Weakened Target Representations in Low Prevalence Visual Search
Weakened Target Representations in Low Prevalence Visual Search
复制标题
低流行度视觉搜索中目标表示的减弱
DOI：
10.1167/13.9.528
复制
发表时间：
2013
影响因子：
1.8
通讯作者：
Godwin H
中科院分区：
文献类型：
--
作者：
Godwin H
我们检查了双目标视觉搜索任务期间不同目标模板的激活强度。我们操纵了提出每个目标的试验比例（称为目标流行率），以评估目标模板是否由环境中的规律性决定。我们记录了参与者在搜索两个目标时的眼动行为，其中一个出现在 45% 的试验中 (TH)，另一个出现在 5% 的试验中 (TL)。我们试图确定指导或识别过程（或两者）是否因目标患病率的降低而被削弱。反应准确性数据表明，参与者检测到 TL 的可能性低于检测到 TH，从而复制了患病率效应。对眼球运动行为的分析表明，在低流行率下，引导作用被削弱：与 TH 相比，参与者注视与 TL 颜色相同的干扰物的可能性和速度都更慢。此外，低流行率搜索中的识别过程也被削弱，首次注视 TL 和响应“当前”之间的时间比首次注视 TH 和响应“当前”之间的时间更长。总而言之，这些结果表明，低目标流行率削弱了目标模板的指导和识别能力。这一发现解释了之前的结果，即参与者无法检测到低流行率的目标，因为表明参与者不太可能注视目标物体，而且当他们注视目标物体时，需要更多的时间来识别这些物体。
We examined the strength of activation of different target templates during a dual-target visual search task. We manipulated the proportion of trials where each target was presented (known as the target prevalence) in order to assess whether target templates are shaped by regularities in the environment. We recorded participants’ eye movement behaviour as they searched for two targets, one of which appeared on 45% of trials (TH) while the other appeared on 5% of trials (TL). We sought to determine whether guidance or identification processes (or both) were weakened by a reduction in target prevalence. Response accuracy data demonstrated that participants were less likely to detect TL than TH, replicating the prevalence effect. Analyses of eye movement behaviour indicated that guidance was weakened in low prevalence: participants were both less likely, and less rapid, to fixate distractors that shared their colour with TL than TH. Furthermore, identification processes in low prevalence search were also shown to be weakened, with the time between first fixating TL and responding ‘present’being longer than the time between first fixating TH and responding ‘present’. Taken together, these results demonstrate that low target prevalence weakens target templates, both for guidance and recognition. This finding accounts for previous results, in which participants to fail to detect low prevalence targets, by showing that participants are less likely to fixate target objects, and, when they do, more time is required in order to identify those objects.