Representational pseudoneglect and reference points both influence geographic location estimates

Evidence for a common mechanism of spatial attention and visual awareness: Towards construct validity of pseudoneglect

Present knowledge of attention and awareness centres on deficits in patients with right brain damage who show severe forms of inattention to the left, called spatial neglect. Yet the functions that are lost in neglect are poorly understood. In healthy people, they might produce “pseudoneglect”—subtle biases to the left found in various tests that could complement the leftward deficits in neglect. But pseudoneglect measures are poorly correlated. Thus, it is unclear whether they reflect anything but distinct surface features of the tests. To probe for a common mechanism, here we asked whether visual noise, known to increase leftward biases in the grating-scales task, has comparable effects on other measures of pseudoneglect. We measured biases using three perceptual tasks that require judgments about size (landmark task), luminance (greyscales task) and spatial frequency (grating-scales task), as well as two visual search tasks that permitted serial and parallel search or parallel search alone. In each task, we randomly selected pixels of the stimuli and set them to random luminance values, much like a poor TV signal. We found that participants biased their perceptual judgments more to the left with increasing levels of noise, regardless of task. Also, noise amplified the difference between long and short lines in the landmark task. In contrast, biases during visual searches were not influenced by noise. Our data provide crucial evidence that different measures of perceptual pseudoneglect, but not exploratory pseudoneglect, share a common mechanism. It can be speculated that this common mechanism feeds into specific, right-dominant processes of global awareness involved in the integration of visual information across the two hemispheres.

Fly on the right: Lateral preferences when choosing aircraft seats

A small preference has been observed for people to choose seats on the left of aircraft when booking via an online system. Although this is consistent with pseudoneglect-the known leftward bias in perception and representation-rightward preferences have been commonly observed in seating selection tasks in other environments. Additionally, the previous research in aircraft seating was unable to dissociate a bias to one side of the screen from a bias to one side of the cabin of the aircraft. Here, we present a study in which participants were asked to select seats for a range of fictional flights. They demonstrated a preference for seats on the right of the cabin, irrespective of whether the right of the cabin appeared to either the right or the left of the screen, a preference for seats towards the front of the aircraft and a preference to favour window and aisle seats. This suggests, in contrast to previous research, that participants demonstrated a rightward lateral bias to representations of an aircraft. These results may have implications for our understanding of asymmetries in cognition as well as having potentially important practical implications for airlines.

Representational pseudoneglect: a review

Pseudoneglect, the tendency to be biased towards the left-hand side of space, is a robust and consistent behavioural observation best demonstrated on the task of visuospatial line bisection, where participants are asked to centrally bisect visually presented horizontal lines at the perceived centre. A number of studies have revealed that a representational form of pseudoneglect exists, occurring when participants are asked to either mentally represent a stimulus or explore a stimulus using touch in the complete absence of direct visuospatial processing. Despite the growing number of studies that have demonstrated representational pseudoneglect there exists no current and comprehensive review of these findings and no discussion of a theoretical framework into which these findings may fall. An important gap in the current representational pseudoneglect literature is a discussion of the developmental trajectory of the bias. The focus of the current review is to outline studies that have observed representational pseudoneglect in healthy participants, consider a theoretical framework for these observations, and address the impact of lifespan factors such as cognitive ageing on the phenomenon.

Left-ear-driven representational pseudoneglect for mentally represented real-word scenes created from aural-verbal description

The current research explored pseudoneglect for the mental representation of real-world scenes generated from aural-verbal description in the complete absence of direct visual processing. Healthy participants listened binaurally or monaurally to aural-verbal descriptions of novel real-world scenes with familiar landmarks (e.g., 'shop', 'cafe', 'school') to be imagined on the left- or right-hand side. Participants were asked to mentally represent the street scene using a visuospatial template though it was up to participants how they mentally represented each individual landmark within the street (i.e., in terms of colour and size). There were two main tasks: a relative judgement task (which side of the street contains the most landmarks?) and a recall task (recall the landmarks on the left vs. right side of the street). When stimuli were presented monaurally to the left ear (favouring the activation of the right hemisphere) participants demonstrated representational pseudoneglect and showed a bias towards responding that there were more landmarks on the left compared to the right. However, this did not lead to enhanced recall for left side landmarks. When stimuli were presented binaurally or monaurally to the right ear, there was no evidence of representational pseudoneglect for the relative judgement or recall task. The current study discusses how the use of monaural presentation may boost right hemisphere activation in aural-verbal experimental paradigms designed to explore representational pseudoneglect.