Altered implicit category learning in anorexia nervosa.

Abstract

Objective Recent research has identified specific cognitive deficits in patients with anorexia nervosa (AN), including impairment in executive functioning and attention. Another such cognitive process, implicit category learning has been less studied in AN. This study examined whether implicit category learning is impaired in AN. Method Twenty-one women diagnosed with AN and 19 control women (CW) were administered an implicit category learning task in which they were asked to categorize simple perceptual stimuli (Gabor patches) into one of two categories. Category membership was based on a linear integration (i.e., an implicit task) of two stimulus dimensions (orientation and spatial frequency of the stimulus). Results AN individuals were less accurate on implicit category learning relative to age-matched CW. Model-based analyses indicated that, even when AN individuals used the appropriate (i.e., implicit) strategy they were still impaired relative to CW who also used the same strategy. In addition, task performance in AN patients was worse the higher they were in self-reported novelty seeking and the lower they were in sensitivity to punishment. Conclusions These results indicate that AN patients have implicit category learning deficits, and given this type of learning is thought to be mediated by striatal dopamine pathways, AN patients may have deficits in these neural systems. The finding of significant correlations with novelty seeking and sensitivity to punishment suggests that feedback sensitivity is related to implicit learning in AN.

Functional MRI investigation of verbal working memory in adults with anorexia nervosa

“…In combination with the current study, it appears that efficiency of ''raw'' vWM is equal between AN and HC groups and the differences in subliminal studies may be driven by a greater negative effect on the HC group. This raises questions regarding implicit processing, a relatively unexplored area that merits attention given that people with AN exhibit deficits in implicit learning [58]. Our imaging findings only strengthen the conclusion that in the absence of distracting stimuli, vWM functioning in AN is similar to HC, as there is no evidence of any compensatory mechanism by which vWM performance could have been sustained.…”

Reduced salience and default mode network activity in women with anorexia nervosa

“…This idea would be consistent with the ability of individuals with anorexia nervosa to restrict food intake and with previously found learning inefficiencies in a DA-based learning paradigm in this population. 58 Reduced intrinsic ACC function in the SN could underlie aberrant motivational drives in individuals with anorexia nervosa, influen cing such things as eating behaviours, reward processing and pathologic body perception. 6 In support of this idea, a previous study found reduced ACC activation in individuals with anorexia nervosa during self-other body comparison.…”

Nothing Tastes as Good as Skinny Feels: the Neurobiology of Anorexia Nervosa

“…However, mixed findings for impaired set-shifting in adolescent AN [24][25][26] call into question whether set-shifting difficulties really are a predisposing trait, a result of chronic AN, or related to a particular stage of brain development.…”