Electrical stimulation of the human homolog of the medial superior temporal area induces visual motion blindness.
Despite tremendous advances in neuroscience research, it is still unclear how neuronal representations of sensory information give rise to the contents of our perception. One of the first and also the most compelling pieces of evidence for direct involvement of cortical signals in perception comes from electrical stimulation experiments addressing the middle temporal (MT) area and the medial superior temporal (MST) area: two neighboring extrastriate cortical areas of the monkey brain housing direction-sensitive neurons. Here we have combined fMRI with electrical stimulation in a patient undergoing awake brain surgery, to separately probe the functional significance of the human homologs, i.e., area hMT and hMST, on motion perception. Both the stimulation of hMT and hMST made it impossible for the patient to perceive the global visual motion of moving random dot patterns. Although visual motion blindness was predominantly observed in the contralateral visual field, stimulation of hMST also affected the ipsilateral hemifield. These results suggest that early visual cortex up to the stage of MT is not sufficient for the perception of global visual motion. Rather, visual motion information must be mediated to higher-tier cortical areas, including hMST, to gain access to conscious perception.
Departments of General Neurology and Cognitive Neurology, Hertie Institute for Clinical Brain Research, and Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, 72076 Tübingen, Germany, Department of Neurosurgery, University Hospital Tübingen, 72076 Tübingen, Germany, and Department of Neurology, Aachen University, D-52074 Aachen, Germany.
Hubertus G T
HG
Becker
Thomas
T
Haarmeier
Marcos
M
Tatagiba
Alireza
A
Gharabaghi
D000328:Adult; D001766:Blindness / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D001932:Brain Neoplasms / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D016343:Monitoring, Intraoperative / Q000379:methods*; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods*; D013702:Temporal Lobe / Q000473:pathology / Q000502:physiology* / Q000601:surgery; D014793:Visual Cortex / Q000473:pathology / Q000502:physiology* / Q000601:surgery