TY - JOUR T1 - Removing Neural Correlations Improves Population Sensitivity in MT/MST in Response to Random Dot Stimuli JF - bioRxiv DO - 10.1101/267732 SP - 267732 AU - Tristan A. Chaplin AU - Maureen A. Hagan AU - Benjamin J. Allitt AU - Marcello G.P. Rosa AU - Leo L. Lui Y1 - 2018/01/01 UR - http://biorxiv.org/content/early/2018/02/19/267732.abstract N2 - The effect of temporal correlations in the activity of sensory neurons remains a subject of debate, with some studies suggesting that correlations may be detrimental to population coding (by reducing the amount of information that can be extracted) or may actually enhance population coding. The study of neuronal responses to random-dot motion patterns has provided the some of the most valuable insights into how the activity of neurons is related to perception. However, it is currently unknown how changes in the strength of motion signals, through the reduction of coherence of random dot patterns, affects correlated activity and population decoding. To address this question, we recorded neuronal populations in the middle temporal (MT) and medial superior temporal (MST) areas of anaesthetized marmosets with electrode arrays, while varying the coherence of random dot patterns. We used the spike rates of simultaneously recorded neurons to decode the direction of motion at each level of coherence using linear classifiers. We found that reducing motion coherence increased neuronal correlations, yet the correlation structure was conserved. We also found that removing correlations with trial shuffling generally improved population decoding performance and ignoring correlations generally impaired decoding performance. Finally, we showed that decoders trained at 100% coherence have similar performance to decoders optimized for each level of coherence, demonstrating that the optimal linear readout is independent of coherence. These results have implications for how information is encoded by populations of neurons, as well as how they may be decoded by downstream areas in decision making tasks. ER -