title: Space, time, and causality in the human brain.
abstract: The ability to perceive causality is a central human ability constructed from elemental spatial and temporal information present in the environment. Although the nature of causality has captivated philosophers and scientists since antiquity, the neural correlates of causality remain poorly understood. In the present study, we used functional magnetic resonance imaging (fMRI) to generate hypotheses for candidate brain regions related to component processes important for perceptual causality in the human brain: elemental space perception, elemental time perception, and decision-making (Experiment 1; n=16). We then used transcranial direct current stimulation (tDCS) to test neural hypotheses generated from the fMRI experiment (Experiment 2; n=16). In both experiments, participants judged causality in billiard-ball style launching events; a blue ball approaches and contacts a red ball. Spatial and temporal contributions to causal perception were assessed by parametrically varying the spatial linearity and the temporal delays of the movement of the balls. Experiment 1 demonstrated unique patterns of activation correlated with spatial, temporal, and decision-making components of causality perception. Using tDCS, we then tested hypotheses for the specific roles of the parietal and frontal cortices found in the fMRI experiment. Parietal stimulation only decreased participants' perception of causality based on spatial violations, while frontal stimulation made participants less likely to perceive causality based on violations of space and time. Converging results from fMRI and tDCS indicate that parietal cortices contribute to causal perception because of their specific role in processing spatial relations, while the frontal cortices contribute more generally, consistent with their role in decision-making.
authors.affiliation: Department of Aging & Geriatric Research, Cognitive Aging & Memory Clinical Translational Research Program, Institute on Aging, University of Florida, Gainesville, FL 32610, USA; Center for Cognitive Neuroscience, Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA. Electronic address: ajwoods@ufl.edu.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Woods
authors.affiliation: Center for Cognitive Neuroscience, Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Roy H
authors.initials: RH
authors.lastname: Hamilton
authors.affiliation: Department of Psychology, Duquesne University, Pittsburgh, PA 15282, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kranjec
authors.affiliation: Department of Biomedical Engineering, City University of New York, New York, NY 10031, USA.
authors.forename: Preet
authors.initials: P
authors.lastname: Minhaus
authors.affiliation: Department of Biomedical Engineering, City University of New York, New York, NY 10031, USA.
authors.forename: Marom
authors.initials: M
authors.lastname: Bikson
authors.affiliation: Center for Cognitive Neuroscience, Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Yu
authors.affiliation: Center for Cognitive Neuroscience, Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Anjan
authors.initials: A
authors.lastname: Chatterjee
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D003657:Decision Making / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D013998:Time Perception / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult
keywords: Decision-making; Perceptual causality; Space; Time; fMRI; tDCS