Retinotopically specific effects of attention on human early visual cortex activity.
Laura Herde1, Mona Schönauer-Firle1, Karsten Rauss1
1Institute of Medical Psychology and Behavioral Neurobiology.
Summary
Attention can filter visual information early in processing, but this effect depends on visual field. High attentional load reduced early visual evoked potential (VEP) amplitudes in the lower visual field.
Area of Science:
- Cognitive Neuroscience
- Visual Perception
- Neuroscience
Background:
- Attention is crucial for selecting relevant sensory information.
- The precise timing of attentional selection within early sensory processing remains under investigation.
- Visual evoked potentials (VEPs) offer a measure of early visual processing.
Purpose of the Study:
- To investigate the earliest point at which attentional selection can occur in visual processing.
- To examine the influence of attentional load on early visual evoked potential (VEP) components.
- To explore potential anisotropies in attentional modulation of early visual processing.
Main Methods:
- Assessed the effect of attentional load on the C1 component of the VEP in healthy volunteers.
- Mapped C1 responses to task-irrelevant peripheral textures.
- Used optimal C1 stimuli as distracters during easy and difficult visual detection tasks at fixation.
Main Results:
- High attentional load selectively reduced C1 amplitudes in the lower visual field.
- This observed asymmetry in attentional modulation was opposite to previous findings.
- The results suggest attentional filtering is possible during early visual processing.
Conclusions:
- Attentional selection can occur during early visual processing.
- The effectiveness of attentional filtering interacts with the visual system's anatomic and functional anisotropies.
- Further research is needed to precisely delineate the mechanisms of attentional filtering in early perception.
