Functional Maps of Cortico-Cortical Beta-Frequency Coherence in a Macaque Monkey Performing a Visual Working Memory Task

• Activity Number: 254
• Type: Topic Contributed
• Date/Time: Tuesday, August 4, 2009 : 8:30 AM to 10:20 AM
• Sponsor: Biometrics Section
• Author(s): Mark C. Greenwood*+ and Olga Vsevolozhskaya and Rodrigo F. Salazar and Charlie M. Gray
• Companies: Montana State University and Montana State University and Montana State University and Montana State University
• Keywords: functional data analysis ; regression tree ; multivariate statistics ; neuroscience ; time series

Abstract

In order to investigate the properties of cortical interactions underlying visual working memory, local field potentials were measured simultaneously at multiple locations in prefrontal and posterior parietal cortical areas of a Macaque monkey while it performed a visual, rule-based, delayed match-to-sample task. Functional interactions were evaluated using the spectral coherency function in the beta-frequency range (12-25 Hz) during four separate epochs of the task. A functional data semi-metric (Ferraty & Vieu, 2006) was used to generate a dissimilarity matrix between locations, providing a "functional map" of cortico-cortical interactions. These dissimilarity matrices were compared using Mantel statistics to generate a dissimilarity matrix between the maps under different experimental conditions. Distance-based regression trees (De'ath, 2002) were used to analyze those results.