當(dāng)一個動物執(zhí)行某一認知任務(wù)時,，前額皮質(zhì)中的單個神經(jīng)元經(jīng)常會根據(jù)與該行為相關(guān)的各種方面進行適應(yīng)性調(diào)整。這樣所產(chǎn)生的組合反應(yīng)經(jīng)常是難以解讀的,。對執(zhí)行一項“目標順序記憶任務(wù)”的猴子的神經(jīng)活動所做的這項研究，目的是為了確定前額皮質(zhì)中的混合選擇性神經(jīng)元的主導(dǎo)地位對于所執(zhí)行的功能是否至關(guān)重要,。結(jié)果表明,，具有混合選擇性的神經(jīng)元跟那些高度專注于編碼與任務(wù)相關(guān)的某一方面的神經(jīng)元所含信息一樣多。而且，混合選擇性神經(jīng)元實際上在某些方面相對于專門化的神經(jīng)元有相當(dāng)大的計算優(yōu)勢,。
為這項工作所開發(fā)的,、用于從所記錄的神經(jīng)活動提取豐富信息的新的計算方法，應(yīng)能使對那些被廣泛觀察到,、但很少分析過的混合選擇性神經(jīng)元的研究工作變得容易一些,。（生物谷Bioon.com）
生物谷推薦英文摘要：
Nature doi:10.1038/nature12160
The importance of mixed selectivity in complex cognitive tasks
Mattia Rigotti, Omri Barak, Melissa R. Warden, Xiao-Jing Wang, Nathaniel D. Daw, Earl K. Miller & Stefano Fusi
Single-neuron activity in the prefrontal cortex (PFC) is tuned to mixtures of multiple task-related aspects. Such mixed selectivity is highly heterogeneous, seemingly disordered and therefore difficult to interpret. We analysed the neural activity recorded in monkeys during an object sequence memory task to identify a role of mixed selectivity in subserving the cognitive functions ascribed to the PFC. We show that mixed selectivity neurons encode distributed information about all task-relevant aspects. Each aspect can be decoded from the population of neurons even when single-cell selectivity to that aspect is eliminated. Moreover, mixed selectivity offers a significant computational advantage over specialized responses in terms of the repertoire of input–output functions implementable by readout neurons. This advantage originates from the highly diverse nonlinear selectivity to mixtures of task-relevant variables, a signature of high-dimensional neural representations. Crucially, this dimensionality is predictive of animal behaviour as it collapses in error trials. Our findings recommend a shift of focus for future studies from neurons that have easily interpretable response tuning to the widely observed, but rarely analysed, mixed selectivity neurons.
