scholarly journals Attention expedites target selection by prioritizing the neural processing of distractor features

2020 ◽  
Author(s):  
Mandy V. Bartsch ◽  
Christian Merkel ◽  
Mircea A. Schoenfeld ◽  
Jens-Max Hopf
Keyword(s):  
Daily Life ◽  
Target Identification ◽  
Target Selection ◽  
Target Color ◽  
Neural Processing ◽  
Brain Response ◽  
Feature Representations ◽  
Feature Attention ◽  
Human Participants ◽  
Neural Gain

AbstractWhether doing the shopping, or driving the car – to navigate daily life, our brain has to rapidly identify relevant color signals among distracting ones. Despite a wealth of research, how color attention is dynamically adjusted is little understood. Previous studies suggest that the speed of feature attention depends on the time it takes to enhance the neural gain of cortical units tuned to the attended feature. To test this idea, we had human participants switch their attention on the fly between unpredicted target color alternatives, while recording the electroencephalographic brain response to probes matching the target, a non-target, or a distracting alternative target color. Paradoxically, we observed a temporally prioritized processing of distractor colors. A larger neural gain for the distractor followed by stronger attenuation expedited target identification. Our results suggest that dynamic adjustments of feature attention involve the temporally prioritized processing and elimination of distracting feature representations.

scholarly journals Attention expedites target selection by prioritizing the neural processing of distractor features

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mandy V. Bartsch ◽  
Christian Merkel ◽  
Mircea A. Schoenfeld ◽  
Jens-Max Hopf
Keyword(s):  
Target Identification ◽  
Target Selection ◽  
Target Color ◽  
Neural Processing ◽  
Brain Response ◽  
Feature Representations ◽  
Neural Modulation ◽  
Feature Attention ◽  
Human Participants ◽  
Neural Gain

AbstractWhether doing the shopping, or driving the car – to navigate daily life, our brain has to rapidly identify relevant color signals among distracting ones. Despite a wealth of research, how color attention is dynamically adjusted is little understood. Previous studies suggest that the speed of feature attention depends on the time it takes to enhance the neural gain of cortical units tuned to the attended feature. To test this idea, we had human participants switch their attention on the fly between unpredicted target color alternatives, while recording the electromagnetic brain response to probes matching the target, a non-target, or a distracting alternative target color. Paradoxically, we observed a temporally prioritized processing of distractor colors. A larger neural modulation for the distractor followed by its stronger attenuation expedited target identification. Our results suggest that dynamic adjustments of feature attention involve the temporally prioritized processing and elimination of distracting feature representations.

scholarly journals Dissociating Reward- and Attention-driven Biasing of Global Feature-based Selection in Human Visual Cortex

2019 ◽  
Vol 31 (4) ◽  
pp. 469-481 ◽  
Author(s):  
Haydee G. Garcia-Lazaro ◽  
Mandy V. Bartsch ◽  
Carsten N. Boehler ◽  
Ruth M. Krebs ◽  
Sarah E. Donohue ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Target Selection ◽  
Target Color ◽  
Selective Area ◽  
Early Visual Cortex ◽  
Feature Based ◽  
Irrelevant Color ◽  
Task Irrelevant ◽  
Open Question ◽  
Attention Demands

Objects that promise rewards are prioritized for visual selection. The way this prioritization shapes sensory processing in visual cortex, however, is debated. It has been suggested that rewards motivate stronger attentional focusing, resulting in a modulation of sensory selection in early visual cortex. An open question is whether those reward-driven modulations would be independent of similar modulations indexing the selection of attended features that are not associated with reward. Here, we use magnetoencephalography in human observers to investigate whether the modulations indexing global color-based selection in visual cortex are separable for target- and (monetary) reward-defining colors. To assess the underlying global color-based activity modulation, we compare the event-related magnetic field response elicited by a color probe in the unattended hemifield drawn either in the target color, the reward color, both colors, or a neutral task-irrelevant color. To test whether target and reward relevance trigger separable modulations, we manipulate attention demands on target selection while keeping reward-defining experimental parameters constant. Replicating previous observations, we find that reward and target relevance produce almost indistinguishable gain modulations in ventral extratriate cortex contralateral to the unattended color probe. Importantly, increasing attention demands on target discrimination increases the response to the target-defining color, whereas the response to the rewarded color remains largely unchanged. These observations indicate that, although task relevance and reward influence the very same feature-selective area in extrastriate visual cortex, the associated modulations are largely independent.

scholarly journals Offline Signature Identification and Verification Based on Capsule Representations

2020 ◽  
Vol 20 (5) ◽  
pp. 60-67
Author(s):  
Dilara Gumusbas ◽  
Tulay Yildirim
Keyword(s):  
Feature Extraction ◽  
Daily Life ◽  
Extraction Methods ◽  
Signature Verification ◽  
Verification Task ◽  
Feature Representations ◽  
Automatic Feature Extraction ◽  
Offline Signature Verification ◽  
Orientation Information ◽  
Trained Network

AbstractOffline signature is one of the frequently used biometric traits in daily life and yet skilled forgeries are posing a great challenge for offline signature verification. To differentiate forgeries, a variety of research has been conducted on hand-crafted feature extraction methods until now. However, these methods have recently been set aside for automatic feature extraction methods such as Convolutional Neural Networks (CNN). Although these CNN-based algorithms often achieve satisfying results, they require either many samples in training or pre-trained network weights. Recently, Capsule Network has been proposed to model with fewer data by using the advantage of convolutional layers for automatic feature extraction. Moreover, feature representations are obtained as vectors instead of scalar activation values in CNN to keep orientation information. Since signature samples per user are limited and feature orientations in signature samples are highly informative, this paper first aims to evaluate the capability of Capsule Network for signature identification tasks on three benchmark databases. Capsule Network achieves 97 96, 94 89, 95 and 91% accuracy on CEDAR, GPDS-100 and MCYT databases for 64×64 and 32×32 resolutions, which are lower than usual, respectively. The second aim of the paper is to generalize the capability of Capsule Network concerning the verification task. Capsule Network achieves average 91, 86, and 89% accuracy on CEDAR, GPDS-100 and MCYT databases for 64×64 resolutions, respectively. Through this evaluation, the capability of Capsule Network is shown for offline verification and identification tasks.

Coordination of Smooth Pursuit and Saccade Target Selection in Monkeys

2007 ◽  
Vol 98 (4) ◽  
pp. 2206-2214 ◽  
Author(s):  
Gilbert R. Case ◽  
Vincent P. Ferrera
Keyword(s):  
Smooth Pursuit ◽  
Target Selection ◽  
Saccade Target ◽  
Target Color ◽  
Smooth Pursuit Eye Movements ◽  
Moving Targets ◽  
Neural Signals ◽  
Pursuit Eye Movements ◽  
Selection For ◽  
Selection Signal

The coordination of saccadic and smooth pursuit eye movements in macaque monkeys was investigated using a target selection paradigm with two moving targets crossing at a center fixation point. A task in which monkeys selected a target based on its color was used to test the hypothesis that common neural signals underlie target selection for pursuit and saccades, as well as testing whether target selection signals are available to the saccade and pursuit systems simultaneously or sequentially. Several combinations of target color, speed, and direction were used. In all cases, smooth pursuit was highly selective for the rewarded target before any saccade occurred. On >80% of the trials, the saccade was directed toward the same target as both pre- and postsaccadic pursuit. The results favor a model in which a shared target selection signal is simultaneously available to both the saccade and pursuit systems, rather than a sequential model.

scholarly journals Exploration of target spaces in the human genome for protein and peptide drugs

2020 ◽  
Author(s):  
Zhongyang Liu ◽  
Honglei Li ◽  
Zhaoyu Jin ◽  
Yang Li ◽  
Feifei Guo ◽  
...  
Keyword(s):  
Human Genome ◽  
Small Molecule ◽  
Target Identification ◽  
Target Selection ◽  
Target Space ◽  
Peptide Drugs ◽  
Small Molecule Drugs ◽  
Genome Wide ◽  
Systematic Exploration ◽  
History Of

AbstractMotivationProtein and peptide drugs, after decades of development have grown into a major drug class of the marketplace. Target identification and validation is crucial for their discovery, and bioinformatics estimation of candidate targets based on characteristics of successful target proteins will help improve efficiency and success rate of target selection. However, owing to the development history of the pharmaceutical industry, previous systematic exploration of target space mainly focused on traditional small-molecule drugs, whereas that for protein and peptide drugs is blank. Here we systematically explored target spaces in the human genome specially for protein and peptide drugs.ResultsWe found that compared with other proteins, targets of both successful protein and peptide drugs have their own characteristics in many aspects and are also significantly different from those of traditional small-molecule drugs. Further based on these features, we developed effective genome-wide target estimation models respectively for protein and peptide drugs.

scholarly journals Visual Working Memory Load Disrupts Template-guided Attentional Selection during Visual Search

2018 ◽  
Vol 30 (12) ◽  
pp. 1902-1915 ◽  
Author(s):  
Nick Berggren ◽  
Martin Eimer
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Visual Working Memory ◽  
Memory Load ◽  
Target Selection ◽  
Target Color ◽  
Control Mechanisms ◽  
Single Feature ◽  
Single Target ◽  
Candidate Target

Mental representations of target features (attentional templates) control the selection of candidate target objects in visual search. The question where templates are maintained remains controversial. We employed the N2pc component as an electrophysiological marker of template-guided target selection to investigate whether and under which conditions templates are held in visual working memory (vWM). In two experiments, participants memorized one or four shapes (low vs. high vWM load) before either being tested on their memory or performing a visual search task. When targets were defined by one of two possible colors (e.g., red or green), target N2pcs were delayed with high vWM load. This suggests that the maintenance of multiple shapes in vWM interfered with the activation of color-specific search templates, supporting the hypothesis that these templates are held in vWM. This was the case despite participants always searching for the same two target colors. In contrast, the speed of target selection in a task where a single target color remained relevant throughout was unaffected by concurrent load, indicating that a constant search template for a single feature may be maintained outside vWM in a different store. In addition, early visual N1 components to search and memory test displays were attenuated under high load, suggesting a competition between external and internal attention. The size of this attenuation predicted individual vWM performance. These results provide new electrophysiological evidence for impairment of top–down attentional control mechanisms by high vWM load, demonstrating that vWM is involved in the guidance of attentional target selection during search.

scholarly journals Face processing in adolescents with positive and negative threat bias

2016 ◽  
Vol 47 (5) ◽  
pp. 800-809 ◽  
Author(s):  
C. M. Sylvester ◽  
S. E. Petersen ◽  
J. L. Luby ◽  
D. M. Barch
Keyword(s):  
Anxiety Disorders ◽  
Neural Mechanisms ◽  
Lower Activity ◽  
Prior History ◽  
Neural Processing ◽  
Brain Response ◽  
Threat Bias ◽  
Novel Treatments ◽  
Fearful Faces ◽  
Threat Avoidance

BackgroundIndividuals with anxiety disorders exhibit a ‘vigilance-avoidance’ pattern of attention to threatening stimuli when threatening and neutral stimuli are presented simultaneously, a phenomenon referred to as ‘threat bias’. Modifying threat bias through cognitive retraining during adolescence reduces symptoms of anxiety, and so elucidating neural mechanisms of threat bias during adolescence is of high importance. We explored neural mechanisms by testing whether threat bias in adolescents is associated with generalized or threat-specific differences in the neural processing of faces.MethodSubjects were categorized into those with (n = 25) and without (n = 27) threat avoidance based on a dot-probe task at average age 12.9 years. Threat avoidance in this cohort has previously been shown to index threat bias. Brain response to individually presented angry and neutral faces was assessed in a separate session using functional magnetic resonance imaging.ResultsAdolescents with threat avoidance exhibited lower activity for both angry and neutral faces relative to controls in several regions in the occipital, parietal, and temporal lobes involved in early visual and facial processing. Results generalized to happy, sad, and fearful faces. Adolescents with a prior history of depression and/or an anxiety disorder had lower activity for all faces in these same regions. A subset of results replicated in an independent dataset.ConclusionsThreat bias is associated with generalized, rather than threat-specific, differences in the neural processing of faces in adolescents. Findings may aid in the development of novel treatments for anxiety disorders that use attention training to modify threat bias.

scholarly journals The druggable genome and support for target identification and validation in drug development

2016 ◽  
Author(s):  
Chris Finan ◽  
Anna Gaulton ◽  
Felix Kruger ◽  
Tom Lumbers ◽  
Tina Shah ◽  
...  
Keyword(s):  
Drug Development ◽  
Drug Target ◽  
Complex Disease ◽  
Target Identification ◽  
Association Studies ◽  
Target Selection ◽  
Genome Wide Association ◽  
Genome Wide Association Studies ◽  
Genome Wide ◽  
Druggable Genome

Target identification (identifying the correct drug targets for each disease) and target validation (demonstrating the effect of target perturbation on disease biomarkers and disease end-points) are essential steps in drug development. We showed previously that biomarker and disease endpoint associations of single nucleotide polymorphisms (SNPs) in a gene encoding a drug target accurately depict the effect of modifying the same target with a pharmacological agent; others have shown that genomic support for a target is associated with a higher rate of drug development success. To delineate drug development (including repurposing) opportunities arising from this paradigm, we connected complex disease- and biomarker-associated loci from genome wide association studies (GWAS) to an updated set of genes encoding druggable human proteins, to compounds with bioactivity against these targets and, where these were licensed drugs, to clinical indications. We used this set of genes to inform the design of a new genotyping array, to enable druggable genome-wide association studies for drug target selection and validation in human disease.

Color Recognition of Video Object Based on HSV Model

2011 ◽  
Vol 143-144 ◽  
pp. 721-725
Author(s):  
Zhao Quan Cai ◽  
Wei Luo ◽  
Zhong Nan Ren ◽  
Han Huang
Keyword(s):  
Real Time ◽  
Moving Objects ◽  
Target Identification ◽  
Target Color ◽  
Video Object ◽  
Color Recognition ◽  
Video Images ◽  
Object Based ◽  
Color Identification ◽  
Color Judgment

In the presented paper, we proposed a common color model and designed the color judgment method, which is based on the HSV model. This method will translate the RGB values of the points in video images to HSV values, and use HSV values to recognize the color. After that, software of real-time video object recognition was developed based on color features, which is also based on their search of target color identification. Besides, the system is developed by VC based on OpenCV, which has achieved the goal of real-time video motion detection and object color recognition. Finally, the experimental results indicate that the algorithm is accurate and similar to human recognition of the moving objects in videos view, which demonstrates the good performance of the target identification and color judgment.

scholarly journals Aberrant brain response after auditory deviance in PTSD compared to trauma controls: An EEG study

2017 ◽  
Author(s):  
Katrin A. Bangel ◽  
Susanne van Buschbach ◽  
Dirk J.A. Smit ◽  
Ali Mazaheri ◽  
Miranda Olff
Keyword(s):  
Spatial Working Memory ◽  
Detection System ◽  
Memory Performance ◽  
Auditory Memory ◽  
Post Traumatic Stress ◽  
Brain Response ◽  
Feature Representations ◽  
Sensory Change ◽  
Post Traumatic ◽  
The Brain

AbstractPart of the symptomatology of post-traumatic stress disorder (PTSD) are alterations in arousal and reactivity which could be related to a maladaptive increase in the automated sensory change detection system of the brain. In the current EEG study we investigated whether the brain’s response to a simple auditory sensory change was altered in patients with PTSD relative to trauma-exposed matched controls who did not develop the disorder. Thirteen male PTSD patients and trauma-exposed controls matched for age and educational level were presented regular auditory pure tones (1000 Hz, 200 ms duration), with 11% of the tones deviating in both duration (50 ms) and frequency (1200 Hz) while watching a silent movie. Relative to the controls, patients who had developed PTSD showed enhanced mismatch negativity (MMN), increased theta power (5-7 Hz), and stronger suppression of upper alpha activity (13-15 Hz) after deviant vs. standard tones. Behaviourally, the alpha suppression in PTSD correlated with decreased spatial working memory performance suggesting it might reflect enhanced stimulus-feature representations in auditory memory. These results taken together suggest that PTSD patients and trauma-exposed controls can be distinguished by enhanced involuntary attention to changes in sensory patterns.

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