Role of the mesoamygdaloid dopamine projection in emotional learning

Amygdala dopamine is crucially involved in the acquisition of Pavlovian associations, as measured via conditioned approach to the location of the unconditioned stimulus (US). However, learning begins before skeletomotor output, so this study assessed whether amygdala dopamine is also involved in earlier 'emotional' learning. A variant of the conditioned reinforcement (CR) procedure was validated where training was restricted to curtail the development of selective conditioned approach to the US location, and effects of amygdala dopamine manipulations before training or later CR testing assessed. Experiment 1a presented a light paired (CS+ group) or unpaired (CS- group) with a US. There were 1, 2 or 10 sessions, 4 trials per session. Then, the US was removed, and two novel levers presented. One lever (CR+) presented the light, and lever pressing was recorded. Experiment 1b also included a tone stimulus. Experiment 2 applied intra-amygdala R(+) 7-OH-DPAT (10 nmol/1.0 A mu l/side) before two training sessions (Experiment 2a) or a CR session (Experiment 2b). For Experiments 1a and 1b, the CS+ group preferred the CR+ lever across all sessions. Conditioned alcove approach during 1 or 2 training sessions or associated CR tests was low and nonspecific. In Experiment 2a, R(+) 7-OH-DPAT before training greatly diminished lever pressing during a subsequent CR test, preferentially on the CR+ lever. For Experiment 2b, R(+) 7-OH-DPAT infusions before the CR test also reduced lever pressing. Manipulations of amygdala dopamine impact the earliest stage of learning in which emotional reactions may be most prevalent

Reliance on habits at the expense of goal-directed control following dopamine precursor depletion

Rationale Dopamine is well known to play an important role in learning and motivation. Recent animal studies have implicated dopamine in the reinforcement of stimulus-response habits, as well as in flexible, goal-directed action. However, the role of dopamine in human action control is still not well understood. Objectives We present the first investigation of the effect of reducing dopamine function in healthy volunteers on the balance between habitual and goal-directed action control. Methods The dietary intervention of acute dietary phenylalanine and tyrosine depletion (APTD) was adopted to study the effects of reduced global dopamine function on action control. Participants were randomly assigned to either the APTD or placebo group (ns = 14) to allow for a between-subjects comparison of performance on a novel three-stage experimental paradigm. In the initial learning phase, participants learned to respond to different stimuli in order to gain rewarding outcomes. Subsequently, an outcome-devaluation test and a slips-of-action test were conducted to assess whether participants were able to flexibly adjust their behaviour to changes in the desirability of the outcomes. Results APTD did not prevent stimulus-response learning, nor did we find evidence for impaired response-outcome learning in the subsequent outcome-devaluation test. However, when goal-directed and habitual systems competed for control in the slips-of-action test, APTD tipped the balance towards habitual control. These findings were restricted to female volunteers. Conclusions We provide direct evidence that the balance between goal-directed and habitual control in humans is dopamine dependent. The results are discussed in light of gender differences in dopamine function and psychopathologies

Psychological markers of longevity in Sardinian centenarians: the impact of developmental factors and social desirability

A body of research documented that the study of mental health of the oldest individuals may contribute to understand the psychological characteristics of longevity. This study had two related aims. First, to fully characterize the psychological health of Sardinian elders in the very late adult span. Second, to determine the psychological health of long-lived individuals (i.e., centenarians) from this population. Three gender-matched age groups (octogenarian, nonagenarian, centenarian) of cognitively healthy, community dwelling adults were recruited in Sardinia, an Italian island characterized by higher levels of longevity. Comparisons of total and sub-scale levels of psychological well-being and depressive symptomatology were made while controlling for social desirability. There were few differences in any index of psychological health between the groups; only a decrease in the coping strategies sub-scale of psychological well-being was observed between the centenarians and the octogenarians. Social desirability was differentially associated with specific dimensions of depressive symptoms and psychological well-being. These findings highlight that there is minimal age-related decline in the psychological health of a longevous population, even among its very oldest members. The present outcomes suggest that older Sardinians represent an advantageous population for the investigation of the psychological markers of longevity, since they demonstrate positive adaptation to the challenges (e.g., changes related to their social network) of very late adulthood

Age Trends in Well-Being and Depressive Symptoms: the Role of Social Desirability

This study was conducted to determine whether age-related variance in social desirability mediates age trends in psychological health. Self-report measures assessing depressive symptoms, well-being and social desirability were administered to wide age range sample (158 participants aged 20–101 years) from Sardinia, an Italian region located in the Mediterranean Sea being characterized by high level of longevity. Binary correlations showed that ageing was significantly correlated with fewer depressive symptoms and greater well-being; social desirability was significantly correlated with fewer depressive symptoms and higher well-being; age and social desirability were positively correlated. Mediation analyses indicated that social desirability explained a significant proportion (7–33%) of age-related variance in perceived well-being and depressive symptomatology. In conclusion, age differences in self-reported depressive symptoms and well-being partially reflect age differences in social desirability. The age-related increase in social desirability may reflect development of an advantageous coping style that contributes to psychological health

SODA: a new questionnaire for the assessment of life satisfaction in late life span

Background: Established measures of well-being rarely examine active lifestyle or religious behaviors. Though these could be assessed using individual measures, in older populations, the availability of a brief composite instrument with adequate psychometric properties would be desirable. Aims: Two studies were conducted to assess the psychometric properties (i.e., item adequacy, factorial structure, reliability and validity) of a new tool that was developed to self-rate personal satisfaction among Italian elders, the SODdisfazione dell’Anziano (SODA) Questionnaire. Methods: 135 young adults (mean age = 29.5 years, SD = 7.4) took part in Study 1, whereas Study 2 was carried out with 474 cognitively healthy 60–98-year-old people, that were asked to complete a battery of well-known well-being measures including the SODA one. Results: Study 1 showed that the SODA questionnaire is a reliable and valid self-report tool defined by three factors, assessing satisfaction about physical and cognitive health, religious well-being, and satisfaction about time spent for leisure activities, respectively. Study 2 replicated the outcomes of Study 1, highlighting the factor structure of the SODA inventory. Moreover, a series of stepwise linear regression analyses pointed out what factors (i.e., education, physical health, social desirability, participation to outdoor leisure activities, gender, and age) predicted the variance relative to the SODA indexes. Discussion: Current findings show the solid psychometric properties of SODA. Conclusions: SODA represents a brief, but reliable and valid, instrument for the assessment of satisfaction (focused on the state level) in late adult span