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Updated: Jun 16, 2026
04:40
Tactile Semiautomatic Passive-Finger Angle Stimulator (TSPAS)
Published on: July 30, 2020
Tactile shape discrimination recruits human lateral occipital complex during early perceptual processing
Joshua N Lucan1, John J Foxe, Manuel Gomez-Ramirez
1Program in Cognitive Neuroscience, Department of Psychology, City College of the City University of New York, New York, USA.
Human Brain Mapping
|February 18, 2010
Summary
This study used high-density electroencephalography (EEG) to investigate somatosensory object recognition. Findings show the lateral occipital complex (LOC) is involved early in tactile shape perception, suggesting a multisensory role.
Area of Science:
- Neuroscience
- Cognitive Science
- Sensory Processing
Background:
- Neuroimaging studies indicate the lateral occipital complex (LOC), typically linked to visual object recognition, is active during somatosensory object recognition.
- The low temporal resolution of hemodynamic responses (e.g., fMRI) has hindered precise timing of LOC involvement in somatosensory recognition.
Purpose of the Study:
- To precisely measure the timing of somatosensory object recognition processes using high-density electroencephalography (EEG).
- To determine if LOC activity during somatosensory object recognition occurs during or after the recognition process itself.
Main Methods:
- Employed a modified version of a visual object recognition paradigm with high-density EEG.
- Presented simple geometric shapes to the index finger of 10 participants, recording time-locked EEG.
- Participants either discriminated the shape (primary condition) or judged stimulus duration (control condition).
- Utilized event-related potential (ERP) analysis and source localization techniques.
Main Results:
- Significantly greater evoked potential amplitudes were observed in the shape discrimination condition between 140 and 160 ms post-stimulus.
- This timeframe aligns with when LOC-mediated perceptual processes are thought to occur during visual object recognition.
- Scalp voltage topography and source analysis implicated the LOC as the neural source of the observed effect.
Conclusions:
- The findings support an early, time-locked involvement of the LOC in somatosensory shape recognition.
- This suggests a multisensory role for the LOC, extending beyond its traditional visual function.
- High-density EEG provides the necessary temporal resolution to elucidate the timing of sensory processing in object recognition.
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