether the French WISC-IV is better described with the four-factor solution or whether an alternative model based on the CHC theory is more appropriate. The intercorrelations matrix reported in the French technical manual was submitted to confirmatory factor analysis. A comparison of competing models suggests that a model based on the CHC theory fits the data better than the current WISC-IV structure. It appears that the French WISC-IV in fact measures six factors: crystallized intelligence (Gc), fluid intelligence (Gf), short-term memory (Gsm), processing speed (Gs), quantitative knowledge (Gq), and visual processing (Gv). We recommend that clinicians interpret the subtests of the French WISC-IV in relation to this CHC model in addition to the four indices.

Dissociating early and late visual processing via the Ebbinghaus illusion

2016 ◽  
Vol 33 ◽  
Author(s):  
FILIPP SCHMIDT ◽  
ANDREAS WEBER ◽  
ANKE HABERKAMP
Keyword(s):  
Visual Processing ◽  
High Frequency ◽  
Time Course ◽  
Temporal Dynamics ◽  
Low Frequency ◽  
Response Speed ◽  
Ebbinghaus Illusion ◽  
Priming Effects ◽  
Parvocellular Pathway ◽  
The Difference

AbstractVisual perception is not instantaneous; the perceptual representation of our environment builds up over time. This can strongly affect our responses to visual stimuli. Here, we study the temporal dynamics of visual processing by analyzing the time course of priming effects induced by the well-known Ebbinghaus illusion. In slower responses, Ebbinghaus primes produce effects in accordance with their perceptual appearance. However, in fast responses, these effects are reversed. We argue that this dissociation originates from the difference between early feedforward-mediated gist of the scene processing and later feedback-mediated more elaborate processing. Indeed, our findings are well explained by the differences between low-frequency representations mediated by the fast magnocellular pathway and high-frequency representations mediated by the slower parvocellular pathway. Our results demonstrate the potentially dramatic effect of response speed on the perception of visual illusions specifically and on our actions in response to objects in our visual environment generally.

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