The Effect of Stimulus Size and Eccentricity on Attention Shift Latencies.

Louisa Kulke

doi:10.3390/vision1040025

Abstract

The ability to shift attention between relevant stimuli is crucial in everyday life and allows us to focus on relevant events. It develops during early childhood and is often impaired in clinical populations, as can be investigated in the fixation shift paradigm and the gap–overlap paradigm. Different tests use stimuli of different sizes presented at different eccentricities, making it difficult to compare them. This study systematically investigates the effect of eccentricity and target size on refixation latencies towards target stimuli. Eccentricity and target size affected attention shift latencies with greatest latencies to big targets that were presented at a small eccentricity. Slowed responses to large parafoveal targets are in line with the idea that specific areas in the superior colliculus can lead to inhibition of eye movements. Findings suggest that the two different paradigms are generally comparable, as long as the target is scaled in proportion to the eccentricity.

Highlights

Eye movements can provide valuable insights into cognitive processes, including visual attention. in infants and non-verbal populations, eye movement can be used to study processes without the use of verbal instructions (e.g., [1,2])
A repeated measures ANOVA was used to analyze the effect on refixation latency of target size, eccentricity and their interaction
There was no significant difference in refixation latency between targets matching the gap–overlap paradigm (Csibra et al [27]) and the fixation shift paradigm (Kulke et al [15]) stimuli in size and eccentricity and Bayesian analyses confirm that these differences are unlikely to affect refixation latency

Summary

Introduction

Eye movements can provide valuable insights into cognitive processes, including visual attention. in infants and non-verbal populations, eye movement can be used to study processes without the use of verbal instructions (e.g., [1,2]). The ability to shift gaze between stimuli is an established measure of development and can be used as a predictor for developmental outcomes in clinical populations for example in children with Williams Syndrome [3], pre-term born infants [4], siblings of autistic children [5,6], infants with hypoxic-ischaemic encephalopathy (HIE) [7,8] and children who had one of their brain’s hemispheres removed (hemispherectomised children, [9]) It is unclear how the visual features of stimuli used to measure attention shifts affect the overall findings. Despite developmental changes in the competition condition, clear differences between competition and non-competition conditions can be observed in healthy infants [15] and adults [26,27], making these tasks suitable to test attention shifts across the life span

Objectives

Methods

Results

Conclusion