Center for the Study of Emotion and Attention, University of Florida, Gainesville, Florida 32610
Center for the Study of Emotion and Attention, University of Florida, Gainesville, Florida 32610.
J Neurosci. 2021 Jun 30;41(26):5723-5733. doi: 10.1523/JNEUROSCI.2889-20.2021. Epub 2021 May 25.
Processing capabilities for many low-level visual features are experientially malleable, aiding sighted organisms in adapting to dynamic environments. Explicit instructions to attend a specific visual field location influence retinotopic visuocortical activity, amplifying responses to stimuli appearing at cued spatial positions. It remains undetermined both how such prioritization affects surrounding nonprioritized locations, and if a given retinotopic spatial position can attain enhanced cortical representation through experience rather than instruction. The current report examined visuocortical response changes as human observers ( = 51, 19 male) learned, through differential classical conditioning, to associate specific screen locations with aversive outcomes. Using dense-array EEG and pupillometry, we tested the preregistered hypotheses of either sharpening or generalization around an aversively associated location following a single conditioning session. Competing hypotheses tested whether mean response changes would take the form of a Gaussian (generalization) or difference-of-Gaussian (sharpening) distribution over spatial positions, peaking at the viewing location paired with a noxious noise. Occipital 15 Hz steady-state visual evoked potential responses were selectively heightened when viewing aversively paired locations and displayed a nonlinear, difference-of-Gaussian profile across neighboring locations, consistent with suppressive surround modulation of nonprioritized positions. Measures of alpha-band (8-12 Hz) activity were differentially altered in anterior versus posterior locations, while pupil diameter exhibited selectively heightened responses to noise-paired locations but did not evince differences across the nonpaired locations. These results indicate that visuocortical spatial representations are sharpened in response to location-specific aversive conditioning, while top-down influences indexed by alpha-power reduction exhibit posterior generalization and anterior sharpening. It is increasingly recognized that early visual cortex is not a static processor of physical features, but is instead constantly shaped by perceptual experience. It remains unclear, however, to what extent the cortical representation of many fundamental features, including visual field location, is malleable by experience. Using EEG and an aversive classical conditioning paradigm, we observed sharpening of visuocortical responses to stimuli appearing at aversively associated locations along with location-selective facilitation of response systems indexed by pupil diameter and EEG alpha power. These findings highlight the experience-dependent flexibility of retinotopic spatial representations in visual cortex, opening avenues toward novel treatment targets in disorders of attention and spatial cognition.
许多低级视觉特征的加工能力具有经验可塑性,有助于有视力的生物适应动态环境。明确的注意特定视野位置的指令会影响视皮质的活动,增强对提示空间位置出现的刺激的反应。目前还不确定这种优先级排序如何影响周围的非优先级位置,以及给定的视皮质空间位置是否可以通过经验而不是指令获得增强的皮质代表。本报告研究了人类观察者(n = 51,男性 19 名)通过差异经典条件作用将特定屏幕位置与厌恶结果相关联时,视皮质反应变化。使用密集阵列 EEG 和瞳孔测量法,我们测试了在单次条件作用后,围绕厌恶相关位置的锐化或泛化的预先注册假设。竞争假设测试了平均反应变化是否会呈现出高斯(泛化)或差高斯(锐化)分布的空间位置,在与有害噪声配对的观察位置达到峰值。当观看厌恶配对的位置时,15 Hz 稳态视觉诱发电位反应选择性地升高,并在相邻位置呈现非线性、差高斯分布,与非优先级位置的抑制性环绕调制一致。α 波段(8-12 Hz)活动的测量值在前部和后部位置发生差异变化,而瞳孔直径对噪声配对位置表现出选择性的高反应,但在非配对位置上没有差异。这些结果表明,视皮质空间表示在对特定位置的厌恶条件作用下变得更加锐利,而由α功率降低表示的自上而下的影响表现出后部泛化和前部锐化。越来越多的人认识到,早期视觉皮层不是物理特征的静态处理器,而是不断受到感知经验的塑造。然而,仍然不清楚许多基本特征的皮质表示,包括视野位置,在多大程度上可以通过经验来改变。使用 EEG 和厌恶经典条件作用范式,我们观察到在与厌恶相关的位置出现刺激时,视皮质反应的锐化,以及由瞳孔直径和 EEGα 功率指示的反应系统的位置选择性促进。这些发现强调了视觉皮层中视皮质空间表示的经验依赖性灵活性,为注意力和空间认知障碍的新型治疗靶点开辟了途径。