title: Individual Differences in Premotor Brain Systems Underlie Behavioral Apathy.
abstract: Lack of physical engagement, productivity, and initiative-so-called "behavioral apathy"--is a common problem with significant impact, both personal and economic. Here, we investigate whether there might be a biological basis to such lack of motivation using a new effort and reward-based decision-making paradigm, combined with functional and diffusion-weighted imaging. We hypothesized that behavioral apathy in otherwise healthy people might be associated with differences in brain systems underlying either motivation to act (specifically in effort and reward-based decision-making) or in action processing (transformation of an intention into action). The results demonstrate that behavioral apathy is associated with increased effort sensitivity as well as greater recruitment of neural systems involved in action anticipation: supplementary motor area (SMA) and cingulate motor zones. In addition, decreased structural and functional connectivity between anterior cingulate cortex (ACC) and SMA were associated with increased behavioral apathy. These findings reveal that effort sensitivity and translation of intentions into actions might make a critical contribution to behavioral apathy. We propose a mechanism whereby inefficient communication between ACC and SMA might lead to increased physiological cost--and greater effort sensitivity--for action initiation in more apathetic people.
authors.affiliation: Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, UK.
authors.forename: Valerie
authors.initials: V
authors.lastname: Bonnelle
authors.affiliation: Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, UK.|Institute of cognitive neuroscience, University College London, London WC1N 3AR, UK.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Manohar
authors.affiliation: Department of Clinical Neurology, Centre for Functional Magnetic Resonance Imaging of the Brain, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK.|Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3BG, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Behrens
authors.affiliation: Department of Experimental Psychology, University of Oxford, Oxford OX1 3UD, UK.|Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK.
authors.forename: Masud
authors.initials: M
authors.lastname: Husain
mesh_terms: D000328:Adult; D057565:Apathy / Q000502:physiology*; D001931:Brain Mapping; D003463:Cues; D003657:Decision Making; D056228:Feedback, Sensory; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007206:Individuality; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000098:blood supply / Q000502:physiology*; D009434:Neural Pathways / Q000098:blood supply / Q000502:physiology; D010775:Photic Stimulation; D011601:Psychophysics; D012201:Reward; D057566:Self Report; D066127:White Matter / Q000502:physiology; D055815:Young Adult
keywords: action initiation; anterior cingulate cortex; cingulum bundle; motivation; supplementary motor area