I am of the opinion that phenomena like catnip orgies are best modeled in terms of dynamic systems theory. According to this line of thought,
intentions are seen as grounded in neural patterns. The autonomous nervous system constrains the path of future firings as long as the pattern or [Resonant Cell Assembly] lasts. (Some intentions entail long strings of firing patterns, yielding coherent complex behavior, as in the intention to play a game of basketball.) Sensory input continually feeds into the system along the way, either reinforcing the settling into a pattern or shocking it out of a pattern into a chaotic zone in which other patterns strive to emerge. Decisions are precisely the brain’s falling into one pattern or another, a falling that is modeled as the settling into a basic of attraction that will constrain neural firing in a pattern. There is no linear causal chain of input, processing, and output. Instead there is a continuall looping as sensory information feeds into an ongoing dynamic system, altering or reinforcing pattern formation; in model terms, the trajectory of the system weaves its way in and out of a continually changing attractor landscape whose layout depends upon both the recent and the remote past of the nervous system. (Protevi, 2009, p. 18)
With this in mind, we can understand cat behavior in terms of the catnip chemicals perturbing the intrinsic homeostatic dynamics of the cat-system such that it triggers a cascade of self-stimulating behaviors. It has been hypothesized that the active chemical in catnip mimics a sex pheromone for cats. And because the neural substrate of sex behaviors is likely based in pleasure pathways, we can assume that the experience of smelling catnip is intensely pleasurable, perhaps orgasmic. We can then argue that pleasurable self-stimulation is a fundamental drive for mammals. The pleasure-pathways are so directly attuned to behavior that any perturbation of the pleasure-equilibrium is bound to set off a behavioral cascade that seeks to amplify pleasure by whatever means available until equilibrium is reestablished.
Moreover, we can generalize from these behaviors to a wide array of self-stimulation in human behavior e.g. sex, drug/food addiction, masturbation, etc. It is only the top-down control networks of adult cognition that allow for the inhibition of self-stimulation. That this might be so is evidenced in how autistic children are largely driven by self-stimulation (known as “stimming“). Without the possibility for reflective self-control, autistic children are more or less locked into repetitive behavioral loops that focus on affective self-stimulation. Accordingly, the theoretical insights of dynamic systems theory may help scientists better understand the mechanisms of self-stimulation, leading to new behavioral therapy techniques.