caa a22 4500 463245350 CHVBK 20180405153324.0 cr unu---uuuuu 170326e20070601xx s 000 0 eng 10.1007/s00422-007-0149-1 doi (NATIONALLICENCE)springer-10.1007/s00422-007-0149-1 Neuronal selectivity, population sparseness, and ergodicity in the inferior temporal visual cortex [Elektronische Daten] [Leonardo Franco, Edmund Rolls, Nikolaos Aggelopoulos, Jose Jerez] The sparseness of the encoding of stimuli by single neurons and by populations of neurons is fundamental to understanding the efficiency and capacity of representations in the brain, and was addressed as follows. The selectivity and sparseness of firing to visual stimuli of single neurons in the primate inferior temporal visual cortex were measured to a set of 20 visual stimuli including objects and faces in macaques performing a visual fixation task. Neurons were analysed with significantly different responses to the stimuli. The firing rate distribution of 36% of the neurons was exponential. Twenty-nine percent of the neurons had too few low rates to be fitted by an exponential distribution, and were fitted by a gamma distribution. Interestingly, the raw firing rate distribution taken across all neurons fitted an exponential distribution very closely. The sparseness a s or selectivity of the representation of the set of 20 stimuli provided by each of these neurons (which takes a maximal value of 1.0) had an average across all neurons of 0.77, indicating a rather distributed representation. The sparseness of the representation of a given stimulus by the whole population of neurons, the population sparseness a p, also had an average value of 0.77. The similarity of the average single neuron selectivity a s and population sparseness for any one stimulus taken at any one time a p shows that the representation is weakly ergodic. For this to occur, the different neurons must have uncorrelated tuning profiles to the set of stimuli. Springer-Verlag, 2007 Franco Leonardo Depto. de Lenguajes y Cs. de la Computacion, Universidad de Malaga, Campus de Teatinos S/N, 29071, Malaga, Spain aut Rolls Edmund Department of Experimental Psychology, University of Oxford, South Parks Road, OX1 3UD, Oxford, UK aut Aggelopoulos Nikolaos Department of Experimental Psychology, University of Oxford, South Parks Road, OX1 3UD, Oxford, UK aut Jerez Jose Depto. de Lenguajes y Cs. de la Computacion, Universidad de Malaga, Campus de Teatinos S/N, 29071, Malaga, Spain aut Biological Cybernetics Springer-Verlag 96/6(2007-06-01), 547-560 0340-1200 96:6<547 2007 96 422 https://doi.org/10.1007/s00422-007-0149-1 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00422-007-0149-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Franco Leonardo Depto. de Lenguajes y Cs. de la Computacion, Universidad de Malaga, Campus de Teatinos S/N, 29071, Malaga, Spain aut NATIONALLICENCE 700 1- Rolls Edmund Department of Experimental Psychology, University of Oxford, South Parks Road, OX1 3UD, Oxford, UK aut NATIONALLICENCE 700 1- Aggelopoulos Nikolaos Department of Experimental Psychology, University of Oxford, South Parks Road, OX1 3UD, Oxford, UK aut NATIONALLICENCE 700 1- Jerez Jose Depto. de Lenguajes y Cs. de la Computacion, Universidad de Malaga, Campus de Teatinos S/N, 29071, Malaga, Spain aut NATIONALLICENCE 773 0- Biological Cybernetics Springer-Verlag 96/6(2007-06-01), 547-560 0340-1200 96:6<547 2007 96 422 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer