A hypothesis concerning the structural relationship between memory and emotion

Limbic and temporal lobe structures have long been implicated as the anatomic substratum for emotion. Recent investigations have localized the processing of short term memory to a virtually identical anatomical locus. It would seem logical that the same structures subserve both functions if one assumes that the strength of the memory trace is dependent on the emotional value of the information for the organism. Under this hypothesis, the hippocampus emotionally weights sensory data as a preliminary to incorporation of such material into long term memory. It is not necessary, nor is it likely, that long term memory reside within the temporal lobe. Previous associations stored in remote memory can be accessed by the temporal lobe and these may serve to modulate the weighting of the present stimulus. Some of the functions of the temporal lobe can be modeled by a simple electronic filter; the addition of a single feedback loop to this system can account for other properties inherent in the hypothesis. The anatomical connections of the system would permit it to be an early and efficient repressor, in the pyschodynamic sense.