Esmeyer Marlon F, Schmidt Timo T, Blankenburg Felix
Neurocomputation and Neuroimaging Unit, Department of Education and Psychology, Freie Universität Berlin, Berlin, Germany.
Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany.
Imaging Neurosci (Camb). 2025 May 22;3. doi: 10.1162/IMAG.a.11. eCollection 2025.
Neuroscientific research has shown that perceptual decision-making occurs in brain regions that are associated with the required motor response. Recent functional magnetic resonance imaging (fMRI) studies that dissociated decisions from coinciding processes, such as the motor response, partly challenge this, indicating that perceptual decisions are represented in an abstract or sensory-specific manner that might vary across sensory modalities. However, comparisons across sensory modalities have been difficult since most task designs differ not only in modality but also in effectors, motor response, and level of abstraction. Here, we describe an fMRI experiment where participants compared frequencies of two sequentially presented visual flicker stimuli in a delayed match-to-comparison task, which controlled for motor responses and stimulus sequence. A whole-brain searchlight support vector machine analysis of multi voxel patterns was used to identify brain regions containing information on perceptual decisions. Furthermore, a conjunction analysis with data from an analogue vibrotactile study was conducted for a comparison between visual and tactile decision-making processes. Both analyses revealed above-chance decoding accuracies in the left dorsal premotor cortex (PMd) as well as in the left intraparietal sulcus (IPS). While previous primate and human imaging research have implicated these regions in transforming sensory information into action, our findings indicate that the IPS processes abstract decision signals while the PMd represents an effector-dependent, but motor response independent encoding of perceptual decisions that is similar across sensory domains.
神经科学研究表明,感知决策发生在与所需运动反应相关的脑区。最近的功能磁共振成像(fMRI)研究将决策与诸如运动反应等同时发生的过程分离,这在一定程度上对这一观点提出了挑战,表明感知决策以抽象或特定于感觉的方式呈现,可能因感觉模态而异。然而,由于大多数任务设计不仅在模态上不同,而且在效应器、运动反应和抽象水平上也不同,因此跨感觉模态的比较一直很困难。在这里,我们描述了一项fMRI实验,参与者在延迟匹配比较任务中比较两个相继呈现的视觉闪烁刺激的频率,该任务控制了运动反应和刺激序列。使用多体素模式的全脑搜索光支持向量机分析来识别包含感知决策信息的脑区。此外,还与一项类似的振动触觉研究的数据进行了联合分析,以比较视觉和触觉决策过程。两项分析均显示,左背侧运动前皮质(PMd)以及左顶内沟(IPS)的解码准确率高于机会水平。虽然先前的灵长类动物和人类成像研究表明这些区域参与将感觉信息转化为行动,但我们的研究结果表明,IPS处理抽象决策信号,而PMd代表一种依赖效应器但独立于运动反应的感知决策编码,这种编码在不同感觉领域是相似的。