Granger causality

Brain activity depends on ongoing behavioural and arousal states, such as attention, eye closure, or sleep. These states display measurable differences in population activity [1], dimensionality [2], noise correlations [3], and autocorrelation timescales [4]. State-dependent changes in the primary visual cortex (V1) are potentially induced by cortico-cortical signals, such as those from V4 to V1, known to mediate visual attention in macaques [5]. However, relationships between such top-down signals and the aforementioned state-dependent changes have not been demonstrated directly. To investig

Major depressive disorder (MDD) significantly impacts the global population. MDD individuals often exhibit a negative processing bias, scrutinized through the approach-avoidance (Ap-Av) decision-making task. The fronto-cingulo-striatal (FCS) network, including the dorsolateral prefrontal cortex (dlPFC), subgenual anterior cingulate cortex (sgACC), pregenual anterior cingulate cortex (pACC) and striatum, is involved in MDD. Further, neural manipulations of the dlPFC and sgACC show promise in alleviating MDD symptoms. In non-human primates, beta-band oscillatory activity in the striatum correlat

Most brain functions rely on constant interactions among specialized brain areas. In primates, synchronized oscillations in distinct frequency bands have been suggested to facilitate the routing of feedforward and feedback signals across hierarchically organized visual areas. However, the underlying mechanisms remain largely unknown. Previous studies in mice identified two distinct visually induced gamma rhythms: a luminance-dependent narrowband high gamma rhythm (~60Hz) in both V1 and higher visual areas and a context-dependent low gamma rhythm (~30Hz) in V1. Our analysis of the open-source A

Object-based visual working memory relies critically on the fronto-temporal cortical network. Investigating interactions within this network is crucial for comprehending the neural mechanisms of goal-directed recall in memory. A delayed color recall task, wherein colors were associated with achromatic images of scenes and geometric drawings, was employed to examine interactions between the temporal and prefrontal cortex through high-density electrocorticography (ECoG) in two macaque monkeys. Regions with similar functionality were identified by clustering the time-varying signal of electrodes

Poor patient outcomes in resective epilepsy surgery remain an area of clinical concern. Regardless of epilepsy type, a third or greater of drug-resistant epilepsy (DRE) patients who undergo resection do not report seizure freedom at a two-year follow-up. One of the likely causes is that current methods for identifying which tissue to resect are subjective and potentially inaccurate. Much of resective surgery planning is based on identification of initial ictogenic tissue--the seizure onset zone (SOZ). However, complete resection of the SOZ, as currently identified, is a poor prognosticator of

…influenced by the choice of causality measure employed, which may not always align with the actual structural connectivity of the network. The relationship between causal and structural connectivity, especially how different causality measures affect the inferred causal links, requires further exploration. In this talk, we examine nonlinear networks characterized by pulse signal outputs, such as spiking neural networks, using four p