Side Of Visual Field Research Articles

Attentional and perceptual asymmetries in an immersive decision-making task.

Pseudoneglect represents the tendency in healthy people to show a slight bias in favour of stimuli appearing in the left visual field. Some studies have shown that this leftward bias can be annulled or reserved towards a rightward bisection bias when lateral attentional biases are assessed in far space. Using an immersive simulated, ecologically valid football task, we investigated whether possible attentional and perceptual asymmetries affect sport-specific decision making. Twenty-seven sport athletes were required to judge different game situations, which involved both perceptual and attentional skills to perceive player configurations in the visual periphery. We did not find any performance differences in accuracy rate between the left and right visual field side for stimuli presented close to the screen centre in an object-detection (perception-based) and feature-recognition (attention-based) task. This result is in line with previous findings showing an absence of a left- or rightward bisection bias in far space. However, accuracy was higher for stimuli being presented at visual angles wide away from the screen centre at the left side compared to the right side of visual field. This finding cannot be explained by literature focusing on pseudoneglect in far space, but rather by previous findings on landmark judgments often showing left bias both in near and in far space. Overall, the current findings provide new perspectives on attentional and perceptual asymmetries in real-world scenarios, and different interpretations of results are discussed.

Attentional guidance by the contents of working memory and the N2PC component

Abstract The Biased Competition Model suggests that stimuli matching the contents of working memory increase the likelihood that memory-matching items will be attended. According to this account, the representations in working memory create an involuntary capture of attention toward memory-matching items in the visual field. This influential assumption proposed by the biased competition model has been explored in a number of studies, showing that the contents of working memory exert an automatic bias in favor of memory matching items. These studies showed that active maintenance of objects in working memory automatically shift attention toward the memory matching-object and produce a negative early lateralized event related potential (ERP), the N2pc, toward the side of visual field where the memorized item appeared. This component, the N2pc is an important tool to investigate the allocation of attention by working memory representations, especially for the activity the activity that is specific to the hemisphere which is contralateral with respect to the hemifield containing e.g. the to-be-remembered items could be measured. This characteristic of the N2pc facilitates measuring the general direction of attention with fine-grained temporal resolution. Therefore, the N2pc could be used as an index to describe the lateralization effect of memorized items on attention related studies.

How the two eyes add together: monocular properties of the visually guided orientation behaviour of flies

In this account fixation and the torque response to a transient moving stripe of flying femaleMusca domestica with monocular sight was tested. This was made by either covering one eye of the fly with opaque paint or by placing a screen in front of one side of the fly's visual field. A stripe was moved with constant speed once around the fly clockwise and, after a pause, counterclockwise. The torque response of the fly was measured during the motion of the stripe and shortly beforehand. The results demonstrated that the monocular torque response to progressive (from front to back) motion and regressive (from back to front) motion essentially do not differ from the binocular response, except for the region of bionocular overlap. The beginning of the response of a fly with monocular vision to progressive motion is 11 ° (on average) before the direction of flight (0°), which means that the maximal functional binocular overlap of femaleMusca domestica is stretched at least 15° to each side (3.1). In addition, the shape of the monocular torque response to a progressively moving stripe was determined (see Figs. 5Ia and 5IIb). In other experiments similar to the ones described above, a screen was placed on one side of the fly's visual field or then on the other, (instead of covering one eye) and the torque response to the moving stripe was measured. Using this method, a delay response of 90 ms was measured. We suggest that this is the delay of the direction-sensitive component of the torque response, and therefore an additional argument for the existence of two components for the optomotor torque response. Flies with a covered eye or with a screen placed in front of one side of the visual field were able to fixate a single narrow long black stripe. This, however, was possible only when an additional offset signal was added, in order to give the stripe a constant velocity component. As a result there was a shift of the fixation towards the unobscured eye. The shift was small for the monocular flies, and it was larger (13° on average) when the screen was on one side of the fly. A new type of laser torquethrust transducer was developed and is described.