Behavioural Brain Sciences Centre, School of Psychology, University of Birmingham Birmingham, UK.
Department of Psychology, Tel Aviv University Tel Aviv, Israel ; Department of Psychology, The College of Management Academic Studies Israel.
Front Psychol. 2014 Jan 10;4:966. doi: 10.3389/fpsyg.2013.00966.
According to perceptual load theory (Lavie, 2005) distractor interference is determined by the availability of attentional resources. If target processing does not exhaust resources (with low perceptual load) distractor processing will take place resulting in interference with a primary task; however, when target processing uses-up attentional capacity (with high perceptual load) interference can be avoided. An alternative account (Tsal and Benoni, 2010a) suggests that perceptual load effects can be based on distractor dilution by the mere presence of additional neutral items in high-load displays so that the effect is not driven by the amount of attention resources required for target processing. Here we tested whether patients with unilateral neglect or extinction would show dilution effects from neutral items in their contralesional (neglected/extinguished) field, even though these items do not impose increased perceptual load on the target and at the same time attract reduced attentional resources compared to stimuli in the ipsilesional field. Thus, such items do not affect the amount of attention resources available for distractor processing. We found that contralesional neutral elements can eliminate distractor interference as strongly as centrally presented ones in neglect/extinction patients, despite contralesional items being less well attended. The data are consistent with an account in terms of perceptual dilution of distracters rather than available resources for distractor processing. We conclude that distractor dilution can underlie the elimination of distractor interference in visual displays.
根据知觉负载理论（Lavie，2005），分心物干扰取决于注意力资源的可利用性。如果目标处理没有耗尽资源（低知觉负载），那么分心物处理将会发生，从而对主要任务造成干扰；然而，当目标处理使用完注意力容量（高知觉负载）时，干扰可以避免。另一种解释（Tsal 和 Benoni，2010a）认为，知觉负载效应可以基于分心物的稀释，即在高负载显示中仅存在额外的中性项目，从而使效应不是由目标处理所需的注意力资源量驱动的。在这里，我们测试了单侧忽略或消光症患者是否会从他们对侧（忽略/消光）场中的中性项目中表现出稀释效应，即使这些项目不会增加目标的知觉负载，同时与同侧场中的刺激相比，吸引的注意力资源减少。因此，这些项目不会影响用于分心物处理的注意力资源量。我们发现，即使对侧项目的注意力较差，对侧中性元素也可以像中央呈现的中性元素一样有效地消除忽略/消光症患者的分心物干扰。数据与分心物的知觉稀释而不是分心物处理的可用资源的解释一致。我们得出结论，分心物稀释可以作为视觉显示中消除分心物干扰的基础。
