I am in the midst of writing a longer, more substantial post, but, because I have not written a post in awhile, I thought it would be better to give a bit of a prelude to the upcoming post. This short post is more about asking the fundamental question regarding those functions relating to 'cognition' and those of 'emotion'. This post is really just something that has been spinning through my head for the past few months, inspired by an article I read questioning such a distinction and the nature of the two terms. As such, I am very much eager to hear others' arguments and opinions on the subject. As should be mentioned before long, I am primarily talking about rodents.
Do these functions matter, meaning can cognition and emotion ever be twisted apart; does this unraveling even matter, since they are so inter-connected and joined that maybe they are one entity; finally, maybe more importantly, are these terms neurally meaningless and just semantically-null labels we give functions because we can simply ask the questions and label the function?
While this cognition/emotion question is relevant to all psychological processes, it seems to be a particularly tricky problem in the hippocampus and especially with non-human animals.
(read more after the jump...)
There are many different theories floating around about what the hippocampus serves behaviorally; it appears to have a multi-functional and disparate hat that it wears. Broadly, the hippocampus can be characterized as those functions involved in cognition and those in emotion (obviously not all aspects of these umbrella terms). Why would one structure appear to serve 'cognitive' functions on one hand and 'emotive' functions on the other?
Obviously, on a neural level, cognition and emotion are null statements. Neurons don't care if the information they receive is either this or that. They just process the incoming information. It is not until we look at the whole circuitry that connects together that we get 'something'. Then, we assign 'cognition' or 'emotion' to that 'something' from that neural network by behaviors we observe or previously observed. If we just look at an EEG, fMRI, or single-unit recording without any context that we assign to it, we don't know what's happening. We give behavioral tasks to determine what type of information it is processing.
When we speak of this dissociation, we are mainly explaining these processes by the behavioral output of the structures, and, in this case, the hippocampus appears to be concerned with depressive-/anxiety-like behaviors and spatial/contextual/mnemonic functions. Even those of cognitive behaviors, such as with contextual 'remembering' and 'encoding' and spatial processing (which, no matter what level we look at them from) we are inferring something about (1) the anatomical area and (2) the behavior of the animal (humans get a bit more complicated with language - so I'll leave that alone for now).
In brief, with regard to the hippocampus, there are those theories that say something about already-stored information, such as those dealing with spatial and contextual maps -- are these maps stored within the hippocampus itself? There are those relating to to-be-stored information, such as those relating to gathering information into a trace memory or long-term memory via relational processes; in the same vein, there is the idea that it is involved with 'systems' consolidation, the transfer and stabilization of a labile memory to the outer cortex. Finally, there are those relating to expectancies and inhibition, such as the inhibition of attention, signals of non-reward, and activation.
So, I ask, at least in the rodent, at what level is the distinction important, if at all? Many of the traditionally thought emotional behaviors can, with a twist of a thought, be re-interpreted to reflect cognitive functions.
I look forward to comments about this!