Life Sciences & Biotechnology
Title : | Optimal neural coding of sensory signals |
Area of research : | Life Sciences & Biotechnology |
Focus area : | Neuroscience and Computational Biology |
Principal Investigator : | Prof. Rama Ratnam, Ahmedabad University, Gujarat |
Timeline Start Year : | 2023 |
Timeline End Year : | 2026 |
Contact info : | rama.ratnam@ahduni.edu.in |
Details
Executive Summary : | Despite extensive research on sensory signal coding, the exact principles by which time-varying input is represented in a neuron's output sequence of actions potentials (impulses or spikes) remain unclear. Neuroscientists are divided on which parameter of the sequence of impulses is relevant to the code, such as timing of impulses or average rate of impulse generation. However, selective pressure has balanced competing physiological demands to arrive at an optimal coding principle. Two of these demands are: 1) limiting energy consumption in neurons and 2) maximizing the information obtained from the input sensory signal. High fidelity coding requires high spike-rates, raising energy consumption, while reducing spike-rate lowers metabolic energy costs but reduces information transfer and loss of coding fidelity. Thus, the neural code is likely to be an optimal trade-off between energy consumption and coding fidelity.
A theory of an optimal neural code that balances energy consumption versus fidelity has been developed. The theory predicts that the optimal code is a spike-timing code, with a testable outcome for predicting spike-times for a given stimulus. This work aims to validate these ideas in primary sensory neurons using experiments and theory. Objective 1 involves obtaining the response of sensory neurons to time-varying signals and predicting the timing of spikes and stimulus features. Objective 2 uses low signal-to-noise ratios and sequential detection schemes to show that optimal coding provides the best possible detection performance for a given SNR. An optimal neural code suggests that a neuron is an exquisitely tuned device that times its spikes precisely to maximize coding fidelity, a fundamental shift in our understanding of how the code has been shaped by selection. |
Co-PI: | Dr. Krishna BS Swamy, Ahmedabad University, Ahmedabad, Gujarat-380009 |
Total Budget (INR): | 34,57,696 |
Organizations involved