Quantitative abilities of invertebrates: a methodological review

Animal Cognition - Quantitative abilities are widely recognized to play important roles in several ecological contexts, such as foraging, mate choice, and social interaction. Indeed, such abilities...     

Values most extolled in Nobel Peace Prize speeches

The authors randomly selected 50 Nobel Peace Prize speeches and content analyzed them to determine which values the speakers extolled most frequently. The 10 most frequently mentioned values were peace (in 100% of the speeches), hope (92%), security (86%), justice (85%), responsibility (81%), liberty (80%), tolerance (79%), altruism (75%), God (49%), and truth (38%). The authors discuss the interplay of these values in the modern world and implications regarding the search for universal moral values.     

Are Episodic Buffer Processes Intact in ADHD? Experimental Evidence and Linkage with Hyperactive Behavior

Working memory deficits are present in a substantial proportion of children with ADHD, and converging evidence links these deficits with ADHD-related behavioral and functional impairments. At the same time, working memory is not a unitary construct, and evidence is lacking regarding the role of several components of this system in ADHD. Preclinical behavioral studies are needed to fractionate the multicomponent working memory system, determine which specific subcomponent(s) are impaired in ADHD, and more importantly link these subcomponent(s) with specific ADHD-related behavioral symptoms/functional impairments. The current study reflects one piece of that puzzle, and focuses on the episodic buffer component of working memory. Across multiple testing days, a well-characterized sample of 86 children ages 8–13 (M=10.52, SD=1.54; 34 girls; 64% Caucasian/Non-Hispanic) with ADHD (n=49) and without ADHD (n=37) completed three counterbalanced working memory tests that were identical in all aspects except the key subcomponent process (phonological, visuospatial, episodic buffer). Gross motor movement during these and control tasks were measured using 4 high-precision actigraphs. There was no evidence of group differences in gender, age, SES, or IQ. Bayesian mixed-model ANOVAs indicated that the ADHD group performed significantly worse on all three working memory tests (d=1.17–1.44) and was significantly more hyperactive than controls (d=0.66–1.05) during the visuospatial and episodic buffer tests. In contrast, the ADHD and Non-ADHD groups were equivalent with regard to effects of episodic buffer demands on performance and hyperactive behavior. The most parsimonious conclusion is that the episodic buffer is likely intact in ADHD, and unrelated to ADHD hyperactivity symptoms.     

The Social Behavior Scale for Preschool Children: Factorial Structure and Concurrent Validity

The aims of the present study were to examine the factor validity of a new social behavior assessment - the Social Behavior Scale (SBS) - using exploratory (sample 1, n = 169) and confirmatory (sample 2, n = 127) factor analysis, and to test factor invariance across gender in a sample of Italian preschoolers. The concurrent validity of the SBS was examined with measures of peer nominations and observed interactions (sample 3, n = 277). Findings confirmed the three-factor structure of the SBS: Emotional Competence, Social Engagement and Aggressiveness. Multigroup analysis provided evidence of factor invariance across gender. Concerning concurrent validity, results confirmed a great association between teacher-rating SBS and the other concurrent measures.     

Experimental setting affects the performance of guppies in a numerical discrimination task

A recent study found that guppies (Poecilia reticulata) can be trained to discriminate 4 versus 5 objects, a numerical discrimination typically achieved only by some mammals and birds. In that study, guppies were required to discriminate between two patches of small objects on the bottom of the tank that they could remove to find a food reward. It is not clear whether this species possesses exceptional numerical accuracy compared with the other ectothermic vertebrates or whether its remarkable performance was due to a specific predisposition to discriminate between differences in the quality of patches while foraging. To disentangle these possibilities, we trained guppies to the same numerical discriminations with a more conventional two-choice discrimination task. Stimuli were sets of dots presented on a computer screen, and the subjects received a food reward upon approaching the set with the larger numerosity. Though the cognitive problem was identical in the two experiments, the change in the experimental setting led to a much poorer performance as most fish failed even the 2 versus 3 discrimination. In four additional experiments, we varied the duration of the decision time, the type of stimuli, the length of training, and whether correction was allowed in order to identify the factors responsible for the difference. None of these parameters succeeded in increasing the performance to the level of the previous study, although the group trained with three-dimensional stimuli learned the easiest numerical task. We suggest that the different results with the two experimental settings might be due to constraints on learning and that guppies might be prepared to accurately estimate patch quality during foraging but not to learn an abstract stimulus–reward association.