Evidence for a Causal Contribution of Macaque Vestibular, But Not Intraparietal, Cortex to Heading Perception
Evidence for a Causal Contribution of Macaque Vestibular, But Not Intraparietal, Cortex to Heading Perception
复制标题
猕猴前庭皮质而非顶内皮质对方向知觉有因果贡献的证据。
DOI：
10.1523/jneurosci.2485-15.2016
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发表时间：
2016-03-30
影响因子：
5.3
通讯作者：
Angelaki, Dora E.
中科院分区：
文献类型：
--
作者：
Chen, Aihua;Gu, Yong;Angelaki, Dora E.
视觉和前庭信号的多感觉会聚已经在涉及表示航向的皮层区域的网络内被观察到。在猕猴顶叶岛前庭皮质（PIVC）和邻近的视觉后外侧裂（VPS）区发现了前庭主导调谐，而在腹侧顶内（VIP）区发现了相对平衡的视觉/前庭调谐，在背内侧上级颞（MSTd）区发现了视觉主导调谐。虽然这些领域各自的功能作用仍然不清楚，知觉赤字在标题歧视可逆的化学失活区MSTd区表明，前庭主导的标题调谐区域也有助于行为。为了探索其他区域在航向感知中的作用，蝇蕈醇注射用于可逆性地阻断猕猴双侧PIVC或VIP区域。失活的前PIVC增加心理物理阈值时，标题的判断是基于视流或前庭线索，虽然效果更强的前庭刺激。所有行为缺陷均在36 h内恢复。PIVC后部失活后，视觉缺陷更大，这可能是因为这些注射侵入了VPS区域，该区域包含具有光流调谐的神经元（与PIVC不同）。相比之下，VIP失活导致没有行为缺陷，尽管事实上，VIP神经元表现出更强的选择相关的活动比MSTd神经元。这些结果表明，VIP区提供了一个平行的和部分冗余的路径，这一任务，或不参与标题歧视。相反，PIVC/VPS区，沿着MSTd区，基于前庭或视觉信号对航向感知做出因果贡献。多感觉前庭和视觉信号被发现在多个皮质区，但他们的因果关系的自我运动知觉的贡献已被以前只在背内侧上级颞（MSTd）区进行了测试。在这些实验中，我们表明，顶岛前庭皮质（PIVC）的失活也导致因果赤字在标题歧视的视觉和前庭线索。相反，腹侧顶内（VIP）区失活导致没有行为缺陷，尽管事实上，VIP神经元表现出更强的选择相关的活动比MSTd或PIVC神经元。这些结果表明，选择相关的活动并不总是意味着在感官知觉的因果关系的作用。
Multisensory convergence of visual and vestibular signals has been observed within a network of cortical areas involved in representing heading. Vestibular-dominant heading tuning has been found in the macaque parietoinsular vestibular cortex (PIVC) and the adjacent visual posterior sylvian (VPS) area, whereas relatively balanced visual/vestibular tuning was encountered in the ventral intraparietal (VIP) area and visual-dominant tuning was found in the dorsal medial superior temporal (MSTd) area. Although the respective functional roles of these areas remain unclear, perceptual deficits in heading discrimination following reversible chemical inactivation of area MSTd area suggested that areas with vestibular-dominant heading tuning also contribute to behavior. To explore the roles of other areas in heading perception, muscimol injections were used to reversibly inactivate either the PIVC or the VIP area bilaterally in macaques. Inactivation of the anterior PIVC increased psychophysical thresholds when heading judgments were based on either optic flow or vestibular cues, although effects were stronger for vestibular stimuli. All behavioral deficits recovered within 36 h. Visual deficits were larger following inactivation of the posterior portion of the PIVC, likely because these injections encroached upon the VPS area, which contains neurons with optic flow tuning (unlike the PIVC). In contrast, VIP inactivation led to no behavioral deficits, despite the fact that VIP neurons show much stronger choice-related activity than MSTd neurons. These results suggest that the VIP area either provides a parallel and partially redundant pathway for this task, or does not participate in heading discrimination. In contrast, the PIVC/VPS area, along with the MSTd area, make causal contributions to heading perception based on either vestibular or visual signals. SIGNIFICANCE STATEMENT Multisensory vestibular and visual signals are found in multiple cortical areas, but their causal contribution to self-motion perception has been previously tested only in the dorsal medial superior temporal (MSTd) area. In these experiments, we show that inactivation of the parietoinsular vestibular cortex (PIVC) also results in causal deficits during heading discrimination for both visual and vestibular cues. In contrast, ventral intraparietal (VIP) area inactivation led to no behavioral deficits, despite the fact that VIP neurons show much stronger choice-related activity than MSTd or PIVC neurons. These results demonstrate that choice-related activity does not always imply a causal role in sensory perception.