 The number of neural properties potentially relevant to explaining mental phenomena is dizzying. This review focuses on the facts that neural sensory systems carry information about the subject’s environment and that neural information processing can be tied to a notion of neural representation. How precisely to understand neural representation is itself a vexed question (Cao 2012, 2014; Shea 2014), but we will deploy a simple assumption with respect to spikes which can be reconfigured for other properties: where a sensory neuron generates spikes when a stimulus is placed in its receptive field, the spikes carry information about the stimulus (strictly speaking, about a random variable). Information as used in neuroscience is typically not a semantic notion, but bearing in mind that caveat, it will simplify matters to speak of a sensory neuron’s activity as representing the relevant aspect of the stimulus that drives the neuron’s response (e.g., direction of motion or intensity of a  sound).[2]  This way of speaking is imprecise, so we shall return to neural representation in the final section when discussing how neural representations might explain conscious contents.