Predictive coding: an account of the mirror neuron system

Is it possible to understand the intentions of other people by simply observing their actions? Many believe that this ability is made possible by the brain’s mirror neuron system through its direct link between action and observation. However, precisely how intentions can be inferred through action observation has provoked much debate. Here we suggest that the function of the mirror system can be understood within a predictive coding framework that appeals to the statistical approach known as empirical Bayes. Within this scheme the most likely cause of an observed action can be inferred by minimizing the prediction error at all levels of the cortical hierarchy that are engaged during action observation. This account identifies a precise role for the mirror system in our ability to infer intentions from actions and provides the outline of the underlying computational mechanisms.     

Analysis of distractor difficulty in multiple-choice items

Two psychometric models are presented for evaluating the difficulty of the distractors in multiple-choice items. They are based on the criterion of rising distractor selection ratios, which facilitates interpretation of the subject and item parameters. Statistical inferential tools are developed in a Bayesian framework: modal a posteriori estimation by application of an EM algorithm and model evaluation by monitoring posterior predictive replications of the data matrix. An educational example with real data is included to exemplify the application of the models and compare them with the nominal categories model.This research was supported by the DGI grant BSO2002-01485.I would like to thank Eric Maris and Vicente Ponsoda for their advice, Juan Botella for providing the data for the empirical application, and three anonymous reviewers for their comments that were essential for improving the quality of the paper.     

Training working memory: Limits of transfer

In two experiments (totaling 253 adult participants), we examined the extent to which intensive working memory training led to improvements on untrained measures of cognitive ability. Although participants showed improvement on the trained task and on tasks that either shared task characteristics or stimuli, we found no evidence that training led to general improvements in working memory. Using Bayes Factor analysis, we show that the data generally support the hypothesis that working memory training was ineffective at improving general cognitive ability. This conclusion held even after controlling for a number of individual differences, including need for cognition, beliefs in the malleability of intelligence, and age.     

Gender Differences and Cognitive Correlates of Mathematical Skills in School-Aged Children

Published information concerning the influence of gender on mathematical ability tests has been controversial. The present study examines the performance of school-aged boys and girls from two age groups on several mathematical tasks and analyzes the predictive value of a verbal fluency test and a spatial test on those mathematical tasks. More specifically, our research attempts to answer the following two questions: (1) Are gender differences in mathematical test performance among children interrelated with age and (2) do verbal and spatial nonmathematical tests mediate gender effects on mathematical test performance? Two hundred and seventy-eight 7- to 10-year-old children and 248 13- to 16-year-olds were selected from schools in Colombia and Mexico (231 boys and 295 girls). The age effect was found to be significant for all measures, with scores improving with age. Results showed that boys and girls in both age groups scored similarly in most subtests, but that differences emerged in the performance of mental mathematical operations and in resolving arithmetical problems. In the latter – but not in mental math – older boys outperformed older girls, whereas no gender differences were observed in the younger groups. After controlling for age, it was found that the spatial test was, indeed, a significant mediator of gender effects, while the verbal task was not.     

Cognitive abilities of street children: Low-SES Bolivian boys with and without experience of living in the street

Objectives: This study compared results on cognitive tests measuring nonverbal visualization and reasoning, executive functions, and creativity between 36 boys with experience of living in the street and 31 housed yet socioeconomically equivalent boys, in Bolivia.

Results: The street children scored significantly higher on the creativity measure, which is discussed in relation to contextual relevance. No significant differences were found on the other cognitive tests. Time elapsed after living in the street and drug use were strongly associated with cognition, while age was not. Both groups scored below average compared to Western norms. The results are discussed in terms of the cultural relevance of the tests and the impact of socioeconomic status, stress, and stimulation on cognition.     

Polite Girls and Creative Boys? Students' Gender Moderates Accuracy of Teachers' Ratings of Creativity

The aim of this study was to examine whether, and to what extent, teachers are able to recognize the creativity of their students. The study measured the creative abilities, creative attitude, creative activity, as well as intrinsic motivation, intelligence, and school functioning of 589 Polish high school students, while their teachers (N = 178) rated students' creativity. The structural equation model (SEM) demonstrated that the accuracy of teachers' ratings of students' creativity is generally low—the latent factor of students' creativity reliably, however weakly, predicted teachers' ratings. The accuracy of teachers' ratings was moderated by gender: Only in the case of male students did the latent creativity factor reliably predict teachers' ratings. Students' school functioning emerged as a key factor positively associated with the perception of students as creative.     

Adults' Acquisition of Novel Dimension Words: Creating a Semantic Congruity Effect

The semantic congruity effect is exhibited when adults are asked to compare pairs of items from a series, and their response is faster when the direction of the comparison coincides with the location of the stimuli in the series. For example, people are faster at picking the bigger of 2 big items than the littler of 2 big items. In the 4 experiments presented, adults were taught new dimensional adjectives (mal/ler and borg/er). Characteristics of the learning situation, such as the nature of the stimulus series and the relative frequency of labeling, were varied. Results revealed that the participants who learned the relative meaning of the artificial dimensional adjectives also formed categories and developed a semantic congruity effect regardless of the characteristics of training. These findings have important implications for our understanding of adult acquisition of novel relational words, the relationship between learning such words and categorization, and the explanations of the semantic congruity effect.     

Predictors for re-employment success in newly unemployed: A prospective cohort study

The aim of the present study was to examine which personal and situational factors affect reemployment success in persons in their first year of unemployment. In a prospective cohort study with a one-year follow-up, we investigated a sample of 3618 subjects who became unemployed. A survey was sent to all participants, including personal and situational factors, based on Wanberg's model, the Theory of Planned Behavior model and the Valence–Instrumentality–Expectancy model. Our results showed that ten key-factors predicted re-employment success in the first year after becoming unemployed. Knowing these factors, and in particular those which are amenable to change through any intervention program, may help to develop effective intervention strategies for those who facilitate reemployment in order to shorten the duration of unemployment.     

The relation between verbal and visuospatial memory and autobiographical memory

The basic-systems approach (Rubin, 2005, 2006) states that autobiographical memory is supported by other cognitive systems and argues that autobiographical memories are constructed from interactions between cognitive systems, such as language, vision and emotion. Although deficiencies in one or more of the basic systems influence the properties of autobiographical memories, little is known about how these cognitive abilities and autobiographical memory are related. To assert whether participants with stronger cognitive abilities also perform better on autobiographical memory tests, participants who completed verbal and visuospatial memory tests also recorded one personal event, which they recalled after a certain interval. Participants who performed well on the verbal memory tests also had better retention for the personal event, providing support for the basic-systems approach to autobiographical memory and preliminary support for the view that people have more memories from adolescence and early adulthood because the memory system works optimally in these lifetime periods.     

The felt presence of other minds: Predictive processing,counterfactual predictions,and mentalising in autism

The mental states of other people are components of the external world that modulate the activity of our sensory epithelia. Recent probabilistic frameworks that cast perception as unconscious inference on the external causes of sensory input can thus be expanded to enfold the brain’s representation of others’ mental states. This paper examines this subject in the context of the debate concerning the extent to which we have perceptual awareness of other minds. In particular, we suggest that the notion of perceptual presence helps to refine this debate: are others’ mental states experienced as veridical qualities of the perceptual world around us? This experiential aspect of social cognition may be central to conditions such as autism spectrum disorder, where representations of others’ mental states seem to be selectively compromised. Importantly, recent work ties perceptual presence to the counterfactual predictions of hierarchical generative models that are suggested to perform unconscious inference in the brain. This enables a characterisation of mental state representations in terms of their associated counterfactual predictions, allowing a distinction between spontaneous and explicit forms of mentalising within the framework of predictive processing. This leads to a hypothesis that social cognition in autism spectrum disorder is characterised by a diminished set of counterfactual predictions and the reduced perceptual presence of others’ mental states.