Neuronal representation of conditioned taste in the basolateral amygdala of rats

Animals develop robust learning and long lasting taste aversion memory once they experience a new taste that is followed by visceral discomfort. A large body of literature has supported the hypothesis that basolateral amygdala (BLA) plays a critical role in the acquisition and extinction of such conditioned taste aversions (CTA). Despite the evidence that BLA is crucially engaged during CTA training, it is unclear how BLA neural activity represents the conditioned tastes. Here, we incorporated a modified behavioral paradigm suitable for single unit study, one which utilizes a sequence of pulsed saccharin and water infusion via intraoral cannulae. After conditioning, we investigated BLA unit activity while animals experience the conditioned taste (saccharin). Behavioral tests of taste reactivity confirmed that the utilized training procedure produced reliable acquisition and expression of the aversion throughout test sessions. When neural activity was compared between saccharin and water trials, half of the recorded BLA units (77/149) showed differential activity according to the types of solution. 76% of those cells (29/38) in the conditioned group showed suppressed activity, while only 44% of taste reactive cells (17/39) in controls showed suppressed activity during saccharin trials (relative to water trials). In addition, the overall excitability of BLA units was increased as shown by altered characteristics of burst activity after conditioning. The changes in BLA activity as a consequence of CTA were maintained throughout test sessions, consistent with the behavioral study. The current study suggests that the neuronal activity evoked by a sweet taste is altered as a consequence of CTA learning, and that the overall change might be related to the learning induced negative affect.     

Temperament and play interaction behavior across infancy

Temporal stability and convergent validity of infant temperament ratings and play interaction behaviors were examined across early to late infancy. Stability was noted for the temperament dimensions activity, rhythmicity, intensity, mood, and persistence. Stability also was noted for the infant play interaction behaviors looking, smiling, and vocalizing. In addition, convergent validity was noted for attentive-affective behaviors and comparable temperament ratings; for example, gaze aversion and nondistractability, and distress brow behavior and negative mood. Generally easier temperament infants were noted to vocalize more and to cry less frequently during their play interactions.     

Affective behavior and weight changes among hospitalized failure-to-thrive infants

The affective behavior and weight change of 12 nonorganic failure-to-thrive, 12 organic failure-to-thrive, and 12 control infants (M age = 8 months) were compared across their hospitalization. Infant affect was evaluated at approximately the beginning, middle, and endpoints of hospitalization using the Behavioral Assessment Scale. Among the failure-to-thrive infants, positive responses to stimulation at the initial assessment were related to weight loss across the course of hospitalization, while positive responses to the same stimulation at the middle assessment were related to weight gain. These unexpected results coupled with the finding that 70% of the failure-to-thrive infants gained weight and 30% lost weight across hospitalization led to a comparison between infants who gained and infants who lost weight. An increase in positive affect across hospitalization occurred only for the infants who gained weight. Paradoxically, the losers may have experienced hospital stimulation as less adequate than maternal stimulation, while the gainers may have experienced hospital stimulation as more adequate than home stimulation.     

Wishes, Gender, Personality, and Well-Being

ABSTRACT Study participants (175 men, 230 women) made three wishes and completed measures of the five-factor model of personality, optimism, life satisfaction, and depression. Common wishes were for achievement, affiliation, intimacy, and power as well as for happiness and money. T tests showed women were more likely to wish for improved appearance, happiness, and health; men were more likely to make power wishes and wishes for sex. Among participants who were highly involved in the wishing process, Extra-version was related to making more interpersonal wishes and wishes for positive affect. Neuroticism was related to wishes for emotional stability. Agreeableness and Openness to Experience related to wishes reflective of these traits. Conscientiousness was related to low impulsivity. Depression was related to making highly idiosyncratic, specific wishes, suggesting the use of wishful thinking as a coping mechanism. In addition, happy participants were more likely to rate their wishes as likely to come true. Results indicate that the relatively commonplace process of wishing relates to traits, gender, and well-being.     

Black College Women's Career Values: A Preliminary Investigation

We identified nine values that guided the career decisions of a sample of Black college women, then explored whether these values were predicted by racial and feminist identify stage sentiments Findings from this study suggest the need for further research on the career development of women of color.     

Valence specific response reversal deficits and risk for mania

Response reversal deficits are well documented in bipolar disorder (BD). Although frequently construed as an index of reward processing abnormalities, these response reversal deficits might simply result from more general cognitive inflexibility. Given that both are implicated in BD, our goal was to more carefully test whether reversal learning deficits are specific to reward processing or reflect more general cognitive inflexibility. To more carefully assess deficits, a novel variant of the response reversal task was used to separate responses to in reward versus punishment feedback. In addition, while response reversal deficits are well documented in BD, it is still unknown if these deficits are observable in people at risk for the disorder, whose performance would be unconfounded by medication use and illness course. To assess the presence of premorbid response reversal deficits, we tested students at risk for developing BD, as defined by the well-validated Hypomanic Personality Scale. Undergraduates (n?=?99) were randomly assigned to complete either a reward only or a punishment only version of a response reversal task. Mania risk was related to difficulty reversing responses following reward, but not punishment feedback. Findings suggest that a deficit in response reversal may be an index of reward dysregulation in BD, and that this deficit can be observed even in those at high risk for the development of BD.     

Serotonergic function, two-mode models of self-regulation, and vulnerability to depression: what depression has in common with impulsive aggression

Evidence from diverse literatures supports the viewpoint that two modes of self-regulation exist, a lower-order system that responds quickly to associative cues of the moment and a higher-order system that responds more reflectively and planfully; that low serotonergic function is linked to relative dominance of the lower-order system; that how dominance of the lower-order system is manifested depends on additional variables; and that low serotonergic function therefore can promote behavioral patterns as divergent as impulsive aggression and lethargic depression. Literatures reviewed include work on two-mode models; studies of brain function supporting the biological plausibility of the two-mode view and the involvement of serotonergic pathways in functions pertaining to it; and studies relating low serotonergic function to impulsiveness, aggression (including extreme violence), aspects of personality, and depression vulnerability. Substantial differences between depression and other phenomena reviewed are interpreted by proposing that depression reflects both low serotonergic function and low reward sensitivity. The article closes with brief consideration of the idea that low serotonergic function relates to even more diverse phenomena, whose natures depend in part on sensitivities of other systems.