Attention strengthens across-trial pre-stimulus phase coherence in visual cortex, enhancing stimulus processing

Abstract

Attention selectively routes the most behaviorally relevant information from the stream of sensory inputs through the hierarchy of cortical areas. previous studies have shown that visual attention depends on the phase of oscillatory brain activities. these studies mainly focused on the stimulus presentation period, rather than the pre-stimulus period. Here, we hypothesize that selective attention controls the phase of oscillatory neural activities to efficiently process relevant information. We document an attentional modulation of pre-stimulus inter-trial phase coherence (a measure of deviation between instantaneous phases of trials) of low frequency local field potentials (LFP) in visual area Mt of macaque monkeys. our data reveal that phase coherence increases following a spatial cue deploying attention towards the receptive field of the recorded neural population. We further show that the attentional enhancement of phase coherence is positively correlated with the modulation of the stimulus-induced firing rate, and importantly, a higher phase coherence is associated with a faster behavioral response. these results suggest a functional utilization of intrinsic neural oscillatory activities for an enhanced processing of upcoming stimuli.One of the most important cognitive functions of the mammalian brain is selective attention. Attention selectively routes the most behaviorally relevant information from the stream of sensory inputs through the hierarchy of cortical areas. This allows the brain to make the most efficient use of its limited neural resources and to create appropriate behavioral responses quickly 1 . Attentional influences on neural responses in sensory cortex have been extensively documented; effects which reflect a multitude of aspects of cortical information processing 1-4 . Covertly directing attention towards the receptive field of a neuron in visual cortex enhances the neural responses even in the absence of visual stimulation 5,6 , alters the shape and profile of receptive fields 7-9 , modulates the variability and temporal structure of the neuron's firing patterns 10,11 , modulates inter-neuronal correlations to increase neural discriminability 12,13 and synchronizes neighboring neurons, presumably to better propagate information to downstream areas [14][15][16] .Attention has been suggested to exploit oscillatory neural activities, as well as oscillatory components of local field potentials (LFP), to enhance the efficacy of cortical processing 17-23 . LFPs represent synaptic activities of local cortical neuronal populations 24 . Their oscillations are tightly linked to attention in both low and high frequencies 18,[25][26][27][28][29] . Previous studies have shown that synchronization in the gamma as well as high gamma band

A Deep Learning-Based Approach to Video-Based Eye Tracking for Human Psychophysics

“…Cognitive neurosciences and neuromarketing rely on gaze tracking ( Lim, 2018 ; Zareian et al, 2020 ; Parto Dezfouli et al, 2021 ; Veith et al, 2021 ); however, a proper solution has been missing due to the high number of degrees of freedom involved with the possible combinations of eye and head movements. Here, we showed that by using a recently introduced pose-estimation tool named DLC, the dimensionality of gaze tracking could be reduced considerably to estimate the point of gaze with a shallow artificial neural network.…”

Attentional brain rhythms during prolonged cognitive activity

“…Second, we show that on high behavioral performance epochs, LFP alpha coherency is higher than on low behavioral performance epochs. Signal coherency within and between brain areas is proposed as a key mechanism at the core of brain computing functions and supports information/stimulus processing(Fries, 2015b), accounting for network connectivity(Vinck et al, 2010), and changes in behavioral performance(Zareian et al, 2018, 2020). Last, we report changes in spike field coherency within the prefrontal cortex between the epochs of high vs. low behavioral performance, in the same frequency ranges as reported by others during attention orientation(Fries et al, 2008; Gregoriou et al, 2009b; Paneri and Gregoriou, 2017), thus pointing to a direct modulation of attentional mechanisms.…”

Phase of neural oscillations as a reference frame for attention-based routing in visual cortex

“…Methodological details concerning our animal subjects, their holding and welfare, our experimental permits, surgeries and implants as well as details of the experimental setup were reported previously [16,70,[73][74][75]. We reiterate relevant details here:…”

“…For example, Montemurro et al previously reported that in the primary visual cortex (i.e., V1 of anaesthetized monkey), the phase of neuronal spikes (relative to low-frequency oscillations) provides additional information, exceeding the information that can be extracted from the spike rate alone [8]. Recent research has provided evidence for the significance of the interaction between the spike times and the oscillatory phase in the ongoing population activity in association with high-level brain functions, such as visual attention [9][10][11][12][13][14][15][16], sensory processing [17,18], decision making [19], and memory [20][21][22][23][24]. In addition to information encoding [24][25][26][27][28], this spike-phase coupling, as an indication of spike timing control, mediates the inter-neuronal synchronization of activity within a region, that is of particular importance for not only optimizing the inter-areal communication via the temporal coordination of postsynaptic potentials [29][30][31], but also the performance of subjects' perceptual decisions [32,33].…”