Eccentricity effects in vision and attention

Abstract

Stimulus eccentricity affects visual processing in multiple ways. Performance on a visual task is often better when target stimuli are presented near or at the fovea compared to the retinal periphery. For instance, reaction times and error rates are often reported to increase with increasing eccentricity. Such findings have been interpreted as purely visual, reflecting neurophysiological differences in central and peripheral vision, as well as attentional, reflecting a central bias in the allocation of attentional resources. Other findings indicate that in some cases, information from the periphery is preferentially processed. Specifically, it has been suggested that visual processing speed increases with increasing stimulus eccentricity, and that this positive correlation is reduced, but not eliminated, when the amount of cortex activated by a stimulus is kept constant by magnifying peripheral stimuli (Carrasco et al., 2003). In this study, we investigated effects of eccentricity on visual attentional capacity with and without magnification, using computational modeling based on Bundesen's (1990) theory of visual attention. Our results suggest a general decrease in attentional capacity with increasing stimulus eccentricity, irrespective of magnification. We discuss these results in relation to the physiology of the visual system, the use of different paradigms for investigating visual perception across the visual field, and the use of different stimulus materials (e.g. Gabor patches vs. letters).

Investigating face and house discrimination at foveal to parafoveal locations reveals category-specific characteristics

“…Our investigations into face-related processing in central to parafoveal locations (up to 4) revealed that, as expected, faces, as well as all tested categories, show an eccentricity effect (i.e. reduced accuracy and d-prime and slower RTs with growing eccentricity 6 . While we anticipated finding that face related processing may outperform other categories at the central visual field (see model in Fig.…”

“…One of the main coding principles in the visual cortex is eccentricity, where the foveal representation is significantly magnified in the visual cortex relative to its size on the retina, and as distance from the fovea grows, the cortical representation is reduced [1][2][3] . This foveal magnification is assumed to be the main factor contributing to reduced performance with growing eccentricity for multiple (but not all) visual tasks [4][5][6] . It has also been shown that this foveal enhancement can be overcome if peripheral information is scaled to match the cortical representation (aka M-scaling 7 ).…”

“…Reasoning that neural coding preferences likely reflect behavioural performance, and based on earlier studies and on reduced visual performance at peripheral locations 6 , we hypothesized that face related tasks, that are associated with a cortical foveal bias would show reduced performance in more peripheral locations relative to the control category of houses which is associated with a cortical peripheral bias. This entails that we expected that place related tasks would be less affected by eccentricity and would show, on top of the expected eccentricity reductions 6 , higher performance than faces as eccentricity increases (as presented in the middle and left models in Fig. 1a) while faces may outperform houses at the centre due to their foveal bias (cf.…”

Does a Flatter General Gradient of Visual Attention Explain Peripheral Advantages and Central Deficits in Deaf Adults?

“…Staugaard et al (2016) reported further that manipulating endogenous attention did not alter these attentional gradients, but cited Proksch and Bavelier’s (2002) study to support the claim that long-term environmental factors may lead to a compensatory trade-off between attentional resources in peripheral vs. central vision.…”

Alteration of brain dynamics during natural dual-task walking

“…First, walking requires visual control of the upcoming area to avoid falls or collisions (Imai et al, 2001;Nomura et al, 2005); as a consequence, an additional visual task will rely on the same resources which are necessary to visually control walking and thus compete (Wickens et al, 1983;Wickens, 2002). Secondly, the sensory features and position of additional visual stimuli (eccentricity in the visual field) have a strong impact on visual information processing (Carrasco et al, 1995;Staugaard et al, 2016). Therefore, detecting peripheral and potentially less salient visual stimuli might require more attentional resources compared to more centrally ones, revealing a higher dual-task cost when concurrently walking.…”