Spatial biases in viewing behavior

TY - JOUR

T1 - Spatial biases in viewing behavior

AU - Ossandón, José P

AU - Onat, Selim

AU - König, Peter

PY - 2014/1/1

Y1 - 2014/1/1

N2 - Viewing behavior exhibits temporal and spatial structure that is independent of stimulus content and task goals. One example of such structure is horizontal biases, which are likely rooted in left-right asymmetries of the visual and attentional systems. Here, we studied the existence, extent, and mechanisms of this bias. Left- and right-handed subjects explored scenes from different image categories, presented in original and mirrored versions. We also varied the spatial spectral content of the images and the timing of stimulus onset. We found a marked leftward bias at the start of exploration that was independent of image category. This left bias was followed by a weak bias to the right that persisted for several seconds. This asymmetry was found in the majority of right-handers but not in left-handers. Neither low- nor high-pass filtering of the stimuli influenced the bias. This argues against mechanisms related to the hemispheric segregation of global versus local visual processing. Introducing a delay in stimulus onset after offset of a central fixation spot also had no influence. The bias was present even when stimuli were presented continuously and without any requirement to fixate, associated to both fixation- and saccade-contingent image changes. This suggests the bias is not caused by structural asymmetries in fixation control. Instead the pervasive horizontal bias is compatible with known asymmetries of higher-level attentional areas related to the detection of novel events.

AB - Viewing behavior exhibits temporal and spatial structure that is independent of stimulus content and task goals. One example of such structure is horizontal biases, which are likely rooted in left-right asymmetries of the visual and attentional systems. Here, we studied the existence, extent, and mechanisms of this bias. Left- and right-handed subjects explored scenes from different image categories, presented in original and mirrored versions. We also varied the spatial spectral content of the images and the timing of stimulus onset. We found a marked leftward bias at the start of exploration that was independent of image category. This left bias was followed by a weak bias to the right that persisted for several seconds. This asymmetry was found in the majority of right-handers but not in left-handers. Neither low- nor high-pass filtering of the stimuli influenced the bias. This argues against mechanisms related to the hemispheric segregation of global versus local visual processing. Introducing a delay in stimulus onset after offset of a central fixation spot also had no influence. The bias was present even when stimuli were presented continuously and without any requirement to fixate, associated to both fixation- and saccade-contingent image changes. This suggests the bias is not caused by structural asymmetries in fixation control. Instead the pervasive horizontal bias is compatible with known asymmetries of higher-level attentional areas related to the detection of novel events.

KW - Adult

KW - Attention

KW - Functional Laterality

KW - Humans

KW - Male

KW - Middle Aged

KW - Perceptual Masking

KW - Photic Stimulation

KW - Saccades

KW - Space Perception

KW - Spatial Behavior

KW - Young Adult

U2 - 10.1167/14.2.20

DO - 10.1167/14.2.20

M3 - SCORING: Journal article

C2 - 24569986

VL - 14

JO - J VISION

JF - J VISION

SN - 1534-7362

IS - 2

ER -