In the original formulation of this question, I was trying to understand what motivates "cut and run" behavior in humans. I was defining this anecdotally to include people that have severed ties with valuable objects, e.g., sentimental/rare possessions or people that have up until that time meant a lot to them, seemingly on a whim.
Hoarders, on the other hand, can place a lot of value on objects that are generally considered to be refuse. I think that what I might be witnessing here is the opposite of hoarding, that is, people getting rid of things that actually do have some value (measured on an objective scale) as if they do not.
Looking into hoarding and it's associated disorders, I found some very recent information in Wang et al (2012) regarding some of the neural substrates of acquisitive behavior (which forms some of the physiological basis of hoarding). These researchers found activation in the orbitalfrontal cortex (OFC), a common substrate of obsessive compulsive disorder, associated with acquisitiveness, and activation in the nucleus accumbens (a motor nucleus within the basal ganglia often associated with addictive behaviors) when possessive participants valued a popular "hot" item. There was also activity in the dorsolateral prefrontal cortex, which is associated with monetary valuation of a stimulus, during "disposal" of items that they had acquired during the experiment.
The results of the study gave a small amount of information about the behavior of those that dispose compulsively. The article cited the example that the OFC area of hoarders was also highly activated when they were disposing of some of their prized possessions, but that this was likely to be related to anxiety rather than to the act itself.
Is there anything that is known from functional imaging about neural substrates of the behavior of disposing compulsively that are directly attributable to the behavior itself?
As a side question, from a psychological perspective, is there any notable (Axis II or otherwise) DSM diagnosis that includes this type of compulsive disposing behavior?
Wang, J.M., Seidler, R.D., et al (2012),The neural bases of acquisitiveness: Decisions to acquire and discard everyday goods differ across frames, items, and individuals. Neuropsychologia, 50:939– 948