A unique role of endogenous visual-spatial attention in rapid processing of multiple targets.

Abstract

Visual spatial attention can be exogenously captured by a salient stimulus or can be endogenously allocated by voluntary effort. Whether these two attention modes serve distinctive functions is debated, but for processing of single targets the literature suggests superiority of exogenous attention (it is faster acting and serves more functions). We report that endogenous attention uniquely contributes to processing of multiple targets. For speeded visual discrimination, response times are faster for multiple redundant targets than for single targets due to probability summation and/or signal integration. This redundancy gain was unaffected when attention was exogenously diverted from the targets, but was completely eliminated when attention was endogenously diverted. This was not due to weaker manipulation of exogenous attention because our exogenous and endogenous cues similarly affected overall response times. Thus, whereas exogenous attention is superior for processing single targets, endogenous attention plays a unique role in allocating resources crucial for rapid concurrent processing of multiple targets.

The association between reading abilities and visual‐spatial attention in Hong Kong Chinese children

“…Research shows that while exogenous attention is important for processing single targets, endogenous attention uniquely contributes to concurrent processing and integration of multiple targets (e.g., Guzman-Martinez, Grabowecky, Palafox, & Suzuki, 2011). As discussed earlier, many Chinese characters are visually similar or complex, such as 士 (person) and 土 (earth) or 辨 (recognize) and辦 (to do).…”

“…Second, because Chinese characters comprise multiple strokes and components whose spatial representation is two-dimensional, Chinese reading requires concurrent processing of the distinct visual elements and their spatial relationships, instead of successive phonological decoding in reading alphabetic scripts. Research shows that while exogenous attention is important for processing single targets, endogenous attention uniquely contributes to concurrent processing and integration of multiple targets (e.g., Guzman-Martinez, Grabowecky, Palafox, & Suzuki, 2011). Therefore, endogenous attention could be more strongly associated to Chinese reading through its unique role in multiple targets processing.…”

Asymmetries in visual acuity around the visual field

“…Thus, to eliminate differences in sensory factors when assessing performance in visual tasks, it does not suffice to place stimuli at the same eccentricity. Moreover, the lack of significant differences along the intercardinal (± 45° polar angle) meridians (e.g., Abrams et al., 2012 ; Altpeter et al., 2000 ; Benson et al., 2020 ; Cameron et al., 2002 ; Carrasco et al., 2001 ; Corbett & Carrasco, 2011 ; Liu et al., 2006 ; Mackeben, 1999 ; Nazir, 1992 ; Talgar & Carrasco, 2002 ) has been used to collapse performance across intercardinal isoeccentric locations (e.g., Barbot & Carrasco, 2017 ; Guzman-Martinez, Grabowecky, Palafox, & Suzuki, 2011 ; Liu & Mance, 2011 ; Montagna, Pestilli, & Carrasco, 2009 ; Sawaki & Luck, 2013 ; Yashar, White, Fang, & Carrasco, 2017 ). It is worth noting that although visual field asymmetries linearly decrease with the angular distance from the vertical meridian and generally become negligible by the intercardinal (± 45° polar angle) meridians, they might still be present and may be worth checking for the specific task at hand.…”

Asymmetries in visual acuity around the visual field

“…Previous studies have reported no significant differences between upper versus lower locations along the intercardinal meridians, with intermediate performance relative to the VM and HM for stimuli presented at 45º within the four quadrants (e.g., Abrams et al, 2012;Cameron et al, 2002;Carrasco et al, 2004;Fuller & Carrasco, 2009). The fact that no significant difference emerges at 45º in most visual tasks has been used to justify collapsing performance across the four intercardinal isoeccentric locations (e.g., Barbot & Carrasco, 2017;Guzman-Martinez et al, 2011;Ling & Carrasco, 2006a, 2006bLiu & Mance, 2011;Montagna, Pestilli & Carrasco, 2009;Sawaki & Luck, 2013;Yashar et al, 2017). It is worth noting, however, that in the present study, a slight VMA asymmetry in SF sensitivity was still observed at 45º, which is consistent with the presence of a marginal asymmetry in contrast sensitivity at 45º (Abrams et al, 2012).…”