Moosavi S Amin, Pastor Antonia, Ornelas Alfredo G, Tring Elaine, Ringach Dario L
Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, California, United States.
Interdepartmental Neuroscience Program, Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, California, United States.
J Neurophysiol. 2025 Jun 1;133(6):2006-2013. doi: 10.1152/jn.00078.2025. Epub 2025 May 5.
Sparse coding enables cortical populations to represent sensory inputs efficiently, yet its temporal dynamics remain poorly understood. Here, we provide direct evidence that stimulus onset initially drives broad cortical activation, transiently reducing sparseness while increasing mutual information. Over time, competitive interactions refine the population response, maintaining high mutual information as activity declines and sparseness increases. Critically, coding efficiency, quantified as the ratio of mutual information to metabolic cost, steadily improves throughout stimulus presentation, revealing an active, time-dependent optimization of sensory representations. The authors show that cortical populations refine sensory representations over time. Initially, broad activation boosts information, but as competition sharpens responses, population sparseness increases while preserving mutual information. This dynamic process steadily improves coding efficiency, revealing an active, time-dependent optimization of sensory representations that balances information and metabolic cost.
稀疏编码使皮层神经元群体能够有效地表征感觉输入，但其时间动态仍知之甚少。在这里，我们提供了直接证据，表明刺激开始时最初会驱动广泛的皮层激活，短暂地降低稀疏性，同时增加互信息。随着时间的推移，竞争性相互作用优化了群体反应，在活动下降和稀疏性增加的同时保持了高互信息。至关重要的是，编码效率（以互信息与代谢成本的比率来量化）在整个刺激呈现过程中稳步提高，揭示了感觉表征的一种主动的、时间依赖性的优化。作者表明，皮层神经元群体随时间优化感觉表征。最初，广泛的激活增加了信息，但随着竞争使反应更加尖锐，群体稀疏性增加，同时保留了互信息。这个动态过程稳步提高了编码效率，揭示了感觉表征的一种主动的、时间依赖性的优化，这种优化平衡了信息和代谢成本。
