The representation of priors and decisions in parietal cortex
The representation of priors and decisions in parietal cortex
复制标题
顶叶皮层先验和决策的表示
DOI：
10.1101/2021.05.03.442155
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Marshall T
中科院分区：
文献类型：
--
作者：
Marshall T
动物们通过诸如跳眼运动之类的定向动作积极地对环境进行采样。扫视目标的选择既基于扫视之前的感官证据，也基于在多次扫视中建立的“显著性地图”。在灵长类动物皮层中，每个眼跳的选择取决于目标选择细胞之间的竞争，这些细胞会提高眼跳释放的放电速率。然而，交叉扫视先验如何表现尚不清楚，是通过神经放电还是通过活动沉默机制，如感觉输入突触权重的修改。在这里，我们提出证据从脑磁图的两个不同的过程的选择，当前的扫视，并表示，在人类顶叶皮层的先验。虽然每次扫视的经典加速决策过程反映在神经放电率上（在事件相关领域中测量），但在多次扫视中建立的先验是通过调制来自首选目标的感官输入的增益来表示的，正如快速频率标记所证明的那样。随着时间的推移，一连串的计算（最初的先验表征，随后的证据积累，然后更新）提供了一种机制，通过这种机制，可以在顶叶皮层中建立一个跨越眼跳的显著性图。它还提供了为什么证据积累信号出现在顶叶皮层，而该区域的失活已被证明不会影响单次试验任务的表现。
Animals actively sample their environment through orienting actions such as saccadic eye movements. Saccadic targets are selected based both on sensory evidence immediately preceding the saccade, and a ‘salience map’ or prior built up over multiple saccades. In the primate cortex, the selection of each individual saccade depends on competition between target-selective cells that ramp up their firing rate to saccade release. However it is less clear how a cross-saccade prior might be represented, either in neural firing or through an activity-silent mechanism such as modification of synaptic weights on sensory inputs. Here we present evidence from magnetoencephalography for two distinct processes underlying the selection of the current saccade, and the representation of the prior, in human parietal cortex. While the classic ramping decision process for each saccade was reflected in neural firing rates (measured in the event related field), a prior built up over multiple saccades was represented via modulation of the gain on sensory inputs from the preferred target, as evidenced by rapid frequency tagging. A cascade of computations over time (initial representation of the prior, followed by evidence accumulation and then updating) provides a mechanism by which a salience map may be built up across saccades in parietal cortex. It also provides insight into why evidence accumulation signals are present in parietal cortex, when inactivation of the region has been shown not to affect performance on single-trial tasks.
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影响因子：
5.4
作者：
M. Usher;James L. McClelland
通讯作者：
M. Usher;James L. McClelland
影响因子：
3.7
作者：
Ding, Long;Gold, Joshua I.
通讯作者：
Gold, Joshua I.
DOI：
10.1093/cercor/bhac160
发表时间：
2023-02-20
期刊：
Cerebral cortex (New York, N.Y. : 1991)
影响因子：
--
作者：
通讯作者：
--
猴子额叶损伤后对视觉刺激反应的变化
DOI：
--
发表时间：
1939
期刊：
影响因子：
--
作者：
M. Kennard
通讯作者：
M. Kennard
影响因子：
2.5
作者：
Shadlen, MN;Newsome, WT
通讯作者：
Newsome, WT