Liu Baiwei, Alexopoulou Zampeta-Sofia, van Ede Freek
Institute for Brain and Behavior Amsterdam, Department of Experimental and Applied Psychology, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Commun Psychol. 2024 Oct 22;2(1):97. doi: 10.1038/s44271-024-00149-7.
Brain circuitry that controls where we look also contributes to attentional selection of visual contents outside current fixation, or content within the spatial layout of working memory. A behavioural manifestation of this contribution comes from modulations in microsaccade direction that accompany spatial attention shifts. Here, we address whether such modulations come about because attention shifts trigger new microsaccades or whether, instead, spatial attention only biases the direction of ongoing microsaccades that would have been made whether or not attention was also shifted. We utilised an internal-selective-attention task that has recently been shown to yield robust spatial microsaccade modulations and compared microsaccade rates following colour retrocues that were carefully matched for sensory input, but differed in whether they invited an attention shift or not. If attention shifts trigger new microsaccades then we would expect more microsaccades following attention-directing cues than following neutral cues. In contrast, we found no evidence for an increase in overall microsaccade rate, despite robust modulations in microsaccade direction. This implies that shifting spatial attention biases the direction of ongoing microsaccades without changing the probability of microsaccade occurrence. These findings help to explain why microsaccades and visual-spatial shifts of attention are often correlated but not obligatorily linked.
控制我们注视方向的脑回路，也有助于对当前注视点之外的视觉内容，或工作记忆空间布局内的内容进行注意力选择。这种作用的一种行为表现，来自于伴随空间注意力转移的微扫视方向的调制。在这里，我们探讨这种调制的产生，是因为注意力转移触发了新的微扫视，还是相反，空间注意力只是偏向了那些无论注意力是否转移都会发生的正在进行的微扫视的方向。我们利用了一项内部选择性注意力任务，最近的研究表明该任务会产生强大的空间微扫视调制，并比较了在颜色提示后微扫视的发生率，这些颜色提示在感觉输入方面经过仔细匹配，但在是否引发注意力转移方面有所不同。如果注意力转移触发新的微扫视，那么我们预计在引导注意力的提示之后比在中性提示之后会有更多的微扫视。相反，尽管微扫视方向有强大的调制，但我们没有发现总体微扫视发生率增加的证据。这意味着转移空间注意力会使正在进行的微扫视方向产生偏差，而不会改变微扫视发生的概率。这些发现有助于解释为什么微扫视和注意力的视觉空间转移经常相关，但并非必然联系。
