Bias for the Left Visual Field in Rapid Serial Visual Presentation: Effects of Additional Salient Cues Suggest a Critical Role of Attention

Abstract

Everyday experience suggests that people are equally aware of stimuli in both hemifields. However, when two streams of stimuli are rapidly presented left and right, the second target (T2) is better identified in the left hemifield than in the right hemifield. This left visual field (LVF) advantage may result from differences between hemifields in attracting attention. Therefore, we introduced a visual cue shortly before T2 onset to draw attention to one stream. Thus, to identify T2, attention was correctly positioned with valid cues but had to be redirected to the other stream with invalid ones. If the LVF advantage is caused by differences between hemifields in attracting attention, invalid cues should increase, and valid cues should reduce the LVF advantage as compared with neutral cues. This prediction was confirmed. ERP analysis revealed that cues evoked an early posterior negativity, confirming that attention was attracted by the cue. This negativity was earlier with cues in the LVF, which suggests that responses to salient events are faster in the right hemisphere than in the left hemisphere. Valid cues speeded up, and invalid cues delayed T2-evoked N2pc; in addition, valid cues enlarged T2-evoked P3. After N2pc, right-side T2 evoked more sustained contralateral negativity than left T2, least long-lasting after valid cues. Difficulties in identifying invalidly cued right T2 were reflected in prematurely ending P3 waveforms. Overall, these data provide evidence that the LVF advantage is because of different abilities of the hemispheres in shifting attention to relevant events in their contralateral hemifield.

Audio-visual synchrony and spatial attention enhance processing of dynamic visual stimulation independently and in parallel: a frequency-tagging study

“…Note that participants performed better in the visual detection task when they attended to the left stimulus. This effect could be due to a left-hemifield advantage as has been described previously for rapid serial visual presentation paradigms (Smigasiewicz et al, 2014; Verleger et al, 2011). Nevertheless, SSR analyses did not show differences in stimulus processing between left and right stimulus positions.…”

Stronger interference from distractors in the right hemifield during visual search

“…This hypothesis was further supported by a cueing manipulation. When a salient exogenous cue was presented close to the RSVP stream that did not contain the inconspicuous target (invalid cue), the cue was more disruptive when it was presented in the LVF compared to the RVF (Śmigasiewicz, Asanowicz, Westphal, & Verleger, 2014).…”

Right visual-field advantage in the attentional blink: Asymmetry in attentional gating across time and space

“…Note, however, that in these studies T2 was embedded within a stream of distractors, requiring top-down attention in order to be selected for further processing. In fact, the LVF advantage disappeared when the relative salience of T2 was increased either by pre-cueing T2 location (Smigasiewicz, Asanowicz, Westphal, & Verleger, 2014), by coloring both targets (Scalf et al, 2007, Exp. 4;Fig.…”