Neuroscience 2004 Abstract
| Presentation Number: | 649.13 |
|---|---|
| Abstract Title: | Implicit motor preparation in response to a visual stimulus might be subserved by the superior colliculus. |
| Authors: |
Minelli, A.*1
; Marzi, C.1
; Girelli, M.1
1Neurological and Vision Sci., Univ. of Verona, Verona, Italy |
| Primary Theme and Topics |
Sensory Systems - Vision -- Visual cortex: Perception and action |
| Secondary Theme and Topics | Cognition and Behavior<br />- Human Cognition, Behavior, and Anatomy<br />-- Perception and imagery |
| Session: |
649. Perception and Action Poster |
| Presentation Time: | Tuesday, October 26, 2004 8:00 AM-9:00 AM |
| Location: | San Diego Convention Center - Hall A-H, Board # BB2 |
| Keywords: | implicit processing, ERP recordings, subcortical pathways |
Recently, we provided evidence that undetected near-threshold visual stimuli are able to trigger motor preparation in primary motor cortex, as witnessed by a component of the event related potentials (ERPs) called lateralized readiness potential (LRP) (Minelli A. et al.; SFN abstract n. 386.19, 2003). A possible candidate for the neural site subserving this effect is the superior colliculus (SC), which might be crucially involved in implicit processing of visual stimuli (Marzi et al.; Progress in Brain Research, 2003). Given that the SC appears not to receive direct projections from short-wave sensitive cones (S cones), we used a short-wave monochromatic purple stimulus to trigger the motor response. Ten normal observers were required to respond to lateralized visual stimuli presented at two different luminance levels following a visual warning signal: i) high luminance stimuli leading to 100% detection; ii) low luminance stimuli leading to 50% detection. Therefore, the same physical stimulation could elicit two different behaviors (response vs. no-response). In a third condition, catch trials with the warning signal only were presented. The prediction was the following: If the SC subserves subliminal detection, by using purple stimuli, no implicit LRP should be observed in response to low luminance undetected stimuli. The ERPs analysis confirmed the above prediction in that no reliable LRP was observed in response to undetected purple stimuli or during catch trials. Taken together, our previous and present results suggest that undetected visual stimuli are able to elicit motor preparation in primary motor cortex and this effect is likely to be mediated by the SC.
Supported by COFIN-Italian MIUR
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2004 Neuroscience Meeting Planner. San Diego, CA: Society for Neuroscience, 2004. Online.
Copyright © 2004-2025 Society for Neuroscience; all rights reserved. Permission to republish any abstract or part of any abstract in any form must be obtained in writing by SfN office prior to publication.
