Brain activity in adults who stutter: similarities across speaking tasks and correlations with stuttering frequency and speaking rate

Many differences in brain activity have been reported between persons who stutter (PWS) and typically fluent controls during oral reading tasks. An earlier meta-analysis of imaging studies identified stutter-related regions, but recent studies report less agreement with those regions. A PET study on adult dextral PWS (n = 18) and matched fluent controls (CONT, n = 12) is reported that used both oral reading and monologue tasks. After correcting for speech rate differences between the groups the task-activation differences were surprisingly small. For both analyses only some regions previously considered stutter-related were more activated in the PWS group than in the CONT group, and these were also activated during eyes-closed rest (ECR). In the PWS group, stuttering frequency was correlated with cortico-striatal-thalamic circuit activity in both speaking tasks. The neuroimaging findings for the PWS group, relative to the CONT group, appear consistent with neuroanatomic abnormalities being increasingly reported among PWS.     

EMOVAL : évaluation automatique de la valence et de l’activation émotionnelles des textes à l’aide d’une méta-norme de 5656 mots-racines

EMOVAL: automatic evaluation the emotional valence and arousal of texts using a 5656 root-words metanorm. EMOVAL is an emotional valence and arousal analysis model of texts. EMOVAL draws from linguistic tradition the hypothesis that every word has a denotative aspect (“meaning”) and a connotative aspect (“affective halo”). It uses a meta-analysis of seven French norms and one English norm with the objective to characterize the emotional valence of texts, paragraphs, or sentences in a pleasant or unpleasant way. The meta-analysis indicates that the seven French norms data are highly correlated in between (0.82 to 0.99), and highly correlated with the Affectiv Norm for English Words (Bradley et Lang, 1999) (0.81 to 0.97). Arousal values taken from Affective Norm for English Words (ANEW) (Bradley et Lang, 1999) and the Leleu (1987) norm are significately correlated (0.55). The metanorm has 5656 words (nouns, verbs, adjectives, adverbs) characterized in valence (−1 to +1), and 3265 words characterized in arousal. These items are used by EMOVAL for valence judgments of texts. Two types of texts are proposed: the evaluation of the whole (702) or of extracts (110) of a corpus of sentences judged in a seven-point scale (−3 very unpleasant to +3 very pleasant) (Bestgen et al., 2004), and of 12 texts positively valenced (happiness and good surprise) and negatively valenced (fear, anger, disgust, sadness, and bad surprise). These two types of tests confirm the psychological pertinence of EMOVAL. Limits regarding the arousal dimension are discussed. The metanorm presented in this article can be obtained from the authors.     

La version française du dictionnaire pour le LIWC : modalités de construction et exemples d’utilisation

LIWC is, originally, a text analysis program that counts words of English texts in psychologically meaningful categories. It provides an analysis (in percentage) for 80 dimensions of language (functional words, topics, punctuation). The goal of this methodological note is to present the French LIWC. This version respects the structure of the categories of the English version of the software and gives explanations about the user guide such the preparation of the to be analyzed texts. Then, we explain the decisions for translating the English dictionary into French. We emphasize the constraints imposed by the morphology of written French language and the difficulties encountered (elision of the article, elision of negation and of verbs’ tense). Presenting the translation problems allows understanding the modalities of construction of the dictionary and allows for a LIWC user to build a personalized dictionary in order to analyze contents more suited to the research needs. A qualitative comparison of dimensions obtained with both the French and English versions for 66 bilingual texts of various types and contents provides satisfactory results. A statistical comparison of 119 expressive writings produced by students from three university courses (Humanities, Sciences and Psychology) about a given event (success or failure to an exam) shows the validity of the French version for identifying the expressed contents. Thus, this tool should be efficient for undertaking research in different fields of psychology (health, work and education) concerning oral and written language produced in different contexts.     

Children's human figure drawings do not measure intellectual ability

Children typically follow a well-defined series of stages as they learn to draw, but the rate at which they progress through these stages varies from child to child. Some experts have argued that these individual differences in drawing development reflect individual differences in intelligence. Here we assessed the validity of a drawing test that is commonly used to assess children’s intellectual abilities. In a single study, 125 5- and 6-year-olds completed the Draw-A-Person: A Quantitative Scoring System (DAP:QSS) and the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R) or the Wechsler Abbreviated Scale of Intelligence (WASI). Although there was a statistically significant correlation between scores on the DAP:QSS and scores on the Wechsler tests, when the scores of individual children were examined, the DAP:QSS yielded a high number of false positives and false negatives for low intellectual functioning. We conclude that the DAP:QSS is not a valid measure of intellectual ability and should not be used as a screening tool.     

Artificial neural networks for analyzing inter-limb coordination: the golf chip shot

Motor control research relies on theories, such as coordination dynamics, adapted from physical sciences to explain the emergence of coordinated movement in biological systems. Historically, many studies of coordination have involved inter-limb coordination of relatively few degrees of freedom. This study looked at the high-dimensional inter-limb coordination used to perform the golf chip shot toward six different target distances. This study also introduces a visualization of high-dimensional coordination relevant within the coordination dynamics theoretical framework. A specific type of Artificial Neural Network (ANN), the Self-Organizing Map (SOM), was used for the analysis. In this study, the trajectory of consecutive best-matching nodes on the output map was used as a collective variable and subsequently fed into a second SOM which was used to create visualization of coordination stability. The SOM trajectories showed changes in coordination between movement patterns used for short chip shots and movement patterns used for long chip shots. The attractor diagrams showed non-linear phase transitions for three out of four players. The methods used in this study may offer a solution for researchers from a coordination dynamics perspective who intend to use data obtained from discrete high-dimensional movements.     

Diagnosing fatigue in gait patterns by support vector machines and self-organizing maps

The aim of the study was to train and test support vector machines (SVM) and self-organizing maps (SOM) to correctly classify gait patterns before, during and after complete leg exhaustion by isokinetic leg exercises. Ground reaction forces were derived for 18 gait cycles on 9 adult participants. Immediately before the trials 7–12, participants were required to completely exhaust their calves with the aid of additional weights (44.4 ± 8.8 kg). Data were analyzed using: (a) the time courses directly and (b) only the deviations from each individual’s calculated average gait pattern. On an inter-individual level the person recognition of the gait patterns was 100% realizable. Fatigue recognition was also highly probable at 98.1%. Additionally, applied SOMs allowed an alternative visualization of the development of fatigue in the gait patterns over the progressive fatiguing exercise regimen.     

Neuro-cognitive mechanisms of decision making in joint action: a human-robot interaction study

In this paper we present a model for action preparation and decision making in cooperative tasks that is inspired by recent experimental findings about the neuro-cognitive mechanisms supporting joint action in humans. It implements the coordination of actions and goals among the partners as a dynamic process that integrates contextual cues, shared task knowledge and predicted outcome of others’ motor behavior. The control architecture is formalized by a system of coupled dynamic neural fields representing a distributed network of local but connected neural populations. Different pools of neurons encode task-relevant information about action means, task goals and context in the form of self-sustained activation patterns. These patterns are triggered by input from connected populations and evolve continuously in time under the influence of recurrent interactions. The dynamic model of joint action is evaluated in a task in which a robot and a human jointly construct a toy object. We show that the highly context sensitive mapping from action observation onto appropriate complementary actions allows coping with dynamically changing joint action situations.     

Cognitive impairment and whole brain diffusion in patients with neuromyelitis optica after acute relapse

The objective of this study investigated cognitive impairments and their correlations with fractional anisotropy (FA) and mean diffusivity (MD) in patients with neuromyelitis optica (NMO) without visible lesions on conventional brain MRI during acute relapse. Twenty one patients with NMO and 21 normal control subjects received several cognitive tests to assess cognitive function. Head diffusion tensor imaging (DTI) of all patients with NMO were collected with a 3-T MR system. Correlations of cognitive test scores and whole brain FA and MD were examined by voxel-based analysis. Region-of-interest analysis was applied to the significantly correlated regions which the most frequently appeared. We found that NMO patients without visible brain lesions had significantly impaired learning and memory, decreased information processing speed, and damaged attention compared with normal control subjects. These impaired cognitive domains were significantly correlated with FA and MD in local regions of corpus callosum, anterior cingulate and medial frontal cortex. In corpus callosum of NMO patients, mean FA was significantly lower and mean MD higher than normal control subjects. Our findings suggest that cognitive impairments in learning and memory, information processing speed and attention occur in NMO patients without visible brain lesions during acute relapse. The impairments in immediate and short-term memory in NMO patients may be due to information encoding deficits in the process of information acquisition. The corpus callosum of such patients may have local microscopic damages that play a role in cognitive impairments during acute relapse.