Catecholamine-mediated increases in gain enhance the precision of cortical representations

Christopher M. Warren, Eran Eldar, Ruud L. van den Brink, Klodianna Daphne Tona, Nic J. van der Wee, Eric J. Giltay, Martijn S. Van Noorden, Jos A. Bosch, Robert C. Wilson, Jonathan D. Cohen, Sander Nieuwenhuis

Research output: Contribution to journalArticleAcademicpeer-review

56 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)5699-5708
Number of pages10
JournalJournal of neuroscience
Volume36
Issue number21
DOIs
Publication statusPublished - 25 May 2016

Keywords

  • Catecholamine
  • Dopamine
  • FMRI
  • Norepinephrine
  • Perception
  • Psychopharmacology

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