A Characterization of von Neumann Games in Terms of Memory

An information completion of an extensive game is obtained by extending the information partition of every player from the set of her decision nodes to the set of all nodes. The extended partition satisfies Memory of Past Knowledge (MPK) if at any node a player remembers what she knew at earlier nodes. It is shown that MPK can be satisfied in a game if and only if the game is von Neumann (vN) and satisfies memory at decision nodes (the restriction of MPK to a player's own decision nodes). A game is vN if any two decision nodes that belong to the same information set of a player have the same number of predecessors. By providing an axiom for MPK we also obtain a syntactic characterization of the said class of vN games.     

Sentences with Strong Psychological Impact in Psychotherapy: Research in Progress

After a brief exposition of Elementary Pragmatic Model about changes in dyadic interactions, the validity and clinical usefulness of the model was evaluated with a newly created test, called SISCI-Sentences. This test is composed of 90 Sentences with strong psychological impact. Administration of this test to non-clinical and clinical participants produced statistically significant differences between the choices of participants in the two groups. Implications of these results for the use of these Sentences in the course of psychotherapy are discussed.

What do children with autism attend to during imitation tasks?

Individuals with autism show a complex profile of differences in imitative ability, including a general deficit in precision of imitating another’s actions and special difficulty in imitating nonmeaningful gestures relative to meaningful actions on objects. Given that they also show atypical patterns of visual attention when observing social stimuli, we investigated whether possible differences in visual attention when observing an action to be imitated may contribute to imitative difficulties in autism in both nonmeaningful gestures and meaningful actions on objects. Results indicated that (a) a group of 18 high-functioning 8- to 15-year-olds with autistic disorder, in comparison with a matched group of 13 typically developing children, showed similar patterns of visual attention to the demonstrator’s action but decreased attention to his face when observing a model to be imitated; (b) nonmeaningful gestures and meaningful actions on objects triggered distinct visual attention patterns that did not differ between groups; (c) the autism group demonstrated reduced imitative precision for both types of imitation; and (d) duration of visual attention to the demonstrator’s action was related to imitation precision for nonmeaningful gestures in the autism group.     

Recognition memory and prefrontal cortex: dissociating recollection and familiarity processes using rTMS

Recognition memory can be supported by both the assessment of the familiarity of an item and by the recollection of the context in which an item was encountered. The neural substrates of these memory processes are controversial. To address these issues we applied repetitive transcranial magnetic stimulation (rTMS) over the right and left dorsolateral prefrontal cortex (DLPFC) of healthy subjects performing a remember/know task. rTMS disrupted familiarity judgments when applied before encoding of stimuli over both right and left DLPFC. rTMS disrupted recollection when applied before encoding of stimuli over the right DLPFC. These findings suggest that the DLPFC plays a critical role in recognition memory based on familiarity as well as recollection.     

Musical groove modulates motor cortex excitability: A TMS investigation

Groove is often described as a musical quality that can induce movement in a listener. This study examines the effects of listening to groove music on corticospinal excitability. Musicians and non-musicians listened to high-groove music, low-groove music, and spectrally matched noise, while receiving single-pulse transcranial magnetic stimulation (TMS) over the primary motor cortex either on-beat or off-beat. We examined changes in the amplitude of the motor-evoked potentials (MEPs), recorded from hand and arm muscles, as an index of activity within the motor system. Musicians and non-musicians rated groove similarly. MEP results showed that high-groove music modulated corticospinal excitability, whereas no difference occurred between low-groove music and noise. More specifically, musicians’ MEPs were larger with high-groove than low-groove music, and this effect was especially pronounced for on-beat compared to off-beat pulses. These results indicate that high-groove music increasingly engages the motor system, and the temporal modulation of corticospinal excitability with the beat could stem from tight auditory–motor links in musicians. Conversely, non-musicians’ MEPs were smaller for high-groove than low-groove music, and there was no effect of on- versus off-beat pulses, potentially stemming from suppression of overt movement. In sum, high-groove music engages the motor system, and previous training modulates how listening to music with a strong groove activates the motor system.     

Towards the DSM‐5 Criteria for Autism: Clinical,Cultural, and Research Implications

The new edition of the DSM is proposing significant changes to current diagnostic definitions of autism and related conditions. In this article, we will discuss the clinical, research, and cultural implications of these changes. We conclude that the new criteria appear to better reflect current understanding of the autism spectrum disorder than the current DSM‐IV criteria. As expected with any major change in classification systems, there are also significant risks, which will have to be carefully monitored and addressed by both policy makers and the scientific community to ensure that best clinical practice and research are facilitated and advanced.     

Measuring gratitude in youth: assessing the psychometric properties of adult gratitude scales in children and adolescents

Before the developmental trajectory, outcomes, and related interventions of gratitude can be accurately and confidently studied among the youth, researchers must ensure that they have psychometrically sound measures of gratitude that are suitable for this population. Thus, considering that no known scales were specifically designed to measure gratitude in youth, this study aimed to answer an important question: Are the existing gratitude scales used with adults valid for use with youth? The present study is an empirical investigation, based on a large youth sample (N = 1,405) with ages ranging from 10 to 19 years old, of the psychometric properties of scores of the Gratitude Questionnaire-6 (GQ-6; M. E. McCullough, R. A. Emmons, & J.-A. Tsang, 2002), the Gratitude Adjective Checklist (GAC; M. E. McCullough, R. A. Emmons, & J.-A. Tsang, 2002), and the Gratitude Resentment and Appreciation Test (GRAT)-short form (M. Thomas & P. Watkins, 2003). Single-group and multiple-group confirmatory factor analyses indicated that the factor structures of these gratitude scales resemble those found with adults and were invariant across age groups. Scores of all three gratitude scales revealed acceptable internal consistency estimates (i.e., >.70) across age groups. Results showed that whereas scores of all three gratitude scales were positively correlated with each other for 14- to 19-year-olds, GRAT-short form scores tended to display relatively low correlations with scores of the other two measures for younger children (10-13 years old). Furthermore, the nomological network analysis showed that scores of all three gratitude scales were positively correlated with positive affect and life satisfaction scores across the age groups. The relationships with negative affect and depression scores, however, seemed dependent on the child's age. Pending results from subsequent research recommendations for researchers interested in studying gratitude in youth are offered.     

A grammar of action generates predictions in skilled musicians

The present study investigates shared representations of syntactic knowledge in music and action. We examined whether expectancy violations in musical harmonic sequences are also perceived as violations of the movement sequences necessary to produce them. Pianists imitated silent videos showing one hand playing chord sequences on a muted keyboard. Results indicate that, despite the absence of auditory feedback, imitation of a chord is fastest when it is congruent with the preceding harmonic context. This suggests that the harmonic rules implied by observed actions induce expectations that influence action execution. As evidence that these predictions are derived at a high representational level, imitation was more accurate for harmonically incongruent chords than for congruent chords executed with unconventional fingering. The magnitude of the effects of context and goal prioritization increased with musical training. Thus, musical training may lead to a domain-general representation of musical grammar, i.e., to a grammar of action.     

Reorganization of functional and effective connectivity during real-time fMRI-BCI modulation of prosody processing

Mechanisms of cortical reorganization underlying the enhancement of speech processing have been poorly investigated. In the present study, we addressed changes in functional and effective connectivity induced in subjects who learned to deliberately increase activation in the right inferior frontal gyrus (rIFG), and improved their ability to identify emotional intonations by using a real-time fMRI Brain-Computer Interface. At the beginning of their training process, we observed a massive connectivity of the rIFG to a widespread network of frontal and temporal areas, which decreased and lateralized to the right hemisphere with practice. Volitional control of activation strengthened connectivity of this brain region to the right prefrontal cortex, whereas training increased its connectivity to bilateral precentral gyri. These findings suggest that changes of connectivity in a functionally specific manner play an important role in the enhancement of speech processing. Also, these findings support previous accounts suggesting that motor circuits play a role in the comprehension of speech.