Electrophysiological Evidence for a Sensory Recruitment Model of Somatosensory Working Memory
Electrophysiological Evidence for a Sensory Recruitment Model of Somatosensory Working Memory
复制标题
DOI：
10.1093/cercor/bhu153
复制
发表时间：
2015-12-01
期刊：
影响因子：
3.7
通讯作者：
Eimer, Martin
中科院分区：
文献类型：
--
作者：
Katus, Tobias;Grubert, Anna;Eimer, Martin
工作记忆的感觉招募模型假设信息存储是由负责感觉信号感知处理的相同皮质区域介导的。为了检验这一假设，我们在触觉延迟匹配样本任务期间测量了体感事件相关的大脑电位（ERP）。参与者记住一只与任务相关的手上的触觉样本集，并将其与同一只手上的后续测试集进行比较。在保留期间，在相关手对侧的初级体感皮层上引发持续的负性（触觉对侧延迟活动，tCDA）。该分量的幅度随着记忆负荷的增加而增加，并且对记忆容量的个体限制敏感，这表明 tCDA 反映了体感工作记忆中触觉信息的维持。 tCDA 之前是短暂的负性（N2cc 成分），具有类似的对侧头皮分布，这可能反映了编码阶段任务相关触觉刺激的选择。 N2cc 和 tCDA 成分的时间序列反映了先前对视觉工作记忆的 ERP 研究的观察结果。持续体感延迟期活动随着记忆负荷的变化而变化的发现支持了触摸空间工作记忆的感觉招募模型。
Sensory recruitment models of working memory assume that information storage is mediated by the same cortical areas that are responsible for the perceptual processing of sensory signals. To test this assumption, we measured somatosensory event-related brain potentials (ERPs) during a tactile delayed match-to-sample task. Participants memorized a tactile sample set at one task-relevant hand to compare it with a subsequent test set on the same hand. During the retention period, a sustained negativity (tactile contralateral delay activity, tCDA) was elicited over primary somatosensory cortex contralateral to the relevant hand. The amplitude of this component increased with memory load and was sensitive to individual limitations in memory capacity, suggesting that the tCDA reflects the maintenance of tactile information in somatosensory working memory. The tCDA was preceded by a transient negativity (N2cc component) with a similar contralateral scalp distribution, which is likely to reflect selection of task-relevant tactile stimuli at the encoding stage. The temporal sequence of N2cc and tCDA components mirrors previous observations from ERP studies of working memory in vision. The finding that the sustained somatosensory delay period activity varies as a function of memory load supports a sensory recruitment model for spatial working memory in touch.