Altered temporal sensitivity in obesity is linked to pro-inflammatory state

Nutrition is associated with differences in multisensory integration in healthy older adults

Diet can influence cognitive functioning in older adults and is a modifiable risk factor for cognitive decline. However, it is unknown if an association exists between diet and lower-level processes in the brain underpinning cognition, such as multisensory integration. We investigated whether temporal multisensory integration is associated with daily intake of fruit and vegetables (FV) or products high in fat/sugar/salt (FSS) in a large sample (N = 2,693) of older adults (mean age = 64.06 years, SD = 7.60; 56% female) from The Irish Longitudinal Study on Ageing (TILDA). Older adults completed a Food Frequency Questionnaire from which the total number of daily servings of FV and FSS items respectively was calculated. Older adults' susceptibility to the Sound Induced Flash Illusion (SIFI) measured the temporal precision of audio-visual integration, which included three audio-visual Stimulus Onset Asynchronies (SOAs): 70, 150 and 230 ms. Older adults who self-reported a higher daily consumption of FV were less susceptible to the SIFI at the longest versus shortest SOAs (i.e. increased temporal precision) compared to those reporting the lowest daily consumption (p = .013). In contrast, older adults reporting a higher daily consumption of FSS items were more susceptible to the SIFI at the longer versus shortest SOAs (i.e. reduced temporal precision) compared to those reporting the lowest daily consumption (p < .001). The temporal precision of multisensory integration is differentially associated with levels of daily consumption of FV versus products high in FSS, consistent with broader evidence that habitual diet is associated with brain health.

Abnormal multisensory integration in relapsing–remitting multiple sclerosis

Temporal Binding Window (TBW) represents a reliable index of efficient multisensory integration process, which allows individuals to infer which sensory inputs from different modalities pertain to the same event. TBW alterations have been reported in some neurological and neuropsychiatric disorders and seem to negatively affects cognition and behavior. So far, it is still unknown whether deficits of multisensory integration, as indexed by an abnormal TBW, are present even in Multiple Sclerosis. We addressed this issue by testing 25 participants affected by relapsing–remitting Multiple Sclerosis (RRMS) and 30 age-matched healthy controls. Participants completed a simultaneity judgment task (SJ2) to assess the audio-visual TBW; two unimodal SJ2 versions were used as control tasks. Individuals with RRMS showed an enlarged audio-visual TBW (width range = from − 166 ms to + 198 ms), as compared to healthy controls (width range = − 177/ + 66 ms), thus showing an increased tendency to integrate temporally asynchronous visual and auditory stimuli. Instead, simultaneity perception of unimodal (visual or auditory) events overall did not differ from that of controls. These results provide first evidence of a selective deficit of multisensory integration in individuals affected by RRMS, besides the well-known motor and cognitive impairments. The reduced multisensory temporal acuity is likely caused by a disruption of the neural interplay between different sensory systems caused by multiple sclerosis.

Behavioural evidence of altered sensory attenuation in obesity

Body ownership (i.e., the conscious belief of owning a body) and sense of agency (i.e., being the agent of one's own movements) are part of a pre-reflective experience of bodily self, which grounds on low-level complex sensory-motor processes. Although previous literature had already investigated body ownership in obesity, sense of agency was never explored. Here, we exploited the sensory attenuation effect (i.e., an implicit marker of the sense of agency; SA effect) to investigate whether the sense of agency was altered in a sample of 18 individuals affected by obesity as compared with 18 healthy-weight individuals. In our experiment, participants were asked to rate the perceived intensity of self-generated and other-generated tactile stimuli. Healthy-weight individuals showed a significantly greater SA effect than participants affected by obesity. Indeed, while healthy-weight participants perceived self-generated stimuli as significantly less intense as compared to externally generated ones, this difference between stimuli was not reported by affected participants. Our results relative to the SA effect pinpointed an altered sense of agency in obesity. We discussed this finding within the motor control framework with reference to obesity. We encouraged future research to further explore such effect and its role in shaping the clinical features of obesity.

The Association of Kinesiophobia and Pain Catastrophizing with Pain-Related Disability and Pain Intensity in Obesity and Chronic Lower-Back Pain

Individuals affected by chronic lower-back pain and obesity have an increased risk of long-lasting disability. In this study, we aimed to explore the contribution of kinesiophobia and pain catastrophizing in explaining pain intensity and pain-related disability in chronic lower-back pain associated to obesity. A cross-sectional study on 106 participants with obesity and chronic lower-back pain was performed. We assessed pain intensity, pain disability, pain catastrophizing, and kinesiophobia levels through self-reporting questionnaire. Hierarchical regressions were performed to assess the role of pain catastrophizing and kinesiophobia on pain intensity and pain disability. According to the results, kinesiophobia, but not pain catastrophing, significantly explained both pain intensity and pain-related disability. Kinesiophobia might play a significant role in enhancing pain-related disability and the pain intensity in individuals with chronic lower-back pain and obesity. We encourage future studies in which beliefs and cognition towards pain might be a therapeutic target in interdisciplinary pain management interventions.