TY  - JOUR
A1  - Meyberg, Susann
A1  - Sinn, Petra
A1  - Engbert, Ralf
A1  - Sommer, Werner
T1  - Revising the link between microsaccades and the spatial cueing of voluntary attention
JF  - Vision research : an international journal for functional aspects of vision.
N2  - Microsaccades - i.e., small fixational saccades generated in the superior colliculus (SC) - have been linked to spatial attention. While maintaining fixation, voluntary shifts of covert attention toward peripheral targets result in a sequence of attention-aligned and attention-opposing microsaccades. In most previous studies the direction of the voluntary shift is signaled by a spatial cue (e.g., a leftwards pointing arrow) that presents the most informative part of the cue (e.g., the arrowhead) in the to-be attended visual field. Here we directly investigated the influence of cue position and tested the hypothesis that microsaccades align with cue position rather than with the attention shift. In a spatial cueing task, we presented the task-relevant part of a symmetric cue either in the to-be attended visual field or in the opposite field. As a result, microsaccades were still weakly related to the covert attention shift; however, they were strongly related to the position of the cue even if that required a movement opposite to the cued attention shift. Moreover, if microsaccades aligned with cue position, we observed stronger cueing effects on manual response times. Our interpretation of the data is supported by numerical simulations of a computational model of microsaccade generation that is based on SC properties, where we explain our findings by separate attentional mechanisms for cue localization and the cued attention shift. We conclude that during cueing of voluntary attention, microsaccades are related to both - the overt attentional selection of the task-relevant part of the cue stimulus and the subsequent covert attention shift.(C) 2017 Elsevier Ltd. All rights reserved.
KW  - Endogenous attention
KW  - Visual search
KW  - Fixational eye movements
KW  - Posner cueing
KW  - Superior colliculus
KW  - Computational modelling
Y1  - 2017
U6  - https://doi.org/10.1016/j.visres.2017.01.001
SN  - 0042-6989
SN  - 1878-5646
VL  - 133
SP  - 47
EP  - 60
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Schwarz, Wolfgang
A1  - Eiselt, Anne-Kathrin
T1  - Numerical distance effects in visual search
JF  - Attention, perception, & psychophysics : AP&P ; a journal of the Psychonomic Society, Inc.
N2  - We present three experiments in which observers searched for a target digit among distractor digits in displays in which the mean numerical target-distractor distance was varied. Search speed and accuracy increased with numerical distance in both target-present and target-absent trials (Exp. 1A). In Experiment 1B, the target 5 was replaced with the letter S. The results suggest that the findings of Experiment 1A do not simply reflect the fact that digits that were numerically closer to the target coincidentally also shared more physical features with it. In Experiment 2, the numerical distance effect increased with set size in both target-present and target-absent trials. These findings are consistent with the view that increasing numerical target-distractor distance affords faster nontarget rejection and target identification times. Recent neurobiological findings (e.g., Nieder, 2011) on the neuronal coding of numerosity have reported a width of tuning curves of numerosity-selective neurons that suggests graded, distance-dependent coactivation of the representations of adjacent numbers, which in visual search would make it harder to reject numerically closer distractors as nontargets.
KW  - Numerical distance effect
KW  - Visual search
KW  - Category effect
KW  - Mental number line
KW  - Numerical magnitude
Y1  - 2012
U6  - https://doi.org/10.3758/s13414-012-0342-8
SN  - 1943-3921
VL  - 74
IS  - 6
SP  - 1098
EP  - 1103
PB  - Springer
CY  - New York
ER  -