Assessing cognitive changes in multiple sclerosis: criteria for a reliable decision.

INTRODUCTION: Quantifying a significant cognitive change on a neuropsychological battery is essential to assess patients' decline or recovery and offer appropriate care. The reliability of change indices is particularly important in multiple sclerosis (MS), as the course of cognitive impairment is quite unpredictable, due at least in part to substantial interindividual variability. The main objective of this study was to compare six different methods for assessing cognitive change in an MS sample: the SD method, two reliable change indices, two standardized regression-based methods (SRB), and the generalized regression-based method (GSRB). METHOD: One hundred and twenty-three patients with clinically definite MS and 89 healthy controls underwent a battery of standardized neuropsychological tests assessing cognitive functions that are frequently affected in this disease (i.e., verbal episodic memory, working memory, processing speed and verbal fluency). RESULTS: We observed fairly similar proportions of improvement, decline or stability in the control group whatever the method. By contrast, in the MS sample, regression-based methods with one predictor (i.e., score at T1) and four predictors (i.e., score at T1 and demographic factors: age, sex, education level) detected a significant worsening more often than the reliable change indices while the GSRB method was more consistent with the RCI methods in tasks associated with ceiling effects. CONCLUSIONS: The interpretation of a patient's cognitive changes depends on which method is used. The (G)SRB methods appear to be relevant indicators for assessing cognitive change in MS. The addition of demographic factors does not seem to play an important role in the prediction of significant worsening in the MS sample, regardless of cognitive domain. For clinicians, an easy-to-use free shiny app is provided.

The influence of vestibular system and fetal presentation on handedness, cognitive and motor development: A comparison between cephalic and breech presentation.

Genetics are undoubtedly implicated in the ontogenesis of laterality. Nonetheless, environmental factors, such as the intrauterine environment, may also play a role in the development of functional and behavioral lateralization. The aim of this study was to test the Left-Otolithic Dominance Theory (LODT; Previc, 1991) by investigating a hypothetical developmental pattern where it is assumed that a breech presentation, which is putatively associated with a dysfunctional and weakly lateralized vestibular system, can lead to weak handedness and atypical development associated with language and motor difficulties. We used the ALSPAC cohort of children from 7 to 10 years of age to conduct our investigation. Our results failed to show an association between the vestibular system and fetal presentation, nor any influence of the latter on hand preference, hand performance, or language and motor development. Bayesian statistical analyses supported these findings. Contrary to our LODT-derived hypotheses, this study offers evidence that fetal presentation does not influence the vestibular system's lateralization and seems to be a poor indicator for handedness. Nonetheless, we found that another non-genetic factor, prematurity, could lead to atypical development of handedness.

Processing Verb Meanings and the Declarative/Procedural Model: A Developmental Study.

According to the Declarative/Procedural Model, the lexicon depends on declarative memory while grammar relies on procedural memory. Furthermore, procedural memory underlies the sequential processing of language. Thus, this system is important for predicting the next item in a sentence. Verb processing represents a good candidate to test this assumption. Semantic representations of verbs include information about the protagonists in the situations they refer to. This semantic knowledge is acquired implicitly and used during verb processing, such that the processing of a verb preactivates its typical patients (e.g., the window for break). Thus, determining how the patient typicality effect appears during children's cognitive development could provide evidence about the memory system that is dedicated to this effect. Two studies are presented in which French children aged 6-10 and adults made grammaticality judgments on 80 auditorily presented sentences. In Experiment 1, the verb was followed by a typical patient or by a less typical patient. In Experiment 2, grammatical sentences were constructed such that the verb was followed either by a typical patient or by a noun that could not be a patient of that verb. The typicality effect occurs in younger children and is interpreted in terms of developmental invariance. We suggest that this effect may depend on procedural memory, in line with studies that showed that meaning is necessary to allow procedural memory to learn the sequence of words in a sentence.

Influence of Psychological Vulnerability Factors for Bipolar Disorders on a Semantic Mediated Priming Task.

Hypomanic personality, hyperthymic temperament and irritable temperament are considered as psychological vulnerability factors to bipolar disorders. Semantic memory is impaired in bipolar patients. Spreading activation is among the probable candidates for accounting this impairment. The aim of this study was to assess spreading activation according to vulnerability factors continuum to determine whether it could be a factor of vulnerability to bipolar disorders. A sample of 61 healthy volunteers was recruited. Spreading activation was assessed by semantic mediated priming implemented in a double lexical decision task. Results shown that semantic mediated priming was negatively associated to hyperthymic temperament and irritable temperament. Impairment in semantic memory, and more specifically spreading activation, appear to be a cognitive factor of vulnerability to bipolar disorders. Our results can contribute to a better understanding of semantic impairment in vulnerable population and in bipolar disorder.

Component process analysis of verbal memory in a sample of students with a binge drinking pattern.

BACKGROUND: Many studies have emphasized the harmful impact of binge drinking on several cognitive functions, including memory. However, the exact nature of the memory processes involved is still unknown. The present study was designed to assess verbal working memory and verbal episodic memory, especially its encoding, storage and retrieval processes, in binge drinking to identify the processes impacted by this behavior. METHODS: Participants were 48 community-recruited college students aged 18-25 years and categorized as either binge drinkers (BDs) or social drinkers (SDs). They were assessed with (a) subtests of the Wechsler scale (digit span, letter-number sequencing) measuring verbal working memory, and (b) a modified version of the Free and Cued Selective Reminding Test (FCSRT), which measures verbal episodic memory functioning in various conditions of encoding (controlled) and recollection (free recall, cued recall, and recognition). RESULTS: Verbal working memory was unaffected by binge drinking, whereas verbal episodic memory performances were reduced. In particular, analysis of the modified FCSRT scores suggested that BDs had less proficient storage and retrieval processes. Furthermore, correlational analyses indicated that the proficiency of these memory components was negatively correlated with several indicators of binge drinking behavior. CONCLUSIONS: Results suggest that binge drinking behavior affects the storage and recollection processes of verbal episodic memory. The academic failure described in binge drinkers could be partly related to this harmful effect. Our results on the negative impact of binge drinking on memory should be used to develop information campaigns targeting students.

Role of implicit learning abilities in metaphor understanding.

Although the use of metaphors is a central component of language, the processes that sustain their comprehension have yet to be specified. Work in the fields of both metaphors and implicit learning suggests that implicit learning abilities facilitate the comprehension of metaphors. However, to date, no study has directly explored the relationships between the understanding of metaphors and so-called implicit learning tasks. We used a meaning decision task comparing literal, metaphorical and meaningless expressions to assess metaphor understanding and a probabilistic serial reaction time task for assessing implicit learning. Our results show that implicit learning positively predicts the time gap between responses to literal and metaphorical expressions and negatively predicts the difference between metaphorical and meaningless expressions. Thus, when confronted with novel metaphors, participants with higher implicit learning abilities are better able to identify that the expressions have some meaning. These results are interpreted in the context of metaphor understanding and psycholinguistic theories.

The Basic Empathy Scale adapted to French middle childhood: Structure and development of empathy.

We adapted the adult French version of the Basic Empathy Scale to French children aged 6-11 years, in order to probe the factorial structure underlying empathy. A total of 410 children (189 girls and 221 boys) were instructed to fill out the resulting Basic Empathy Scale in Children (BES-C). Results showed that, as in adulthood, the three-factor model of empathy (i.e., emotional contagion, cognitive empathy, and emotional disconnection) was more relevant than the one- and two-factor ones. This means that as early as 6 years of age, children's responses should reflect the same organization of the three components of empathy as those of adults. In line with the literature, cognitive empathy increased and emotional disconnection decreased in middle childhood, while emotional contagion remained stable. Moreover, girls exhibited greater emotional contagion than boys, with the reverse pattern being observed for emotional disconnection. No sex difference was found regarding cognitive empathy.

Factor structure of the French version of the Hypomanic Personality Scale (HPS) in non-clinical young adults.

BACKGROUND: Hypomanic Personality Scale (HPS) is a self-report questionnaire designed to identify vulnerable individuals at high risk of bipolar disorders in non-clinical samples. Our aim was to identify the factorial structure of HPS in a French non-clinical sample and to compare this with different factor solutions described in the literature. We carried out a survey in a French population using a French version of HPS. METHODS: A total of 698 participants were included in the study. They completed the HPS, the Schizotypal Personality Questionnaire-Brief (SPQ-B), the Positive And Negative Affect Schedule (PANAS), and the Beck Depression Inventory (BDI-II). We tested the 1, 3 and 4-factor solutions and used a Confirmatory Factor Analysis to compare these with the factor solutions suggested by Rawling et al. and Schalet et al. RESULTS: Goodness-of-fit indices showed that Schalet et al.'s solution "fits" our data better than Rawling et al.'s factorial solutions. HPS scores correlated with the PANAS Positive score and the SPQ-B total score. We confirmed the 3-factor structure of the HPS in a large non-clinical population of young adults and found consistent correlations with BDI, affectivity and schizotypal traits.

Impaired conscious memory in non-clinical schizotypy.

INTRODUCTION: Impaired controlled and preserved/enhanced automatic memory processes have been reported in schizotypy. This memory pattern has been considered as a marker of vulnerability to schizophrenia. Our aim was to further explore this memory pattern in non-clinical schizotypy in order to determine which specific dimensions of schizotypy (i.e., positive, negative or disorganised), and more specifically which components of the dimensions, are most closely related to memory dysfunctions. METHODS: Fifty-seven undergraduate students performed a category-production task. This was adapted for use with the process dissociation procedure in order to dissociate between automatic and controlled memory processes. The level of schizotypy was assessed using the Schizotypal Personality Questionnaire. RESULTS: Regression analyses confirmed that controlled memory processes decreased as schizotypy increased. The positive factors (more specifically, the ideas of reference subscale) and disorganised factors (more specifically, the odd or eccentric behaviour subscale) were negatively correlated with the controlled memory processes. CONCLUSIONS: Our study supports the idea that impaired controlled processes are an early cognitive marker of vulnerability to schizophrenia and confirm that the disorganised factor contributes the most to vulnerability to memory dysfunction. It also emphasises the importance of dissociating between each of the features characterising schizotypy rather than considering it as a whole.

Theory of mind and hypomanic traits in general population.

Theory of Mind (ToM) is the ability to assign a set of mental states to yourself and others. In bipolar disorders, alteration of social relationship can be explained by the impairment of the functioning of ToM. Deficit in ToM could be a trait marker of bipolar disorder and people in the general population with high hypomanic personality scores would be more likely to develop bipolar disorders. This study examined 298 participants. Measures of hypomanic personality were evaluated using the Hypomanic Personality Scale. ToM was explored using the Yoni task. Participants also completed the BDI-II. Forward multiple regressions were performed to examine the effect of components of the HPS on the total score in the ToM task. In the women's group, no subscales of the HPS were included in the model. Conversely, the analyses performed on men revealed that the mood vitality and excitement subscale was a significant predictor of ToM abilities. Our study is the first to show the impact of certain dimensions of hypomanic personality on performance in ToM in a male sample. This result supports the idea that deficits in ToM can be a trait marker of bipolar disorder in a healthy male population.

The Basic Empathy Scale in adults (BES-A): factor structure of a revised form.

Initially thought of as a unitary ability, empathy has been more recently considered to consist of 2 components (i.e., an affective and a cognitive component). The Basic Empathy Scale (BES) is a tool that has been used to assess empathy in young people and adolescents on the basis of this dual-component conception (Jolliffe & Farrington, 2006). Recent studies of empathy have led to it being defined as underpinned by 3 components, namely, emotional contagion, emotional disconnection, and cognitive empathy. The aims of this study were (a) to validate the BES in Adults and (b) to compare the different conceptions of empathy. Three hundred seventy French adults took part in the study, and 160 of them filled out complementary scales measuring empathy, alexithymia, and emotional consciousness. The confirmatory factor analyses showed that the 3-factor model was the model that was best able to account for the data. Complementary tools confirmed the relationships previously observed between empathy as assessed with the BES and other scales assessing emotional processes. The results of this study make it clear that empathy can be seen as process-dependent. This conception of empathy, which is based on 3 factors, is consistent with the current, more integrated view of empathy. The implications of this conception and the opportunity to use the 2 or 3 factors of the BES in adults are presented in the discussion.

Brain-derived neurotrophic factor (BDNF) Val66Met polymorphism and its implication in executive functions in adult offspring of alcohol-dependent probands.

Impairment of executive functions (EFs) mediated by the prefrontal lobe is regarded as a cognitive endophenotype of alcohol dependence, being observed both in probands and in healthy offspring. Given its impact on the anatomy of the prefrontal cortex, the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism may well be involved in this specific endophenotype. Forty-six healthy adult children of alcoholics (HACA) and 82 healthy controls (HC) took part in the study. All the participants were assessed with the Diagnostic Interview for Genetic Studies, and their family histories of alcohol and substance use were assessed with the Family Informant Schedule and Criteria. The Trail Making Test, Arithmetic Switching Task, Stroop Color-Word Test and Wisconsin Card Sorting Test were administered to assess EFs. An overall executive factor score was calculated using factorial analyses. Genotyping of the BDNF Val66Met polymorphism was performed using the TaqMan® allelic discrimination assay. HACA had significantly lower EFs performance than HC. Genetic analysis showed that BDNF genotype distributions were in Hardy-Weinberg equilibrium in the HACA and HC. Genotype and allele distributions did not differ significantly between the two groups. Participants with the Met allele performed significantly more poorly than participants with the Val allele, and a group by allele interaction was observed, the BDNF Met allele being associated with a poorer executive factor score in the HACA group. These results suggest that the BDNF Val66Met polymorphism may contribute to alcohol dependence vulnerability via lower EFs performance.

Procedural learning in specific language impairment: effects of sequence complexity.

According to the procedural deficit hypothesis (PDH), abnormal development in the procedural memory system could account for the language deficits observed in specific language impairment (SLI). Recent studies have supported this hypothesis by using a serial reaction time (SRT) task, during which a slower learning rate is observed in children with SLI compared to controls. Recently, we obtained contrasting results, demonstrating that children with SLI were able to learn a sequence as quickly and as accurately as controls. These discrepancies could be related to differences in the statistical structure of the SRT sequence between these studies. The aim of this study was to further assess, in a group of 21 children with SLI, the PDH with second-order conditional sequences, which are more difficult to learn than those used in previous studies. Our results show that children with SLI had impaired procedural memory, as evidenced by both longer reaction times and no sign of sequence-specific learning in comparison with typically developing controls. These results are consistent with the PDH proposed by Ullman and Pierpont (2005) and suggest that procedural sequence-learning in SLI children depends on the complexity of the to-be-learned sequence.

Executive functions in adult offspring of alcohol-dependent probands: toward a cognitive endophenotype?

BACKGROUND: Executive function (EF) impairment in alcohol dependence (AD) has been related to the toxic effects of alcohol on frontal lobes. However, this impairment could be partially present before the onset of the disease and might constitute a vulnerability factor. Although a considerable body of research has investigated executive functioning among AD patients, much less attention has been directed toward high-risk individuals. Most studies were carried out among children or adolescents, and very few were conducted in adults. The aim of this study was to examine EF in a group of adult offspring of AD individuals. METHODS: One hundred and fifty-five nonalcoholic adults with (family history positive [FHP]) or without (family history negative [FHN]) family history of AD were included in the study. All participants were screened for past and current psychiatric diagnoses, and alcohol, tobacco, and other substance use. They were compared on self-rated impulsiveness using the Barratt Impulsiveness Scale-11 (BIS-11) and EF using a neuropsychological test battery. RESULTS: Group comparison revealed that FHP participants had significantly higher BIS-11 scores than the FHN participants, while neuropsychological examination revealed lower EF scores for FHP participants. Hierarchical regression analysis revealed that the number of AD family members was a predictor of EF results, whereas impulsiveness was not. CONCLUSIONS: Nonalcoholic adult offspring of AD individuals showed increased impulsiveness and decreased EF, suggesting weakness of 2 distinct neurobehavioral decision systems. Findings support evidence that EF weaknesses may qualify as a suitable endophenotype candidate for AD.

Procedural visual learning in children with specific language impairment.

PURPOSE: According to the procedural deficit hypothesis (PDH), difficulties in the procedural learning (PL) system may contribute to the language difficulties observed in children with specific language impairment (SLI). METHOD: Fifteen children with SLI and their typically developing (TD) peers were compared on visual PL tasks-specifically, deterministic serial reaction time (SRT) tasks. In the first experiment, children with SLI and their TD peers performed the classical SRT task using a keyboard as response mode. In the second experiment, they performed the same SRT task but gave their responses through a touchscreen (instead of a keyboard) to reduce the motor and cognitive demands of the task. RESULTS: Although in Experiment 1, children with SLI demonstrated learning, they were slower and made more errors than did their TD peers. Nevertheless, these relative weaknesses disappeared when the nature of the response mode changed ( Experiment 2). CONCLUSIONS: In this study, the authors report that children with SLI may exhibit sequential learning. Moreover, the generally slower reaction times observed in previous deterministic SRT studies may be explained by the response mode used. Thus, our findings are not consistent with the predictions of the PDH, and these findings suggest that language impairments in SLI are not sustained by poor procedural learning abilities.

Exploration of serial structure procedural learning in children with language impairment.

Recent studies on specific language impairment (SLI) have suggested that language deficits are directly associated with poor procedural learning abilities. Findings from our previous work are contrary to this hypothesis; we found that children with SLI were able to learn eight-element-long sequences as fast and as accurately as children with normal language (NL) on a serial reaction time (SRT) task. A probabilistic rather than a deterministic SRT paradigm was used in the current study to explore procedural learning in children with SLI to mimic real conditions of language learning. Fifteen children with or without SLI were compared on an SRT task including a probabilistic eight-element-long sequence. Results show that children with SLI were able to learn this sequence as fast and as accurately as children with NL, and that similar sequence-specific learning was observed in both groups. These results are novel and suggest that children with SLI do not display global procedural system deficits.

Semantic hyperpriming in normal aging: a consequence of instructions?

Semantic hyperpriming has consistently been found in normal aging. However, because the standard instructions to test semantic priming are generally ambiguous (focusing on both accuracy and speed), it is difficult to account for hyperpriming in older adults. By using the direct and mediated priming paradigms, this study investigates whether older adults' response mode at testing may explain hyperpriming. First, we show that, under identical conditions, inducing a response mode that favors speed leads to greater priming effects in older adults. The pattern of results is similar to what is observed under standard instructions. Second, prompting a response mode that favors accuracy leads to greater priming effects in younger adults. We discuss various explanations for these findings and conclude, in accordance with the Ratcliff, Thapar, Gomez, and McKoon (2004a) diffusion model, that hyperpriming in normal aging is contingent on older adults' response mode at testing.

What is the impact of the explicit knowledge of sequence regularities on both deterministic and probabilistic serial reaction time task performance?

The aim of this study was to explore the role of prior explicit sequence knowledge by comparing its influence on serial reaction time (SRT) performance with either a deterministic or a probabilistic sequence. The results confirm that, with a deterministic sequence, preliminary explicit learning improves SRT performance. On the other hand, with a probabilistic sequence, the results show no advantage for SRT performance in explicit-learning conditions. In addition, by using the process dissociation procedure (Jacoby, 1991), we show that performance on a subsequent generation task was more sustained by controlled processes for participants in the explicit-learning conditions than for those in the incidental condition. On the whole, these results, showing that the influence of explicit knowledge can be suppressed in certain specific conditions, are consistent with the intervention of both implicit and explicit mechanisms in SRT tasks, and the results also show that their relative influence can be modulated by the particular demands of the task.