However, parsimony is habitual to the administration's anti-poverty schemes.
Also, the cocaine self-administration test following cocaine devaluation does not definitively test whether cocaine self-administration is habitual or goal-directed because cocaine is a stimulus which can engender responding on its own [15].
Detailed methods used to assess height, weight, blood pressure, body composition (i.e., skin fold measurements), exercise capacity (i.e., an incremental cycling test to determine peak aerobic capacity (VO2peak)), and the administration of the Habitual Activity Estimation Scale (HAES) have been previously published [8].
A study by Dickinson and colleagues (2002) used this approach to examine potential habitual components to alcohol self-administration in rats.
However, the finding that responding during the absence of the SD was habitual suggests that over cocaine self-administration training, habitual behavior was latently developing, but was not expressed until induced by environment-cocaine associations under abstinence conditions.
Following thirty days of abstinence, no difference in responding between groups was found when animals were reintroduced to the self-administration environment alone, indicating habitual behavior.
Cocaine administration accelerates the emergence of habitual responding for food (Nelson & Killcross, 2006) and also the shift from ventral to dorsal striatum of neuronal firing evoked by presentation of a pavlovian CS (Takahashi et al., 2007).
The importance of this interaction between drugs of abuse and salient sensory cues for the acquisition of habitual drug-taking may be less applicable in the human context of systemic administration, since we found that systemic administration of amphetamine was not as effective as intra-tubercle administration in enhancing behavioral interaction with visual signals.
However, research has shown that resistance to outcome devaluation (e.g. habitual responding) can develop for oral sucrose or food self-administration using similar discrete noncontingent SD paradigms [62], [63].
