ABSTRACT

Many eye tracking studies of visual search have focused on the role of the number of fixations and the nature of scan paths. Less attention has been paid to fixation durations and to how those durations are affected by stimulus features. Previous studies have shown that fixation durations can be as important as the number of fixations in explaining search times with complex stimuli (e.g., in search for specific faces). In the present study, simple stimuli were used in a search experiment where participants searched for a closed ring among rings with a gap. We manipulated distractor heterogeneity (DH), target-distractor similarity (TDS), and stimulus density (SDY, set size within a constant search window), and estimated the contributions of these factors to gaze behaviour and trial search time. The results show that fixation durations contribute less to variation in overall search time with simple search stimuli as compared to previous studies with more complex stimuli. However, fixation durations still increased with DH, TDS, and SDY. These effects were mainly additive, and we did not find an interaction between DH and closer element spacing at high levels of SDY that might have been expected since both DH and SDY influence distractor grouping.

摘要

许多视觉搜索的眼动追踪研究都集中在注视次数的作用和扫描路径的性质上。较少关注注视持续时间以及这些持续时间如何受到刺激特征的影响。先前的研究表明，在解释复杂刺激的搜索时间（例如，搜索特定面孔）时，注视持续时间可能与注视次数一样重要。在本研究中，在搜索实验中使用了简单的刺激，参与者在有间隙的环中搜索闭合环。我们操纵干扰物异质性 (DH)、目标干扰物相似性 (TDS) 和刺激密度 (SDY，在恒定搜索窗口内设置大小)，并估计这些因素对凝视行为和试验搜索时间的贡献。结果表明，与先前具有更复杂刺激的研究相比，固定持续时间对简单搜索刺激的总体搜索时间变化的贡献较小。然而，DH、TDS 和 SDY 的注视持续时间仍然增加。这些影响主要是相加的，并且我们没有发现在高水平的 SDY 下 DH 和更接近的元素间距之间的相互作用，这可能是由于 DH 和 SDY 都会影响干扰分组而预期的。