Sense of ownership influence on tactile perception: Is the predictive coding account valid for the somatic rubber hand Illusion?

According to the predictive coding account, the attenuation of tactile perception on the hand exposed to the visuo-tactile Rubber Hand Illusion (vtRHI) relies on a weight increase of visual information deriving from the fake hand and a weight decrease of tactile information deriving from the individual's hand. To explore if this diametrical modulation persists in the absence of vision when adopting the somatic RHI (sRHI), we recorded tactile acuity measures before and after both RHI paradigms in 31 healthy individuals, hypothesizing a weight decrease for somatosensory information deriving from the hand undergoing the illusion and a weight increase for those deriving from the contralateral hand in the sRHI. Our results showed a significant overall decrease in tactile acuity on the hand undergoing the illusion whilst no changes emerged on the contralateral hand during sRHI. Since the sRHI was not accompanied by the hand spatial remapping, despite the generation of the feeling of ownership toward the fake hand, we hypothesized spatial remapping might play a pivotal role in determining sensory information weight attribution.

Sexual Dysfunction in Multiple Sclerosis: The Role of Executive Function.

Cognitive impairment and sexual dysfunction are common symptoms in persons with Multiple Sclerosis (MS). The present study focuses on the relationship between these two dimensions by means of a specific assessment commonly used in clinical practice with this population. Fifty-five persons with a diagnosis of MS underwent specific cognitive tests and answered clinical questionnaires. Two cognitive tests, one for memory (the Selective Reminding Test), and one for attention (the Symbol Digit Modalities Test), were administered together with two tests for executive functions (the D-KEFS Sorting Test and Stroop Test). Two self-report questionnaires to investigate clinical, psychological and sexual features (the Beck Depression Inventory-II and Self-perception of Cognition in Multiple Sclerosis and Multiple Sclerosis Intimacy and Sexuality Questionnaire-19), were also administered. The main result highlights that sexual difficulties are associated with cognitive deficits, particularly with executive disorders, but not with memory and attention. Furthermore, sexual difficulties are better explained when depression symptoms are also taken into account. This study disentangles the interaction between sexual dysfunction, cognitive impairment and depression in persons with MS by emphasising the role of very high cognitive processing (i.e., executive functioning) in determining human behaviour.

Non-Functional Jaw Muscular Activity in Patients with Disorders of Consciousness Revealed by A Long-Lasting Polygraphy.

The presence of involuntary, non-functional jaw muscle activity (NFJMA) has not yet been assessed in patients with disorders of consciousness (DOC), although the presence of bruxism and other forms of movement disorders involving facial muscles is probably more frequent than believed. In this work, we evaluated twenty-two prolonged or chronic DOC patients with a long-lasting polygraphic recording to verify NFJMA occurrence and assess its neurophysiological patterns in this group of patients. A total of 5 out of 22 patients showed the presence of significant NFJMA with electromyographic patterns similar to what can be observed in non-DOC patients with bruxism, thus suggesting a disinhibition of masticatory motor nuclei from the cortical control. On the other hand, in two DOC patients, electromyographic patterns advised for the presence of myorhythmia, thus suggesting a brainstem/diencephalic involvement. Functional, non-invasive tools such as long-lasting polygraphic recordings should be extended to a larger sample of patients, since they are increasingly important in revealing disorders potentially severe and impacting the quality of life of DOC patients.