Effects of age and expertise on tactile perception: Investigation of underlying neural mechanisms using transcranial direct current stimulation

年龄和专业知识对触觉感知的影响：使用经颅直流电刺激研究潜在的神经机制

• 批准号: 407249047
• 负责人: Professor Dr. Ben Godde
• 金额: --
• 依托单位: Chair of Neuroscience and Human Performance
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/407249047?language=en
• 关键词: Effects; age; expertise; tactile; perception

Our overarching goal is to examine with transcranial direct current stimulation (tDCS) how age and expertise affect the mutual balance between excitation and inhibition within the somatosensory cortex. Tactile perception contributes importantly to manual dexterity and therefore to the mastering of many activities of daily living. Impairment of tactile perception in older age often results in loss of independence. However, age-related decline in tactile performance can be delayed or prevented by training and acquisition of tactile expertise in middle adulthood, for example on the job. Tactile aging is accompanies by alterations on the neural level which can be observed as changes in early (somatosensory) and late (cognitive) ERP components. Interestingly also these changes in ERP components seem to be reversible of delayed by tactile expertise. Supposedly, an altered balance between local excitation and inhibition play an important role in these processes. Although expertise and aging have been suggested to have different effects on inhibition and excitation during perception and learning, namely a focal increase of exciation with expertise and a decrease of lateral inhibition with aging, is seems that these different effects on the synaptic level have similar effects on the EEG measures. This question we want to further examine with this follow-up study to the Bremen Hand Study @ Jacobs. For this purpose we will use tDCS to modulate intracortical exciation and inhibition within the somatosensory cortex. To further investigate how sensory plasticity differs in experts and older adults we also aim to combine a tactile training paradigm with tDCS. Based on the assumption that effects of expertise and age on the balance between excitation and inhibition are basically different we expect on the electrophysiological level (measured with EEG) as well as on the behavioral level (tactile discrimination and learning progress) an interaction between the type of modulation (excitatory versus inhibitory) with the factors age and expertise. Particularly in older adults, inhibitory (cathodal) tDCS should counteract the hypothesized unspecific increase of excitation und improve tactile performance. Young adults and experts should reveal less effects on the behavioral level even with a reduced but still specific activation. Opposite effects are expected of anodal (excitatory) tDCS. For facilitation of tactile learning we hypothesize a comparable dissociation.

我们的首要目标是通过经颅直流电刺激 (tDCS) 检查年龄和专业知识如何影响体感皮层内兴奋和抑制之间的相互平衡。触觉对于手的灵活性有重要贡献，因此有助于掌握许多日常生活活动。老年触觉受损通常会导致独立性的丧失。然而，通过在成年中期（例如在工作中）接受触觉专业知识的培训和获得，可以延迟或预防与年龄相关的触觉表现下降。触觉老化伴随着神经水平的改变，这可以通过早期（体感）和晚期（认知）ERP 成分的变化来观察。有趣的是，ERP 组件中的这些变化似乎可以通过触觉专业知识来逆转或延迟。据推测，局部兴奋和抑制之间的平衡改变在这些过程中发挥着重要作用。尽管专业知识和衰老被认为对感知和学习过程中的抑制和兴奋有不同的影响，即随着专业知识的兴奋的局部增加和随着年龄的增长侧抑制的减少，但似乎这些对突触水平的不同影响对脑电图测量有类似的影响。我们希望通过不来梅手部研究@Jacobs 的后续研究进一步研究这个问题。为此，我们将使用 tDCS 来调节体感皮层内的皮质内兴奋和抑制。为了进一步研究专家和老年人的感觉可塑性有何不同，我们还致力于将触觉训练范例与 tDCS 相结合。基于专业知识和年龄对兴奋和抑制之间平衡的影响基本上不同的假设，我们预计在电生理水平（用脑电图测量）以及行为水平（触觉辨别和学习进度）上，调节类型（兴奋性与抑制性）与年龄和专业知识因素之间存在相互作用。特别是在老年人中，抑制性（阴极）tDCS 应该抵消假设的非特异性兴奋增加并改善触觉表现。年轻人和专家应该揭示，即使激活减少但仍然是特定的，对行为水平的影响也较小。阳极（兴奋性）tDCS 预计会产生相反的效果。为了促进触觉学习，我们假设存在类似的分离。