ePoster

Bimodal multistability during perceptual detection in the ventral premotor cortex

Bernardo Andrade-Ortega, Sergio Parra, Antonio Zainos, Héctor Díaz, Ranulfo Romo, Lucas Bayones, Roman Rossi-Pool
Bernstein Conference 2024(2024)
Goethe University, Frankfurt, Germany

Conference

Bernstein Conference 2024

Goethe University, Frankfurt, Germany

Resources

Authors & Affiliations

Bernardo Andrade-Ortega, Sergio Parra, Antonio Zainos, Héctor Díaz, Ranulfo Romo, Lucas Bayones, Roman Rossi-Pool

Abstract

How does the brain process and integrate information from different sensory modalities? This intriguing question has been explored in this study by recording the activity of the Ventral Premotor Cortex (VPC) in two trained macaques (Macaca mulatta) while performing a Bimodal Detection Task (BDT) previously used by Parra et al., 2022. In BDT, subjects were required to identify and report the modality, or the absence thereof, of a near-threshold stimulus that could be either tactile or acoustic. An initial approach on single cells revealed the presence of neurons that were responsive to tactile and/or acoustic stimuli. Moreover, some units predominantly demonstrated sensory responses, while others exhibited sustained activity during the decision maintenance delay—i.e. between the onset of the stimulus and the motor execution. To delve deeper, we employed dimensional reduction techniques to scrutinize the population dynamics. These analyses in biological networks were also compared with theoretical models based on Recurrent Neural Networks (RNN), where a striking finding was the clear divergence between tactile and acoustic responses during the stimulation period. This phenomenon was consistent across both the VPC and the RNN models; and is a multimodal extension of what has been observed for the tactile detection task (Carnevale et al., 2015). During the delay, the neural trajectories rotated within a subspace orthogonal to the initial sensory responses, effectively preserving the decision memory. This suggests that the network can sustain different stable responses that correlate with the three potential outcomes of the task. In summary, our findings indicate that the VPC is equipped with neurons capable of bimodal coding. Likewise, its neuronal population possesses the remarkable ability to integrate competing sensory information and preserve a decision regarding the modality throughout a delay period.

Unique ID: bernstein-24/bimodal-multistability-during-perceptual-fbcde22d