Sensory processing disorder | EPFL Graph Search

Sensory processing disorder (SPD, formerly known as sensory integration dysfunction) is a condition in which multisensory input is not adequately processed in order to provide appropriate responses to the demands of the environment. Sensory processing disorder is present in many people with dyspraxia, autism spectrum disorder and attention deficit hyperactivity disorder. Individuals with SPD may inadequately process visual, auditory, olfactory (smell), gustatory (taste), tactile (touch), vestibular (balance), proprioception (body awareness), and interoception (internal body senses) sensory stimuli. Sensory integration was defined by occupational therapist Anna Jean Ayres in 1972 as "the neurological process that organizes sensation from one's own body and from the environment and makes it possible to use the body effectively within the environment". Sensory processing disorder has been characterized as the source of significant problems in organizing sensation coming from the body and

Peri-personal space encoding in patients with disorders of consciousness and cognitive-motor dissociation

Maria Manuela da Silva Marques, Jean-Paul Noel, Serafeim Perdikis, Andrea Serino

Behavioral assessments of consciousness based on overt command following cannot differentiate patients with disorders of consciousness (DOC) from those who demonstrate a dissociation between intent/awareness and motor capacity: cognitive motor dissociation (CMD). We argue that delineation of peri-personal space (PPS) - the multisensory-motor space immediately surrounding the body - may differentiate these patients due to its central role in mediating human-environment interactions, and putatively in scaffolding a minimal form of selfhood. In Experiment 1, we determined a normative physiological index of PPS by recording electro-physiological (EEG) responses to tactile, auditory, or audio-tactile stimulation at different distances (5 vs. 75 cm) in healthy volunteers (N = 19). Contrasts between paired (AT) and summed (A + T) responses demonstrated multisensory supra-additivity when AT stimuli were presented near, i.e., within the PPS, and highlighted somatosensory-motor sensors as electrodes of interest. In Experiment 2, we recorded EEG in patients behaviorally diagnosed as DOC or putative CMD (N = 17, 30 sessions). The PPS-measure developed in Experiment 1 was analyzed in relation with both standard clinical diagnosis (i.e., Coma Recovery Scale; CRS-R) and a measure of neural complexity associated with consciousness. Results demonstrated a significant correlation between the PPS measure and neural complexity, but not with the CRS-R, highlighting the added value of the physiological recordings. Further, multisensory processing in PPS was preserved in putative CMD but not in DOC patients. Together, the findings suggest that indexing PPS allows differentiating between groups of patients whom both show overt motor impairments (DOC and CMD) but putatively distinct levels of awareness or motor intent.

ELSEVIER SCI LTD2019

Thalamic microcircuitry: neurons, synapses, and circuit motifs in receptive field structure and sensory processing

Jane Yi

Our perception of the world is first shaped by the thalamus, a structure composed of many nuclei in the center of our brains. Different nuclei hold different responsibilities - vision (dorsal lateral genicular nucleus; dLGN), audition (medial geniculate nucleus; MGN), somatosensation (ventro-basal nuclei; VB), though many properties across these sensory modalities appear to be universal. In this thesis, we completed a comprehensive characterization of the neurons, connections, and microcircuitries within the rodent VB thalamus. Our most prominent finding is the confirmation of the existence of local interneurons in the VB and the discovery of their profoundly active and diverse role in thalamic processes. Thus, we have observed that the fundamental excitatory and inhibitory neurons of dLGN and VB nuclei and their intrinsic circuit motifs are indistinguishable. Only a few notable differences are, however, present. (1), Principal excitatory neurons of the VB, the thalamocortical (TC) relays, have morphological types that appear to be distributed heteroge-neously throughout the VB whereas dLGN TC morphological types have regional preferences. (2), VB inhibitory local interneurons represent a smaller proportion of the total neuronal popula-tion compared to their dLGN counterparts. The similarities between these thalamic regions great-ly outnumber the differences. It then introduces new questions of how different vision and soma-tosensation of the physical world are when these senses are ultimately represented as binary sig-nals and are processed in similar manners in the thalamus. Following these questions may lead to new therapeutic solutions for retinally blind patients, tactile prostheses, or neurological disorders of sensory perception like schizophrenia.

EPFL2021

Shedding light on excessive crying in babies

François Lazeyras, Dimitri Nestor Alice Van De Ville

Background Excessive and inconsolable crying behavior in otherwise healthy infants (a condition called infant colic (IC)) is very distressing to parents, may lead to maternal depression, and in extreme cases, may result in shaken baby syndrome. Despite the high prevalence of this condition (20% of healthy infants), the underlying neural mechanisms of IC are still unknown. Methods By employing the latest magnetic resonance imaging (MRI) techniques in newborns, we prospectively investigated whether newborns' early brain responses to a sensory stimulus (smell) is associated with a subsequent crying behavior. Results In our sample population of 21 healthy breastfed newborns, those who developed IC at 6 weeks exhibited brain activation and functional connectivity in primary and secondary olfactory brain areas that were distinct from those in babies that did not develop IC. Different activation in brain regions known to be involved in sensory integration was also observed in colicky babies. These responses measured shortly after birth were highly correlated with the mean crying time at 6 weeks of age. Conclusions Our results offer novel insights into IC pathophysiology by demonstrating that, shortly after birth, the central nervous system of babies developing IC has already greater reactivity to sensory stimuli than that of their noncolicky peers. Impact Shortly after birth, the central nervous system of colicky infants has a greater sensitivity to olfactory stimuli than that of their noncolicky peers. This early sensitivity explains as much as 48% of their subsequent crying behavior at 6 weeks of life. Brain activation patterns to olfactory stimuli in colicky infants include not only primary olfactory areas but also brain regions involved in pain processing, emotional valence attribution, and self-regulation. This study links earlier findings in fields as diverse as gastroenterology and behavioral psychology and has the potential of helping healthcare professionals to define strategies to advise families.

NATURE PUBLISHING GROUP2020