Mapping human temporal and parietal neuronal population activity and functional coupling during mathematical cognition.
Brain areas within the lateral parietal cortex (LPC) and ventral temporal cortex (VTC) have been shown to code for abstract quantity representations and for symbolic numerical representations, respectively. To explore the fast dynamics of activity within each region and the interaction between them, we used electrocorticography recordings from 16 neurosurgical subjects implanted with grids of electrodes over these two regions and tracked the activity within and between the regions as subjects performed three different numerical tasks. Although our results reconfirm the presence of math-selective hubs within the VTC and LPC, we report here a remarkable heterogeneity of neural responses within each region at both millimeter and millisecond scales. Moreover, we show that the heterogeneity of response profiles within each hub mirrors the distinct patterns of functional coupling between them. Our results support the existence of multiple bidirectional functional loops operating between discrete populations of neurons within the VTC and LPC during the visual processing of numerals and the performance of arithmetic functions. These findings reveal information about the dynamics of numerical processing in the brain and also provide insight into the fine-grained functional architecture and connectivity within the human brain.
Laboratory of Behavioral and Cognitive Neuroscience, Stanford Human Intracranial Cognitive Electrophysiology Program, Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305; jparvizi@stanford.edu adaitch@stanford.edu.
Amy L
AL
Daitch
Laboratory of Behavioral and Cognitive Neuroscience, Stanford Human Intracranial Cognitive Electrophysiology Program, Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305.|Department of Neurosurgery, Baylor College of Medicine, Houston, TX 77030.
Brett L
BL
Foster
Laboratory of Behavioral and Cognitive Neuroscience, Stanford Human Intracranial Cognitive Electrophysiology Program, Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305.|Department of Computer Science, University College London, London WC1E 6BT, United Kingdom.
Jessica
J
Schrouff
Laboratory of Behavioral and Cognitive Neuroscience, Stanford Human Intracranial Cognitive Electrophysiology Program, Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305.|Department of Psychology, University of California, Berkeley, CA 94720.
Vinitha
V
Rangarajan
Laboratory of Behavioral and Cognitive Neuroscience, Stanford Human Intracranial Cognitive Electrophysiology Program, Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305.|Graduate School of Neuroscience, Istanbul University, Istanbul 34393, Turkey.
Itır
I
Kaşikçi
Laboratory of Behavioral and Cognitive Neuroscience, Stanford Human Intracranial Cognitive Electrophysiology Program, Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305.|Medical Scientist Training Program, University of California, Irvine, CA 92697.
Sandra
S
Gattas
Laboratory of Behavioral and Cognitive Neuroscience, Stanford Human Intracranial Cognitive Electrophysiology Program, Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305; jparvizi@stanford.edu adaitch@stanford.edu.
Josef
J
Parvizi
D003071:Cognition / Q000502:physiology; D000069280:Electrocorticography; D006801:Humans; D055641:Mathematical Concepts; D009474:Neurons / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*
ECoG; brain network; numerical processing; parietal cortex; ventral temporal cortex