Dorsal premotor cortex: neural correlates of reach target decisions based on a color-location matching rule and conflicting sensory evidence.
Journal of Neurophysiology. 2015-06-01; 113(10): 3543-3573
DOI: 10.1152/jn.00166.2014
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1. J Neurophysiol. 2015 Jun 1;113(10):3543-73. doi: 10.1152/jn.00166.2014. Epub 2015
Mar 18.
Dorsal premotor cortex: neural correlates of reach target decisions based on a
color-location matching rule and conflicting sensory evidence.
Coallier É(1), Michelet T(2), Kalaska JF(3).
Author information:
(1)Groupe de recherche sur le système nerveux central (Fonds de recherche du
Québec-Santé), Département de Neurosciences, Faculté de Médecine, Université de
Montréal, succursale Centre-Ville, Montréal, Québec, Canada; and.
(2)Université Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293,
Bordeaux, France; and Centre National de la Recherche Scientifique, Institut des
Maladies Neurodégénératives, UMR 5293, Bordeaux, France.
(3)Groupe de recherche sur le système nerveux central (Fonds de recherche du
Québec-Santé), Département de Neurosciences, Faculté de Médecine, Université de
Montréal, succursale Centre-Ville, Montréal, Québec, Canada; and
.
We recorded single-neuron activity in dorsal premotor (PMd) and primary motor
cortex (M1) of two monkeys in a reach-target selection task. The monkeys chose
between two color-coded potential targets by determining which target’s color
matched the predominant color of a multicolored checkerboard-like Decision Cue
(DC). Different DCs contained differing numbers of colored squares matching each
target. The DCs provided evidence about the correct target ranging from
unambiguous (one color only) to very ambiguous and conflicting (nearly equal
number of squares of each color). Differences in choice behavior (reach response
times and success rates as a function of DC ambiguity) of the monkeys suggested
that each applied a different strategy for using the target-choice evidence in
the DCs. Nevertheless, the appearance of the DCs evoked a transient coactivation
of PMd neurons preferring both potential targets in both monkeys. Reach response
time depended both on how long it took activity to increase in neurons that
preferred the chosen target and on how long it took to suppress the activity of
neurons that preferred the rejected target, in both correct-choice and
error-choice trials. These results indicate that PMd neurons in this task are not
activated exclusively by a signal proportional to the net color bias of the DCs.
They are instead initially modulated by the conflicting evidence supporting both
response choices; final target selection may result from a competition between
representations of the alternative choices. The results also indicate a temporal
overlap between action selection and action initiation processes in PMd and M1.
Copyright © 2015 the American Physiological Society.
DOI: 10.1152/jn.00166.2014
PMCID: PMC4461887
PMID: 25787952 [Indexed for MEDLINE]