Related Experiment Videos
Dissociating detection from localization of tactile stimuli
Justin A Harris1, Thida Thein, Colin W G Clifford
1School of Psychology, University of Sydney, Sydney 2052, Australia. justinh@psych.usyd.edu.au
Summary
This study investigated tactile perception, finding that while people are better at detecting touch than locating it, localization follows detection in a sensory processing hierarchy. This challenges previous notions of double dissociation in tactile processing.
Area of Science:
- Neuroscience
- Psychology
- Sensory Perception
Background:
- Neurological studies suggest tactile detection and localization are doubly dissociable.
- Some patients can detect stimuli but not locate them, while others show the opposite deficit.
Purpose of the Study:
- To investigate the relationship between tactile detection and localization in neurologically intact individuals.
- To determine if tactile detection and localization are independent processes or part of a serial hierarchy.
Main Methods:
- Four psychophysical experiments were conducted using tactile stimuli and vibrotactile masking.
- Participants judged stimulus presence (detection) and location (localization).
- Accuracy was measured using bias-free signal detection theory (d') and analyzed with computational models.
Main Results:
- Subjects demonstrated higher accuracy in detecting tactile stimuli compared to localizing them.
- Tactile detection was more sensitive to masking effects (target-mask interval, mask frequency) than localization.
- Localization accuracy was more affected by the target-mask interval than detection accuracy.
Conclusions:
- Tactile detection and localization are not mutually independent.
- Localization appears to be a process that follows tactile detection in a serial sensory processing hierarchy.
- Findings challenge previous neurological evidence suggesting a double dissociation.