Biology subjects

katkov, m.

Publications and source records attributed to katkov, m..

3 recordsLinked to original sources

bioRxiv2022

Forgetting Dynamics For Items of Different Categories

AO_SCPLOWBSTRACTC_SCPLOWHow the dynamic evolution of forgetting changes for different materials is unexplored. By using a common experimental paradigm with stimuli of different types, we were able to directly cross-examine the emerging dynamics and we found that even though the presentation sets differ minimally by design, the obtained curves appear to fall on a discrete spectrum. Furthermore, we have previously proposed a model of forgetting based on the notion of retrograde interference with a single integer parameter. All measured curves were compatible with the model with different values of the parameter, hinting to a potential common underlying mechanism of forgetting.

neuroscience↗

bioRxiv2022

Motion-Induced Blindness as a Noisy Excitable System

Perceptual disappearance of a salient target induced by a moving texture mask (MIB: Motion Induced Blindness) is a striking effect, currently poorly understood. Here, we investigated whether the mechanisms underlying MIB qualify as an excitable system. Excitable systems exhibit fast switches from one state to another (e.g., visible/invisible) induced by an above-threshold perturbation and stimulus-independent dynamics, followed by a refractory period. In the experiments, disappearance was induced by masks consisting of slowly rotating radial bars with a gap at the target location, leading to periodic perturbation of the visual field around the target (a bright parafoveal spot). When passed around the target location, masks frequently induced an abrupt target disappearance, pointing to locality. As expected from excitable systems, the disappearance time was not affected by additional bars crossing the target during invisibility, and there was little dependence on the mask configuration. After the target reappeared, it stayed for at least 0.5-2 seconds (the refractory period). Therefore, the mechanisms governing MIB represent an example of an excitable system, where the transition to the invisible state is induced by the mask, with the dynamics that follow determined mostly by the internal network properties.

neuroscience↗

bioRxiv2021

Putative role of PV and SOM interneuron subtypes in working memory

Working memory is an essential human trait required for all cognitive activities. Our previous model from Mongillo et al. (1), Mi et al. (2) uses synaptic facilitation to store traces of working memory. Thus memories can be maintained without persistent neural activity. A critical component of this model is a central inhibition which prevents multiple item representations from being active at the same time. We know from experimental studies that multiple genetically-defined interneuron subtypes (e.g. PV, SOM) with different excitability and connectivity properties mediate inhibition in the cortex. The role of these sub-types in working memory however is not known. Here we develop a modified model with these interneuron subtypes, and propose their functional roles in working memory. We make concrete testable predictions about the roles of these groups.

neuroscience↗