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TY - JOUR AU - Zohary, Ehud AU - Shadlen, Michael N. AU - Newsome, William T. PY - 1994 DA - 1994/07/01 TI - Correlated neuronal discharge rate and its implications for psychophysical performance JO - Nature SP - 140 EP - 143 VL - 370 IS - 6485 AB - SINGLE neurons can signal subtle changes in the sensory environment with surprising fidelity, often matching the perceptual sensitivity of trained psychophysical observers1–10. This similarity poses an intriguing puzzle: why is psychophysical sensitivity not greater than that of single neurons? Pooling responses across neurons should average out noise in the activity of single cells, leading to substantially improved psychophysical performance. If, however, noise is correlated among these neurons, the beneficial effects of pooling would be diminished10–12. To assess correlation within a pool, the responses of pairs of neurons were recorded simultaneously during repeated stimulus presentations. We report here that the observed covariation in spike count was relatively weak, the correlation coefficient averaging 0.12. A theoretical analysis revealed, however, that weak correlation can limit substantially the signalling capacity of the pool. In addition, theory suggests a relationship between neuronal responses and psychophysical decisions which may prove useful for identifying cell populations underlying specific perceptual capacities. SN - 1476-4687 UR - https://doi.org/10.1038/370140a0 DO - 10.1038/370140a0 ID - Zohary1994 ER -