Dysexecutive syndrome in Parkinson’s disease: the GREFEX study

The objectives of this study were to characterize the frequencies and profiles of behavioral and cognitive dysexecutive syndromes in PD (based on validated battery and diagnostic criteria) and to develop a shortened diagnostic battery. Eighty-eight non-demented patients with a diagnosis of PD were examined with an executive validated battery. Using a validated framework, the patients’ test results were interpreted with respect to normative data from 780 controls. A dysexecutive syndrome was observed in 80.6% of the patients [95% confidence interval: 71.1–90.1]. The dysexecutive profile was characterized by prominent impairments in deduction, flexibility, inhibition and initiation in the cognitive domain, and by global hypoactivity with apathy and hyperactivity in the behavioral domain. This finding implies that patients with PD should be assessed with cognitive tests and a validated inventory for behavioral dysexecutive syndromes. A shortened battery (based on three cognitive tests and three behavioral domains) provided high diagnostic accuracy.     

Transgender and anxiety: A comparative study between transgender people and the general population

Background: Anxiety disorders pose serious public health problems. The data available on anxiety disorders in the transgender population is limited by the small numbers, the lack of a matched controlled population and the selection of a nonhomogenous group of transgender people.

Aims: The aims of the study were (1) to determine anxiety symptomatology (based on the HADS) in a nontreated transgender population and to compare it to a general population sample matched by age and gender; (2) to investigate the predictive role of specific variables, including experienced gender, self-esteem, victimization, social support, interpersonal functioning, and cross-sex hormone use regarding levels of anxiety symptomatology; and (3) to investigate differences in anxiety symptomatology between transgender people on cross-sex hormone treatment and not on hormone treatment.

Methods: A total of 913 individuals who self-identified as transgender attending a transgender health service during a 3-year period agreed to participate. For the first aim of the study, 592 transgender people not on treatment were matched by age and gender, with 3,816 people from the general population. For the second and third aim, the whole transgender population was included.

Measurements: Sociodemographic variables and measures of depression and anxiety (HADS), self-esteem (RSE), victimization (ETS), social support (MSPSS), and interpersonal functioning (IIP-32).

Results: Compared with the general population transgender people had a nearly threefold increased risk of probable anxiety disorder (all p < .05). Low self-esteem and interpersonal functioning were found to be significant predictors of anxiety symptoms. Trans women on treatment with cross-sex hormones were found to have lower levels of anxiety disorder symptomatology.

Conclusions: Transgender people (particularly trans males) have higher levels of anxiety symptoms suggestive of possible anxiety disorders compared to the general population. The findings that self-esteem, interpersonal functioning, and hormone treatment are associated with lower levels of anxiety symptoms indicate the need for clinical interventions targeting self-esteem and interpersonal difficulties and highlight the importance of quick access to transgender health services.     

Learning nonadjacent dependencies: no need for algebraic-like computations

Is it possible to learn the relation between 2 nonadjacent events? M. Pena, L. L. Bonatti, M. Nespor, and J. Mehler (2002) claimed this to be possible, but only in conditions suggesting the involvement of algebraic-like computations. The present article reports simulation studies and experimental data showing that the observations on which Pena et al. grounded their reasoning were flawed by deep methodological inadequacies. When the invalid data are set aside, the available evidence fits exactly with the predictions of a theory relying on ubiquitous associative mechanisms. Because nonadjacent dependencies are frequent in natural language, this reappraisal has far-reaching implications for the current debate on the need for rule-based computations in human adaptation to complex structures.     

Encoding numbers: Behavioral evidence for processing-specific representations

The aim of this study was to test the hypothesis of a complex encoding of numbers according to which each numerical processing requires a specific representational format for input In three experiments, adult participants were given two numbers presented successively on screen through a self-presentation procedure after being asked to add, to subtract, or to compare them. We considered the self-presentation time of the first number as reflecting the complexity of the encoding for a given planned processing. In line with Dehaene's triple-code model, self-presentation times were longer for additions and subtractions than for comparisons with two-digit numbers but longer for subtractions than for additions and comparisons with one-digit numbers. The implications of these results for different theories of number processing are discussed.     

Recognition thresholds for plane-rotated pictures of familiar objects

We investigated picture plane rotation effects on the minimum stimulus duration required to recognise pictures of familiar objects in a picture-word verification task. Participants made unspeeded responses, selecting from 126 written alternatives. Longer stimulus durations were needed to identify plane-misoriented views. These orientation effects were non-linear, arguing against a simple mental rotation account of compensation for plane misorientation in identification tasks. Orientation effects were found for almost all items, in particular including those labelled at the basic level (cf. Hamm, McMullen, 1998, Journal of Experimental Psychology: Human Perception and Performance 24, 413-426). We suggest that plane misorientation increases the difficulty of basic level as well as subordinate level identification unless only a small, visually dissimilar set of stimuli are presented. Errors in the task were analysed to provide an alternative, objective measure of perceived visual similarity, by assessing the number and nature of mistaken identifications made to a given target object. We propose that misorientation effects are best understood in terms of the effects of the perceived visual similarity of a target to its set of response alternatives rather than in terms of the level (basic or subordinate) at which the target is to be identified.     

Effect of bilateral stimulation of the subthalamic nucleus on parkinsonian dysarthria

Never was the effect of bilateral stimulation of the subthalamic nucleus (STN) evaluated quantitatively on all the components of speech production, that is articulation, respiration and phonation, at the same time. It is the purpose of this study which uses force measurements of the articulatory organs and acoustic analysis in 16 parkinsonian patients. With STN stimulation, reaction and movement time of the articulatory organs decreased and their maximal strength, as well as their precision increased. We also noted a large beneficial effect on voice with a significant improvement in respiratory and phonatory functions.     

Neural correlates of dual task interference in rapid visual streams: an fMRI study

In rapid streams of visual stimuli, identification of a first target interferes with identification of a second target presented within the next half second (the attentional blink or AB). It has been suggested that rapid perceptual decisions under masking interference involve interactions between frontal and posterior cortex. We investigated the neural correlates of the AB using functional magnetic resonance imaging (fMRI). Twelve subjects viewed rapid streams of black letters in which were embedded two white target letters (T1 and T2) separated by either 300 or 700 ms. As expected, fewer correct T2 identifications were observed in the short-delay condition. Corresponding fMRI statistical images showed increased activation in inferotemporal and posterior parietal cortex, but also in lateral frontal cortex and cerebellum in the short-delay condition suggesting that these brain regions are associated with perceptual decisions under masking interference.     

Spatial learning in the 5-HT1B receptor knockout mouse: selective facilitation/impairment depending on the cognitive demand

Age-related memory decline is associated with a combined dysfunction of the cholinergic and serotonergic systems in the hippocampus and frontal cortex, in particular. The 5-HT1B receptor occupies strategic cellular and subcellular locations in these structures, where it plays a role in the modulation of ACh release. In an attempt to characterize the contribution of this receptor to memory functions, 5-HT1B receptor knockout (KO) mice were submitted to various behavioral paradigms carried out in the same experimental context (water maze), which were aimed at exposing mice to various levels of memory demand. 5-HT1BKO mice exhibited a facilitation in the acquisition of a hippocampal-dependent spatial reference memory task in the Morris water maze. This facilitation was selective of task difficulty, showing thus that the genetic inactivation of the 5-HT1B receptor is associated with facilitation when the complexity of the task is increased, and reveals a protective effect on age-related hippocampal-dependent memory decline. Young-adult and aged KO and wild-type (WT) mice were equally able to learn a delayed spatial matching-to-sample working memory task in a radial-arm water maze with short (0 or 5 min) delays. However, 5-HT1BKO mice, only, exhibited a selective memory impairment at intermediate and long (15, 30, and 60 min) delays. Treatment by scopolamine induced the same pattern of performance in wild type as did the mutation for short (5 min, no impairment) and long (60 min, impairment) delays. Taken together, these studies revealed a beneficial effect of the mutation on the acquisition of a spatial reference memory task, but a deleterious effect on a working memory task for long delays. This 5-HT1BKO mouse story highlights the problem of the potential existence of "global memory enhancers."     

Social inequalities in suicide mortality: Spain and France, 1980-1982 and 1988-1990

In this study we analyzed the socioeconomic differences in mortality from suicide in the economically active male population aged 25-64 years in Spain and France in 1980-1982 and 1988-1990; in the case of Spain the data came from the Eight Provinces Study (Regidor, Gutierrez-Fisac, & Rodríguez, 1995). Individuals were grouped into four categories: professional/managerial, clerical/sales/ service, agricultural, and manual workers. For 1980-1982, among those aged 25-44, professionals and managers had the lowest risk of mortality in Spain, and clerical/sales/service workers in France. These socioeconomic differences in mortality increased in 1988-1990. In 1980-1982, among those aged 45-64, clerical/ sales/service workers had the lowest risk of mortality from suicide relative to the other occupational groups in both countries, but this difference was not maintained in 1988-1990. Thus, differences in suicide mortality for men by occupational status depended in the present study upon both the nation studied and the time period chosen for study.