1998-08-27Z2011-03-11T08:53:39Zhttp://cogprints.org/id/eprint/63This item is in the repository with the URL: http://cogprints.org/id/eprint/631998-08-27ZA paradigmatic working memory (attractor) cell in it cortexWe discuss paradigmatic properties of activity of single cells comprising an attractor -- a developed stable delay activity distribution. To demonstrate these properties and a methodology for measuring their values, we present a detailed account of the spike activity recorded from one single cell in infero-temporal (IT) cortex of a monkey performing a delayed match-to-sample (DMS) task of visual images. In particular, we discuss and exemplify: 1. the relation between spontaneous activity and activity immediately preceding the first stimulus in each trial during a series of DMS trials; 2. the effect on the visual response (i.e. activity {\bf during} stimulation) of stimulus degradation (moving in the space of IT afferents); 3. the behaviour of the delay activity (i.e. activity {\bf following} visual stimulation) under stimulus degradation (attractor dynamics, and the basin of attraction); and, 4. the propagation of information between trials -- the vehicle for the formation of (contextual) correlations by learning a fixed stimulus sequence, as found in Miyashita 1988. In the process of the discussion and demonstration, we expose effective tools for the identification and characterisation of attractor dynamics.Daniel J. AmitStefano FusiVolodya Yakovlev