Thus the response of a neuron may depend not only upon the external environment but also upon its internal environment. Dostrovsky, 1971) are neurons located in the CA1 region of the rat hippocampus which show tuning of their firing rates in response to the animal being located in specific locations in the physical environment which it inhabits. Mc Naughton, 1996) have been able to track the neural response patterns of a behaving animal or several days. Memories would not be stored in an invariant form but would be created on the spot given a specific context.
The simplest understanding was based upon the concept of the reflex arc, that is, the existence of a more or less direct connection between a stimulus and the behavior which it elicits.
This simple model quickly gave way to behaviorism, in which the direct reflex connection was replaced with a more complicated chain of intermediary connections.
While providing a more parsimonious explanation than behaviorism, the idea of representation lacks neurophysiological grounding.
It is not at all clear what exactly constitutes a mental representation, nor how this representation is implemented by the brain.
Thus a grounding of mental representations at the neurophysiological level appears to a rather dubious proposition.