Posterior Parietal Cortex Regulates Intrinsic Neural Timescales and Attentional Processing in Frontal Eye Field

Intrinsic neural timescales characterize the dynamics of endogenous fluctuations in neural activity. We measured the intrinsic timescales of frontal eye field (FEF) neurons and examined changes during posterior parietal cortex (PPC) inactivation. FEF neurons exhibit a bimodal distribution of intrinsic timescales, with shorter timescale neurons processing rapid visual information and longer timescale neurons more involved in sustained attentional modulation. PPC inactivation significantly increased intrinsic timescales in both neuron types, with a 15-fold greater increase in shorter timescale neurons. Additionally, PPC inactivation reduced visual and attentional responses, with a stronger effect on attention in longer timescale neurons. This disruption eliminated the correlation between timescales and attentional responses observed in the control condition. Our results provide the first causal evidence that FEF intrinsic timescales depend on long-range projections from PPC, suggesting the presence of at least two network motifs with different timescales that contribute to neuronal dynamics and functional computations within FEF.