scholarly journals Color Can Shorten Breakthrough Times in Continuous Flash Suppression through Increased Salience and Task Relevance

Vision ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 13
Author(s):  
Christian Valuch
Keyword(s):  
Visual Search ◽  
Response Times ◽  
Top Down ◽  
Interocular Suppression ◽  
Continuous Flash Suppression ◽  
Task Relevance ◽  
Mediated Effects ◽  
Dominant Eye ◽  
Human Participants ◽  
And Task

Color can enhance the perception of relevant stimuli by increasing their salience and guiding visual search towards stimuli that match a task-relevant color. Using Continuous Flash Suppression (CFS), the current study investigated whether color facilitates the discrimination of targets that are difficult to perceive due to interocular suppression. Gabor patterns of two or four cycles per degree (cpd) were shown as targets to the non-dominant eye of human participants. CFS masks were presented at a rate of 10 Hz to the dominant eye, and participants had the task to report the target’s orientation as soon as they could discriminate it. The 2-cpd targets were robustly suppressed and resulted in much longer response times compared to 4-cpd targets. Moreover, only for 2-cpd targets, two color-related effects were evident. First, in trials where targets and CFS masks had different colors, targets were reported faster than in trials where targets and CFS masks had the same color. Second, targets with a known color, either cyan or yellow, were reported earlier than targets whose color was randomly cyan or yellow. The results suggest that the targets’ entry to consciousness may have been speeded by color-mediated effects relating to increased (bottom-up) salience and (top-down) task relevance.

scholarly journals Color Modulates the Timing of Conscious Perception via Bottom-Up and Top-Down Attention

2021 ◽  
Author(s):  
Christian Valuch
Keyword(s):  
High Spatial Frequency ◽  
Human Perception ◽  
Target Color ◽  
Central Feature ◽  
Conscious Perception ◽  
Top Down ◽  
Bottom Up ◽  
Continuous Flash Suppression ◽  
Dominant Eye ◽  
Human Participants

Color can direct visual attention to specific locations through bottom-up and top-down mechanisms. Using Continuous Flash Suppression (CFS) as way to investigate the factors that gate access to consciousness, the current study investigated whether color also directly affected the timing of conscious perception. Low or high spatial frequency (SF) gratings with different orientations were shown as targets to the non-dominant eye of human participants. CFS patterns were presented at a rate of 10Hz to the dominant eye to delay conscious perception of the targets, and participants had the task to report the target’s orientation as soon as they could see it. With low-SF targets, two types of color-based effects became evident. First, when the targets and the CFS patterns had different colors, the targets entered consciousness faster than in trials where the targets and CFS patterns had the same color. Second, when participants searched for a specific target color, targets that matched these search settings entered consciousness faster compared to conditions where the target color was irrelevant and could vary from trial to trial. Thus, the current study demonstrates that color is a central feature of human perception and leads to faster conscious perception of visual stimuli through bottom-up and top-down attentional mechanisms.

scholarly journals Oculomotor capture by stimuli that signal the availability of reward

2015 ◽  
Vol 114 (4) ◽  
pp. 2316-2327 ◽  
Author(s):  
Michel Failing ◽  
Tom Nissens ◽  
Daniel Pearson ◽  
Mike Le Pelley ◽  
Jan Theeuwes
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Early Selection ◽  
Top Down ◽  
Oculomotor Capture ◽  
Task Relevance ◽  
Selection Processes ◽  
High Reward ◽  
Task Irrelevant ◽  
And Task

It is well known that eye movement patterns are influenced by both goal- and salience-driven factors. Recent studies, however, have demonstrated that objects that are nonsalient and task irrelevant can still capture our eyes if moving our eyes to those objects has previously produced reward. Here we demonstrate that training such an association between eye movements to an object and delivery of reward is not needed. Instead, an object that merely signals the availability of reward captures the eyes even when it is physically nonsalient and never relevant for the task. Furthermore, we show that oculomotor capture by reward is more reliably observed in saccades with short latencies. We conclude that a stimulus signaling high reward has the ability to capture the eyes independently of bottom-up physical salience or top-down task relevance and that the effect of reward affects early selection processes.

scholarly journals A paradigm for investigating the effects of top-down processes on visual search

2019 ◽  
Author(s):  
Arnab Biswas ◽  
Devpriya Kumar
Keyword(s):  
Visual Search ◽  
Response Times ◽  
Pairwise Comparison ◽  
Search Performance ◽  
Top Down ◽  
Bottom Up ◽  
Search Tasks ◽  
Selection History ◽  
Significant Difference ◽  
The Difference

Searching for things is an essential part of our everyday life. The way we search gives us clues on how our cognitive processes function. Scientists have used the visual search task to study attention, perception, and memory. Visual search performance depends upon a combination of stimulus-driven, bottom-up information, goal-oriented, top-down information, and selection history bias. It is difficult to separate these factors due to their close interaction. Our current study presents a paradigm to isolate the effects of top-down factors in visual search. In our experiments, we asked subjects to perform two different search tasks. A part of the total trials in each of these tasks had the same bottom-up information. That is, they had the same target, distractor, and target-distractor arrangement. We controlled for selection history bias by having an equivalent proportion of target types for all tasks and randomized the trial-order for each subject. We compared the mean response times for the critical trials, which had identical bottom-up information shared across the two pairs of tasks. The results showed a significant difference in mean response times of critical trials for both our experiments. Thus, this paradigm allows us to compare the difference in top-down guidance when controlling for bottom-up factors. Pairwise comparison of top-down guidance for different features given the same bottom-up information allows us to ask interesting questions such as, “Visual search guidance for which features can or cannot be easily increased by top-down processes?” Answers to these questions can further shed light on the ecological and evolutionary importance of such features in perception.

scholarly journals Visual search behavior and performance in luggage screening: effects of time pressure, automation aid, and target expectancy

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Tobias Rieger ◽  
Lydia Heilmann ◽  
Dietrich Manzey
Keyword(s):  
Visual Search ◽  
Target Location ◽  
Time Pressure ◽  
Response Times ◽  
Search Behavior ◽  
High Time ◽  
Luggage Screening ◽  
Negative Effect ◽  
And Performance ◽  
Automated Support

AbstractVisual inspection of luggage using X-ray technology at airports is a time-sensitive task that is often supported by automated systems to increase performance and reduce workload. The present study evaluated how time pressure and automation support influence visual search behavior and performance in a simulated luggage screening task. Moreover, we also investigated how target expectancy (i.e., targets appearing in a target-often location or not) influenced performance and visual search behavior. We used a paradigm where participants used the mouse to uncover a portion of the screen which allowed us to track how much of the stimulus participants uncovered prior to their decision. Participants were randomly assigned to either a high (5-s time per trial) or a low (10-s time per trial) time-pressure condition. In half of the trials, participants were supported by an automated diagnostic aid (85% reliability) in deciding whether a threat item was present. Moreover, within each half, in target-present trials, targets appeared in a predictable location (i.e., 70% of targets appeared in the same quadrant of the image) to investigate effects of target expectancy. The results revealed better detection performance with low time pressure and faster response times with high time pressure. There was an overall negative effect of automation support because the automation was only moderately reliable. Participants also uncovered a smaller amount of the stimulus under high time pressure in target-absent trials. Target expectancy of target location improved accuracy, speed, and the amount of uncovered space needed for the search.Significance Statement Luggage screening is a safety–critical real-world visual search task which often has to be done under time pressure. The present research found that time pressure compromises performance and increases the risk to miss critical items even with automation support. Moreover, even highly reliable automated support may not improve performance if it does not exceed the manual capabilities of the human screener. Lastly, the present research also showed that heuristic search strategies (e.g., areas where targets appear more often) seem to guide attention also in luggage screening.

Current Task Activation Predicts General Effects of Advance Preparation in Task Switching

2006 ◽  
Vol 53 (4) ◽  
pp. 260-267 ◽  
Author(s):  
Edita Poljac ◽  
Ab de Haan ◽  
Gerard P. van Galen
Keyword(s):  
Task Performance ◽  
Task Switching ◽  
Shape Matching ◽  
Response Times ◽  
Error Rates ◽  
Matching Task ◽  
Task Switch ◽  
Current Task ◽  
Within Subjects ◽  
And Task

Two experiments investigated the way that beforehand preparation influences general task execution in reaction-time matching tasks. Response times (RTs) and error rates were measured for switching and nonswitching conditions in a color- and shape-matching task. The task blocks could repeat (task repetition) or alternate (task switch), and the preparation interval (PI) was manipulated within-subjects (Experiment 1) and between-subjects (Experiment 2). The study illustrated a comparable general task performance after a long PI for both experiments, within and between PI manipulations. After a short PI, however, the general task performance increased significantly for the between-subjects manipulation of the PI. Furthermore, both experiments demonstrated an analogous preparation effect for both task switching and task repetitions. Next, a consistent switch cost throughout the whole run of trials and a within-run slowing effect were observed in both experiments. Altogether, the present study implies that the effects of the advance preparation go beyond the first trials and confirms different points of the activation approach ( Altmann, 2002) to task switching.

scholarly journals Visual Search Bottom-Up or Top-Down

10.2741/a503 ◽  
2000 ◽  
Vol 5 (3) ◽  
pp. d169-193 ◽  
Author(s):  
K. Sathian
Keyword(s):  
Visual Search ◽  
Top Down ◽  
Bottom Up
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