Stimulus representations in visual cortex shaped by spatial attention and microsaccades

• 成果类型: Article
• 署名作者: Srinivasan, Karthik; Lowet, Eric; Gomes, Bruno; Desimone, Robert
• 署名单位: Massachusetts Institute of Technology (MIT); Erasmus University Rotterdam; Erasmus MC; Boston University; Universidade Federal do Para
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-15265
• DOI: 10.1073/pnas.2420704122
• 发表日期: 2025-06-03
• 关键词: fixational eye-movements; modulates neuronal responses; monkey superior colliculus; area v4; selective attention; neural mechanisms; sustained attention; target selection; shifts; features

摘要

Microsaccades (MSs) are commonly associated with covert spatial attention, yet their impact on cortical processing of visual objects remains unclear. Rhesus macaques, randomly cued to attend to a target object amid distracters, were rewarded for detecting a color change in the target. While spatial attention does not affect the object tuning curves of V4 cells, the direction of MS significantly influenced object representations in V4 throughout the entire trial. Specifically, intervals following an MS toward the target exhibited superior stimulus decoding and sharper tuning curves compared to intervals following an MS away from the target. Furthermore, MSs directed toward the target enhanced neuronal responses to behaviorally relevant color changes, leading to faster reaction times. This sharpening effect stems from both a refreshing of the initial sensory response and an amplification of attention effects. The firing rate enhancement associated the target. Subsequently, a positive effect of attention on firing rate, influenced by MS pulvinar, and IT cortex. In summary, these findings underscore a crucial link between covert attention, object processing, and their coordination with MSs.