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

Abstract

Individuals deaf from early age often outperform hearing individuals in the visual periphery on attention-dependent dorsal stream tasks (e.g., spatial localization or movement detection), but sometimes show central visual attention deficits, usually on ventral stream object identification tasks. It has been proposed that early deafness adaptively redirects attentional resources from central to peripheral vision to monitor extrapersonal space in the absence of auditory cues, producing a more evenly distributed attention gradient across visual space. However, little direct evidence exists that peripheral advantages are functionally tied to central deficits, rather than determined by independent mechanisms, and previous studies using several attention tasks typically report peripheral advantages or central deficits, not both. To test the general altered attentional gradient proposal, we employed a novel divided attention paradigm that measured target localization performance along a gradient from parafoveal to peripheral locations, independent of concurrent central object identification performance in prelingually deaf and hearing groups who differed in access to auditory input. Deaf participants without cochlear implants (No-CI), with cochlear implants (CI), and hearing participants identified vehicles presented centrally, and concurrently reported the location of parafoveal (1.4°) and peripheral (13.3°) targets among distractors. No-CI participants but not CI participants showed a central identification accuracy deficit. However, all groups displayed equivalent target localization accuracy at peripheral and parafoveal locations and nearly parallel parafoveal-peripheral gradients. Furthermore, the No-CI group’s central identification deficit remained after statistically controlling peripheral performance; conversely, the parafoveal and peripheral group performance equivalencies remained after controlling central identification accuracy. These results suggest that, in the absence of auditory input, reduced central attentional capacity is not necessarily associated with enhanced peripheral attentional capacity or with flattening of a general attention gradient. Our findings converge with earlier studies suggesting that a general graded trade-off of attentional resources across the visual field does not adequately explain the complex task-dependent spatial distribution of deaf-hearing performance differences reported in the literature. Rather, growing evidence suggests that the spatial distribution of attention-mediated performance in deaf people is determined by sophisticated cross-modal plasticity mechanisms that recruit specific sensory and polymodal cortex to achieve specific compensatory processing goals.

Retinotopic remapping of the visual system in deaf adults

“…Although many studies show no perceptual differences between deaf and hearing adults within the central visual field (Bosworth and Dobkins 1999;Brozinsky and Bavelier 2004;Stevens and Neville 2006), some disadvantages have been noted in deaf adults (Proksch & Bavelier, 2002;Parasnis, Samar & Berent, 2003;Samar & Berger, 2017), possibly explained by the reduction of neural resources we find in the central visual field representations. Furthermore, there is evidence of a central/peripheral trade-off in visual attention of deaf individuals (Proksch & Bavelier, 2002;Parasnis, Samar & Berent, 2003) and responses measured in visual motion area V5/hMT+ (Bavelier et al, 2001).…”

Retinotopic Remapping of the Visual System in Deaf Adults

“…Enhanced peripheral visual sensitivity is reported in deaf cats [3] and adult humans [1,2,13], particularly in the far peripheral visual field [4,5]. Although many studies show no perceptual differences within the central visual field between deaf and hearing adults [1,14], evidence of a central/peripheral trade-off has been reported in deaf adults for some tasks [15,16,17].…”

Evidence of an Effect of Gaming Experience on Visuospatial Attention in Deaf but Not in Hearing Individuals

“…In addition, detection of changes outside foveal vision seems to be faster in deaf than in hearing individuals (Loke and Song, 1991;Chen et al, 2006;Dye et al, 2009), suggesting that stimuli outside the fovea are more likely to challenge attentional control in deaf populations, at least when those stimuli are of relevance to solving the task (Bavelier et al, 2006;Belanger and Rayner, 2015). For the ventral stream, Armstrong et al (2002) showed no effect of deafness, whereas others showed altered effects of deafness in both ventral and dorsal streams (Weisberg et al, 2012;Samar and Berger, 2017). Because the dorsal stream is susceptible to effects of deafness, with increased attentional resources used for processing of stimuli in the periphery, deaf individuals might perform worse than hearing individuals on visual tasks where stimuli outside the fovea need to be suppressed.…”

“…In other trials, flanking stimuli are congruent with the target stimulus, which leads to faster responses. The difference in response times between incongruent and congruent trials is an indicator of visuospatial attentional control (Rueda et al, 2004), and with an increase in attentional allocation to stimuli outside the fovea in deaf individuals (Bavelier et al, 2006) as well as altered ventral stream processing (Weisberg et al, 2012;Samar and Berger, 2017), an incongruence effect is likely to be stronger for deaf compared to hearing individuals. Thus, despite superior performance on some tasks related to the dorsal stream, deaf individuals are more distracted by flanking stimuli in a Flanker task than hearing participants (Dye et al, 2007;Dye and Hauser, 2014), irrespective of sign language skill (Proksch and Bavelier, 2002;Dye et al, 2007; also see Bosworth and Dobkins, 2002;Dye et al, 2009).…”