TY - JOUR
T1 - Catecholamine-mediated increases in gain enhance the precision of cortical representations
AU - Warren, Christopher M.
AU - Eldar, Eran
AU - van den Brink, Ruud L.
AU - Tona, Klodianna Daphne
AU - van der Wee, Nic J.
AU - Giltay, Eric J.
AU - Van Noorden, Martijn S.
AU - Bosch, Jos A.
AU - Wilson, Robert C.
AU - Cohen, Jonathan D.
AU - Nieuwenhuis, Sander
N1 - Funding Information: This work was supported by a Consolidator Grant of the European Research Council. We thank P. Murphy and L. Nystrom for helpful discussion. Publisher Copyright: © 2016 the authors.
PY - 2016/5/25
Y1 - 2016/5/25
N2 - Neurophysiological evidence suggests that neuromodulators, such as norepinephrine and dopamine, increase neural gain in target brain areas. Computational models and prominent theoretical frameworks indicate that this should enhance the precision of neural representations, but direct empirical evidence for this hypothesis is lacking. In two functional MRI studies, we examine the effect of baseline catecholamine levels (as indexed by pupil diameter and manipulated pharmacologically) on the precision of object representations in the human ventral temporal cortex using angular dispersion, a powerful, multivariate metric of representational similarity (precision). We first report the results of computational model simulations indicating that increasing catecholaminergic gain should reduce the angular dispersion, and thus increase the precision, of object representations from the same category, as well as reduce the angular dispersion of object representations from distinct categories when distinct-category representations overlap. In Study 1 (N = 24), we show that angular dispersion covaries with pupil diameter, an index of baseline catecholamine levels. In Study 2 (N = 24), we manipulate catecholamine levels and neural gain using the norepinephrine transporter blocker atomoxetine and demonstrate consistent, causal effects on angular dispersion and brain-wide functional connectivity. Despite the use of very different methods of examining the effect of baseline catecholamine levels, our results show a striking convergence and demonstrate that catecholamines increase the precision of neural representations.
AB - Neurophysiological evidence suggests that neuromodulators, such as norepinephrine and dopamine, increase neural gain in target brain areas. Computational models and prominent theoretical frameworks indicate that this should enhance the precision of neural representations, but direct empirical evidence for this hypothesis is lacking. In two functional MRI studies, we examine the effect of baseline catecholamine levels (as indexed by pupil diameter and manipulated pharmacologically) on the precision of object representations in the human ventral temporal cortex using angular dispersion, a powerful, multivariate metric of representational similarity (precision). We first report the results of computational model simulations indicating that increasing catecholaminergic gain should reduce the angular dispersion, and thus increase the precision, of object representations from the same category, as well as reduce the angular dispersion of object representations from distinct categories when distinct-category representations overlap. In Study 1 (N = 24), we show that angular dispersion covaries with pupil diameter, an index of baseline catecholamine levels. In Study 2 (N = 24), we manipulate catecholamine levels and neural gain using the norepinephrine transporter blocker atomoxetine and demonstrate consistent, causal effects on angular dispersion and brain-wide functional connectivity. Despite the use of very different methods of examining the effect of baseline catecholamine levels, our results show a striking convergence and demonstrate that catecholamines increase the precision of neural representations.
KW - Catecholamine
KW - Dopamine
KW - FMRI
KW - Norepinephrine
KW - Perception
KW - Psychopharmacology
UR - http://www.scopus.com/inward/record.url?scp=84969844561&partnerID=8YFLogxK
U2 - https://doi.org/10.1523/JNEUROSCI.3475-15.2016
DO - https://doi.org/10.1523/JNEUROSCI.3475-15.2016
M3 - Article
C2 - 27225761
SN - 0270-6474
VL - 36
SP - 5699
EP - 5708
JO - Journal of neuroscience
JF - Journal of neuroscience
IS - 21
ER -