Multisensory integration and age-dependent sensitivity to body representation modification induced by the rubber hand illusion.

The aim of the present study was to compare junior and senior healthy participants for their multimodal integration capability. The instrument used for the investigation was the rubber hand illusion (RHI) where synchronous and asynchronous multimodal stimulation were applied. The study focused on assessing the rate of integration for visuo-tactile and visuo-proprioceptive stimuli. METHODS: From a large sample of right-handed volunteers, 50 senior employees (containing younger and middle age adults) and 51 senior retired (senior adults) participants were recruited. RESULTS: The between-subject analyses revealed that individuals both the junior and the senior participants responded to induction of RHI with vivid ownership and disownership experiences and a higher mislocalization error in the synchronous condition. However, the between-group analysis showed that participants in the senior group reported less vivid ownership and less vivid total RHI experiences scores compared to members of the junior group, but no mislocalization error differences were found between the groups. CONCLUSION: The results indicated that when visuo-tactile stimuli synchronously presented, the gain in multisensory integration decreased in seniors group. In contrast, in the case of visuo-proprioceptive synchronous presentation, the efficiency of multisensory integration remained unchanged across the lifespan.

Comparing Sensitivity and Specificity of Addenbrooke's Cognitive Examination-I, III and Mini-Addenbrooke's Cognitive Examination in Parkinson's Disease.

BACKGROUND: Parkinson's disease (PD) is the second most common neurodegenerative disorder characterized by numerous motor and nonmotor symptoms. Neurocognitive disorders (NCD) are one of the most troublesome problems and their diagnosis is often challenging. METHODS: We compared the sensitivity and specificity of several versions of Addenbrooke Cognitive Examination (ACE, ACE-III, and Mini-ACE) on 552 subjects with PD. Normal cognition, mild and major NCD were judged in accordance with the respective criteria of the Diagnostic and Statistical Manual of Mental Disorders 5th edition. Subsequently, we applied the receiver operation characteristic (ROC) analysis in comparison of different education levels. RESULTS: For subjects with education level 0-8 and 9-12 years, the ACE-III had the best discriminating capabilities for mild NCD (cut-off scores: 83.5 and 85.5 points, respectively), while Mini-ACE was the best for subjects having education > 12 years (cut-off score: 25.5 points). For detecting major NCD, ACE-III had the best diagnostic accuracy in all levels of education (cut-off scores: 70.5, 77.5, and 78.5 points for subjects having education level 0-8, 9-12, and >12 years, respectively). CONCLUSION: ACE-III and its nested version, the Mini-ACE, had the best screening abilities for detecting mild and major NCD in PD.

Understanding deceptive intentions behind pointing gestures in 12-15-month-old infants.

We examined the comprehension of deceptive intentions revealed in searching task in infancy, on the theoretical basis of natural pedagogy and epistemic trust. The main findings showed that 12-15-month-old infants are able to discriminate the reliable and the deceptive actions of adults, but they do not generalize their previous experience in connection with a novel person, who is treated as a new reliable source of information.

Association of Gait Characteristics and Depression in Patients with Parkinson's Disease Assessed in Goal-Directed Locomotion Task.

Introduction. In the genesis of Parkinson's disease (PD) clinical phenomenology the exact nature of the association between bradykinesia and affective variables is unclear. In the present study, we analyzed the gait characteristics and level of depression in PD and healthy volunteers. Methods. Patients with PD (n = 48) and healthy controls (n = 52) were recruited for the present study. Walking speed, stride length, and cadence were compared between groups while participants completed a goal-directed locomotion task under visually controlled (VC) and visually noncontrolled conditions (VnC). Results. Significantly higher depression scores were found in PD comparing to healthy control groups. In PD, depression was associated with gait components in the VC wherein the place of the target was visible. In contrast, in healthy subjects the depression was associated with gait components in VnC wherein the location and image of the target were memorized and recalled. In patients with PD and depression, the visually deprived multitask augments the rate of cadence and diminishes stride length, while velocity remains relatively unchanged. The depression associated with gait characteristics as a comorbid affective factor in PD, and that impairs the coherence of gait pattern. Conclusion. The relationship between depression and gait parameters appears to indicate that PD not only is a neurological disease but also incorporates affective disturbances that associate with the regulation of gait characteristics.

Temperament and psychopathological syndromes specific susceptibility for rubber hand illusion.

The aim of this study is to explore individual capacity for self-integration, susceptibility to the Rubber Hand Illusion (RHI) and the role of temperament factors in the emergence of body schema and body image dissociation. The RHI factors, proprioceptive drift, body ownership and body disownership were assessed in 48 university students. Personality and psychiatric vulnerability were measured by the Temperament and Character Inventory (TCI-R) and the Symptom Checklist-90-R (SCL-90-R). Our study pointed to the fact that the extent of behaviourally defined proprioceptive drift was associated with temperament factors, especially with Novelty Seeking and Harm Avoidance. Further, the ownership was associated with Symptom Checklist factors, especially with elevated Interpersonal Sensitivity and vulnerability to Schizotypy and Paranoid Ideation and elevated disownership score was found in the case of elevated Schizotypy, including a depersonalisation feeling when the RHI was induced. The RHI may be considered as a conflicting situation, in which a way to cope with incongruent multimodal, visual, haptic and proprioceptive stimulation provides an opportunity to test body integration and embodiment processes in healthy participants and patients without disadvantageous outcomes. The results support and replenish the two opposite processing models of the RHI with a third, temperament-based procedural mechanism.