Dissociable Contribution of Extrastriate Responses to Representational Enhancement of Gaze Targets

Abstract

Before saccadic eye movements, our perception of the saccade targets is enhanced. Changes in the visual representation of saccade targets, which presumably underlie this perceptual benefit, emerge even before the eye begins to move. This perisaccadic enhancement has been shown to involve changes in the response magnitude, selectivity, and reliability of visual neurons. In this study, we quantified multiple aspects of perisaccadic changes in the neural response, including gain, feature tuning, contrast response function, reliability, and correlated activity between neurons. We then assessed the contributions of these various perisaccadic modulations to the population's enhanced perisaccadic representation of saccade targets. We found a partial dissociation between the motor information, carried entirely by gain changes, and visual information, which depended on all three types of modulation. These findings expand our understanding of the perisaccadic enhancement of visual representations and further support the existence of multiple sources of motor modulation and visual enhancement within extrastriate visual cortex.

Pre-saccadic neural enhancements in marmoset area MT

“…Pre-saccadic modulation of firing includes increases in average rate, higher stimulus selectivity, and reductions in variability of response (Moore & Chang 2009; Steinmetz & Moore 2010; Merrikhi et al 2017). Similar enhancements have been identified as well in extra-striate macaque area MT and related to increases in neural sensitivity (Merrikhi et al, 2021). It has also been shown that at off-target locations there are enhancements when the RF stimulus matches features of the saccade target (Burrows et al, 2014).…”

“…However, these differences could also reflect differences in the behavioral tasks, which would be interesting to explore in future studies. Specifically, while previous paradigms measured variability during extended periods of sustained central fixation (Mitchell et al, 2007; Li & Basso, 2008; Moore & Chang, 2009; Cohen & Maunsell, 2009; Steinmetz & Moore, 2010; Merrikhi et al, 2021) we allowed marmosets to initiate saccades with no delay at stimulus onset. It is known that stimulus onsets can quench noise correlations (Churchland et al, 2010), which could explain the modest reductions in our task where saccades were initiated within 150 to 250ms of stimulus onset.…”

“…One difference is that pre-saccadic attention involves an automatic enhancement concentrated around the features of the saccade target, such as its orientation, whereas spatial attention in covert attention enhances stimulus features uniformly (Li et al, 2016; Ohl et al, 2017). While previous neurophysiological studies have found that pre-saccadic attention enhances neural responses (Moore et al, 1998; Li & Basso, 2008; Moore & Chang, 2009; Steinmetz & Moore 2010; Merrikhi et al, 2021), no studies have tested for changes in tuning that would support a concentration of enhancement around target features. Here we examined pre-saccadic attention using a saccade foraging task developed for marmoset monkeys.…”

Neural correlates of perisaccadic visual mislocalization in extrastriate cortex

“…We found unexpectedly that the time course and response components of the spatial bias matched that of another perisaccadic perceptual phenomenon, namely the enhancement of neural sensitivity around the ST. This representational ST enhancement can link to presaccadic enhanced ST perception reported in psychophysical studies 35,37,50 and to presaccadic increased stimulus selectivity 24,26,51,52 or ST remapping 38,39 evidenced in neurophysiological studies. The shared neural response components underlying the ST representational enhancement and bias suggest that the brain likely trades off and prioritizes saccade target representation with consequential biases in location perception.…”

Dynamical Analysis and Synchronization of a New Memristive Chialvo Neuron Model

“…A complete synchronization is a state where all the neurons in the network oscillate at the same dynamics simultaneously. Synchronization plays an essential role in the brain's general functioning, including working memory and motor planning [20][21][22][23]. A variety of types of synchronization have also been observed in patients with epileptic seizures [24], Parkinson's disease [25], schizophrenia [26], and other brain disorders.…”