Dynamic Modulation of Sensory Cortex by Top-Down Spatial Attention
Abstract
The concept of attention provides a compelling bridge between the descriptions of higher cognitive processes at the mental and neural levels. We are all intuitively aware of the state of attending--its psychological quality and associated behavioral benefits, yet only in recent decades has the neural basis for these benefits begun to be studied. The studies presented here use EEG and MEG to identify patterns of neural activity related to the deployment of attention in extra personal space, and examine the temporal dynamics of these signals as they evolve in response to attentional cues. In our first experiment, we use cued attention to auditory stimuli with similar spectral features to characterize the spatio-temporal and frequency structure of attention-related EEG signals. In a second experiment we use simultaneously recorded EEG/MEG to examine the interaction of these top-down signals with neural responses evoked by attended and unattended visual stimuli, tagged using gamma-band SSVEP. Finally, we present a physiologically motivated cortical population model capable of treating these interactions, and test its predictions against the effects observed in our data. Together, these studies suggest a picture of spatial attention signals originating in distributed fronto-parietal networks which operate via modulations of endogenous low-frequency activity.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 15, 2015
- Accession Number
- AD1010493
Entities
People
- Samuel Thorpe
Organizations
- University of California, Irvine