Tang Kenneth, Staines W Richard, Black Sandra E, McIlroy William E
Graduate Department of Rehabilitation Science, University of Toronto, Toronto, Ontario, Canada.
J Neurosci Methods. 2009 Mar 30;178(1):65-74. doi: 10.1016/j.jneumeth.2008.11.024. Epub 2008 Dec 7.
Innovative perceptual-motor learning paradigms applicable for functional magnetic resonance imaging (fMRI) offer much potential for elucidating the specific cortical mechanisms that underpin short-term learning. In this study, a novel, fMRI-compatible, vibrotactile discrimination task, adapted from a tactile version of the Morse-code, was introduced. Uniquely, this task featured distinct components of training and testing, such that cortical changes associated with these modalities of learning may be dissociated. During testing, the ability to correctly associate matching and non-matching vibrotactile/visual stimulus pairs was assessed. Initial testing in naïve healthy subjects (n = 23) revealed a training-dependent decrease in discrimination error rates and discrimination reaction time over the course of a single fMRI session. The rate and extent of learning were significantly decreased when the complexity of vibrotactile stimuli to be discriminated was increased. In a subgroup of subjects (n = 15) who participated in repeated testing, it was revealed that both initial testing and retesting sessions were characterized by similar within-subject training-related behavioral properties, when different vibrotactile patterns of similar challenge level were presented for the retesting session. Preliminary functional imaging data from a single subject case-study revealed task-related cortical activations over a widely distributed frontoparietal network, which demonstrated spatial consistency within- and also between-sessions (test-retest). Observed behavioral and cortical properties suggest that the current methodology may be suitable for assessing neural changes linked to short-term vibrotactile learning. In addition, demonstrated test-retest capability of the proposed task may uniquely permit applications where test conditions are to be manipulated within-subjects.
适用于功能磁共振成像（fMRI）的创新性感知运动学习范式，在阐明支撑短期学习的特定皮层机制方面具有很大潜力。在本研究中，引入了一种新颖的、与fMRI兼容的振动触觉辨别任务，该任务改编自摩尔斯电码的触觉版本。独特的是，此任务具有不同的训练和测试组件，因此与这些学习模式相关的皮层变化可能会被区分开来。在测试期间，评估正确关联匹配和不匹配的振动触觉/视觉刺激对的能力。对23名未经训练的健康受试者进行的初始测试表明，在单次fMRI实验过程中，辨别错误率和辨别反应时间会随着训练而降低。当要辨别的振动触觉刺激的复杂性增加时，学习的速度和程度会显著降低。在参与重复测试的15名受试者亚组中发现，当在重新测试阶段呈现相似挑战水平的不同振动触觉模式时，初始测试和重新测试阶段在个体内部均具有与训练相关的相似行为特性。来自单个受试者案例研究的初步功能成像数据显示，在广泛分布的额顶叶网络上存在与任务相关的皮层激活，这在实验内和实验间（重测）均表现出空间一致性。观察到的行为和皮层特性表明，当前方法可能适用于评估与短期振动触觉学习相关的神经变化。此外，所提出任务展示的重测能力可能独特地允许在个体内部操纵测试条件的应用。
