1,721,011 research outputs found
Age-dependent changes in the anger superiority effect: Evidence from a visual search task
Full text linkThe perception of threatening facial expressions is a critical skill necessary for detecting the emotional states of others and responding appropriately. The anger superiority effect hypothesis suggests that individuals are better at processing and identifying angry faces compared with other nonthreatening facial expressions. In adults, the anger superiority effect is present even after controlling for the bottom-up visual saliency, and when ecologically valid stimuli are used. However, it is as yet unclear whether this effect is present in children. To fill this gap, we tested the anger superiority effect in children ages 6–14 years in a visual search task by using emotional dynamic stimuli and equating the visual salience of target and distractors. The results suggest that in childhood, the angry superiority effect consists of improved accuracy in detecting angry faces, while in adolescence, the ability to discriminate angry faces undergoes further development, enabling faster and more accurate threat detection
Binocular vision with null disparity disrupts the effects of extra-retinal signals
No full textWe studied a novel phenomenon indicating that the integration of extra-retinal information and the optic flow is a necessary but not sufficient condition for slant constancy during active head motion; congruency between monocular and binocular cues to depth is also required.
In two experiments, we measured observers' performance in a rotation-detection task during active vision. Two viewing conditions were compared: binocular vision with null disparity (same image projected to the two eyes) and monocular vision. Static or rotating slanted planar surfaces were simulated with 90/270-deg tilt (Experiment 1) and 0/180-deg tilt (Experiment 2). Observers produced oscillatory lateral head movements which were recorded by an Optotrack Certus system. The position of random dots on a CRT monitor were updated in real time, simulating the correct projection of a random-dot planar surface on the image screen by taking into account the head position of the observer and the rotation of the surface.
Full perceptual constancy was found for simulated stationary surfaces under monocular vision, but not under binocular vision with null disparity. A stationary surface appeared to be stationary when it was viewed monocularly; however, it appeared to be rotating when it was viewed binoculary with null disparity. Moreover, in both experiments, rotation sensitivity was larger for monocular than for binocular vision. Response bias was shifted in opposite directions, with an overall tendency to judge surfaces as being stationary in monocular vs. rotating in binocular vision.
Monocular vision supports full slant constancy. Binocular vision with null disparity (1) disrupts the effect of extra-retinal signals produced by head movement, and (2) induces the perception of an apparent rotation counter to the heading direction
Reaching movement accuracy is mainly determined by visual online control
No full textHere we demonstrate that the accuracy of reaching a target is affected by neither the representation of the target location nor the visual feedback provided up to 250ms before movement completion. Observers performed reach-to-point movements for a real cylinder positioned at variable locations. We manipulated the visual information (monocular/binocular) provided in two contiguous segments. Main segment: trajectory from the movement start up to 250 ms before movement completion. Final segment: trajectory during the final 250 ms to reach the target. The accuracy of the end position (z-depth) of the reaching movement was measured. We found reliable effects of visual information sampled during the final segment, but not during the main segment. Reaching was accurate if disparity information was provided throughout the whole movement or only in the last 250 ms segment. Overshooting of 1 cm was found when disparity information was absent during the whole movement or in the last 250 ms segment. The latter is surprising, as the target appeared binocular for most of the movement duration allowing for ample time to plan the movement-end. Thus, accuracy in reaching performance can be explained by nulling the relative disparity between the finger and the target. Our results indicate the importance of the online component of visual-motor control
Obsessive-compulsive symptoms and dimensional models of psychopathology: The contribution of “not just right experiences”
Full text linkDimensional models provide a framework for characterizing psychopathology and personality disorders based on lower-order maladaptive traits, typically organized into five overarching domains: Negative Affect or Internalizing, Detachment, Antagonism, Disinhibition, and Psychoticism or Thought Disorder. Within the context of these dimensional models, the classification of Obsessive-Compulsive (OC) symptoms has raised questions, as they are often placed within the Negative Affect/Internalizing or Psychoticism/Thought Disorder domains. The discrepancy in their categorization may be attributed to the diversity in how these symptoms manifest. An alternative perspective involves the adoption of a measure associated with a vulnerability factor for OCD, which may transcend the specific symptoms of the disorder. In this study, our objective was to explore the association between 'Not Just Right Experiences' (NJREs) and the dimensions specified in the DSM-5 Alternative Model of Personality Disorders (AMPD). We utilized two distinct samples, one consisting of 978 participants and the other comprising 1004, all of whom were non-clinical individuals. Through a series of exploratory factor analyses conducted on the initial sample, we uncovered a hierarchical structure of general psychopathology. Within this structure, NJREs were situated within the AMPD's Psychoticism domain. Furthermore, the Psychoticism domain exhibited a strong and unique association with all OC symptoms, surpassing the influence of other AMPD components. A structural equation model applied to the second sample validated these findings, indicating that both the Psychoticism and Negative Affect played significant roles in explaining a substantial portion of the variance observed in NJRE measures. These outcomes have pertinent clinical implications, particularly in the context of Cognitive-Behavioral Therapy for individuals with OCD
Systematic distortions of perceived planar surface motion in active vision
No full textRecent studies suggest that the active observer combines optic flow information with extra-retinal signals resulting from head motion. Such a combination allows, in principle, a correct discrimination of the presence or absence of surface rotation. In Experiments 1 and 2, observers were asked to perform such discrimination task while performing a lateral head shift. In Experiment 3, observers were shown the optic flow generated by their own movement with respect to a stationary planar slanted surface and were asked to classify perceived surface rotation as being small or large. We found that the perception of surface motion was systematically biased. We found that, in active, as well as in passive vision, perceived surface rotation was affected by the deformation component of the first-order optic flow, regardless of the actual surface rotation. We also found that the addition of a null disparity field increased the likelihood of perceiving surface rotation in active, but not in passive vision. Both these results suggest that vestibular information, provided by active vision, is not sufficient for veridical 3D shape and motion recovery from the optic flow
Integration of stereo-motion information for guiding calibrated reach-to-grasp movements
No full textOne frequently reported result is that, for perceptual tasks, the amount of perceived depth is larger when motion and disparity cues are presented together than when only one of these depth cues is shown at a time. It is not known whether this increase of perceived depth in the combined condition is also found when depth estimation is aided by action. The action of reaching-to-grasp might provide additional information about the depth of target objects, thus further disambiguating the estimation of 3D depth from projected images.
We tested this through an experiment investigating the problem of integration of motion and stereoscopic depth information for two manual depth estimation tasks: one based in perception [depth estimated through fingers adjustments], and one in action [depth estimated through reach-to-grasp]. In both tasks, observers viewed a display composed of three vertical lines embedded in a cloud of random dots; two flanking lines were positioned at fixation distance with the third line midway between the two located in depth (in front of the flankers). Observers estimated five different levels of depth separation between the flankers and the central line. 3D information was provided either by binocular disparities (stereo only), image velocities (motion only) or both (stereo-motion). Haptic feedback was provided in one fourth of the trials to calibrate depth estimates and ensure that normal visual-open-loop prehension occurred even in trials lacking haptic feedback (Bingham, Coats, Mon-Williams 2007).
The results show that in the combined condition, observers perceived a larger amount of estimated depth with both the perception and action tasks
Non-informative components of retinal and extra-retinal signals affect perceived surface orientation from optic flow
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