Philippe Bonnet

Bio: Philippe Bonnet is an academic researcher from Paris Descartes University. The author has contributed to research in topics: Population & Social class. The author has an hindex of 3, co-authored 7 publications receiving 53 citations.

How should "ambidexterity" be estimated?

Abstract: Weak and absent hand preferences have often been associated with developmental disorders or with cognitive functioning in the typical population. The results of different studies in this area, however, are not always coherent. One likely reason for discrepancies in findings is the diversity of cut-offs used to define ambidexterity and mixed right- and mixed left-handedness. Establishing and applying a common criterion would constitute an important step on the way to producing systematically comparable results. We thus decided to try to identify criteria for classifying individuals ambidextrous, mixed right- or left-handed or strong right- or left-handed. For that purpose, we first administered a handedness questionnaire to 716 individuals and performed multiple correspondence analyses to define handedness groups. Twenty-four participants were categorized as ambidextrous (3.3%), as opposed to mixed (29.2%) and strong (56%) right-handers, and to mixed (9.1%) and strong (2.4%) left-handers. We then compared this categorization with laterality index (LI)-based categories using different cut-offs and found that it was most correlated with LI cut-offs at -90, -30, +30 and +90, successively delimiting strong left-handedness, mixed left-handedness, ambidexterity (-30 to +30), mixed right-handedness and strong right-handedness. The characteristics of ambidextrous and lateralized individuals are also compared.

Influence of early maladaptive schemas, depression, and anxiety on the intensity of self-reported cognitive complaint in older adults with subjective cognitive decline.

Abstract: Background: Subjective cognitive decline (SCD) designates a self-reported cognitive decline despite preserved cognitive abilities. This study aims to explore, in older adults with SCD, the association between intensity of self-reported cognitive complaint and psychological factors including Young's early maladaptive schemas (EMSs) (i.e. enduring cognitive structures giving rise to beliefs about oneself and the world), as well as depression and anxiety. Methods: Seventy-six subjects (69.22 years ± 6.1) with intact cognitive functioning were recruited through an advertisement offering free participation in an intervention on SCD. After undergoing a neuropsychological examination (including global cognition (MMSE) and episodic memory (FCSRT)) and a semi-structured interview to assess depressive symptoms (MADRS), they completed a set of online self-reported questionnaires on SCD (McNair questionnaire), Young's EMSs (YSQ-short form), depression (HADS-D), and anxiety (HADS-A and trait-STAI-Y). Results: The McNair score did not correlate with the neuropsychological scores. Instead, it was highly (r > 0.400; p < 0.005) correlated with trait anxiety and three EMSs belonging to the “Impaired autonomy and performance” domain: Dependence/incompetence, Failure to achieve and Vulnerability to harm or illness. Our final regression model comprising depression, anxiety, and these three EMSs as predictors (while controlling for age, gender, and objective cognition) accounted for 38.5% of the observed variance in SCD intensity. Conclusions: The level of cognitive complaint is significantly associated with Young's EMSs in the category of “Impaired autonomy and performance”. We assume that SCD may primarily be driven by profound long-term inner beliefs about oneself that do not specifically refer to self-perceived memory abilities.

Validation de 120 images de l’IAPS auprès d’une population française âgée de 20 à 88 ans

Abstract: L’International affective picture system (IAPS) est une banque d’images standardisees constituant autant de stimuli emotionnels. L’objectif de notre etude est de presenter la validation de 120 images issues de l’IAPS dans une population francaise. Cent cinquante participants sains, âges de 20 a 88 ans et repartis en cinq groupes d’âge ont ete inclus. La tâche consistait pour chaque image presentee dans un ordre aleatoire, a juger a l’aide du Self assessment manikin, de sa valence emotionnelle (variant de plaisant a deplaisant) et de l’intensite de l’emotion ressentie ou arousal (variant de calme a excite).En ce qui concerne la valence, lesdeux modalites positives de valence sont moins nettement distinguees que les deux modalites negatives de valence. En terme d’arousal, ce sont les images negatives qui entrainent les emotions les plus fortes, suivies des images positives et des images neutres. Que ce soit pour la valence ou pour l’arousal, ce sont les groupes d’âge les plus âges qui ont les plus faibles variances. Nous disposons maintenant de la valence et de l’arousal de 120 stimuli emotionnels dans cinq classes d’âges differentes.

Amnestic syndrome of the medial temporal type identifies prodromal AD: A longitudinal study

Abstract: In the article “Amnestic syndrome of the medial temporal type identifies prodromal AD: A longitudinal study,” by M. Sarazin …

Translation, cultural adaption, and test-retest reliability of Chinese versions of the Edinburgh Handedness Inventory and Waterloo Footedness Questionnaire.

Abstract: Quantitative assessments of handedness and footedness are often required in studies of human cognition and behaviour, yet no reliable Chinese versions of commonly used handedness and footedness questionnaires are available. Accordingly, the objective of the present study was to translate the Edinburgh Handedness Inventory (EHI) and the Waterloo Footedness Questionnaire-Revised (WFQ-R) into Mandarin Chinese and to evaluate the reliability and validity of these translated versions in healthy Chinese people. In the first stage of the study, Chinese versions of the EHI and WFQ-R were produced from a process of translation, back translation and examination, with necessary cultural adaptations. The second stage involved determining the reliability and validity of the translated EHI and WFQ-R for the Chinese population. One hundred and ten Chinese participants were tested online, and the results showed that the Cronbach's alpha coefficient of internal consistency was 0.877 for the translated EHI and 0.855 for the translated WFQ-R. Another 170 Chinese participants were tested and re-tested after a 30-day interval. The intra-class correlation coefficients showed high reliability, 0.898 for the translated EHI and 0.869 for the translated WFQ-R. This preliminary validation study found the translated versions to be reliable and valid tools for assessing handedness and footedness in this population.

Subjective cognitive decline: preclinical manifestation of Alzheimer's disease.

Abstract: Subjective cognitive decline (SCD), characterized by a very early and subtle cognitive decline prior to the appearance of objective cognitive impairment, is considered to be the preclinical manifestation of Alzheimer's disease (AD). Given the lack of significant abnormalities in standardized neuropsychological assessments for individuals with SCD, biochemical and neuroimaging biomarkers may be important indicators of the preclinical stage of AD. The application of various biomarkers derived from the cerebrospinal fluid and neuroimaging thus has the potential to make AD-related pathology detectable in vivo. In this review, we discuss the conceptual evolution of SCD as an entity and further elucidate characteristic cerebrospinal fluid and neuroimaging biomarkers of SCD.

Missing depth cues in virtual reality limit performance and quality of three dimensional reaching movements

Abstract: BACKGROUND Goal-directed reaching for real-world objects by humans is enabled through visual depth cues. In virtual environments, the number and quality of available visual depth cues is limited, which may affect reaching performance and quality of reaching movements. METHODS We assessed three-dimensional reaching movements in five experimental groups each with ten healthy volunteers. Three groups used a two-dimensional computer screen and two groups used a head-mounted display. The first screen group received the typically recreated visual depth cues, such as aerial and linear perspective, occlusion, shadows, and texture gradients. The second screen group received an abstract minimal rendering lacking those. The third screen group received the cues of the first screen group and absolute depth cues enabled by retinal image size of a known object, which realized with visual renderings of the handheld device and a ghost handheld at the target location. The two head-mounted display groups received the same virtually recreated visual depth cues as the second or the third screen group respectively. Additionally, they could rely on stereopsis and motion parallax due to head-movements. RESULTS AND CONCLUSION All groups using the screen performed significantly worse than both groups using the head-mounted display in terms of completion time normalized by the straight-line distance to the target. Both groups using the head-mounted display achieved the optimal minimum in number of speed peaks and in hand path ratio, indicating that our subjects performed natural movements when using a head-mounted display. Virtually recreated visual depth cues had a minor impact on reaching performance. Only the screen group with rendered handhelds could outperform the other screen groups. Thus, if reaching performance in virtual environments is in the main scope of a study, we suggest applying a head-mounted display. Otherwise, when two-dimensional screens are used, achievable performance is likely limited by the reduced depth perception and not just by subjects' motor skills.