Neuropsychological tools to predict conversion from amnestic mild cognitive impairment to dementia. The TREDEM Registry

Most of the studies about conversion from Mild cognitive impairment (MCI) to dementia have focused on amnestic MCI (aMCI) which is considered a preclinical phase of Alzheimer’s disease. The aim of the present study was to identify neuropsychological tools that would best predict conversion from aMCI to dementia. Fifty-five aMCI subjects on the Treviso Dementia Registry were investigated. They underwent a neuropsychological evaluation during their first assessment and again at follow-up. Cox proportional-hazard regression models were created to measure the association between the dependent variable (dementia diagnosis or MCI status maintenance) and the neuropsychological test scores at baseline. The sample (28 women and 27 men; mean age 76.82 ± 5.88 years; education 7.62 ± 3.99 years) was observed for an average time of 2.17 ± 1.25 years. A Cox backward stepwise regression showed that the Rey Auditory Verbal Learning Test, Delayed Recall (p = .041) and Semantic Verbal Fluency tests (p = .031) appear to be useful in predicting conversion to dementia.     

The handedness of imagined bodies in action and the role of perspective taking

Past research at the nexus of motor control and perception investigated the role of perspective taking in many behavioral and neuroimaging studies. Some investigators addressed the issue of one's own vs. others' action imagination, but the possible effects of a front or a back view in imagining others' actions have so far been neglected. We report two 'single trial' experiments in which a total of 640 participants were asked to imagine a person performing a manual action - either in a front or in a back view - and then to indicate the hand used by the imagined person during movement execution. In such a task, we assume the existence of two distinct biases: a perceptual-mnemonic bias due to subjects' visual experience of others' actions, encouraging them to imagine right-handed movements, and a motor bias due to subjects' experience of self-made actions, encouraging them to imagine movements performed with the same hand as their dominant hand. We hypothesized that a greater involvement of motor representations in the back view compared to the front view could result in an increased correspondence between one's own manual preference and the hand used by the imagined agent in the former condition. The results of both experiments were consistent with this hypothesis, suggesting that while imagining others' actions we employ motor simulations in different degrees according to the perspective adopted.     

Associations between serotonin transporter gene promoter region (5-HTTLPR) polymorphism and gaze bias for emotional information

The serotonin transporter promoter region polymorphism (5-HTTLPR) is associated with neural response to negative images in brain regions involved in the experience of emotion. However, the behavioral implications of this sensitivity have been studied far less extensively. The current study used eye-tracking methodology to examine how individuals genotyped for the 5-HTTLPR, including the single nucleotide polymorphism (SNP) rs25531, allocated attention during prolonged (30-s) exposure to face stimuli depicting positive and negative emotion. Short 5-HTTLPR allele carriers and carriers of the long allele with guanine at the sixth nucleotide (S/LG) displayed a stronger gaze bias (total fixation time, number of fixations, mean fixation length) for positive than for sad, threat, or neutral stimuli. In contrast, those homozygous for the long 5-HTTLPR allele with adenine at the sixth nucleotide (LA) viewed the emotion stimuli in an unbiased fashion. Time course analyses indicated no initial 5-HTTLPR group differences; however, S/LG 5-HTTLPR allele carriers were more likely than LA 5-HTTLPR homozygotes to direct gaze toward happy than toward sad stimuli over time. This bias toward positive stimuli during the later stages of information processing likely reflects a strategic effort to downregulate heightened reactivity to negative stimuli among 5-HTTLPR S/LG allele carriers.     

A comparison of ultra-endurance cyclists in a qualifying ultra-cycling race for Paris-Brest-Paris and Race Across America-Swiss cycling marathon

Ultra-endurance events test the adaptation of human physiology to extreme physical and mental demands, high levels of training, motivation, and physical conditioning among participants. To understand basic differences among participants according to the severity of the race, participants in qualifying events for two ultra-endurance cycling races, differing in length and intensity, were compared on measures of anthropometry, training, and support. One race was four times longer, required supporting teams, and racers typically had little sleep, which should lead to the qualifiers being substantially more highly trained than those from the shorter race. The qualifiers in the longer race had greater intensity in training while the qualifiers in the shorter race relied more on training volume. Different strategies and types of training reflected the different demands of the races. Future studies should evaluate personality and motivational differences in ultra-endurance events and between these athletes and athletes in other sports.     

Reduced substance use as a secondary benefit of an indicated cognitive-behavioral adolescent depression prevention program

Our first aim was to test whether a group cognitive-behavioral (CB) depression prevention program reduces substance use escalation over 2-year follow-up relative to two active comparison interventions and a brochure assessment control. Our second aim examined whether reductions in depressive symptoms mediate intervention effects, as posited by the affect-regulation model of substance use. In this indicated prevention trial, 341 high school adolescents at risk for depression because of the presence of elevated depressive symptoms were randomized to a Group CB intervention, group supportive-expressive group intervention, CB bibliotherapy, or educational brochure control condition. Participants in Group CB had significantly lower rates of substance use compared with brochure control participants at both 1- and 2-year follow-up and lower substance use at 2-year follow-up relative to bibliotherapy participants; no other condition differences were significant. Mediational analyses suggested that reductions in depressive symptoms from baseline to posttest accounted for changes in substance use over 2 years for participants in Group CB relative to brochure control participants but did not mediate effects relative to those receiving bibliotherapy. Results suggest that a secondary benefit of this CB group indicated depression prevention program is lower rates of long-term substance use. Findings supported the hypothesis that, relative to a nonactive comparison condition, reductions in depressive symptoms mediated the effects of Group CB prevention on substance use escalation. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Appetitive and aversive olfactory learning induce similar generalization rates in the honey bee

Appetitive and aversive learning drive an animal toward or away from stimuli predicting reinforcement, respectively. The specificity of these memories may vary due to differences in cost–benefit relationships associated with appetitive and aversive contexts. As a consequence, generalization performances may differ after appetitive and aversive training. Here, we determined whether honey bees show different rates of olfactory generalization following appetitive olfactory conditioning of the proboscis extension response, or aversive olfactory conditioning of the sting extension response. In both cases, we performed differential conditioning, which improves discrimination learning between a reinforced odor (CS+) and a non-reinforced odor (CS?) and evaluated generalization to two novel odors whose similarity to the CS+ and the CS? was different. We show, given the same level of discriminatory performance, that rates of generalization are similar between the two conditioning protocols and discuss the possible causes for this phenomenon.     

Personality and Optimal Experience in Adolescence: Implications for Well-Being and Development

Past research has repeatedly identified relations between optimal experience—or flow—and well-being across the lifespan. In the attempt to identify the conditions favoring this experience, some studies took into account personality traits. While most of them operationalized flow in terms of intensity, we presently focused on perceived occurrence versus absence of flow. Specifically, we investigated the relations between flow occurrence, hedonic and eudaimonic well-being, activities associated with flow, and personality in adolescence. A group of 408 Italian teenagers (mean age = 17.31; SD = 1.13) were administered Flow Questionnaire, Satisfaction with Life Scale, Positive and Negative Affect Schedule, Psychological Well-being Scales, and the Big Five Questionnaire. Participants reporting optimal experience in their lives were compared with those not reporting it. Results showed that adolescents experiencing flow reported higher satisfaction with life, hedonic balance, and psychological well-being than their counterparts. Findings from logistic regression analyses further showed that openness to experience was the sole personality factor predicting flow occurrence, and that no personality factors were predictive of type of activities adolescents associated with flow. Findings point to the promotion of optimal experience among adolescents through the support of curiosity and openness to new experiences in engaging opportunities for action. They further call for the development of an integrated model taking into account both individual predispositions and social and cultural factors in well-being promotion.     

Drawing perseveration in neglect: Effects of target density

In cancellation tasks, patients with unilateral spatial neglect typically fail to mark targets within the side of the sheet contralateral to the side of the lesion (contralesional). Moreover, they can show a perseverative behaviour, which consists in repeatedly cancelling stimuli, mainly in the side of the display ipsilateral to the side of the lesion (ipsilesional). We investigated in 13 right‐brain‐damaged patients with left spatial neglect and perseverative behaviour whether and how different densities of horizontal targets modulated omission and perseverative errors. We found that the density of targets modulated the patients’ distribution of neglect (area of omission), but not its extent, as indexed by the percentage of omissions. Specifically, the area of omissions tightened when target density increased leftwards. On the other hand, target density did not affect the distribution of perseverative behaviour (area of perseveration), as well as its extent, as indexed by the percentage of perseverations. Correlation analyses showed that both the extent and the distribution of omissions were positively correlated to clinical measures of spatial neglect. Conversely, perseverations did not show such a correlation. These findings support the view that two different pathological mechanisms might be involved in left spatial neglect and in ipsilesional perseverative behaviour.     

Promoting Functional Ambulation with People with Blindness and Multiple Disabilities

An intervention package comprising auditory cues, physical prompts preceded by vibratory (anticipatory) stimuli, and reinforcement was used to promote ambulation to target places with 2 men with total blindness, profound intellectual disability, and behavioural problems. Data showed that both men acquired successful ambulation to the target places, becoming almost totally independent of the physical prompts. Implications of the findings are discussed.