Reconciling coherent oscillation with modulation of irregular spiking activity in selective attention: gamma-range synchronization between sensory and executive cortical areas.
In this computational work, we investigated gamma-band synchronization across cortical circuits associated with selective attention. The model explicitly instantiates a reciprocally connected loop of spiking neurons between a sensory-type (area MT) and an executive-type (prefrontal/parietal) cortical circuit (the source area for top-down attentional signaling). Moreover, unlike models in which neurons behave as clock-like oscillators, in our model single-cell firing is highly irregular (close to Poisson), while local field potential exhibits a population rhythm. In this "sparsely synchronized oscillation" regime, the model reproduces and clarifies multiple observations from behaving animals. Top-down attentional inputs have a profound effect on network oscillatory dynamics while only modestly affecting single-neuron spiking statistics. In addition, attentional synchrony modulations are highly selective: interareal neuronal coherence occurs only when there is a close match between the preferred feature of neurons, the attended feature, and the presented stimulus, a prediction that is experimentally testable. When interareal coherence was abolished, attention-induced gain modulations of sensory neurons were slightly reduced. Therefore, our model reconciles the rate and synchronization effects, and suggests that interareal coherence contributes to large-scale neuronal computation in the brain through modest enhancement of rate modulations as well as a pronounced attention-specific enhancement of neural synchrony.
Ardid
Salva
S
Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
Wang
Xiao-Jing
XJ
Gomez-Cabrero
David
D
Compte
Albert
A
D000200:Action Potentials / Q000502:physiology*; D000465:Algorithms; D000818:Animals; D001288:Attention / Q000502:physiology*; D001683:Biological Clocks / Q000502:physiology*; D002540:Cerebral Cortex / Q000033:anatomy & histology / Q000502:physiology*; D003198:Computer Simulation; D003344:Cortical Synchronization; D056344:Executive Function / Q000502:physiology; D006801:Humans; D008432:Mathematical Computing; D009415:Nerve Net / Q000033:anatomy & histology / Q000502:physiology; D016571:Neural Networks, Computer; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D010465:Perception / Q000502:physiology; D016012:Poisson Distribution; D012677:Sensation / Q000502:physiology; D011984:Sensory Receptor Cells / Q000502:physiology*; D014793:Visual Cortex / Q000033:anatomy & histology / Q000502:physiology