Representation of Cortical Unit Response to Texture and Orientation of Tactile Gratings in the Rat

Karl H. Pribram^1,2,3*, Min Xie¹, Bibo Zheng¹, Michael P. SantaMaria¹, Shannon Hovis¹, Peijun Shan¹ and Joseph King¹

¹Laboratory for Brain Research and Informational Sciences and Department of Psychology, Radford University, Radford VA, U.S.A.
²Cognitive Neuroscience Program, Department of Psychology, Georgetown University, Washington, D.C., U.S.A.
³School of Computational Sciences, George Mason University, Fairfax VA, U.S.A.
*E-mail address: pribramk@georgetown.edu

(Received February 1, 2004; Accepted March 15, 2004)

Keywords: Spectral Density, Vector Representation, Cortical Mapping, Receptive Fields

Abstract. Data obtained as a result of experimental procedures must become encoded and/or displayed in some form to assure communication. The decision as to what form is chosen is not a trivial one. Interpretation hangs on that decision. We have chosen two forms of display of data obtained in mapping receptive fields of units in somatosensory cortex responding to whisker stimulation. Vector representation is a popular form that allows ready interpretation, communication and manipulation. However, the vector representation is less complete than one that maps the entire field in terms of spectral density. Spectral density maps provide a deeper understanding of the response of the cortex because of their greater detail but suffer from being highly convoluted and therefore difficult to use per se in further analyses.