ABSTRACT
This study examined neural anticipation of monetary reward in pathological gamblers (PG) by varying the type of uncertainty associated with the reward. Ten PG and ten controls were scanned while deciding whether to accept ("bet" option, featuring high-uncertain monetary rewards) or reject ("safe" option, featuring low-certain rewards) a bet, within situations of decision-making under risk (probability of the "bet" reward is known) or ambiguity (probability of the "bet" reward is unknown). During decision under risk (as compared to ambiguity), controls exhibited activation in brain areas involved in reward processing (putamen), interoception (insula) and cognitive control (dorsolateral prefrontal cortex; middle frontal gyrus). By contrast, PG exhibited no differential brain activation as a function of the type of uncertainty associated with the "bet" option. Moreover, prior choosing of the "safe" option (as compared to "bet" choices), controls exhibited activation in the posterior insula, dorsolateral prefrontal cortex and middle frontal gyrus. By contrast, PG exhibited higher neural activation during the elaboration of "bet" choices, and in motivational-arousal areas (caudate; putamen; posterior insula). Between-groups contrasts revealed that, as compared to controls, PG showed (i) decreased neural activity in the globus pallidus for decision-making under risk, as opposed to decision under ambiguity, and (ii) increased neural activity within the putamen prior to bet choices, as opposed to safe choices. These findings suggest that (i) unlike control participants, a variation in the level of uncertainty associated with monetary rewards seems to have no significant impact on PGs' decision to gamble and (ii) PG exhibit stronger brain activation while anticipating high-uncertain monetary rewards, as compared with lower-certain rewards.
Subject(s)
Brain/physiopathology , Gambling/physiopathology , Gambling/psychology , Magnetic Resonance Imaging , Reward , Uncertainty , Adult , Case-Control Studies , Choice Behavior , Decision Making , Female , Humans , Male , Middle Aged , MotivationABSTRACT
Autoimmune encephalopathy is a rare but potentially reversible cause of cognitive deterioration and neuropsychiatric disturbances. We describe two older female patients with subacute cognitive decline and marked neuropsychiatric disturbances in the presence of high serum anti-thyroid peroxidase antibodies and with normal dosage of free thyroxine 4. One patient recovered almost completely after oral corticotherapy. Differential diagnosis and the role of biomarkers, in particular, are discussed. We support a pragmatic approach involving a short empirical therapeutic trial with intravenous or oral corticoids; this should be considered in all patients with subacute encephalopathy and with laboratory arguments for an underlying autoimmune aetiology.
