Dissociating neuronal signatures of spatial attention and behavioural state in the primary vibrissal cortex of mice

The prioritisation and selective processing of information is imperative to survival. One form of prioritisation, known as spatial attention, allows an animal to selectively process sensory input based on its location. While spatial attention is known to produce changes in neuronal activity, as early as the primary sensory cortex, it is unclear whether phasic changes induced by selective spatial attention differ from those observed with non-selective fluctuations in behavioural states such as arousal. To study attention, the rodent whisker system represents a structurally elegant, and functionally efficient alternative to the often-studied primate visual system. Here, we implemented a novel, ecologically relevant paradigm to incorporate spatial attention in a whisker vibration detection task in mice. We demonstrated that mice (n=11) exhibit spatially selective evidence accumulation behaviour within their responses to single vibration stimuli, across their responses to tens of stimuli, and throughout each day of training. To dissociate the neuronal signatures of spatial attention from those of spatially non-specific behavioural state, we recorded 1461 responsive units in the primary vibrissal cortex (vS1) as mice engaged in the detection task. The strength of neuronal responses to vibrissal stimulation correlated significantly with spatial attention, but not with spatially non-specific behavioural state. We found that spatial attention elevates both baseline and stimulus-evoked neuronal activity, especially during a later (200-600 ms) component of stimulus-evoked responses. These results have implications for the microcircuitry of spatial attention in vS1 and value-driven attentional capture in mice.