Mere Exposure: Preference Change for Novel Drinks Reflected in Human Ventral Tegmental Area.

Preferences for novel stimuli tend to develop slowly over many exposures. Psychological accounts of this effect suggest that it depends on changes in the brain's valuation system. Participants consumed a novel fluid daily for 10 days and underwent fMRI on the first and last days.

Distinct midbrain and habenula pathways are involved in processing aversive events in humans.

Emerging evidence implicates the midbrain dopamine system and its interactions with the lateral habenula in processing aversive information and learning to avoid negative outcomes. We examined neural responses to unexpected, aversive events using methods specialized for imaging the midbrain and habenula in humans. Robust activation to aversive relative to neutral events was observed in the habenula and two regions within the ventral midbrain: one located within the ventral tegmental area (VTA) and the other in the substantia nigra (SN).

Social cognitive conflict resolution: contributions of domain-general and domain-specific neural systems.

Cognitive control mechanisms allow individuals to behave adaptively in the face of complex and sometimes conflicting information. Although the neural bases of these control mechanisms have been examined in many contexts, almost no attention has been paid to their role in resolving conflicts between competing social cues, which is surprising given that cognitive conflicts are part of many social interactions. Evidence about the neural processing of social information suggests that two systems--the mirror neuron system (MNS) and mental state attribution system (MSAS)--are specialized for processing nonverbal and contextual social cues, respectively.

Predictive knowledge of stimulus relevance does not influence top-down suppression of irrelevant information in older adults.

Our ability to focus attention on task-relevant stimuli and ignore irrelevant distractions is reflected by differential enhancement and suppression of neural activity in sensory cortices. Previous research has shown that older adults exhibit a deficit in suppressing task-irrelevant information, the magnitude of which is associated with a decline in working memory performance. However, it remains unclear if a failure to suppress is a reflection of an inability of older adults to rapidly assess the relevance of information upon stimulus presentation when they are not aware of the relevance beforehand.