scholarly journals What’s Up: an assessment of Causal Inference in the Perception of Verticality

2017 ◽  
Author(s):  
K.N. de Winkel ◽  
M. Katliar ◽  
D. Diers ◽  
H.H. Büelthoff
Keyword(s):  
Causal Inference ◽  
Inertial Sensors ◽  
Sensory System ◽  
Considerable Variability ◽  
Sensory Signals ◽  
Partial Gravity ◽  
The Central Nervous System ◽  
Perception Of Verticality ◽  
Vector Sum ◽  
Combining Estimates

The perceptual upright is thought to be constructed by the central nervous system (CNS) as a vector sum; by combining estimates on the upright provided by the visual system and the body’s inertial sensors with prior knowledge that the upright is usually above the head. Results from a number of recent studies furthermore show that the weighting of the respective sensory signals is proportional to their reliability, consistent with a Bayesian interpretation of the idea of a vector sum (Forced Fusion, FF). However, findings from a study conducted in partial gravity suggest that the CNS may rely on a single sensory system (Cue Capture, CC), or choose to process sensory signals differently based on inferred signal causality (Causal Inference, CI). We developed a novel Alternative-Reality system to manipulate visual and physical tilt independently, and tasked participants (n=28) to indicate the perceived upright for various (in-)congruent combinations of visual-inertial stimuli. Overall, the data appear best explained by the FF model. However, an evaluation of individual data reveals considerable variability, favoring different models in about equal proportions of participants (FF, n=12; CI, n=7, CC, n=9). Given the observed variability, we conclude that the notion of a vector sum does not provide a comprehensive explanation of the perception of the upright.

scholarly journals Impact or push-off lameness presentation is not altered by the type of track surface where horses are trotted

2015 ◽  
Vol 67 (6) ◽  
pp. 1475-1482 ◽  
Author(s):  
M.S. Azevedo ◽  
F.D.D.L. Côrte ◽  
K.E. Brass ◽  
M. Gallio ◽  
S.L Dau ◽  
...  
Keyword(s):  
Inertial Sensors ◽  
Concrete Surface ◽  
Variation Coefficient ◽  
Soft Ground ◽  
Loose Sand ◽  
Significance Level ◽  
Tukey Test ◽  
Minimum Height ◽  
Track Surface ◽  
Vector Sum

This study aimed to evaluate the influence of the track surface on which horses are examined, regarding the phase of lameness presentation. Ten horses with lameness in at least one limb were evaluated with wireless inertial sensors on three track surfaces (concrete, loose sand and grass). Six crossover track sequences were established. The variables vector sum, maximum and minimum height of the head and pelvis, variation coefficient of the maximum and minimum height of the head and pelvis were analyzed using ANOVA, followed by Tukey test to compare means between track surface and sequence, at 5% significance level. The lameness phase (impact or pushoff) was analyzed considering the proportion of affected animals. There were no differences on vector sum, maximum and minimum height or variation coefficient of head and pelvis. Difference was observed on the number of strides registered on sand compared to grass and concrete (p <0.0001) for fore and hindlimbs. Impact lameness on forelimbs was presented by a larger number of animals on the concrete surface; pushoff lameness was more evident on the grass surface. In the hindlimbs, impact lameness was more evident on the grass surface, while pushoff lameness was in greater number of animals on concrete surfaces. The track sequence on which horses were trotted during evaluation does not seem to be a factor, but the number of lame horses and the phase of lameness manifestation can vary between track surfaces, as some horses showed impact lameness on soft ground and elevation lameness on hard ground.

scholarly journals Attention controls multisensory perception via 2 distinct mechanisms at different levels of the cortical hierarchy

PLoS Biology ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. e3001465
Author(s):  
Ambra Ferrari ◽  
Uta Noppeney
Keyword(s):  
Causal Inference ◽  
Causal Structure ◽  
Multisensory Perception ◽  
Spatial Representations ◽  
Perceptual Inference ◽  
Sensory Signals ◽  
Cortical Hierarchy ◽  
Parietal Cortices ◽  
The Brain ◽  
Different Levels

To form a percept of the multisensory world, the brain needs to integrate signals from common sources weighted by their reliabilities and segregate those from independent sources. Previously, we have shown that anterior parietal cortices combine sensory signals into representations that take into account the signals’ causal structure (i.e., common versus independent sources) and their sensory reliabilities as predicted by Bayesian causal inference. The current study asks to what extent and how attentional mechanisms can actively control how sensory signals are combined for perceptual inference. In a pre- and postcueing paradigm, we presented observers with audiovisual signals at variable spatial disparities. Observers were precued to attend to auditory or visual modalities prior to stimulus presentation and postcued to report their perceived auditory or visual location. Combining psychophysics, functional magnetic resonance imaging (fMRI), and Bayesian modelling, we demonstrate that the brain moulds multisensory inference via 2 distinct mechanisms. Prestimulus attention to vision enhances the reliability and influence of visual inputs on spatial representations in visual and posterior parietal cortices. Poststimulus report determines how parietal cortices flexibly combine sensory estimates into spatial representations consistent with Bayesian causal inference. Our results show that distinct neural mechanisms control how signals are combined for perceptual inference at different levels of the cortical hierarchy.

scholarly journals RESPONSE PROPERTIES OF INTERNEURONS OF THE CRICKET CERCAL SENSORY SYSTEM ARE CONSERVED IN SPITE OF CHANGES IN PERIPHERAL RECEPTORS DURING MATURATION

1992 ◽  
Vol 164 (1) ◽  
pp. 205-226 ◽  
Author(s):  
AKIRA CHIBA ◽  
GÜNTER KÄMPER ◽  
R. K. MURPHEY
Keyword(s):  
Sensory Neurons ◽  
Sensory System ◽  
Postembryonic Development ◽  
Response Decrement ◽  
Response Properties ◽  
Hair Sensilla ◽  
Intensity Response ◽  
The Central Nervous System ◽  
Constant Output ◽  
Rate Of Response

During postembryonic development of the cricket, the total number of filiform hair sensilla in the cereal sensory system increases approximately 40-fold. In addition, individual receptor hairs grow in size, changing the transducer properties of the sensilla and, thereby, the information transmitted to the central nervous system (CNS) by the sensory neurons. Interneurons MGI and 10–3 receive monosynaptic inputs from these sensory neurons and send outputs to anterior ganglia. We show that, in spite of the changes in the periphery, the response properties of these interneurons are relatively constant during development. The two interneurons differ in their frequency response, intensity response and rate of response decrement. Their respective response properties are conserved during the postembryonic period. The results suggest that systematic rearrangement of the sensory neuron-to-interneuron synapses plays an important role in maintaining a constant output of this sensory system to higher centers of the CNS during maturation of the cricket.

scholarly journals A Perspective on Muscle Synergies and Different Theories Related to Their Adaptation

Biomechanics ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 253-263
Author(s):  
Ashar Turky Abd ◽  
Rajat Emanuel Singh ◽  
Kamran Iqbal ◽  
Gannon White
Keyword(s):  
Sensory System ◽  
Principal Component ◽  
Building Blocks ◽  
Muscle Synergies ◽  
Clinical Settings ◽  
Decomposition Algorithms ◽  
Small Set ◽  
The Central Nervous System ◽  
Human Motor ◽  
Electromyographic Signals

The human motor system is a complex neuro-musculo sensory system that needs further investigations of neuro-muscular commands and sensory-motor coupling to decode movement execution. Some researchers suggest that the central nervous system (CNS) activates a small set of modules termed muscle synergies to simplify motor control. Further, these modules form functional building blocks of movement as they can explain the neurophysiological characteristics of movements. We can identify and extract these muscle synergies from electromyographic signals (EMG) recorded in the laboratory by using linear decomposition algorithms, such as principal component analysis (PCA) and non-Negative Matrix Factorization Algorithm (NNMF). For the past three decades, the hypothesis of muscle synergies has received considerable attention as we attempt to understand and apply the concept of muscle synergies in clinical settings and rehabilitation. In this article, we first explore the concept of muscle synergies. We then present different strategies of adaptation in these synergies that the CNS employs to accomplish a movement goal.

scholarly journals Aberrant causal inference and presence of a compensatory mechanism in Autism Spectrum Disorder

2021 ◽  
Author(s):  
Jean-Paul Noel ◽  
Sabyasachi Shivkumar ◽  
Kalpana Dokka ◽  
Ralf Haefner ◽  
Dora Angelaki
Keyword(s):  
Autism Spectrum Disorder ◽  
Causal Inference ◽  
Formal Model ◽  
Causal Structure ◽  
Model Fitting ◽  
Autism Spectrum ◽  
Spectrum Disorder ◽  
Compensatory Mechanism ◽  
Common Cause ◽  
Sensory Signals

Autism Spectrum Disorder (ASD) is characterized by a panoply of social, communicative, and sensory anomalies. As such, a central goal of computational psychiatry is to ascribe the heterogenous phenotypes observed in ASD to a limited set of canonical computations that may have gone awry in the disorder. Here, we posit causal inference – the process of inferring a causal structure linking sensory signals to hidden world causes – as one such computation. We show that (i) audio-visual integration is intact in ASD and in line with optimal models of cue combination, yet (ii) multisensory behavior is anomalous in ASD because they operate under an internal model favoring integration (vs. segregation). Paradoxically, during explicit reports of common cause across spatial or temporal disparities, individuals with ASD were less, and not more, likely to report common cause. Formal model fitting highlighted alterations in both the prior probability for common cause (p-common) and choice biases, which are dissociable in implicit, but not explicit causal inference tasks. Together, this pattern of results suggests (i) distinct internal models in attributing world causes to sensory signals in ASD relative to neurotypical individuals given identical sensory cues, and (ii) the presence of an explicit compensatory mechanism in ASD, with these individuals having learned to compensate for their bias to integrate in their explicit reports.

scholarly journals Advances in Fetal Neurophysiology

2008 ◽  
Vol 2 (3) ◽  
pp. 19-34 ◽  
Author(s):  
Maja Predojevic ◽  
Aida Salihagic Kadic
Keyword(s):  
Brain Function ◽  
State Of The Art ◽  
Sensory System ◽  
Nerve Cells ◽  
Long Term Effects ◽  
Intrauterine Life ◽  
Period 2 ◽  
The Central Nervous System ◽  
The Brain

Abstract The human brain function is certainly one of the most amazing phenomena known. All behavior is the result of the brain function. The 100 billion nerve cells are the home to our centers of feelings and senses, pleasure and satisfaction; it is where the centers for learning, memory and creative work are located; where laughing and crying areas and the centers of our mind are. Our cognitive functions, such as thinking, speaking or creating works of art and science, all reside within the cerebral cortex. One of the tasks of the neural science is to explain how the brain marshals its millions of individual nerve cells to produce behavior and how these cells are affected by the environment.1 The brain function still remains shrouded in a veil of mystery. But what is known is that over 99 percent of the human neocortex is produced during the fetal period.2 Owing to the employment of state-of-the-art methods and techniques in prenatal investigations, a growing pool of information on the development of the central nervous system (CNS) and behavioral patterns during intrauterine life has been made available. This review outlines these events, along with the development of the fetal sensory system and circadian rhythms, the senses of vision and hearing, fetal learning and memory, and long-term effects of fetal stress on behavior. In brief, this review offers a glimpse of the fascinating world of the intrauterine life.

Observations on the Nervous System of the Flight Apparatus in the Locust Schistocerca Gregaria

1964 ◽  
Vol s3-105 (70) ◽  
pp. 183-201
Author(s):  
D. M. GUTHRIE
Keyword(s):  
Nervous System ◽  
Schistocerca Gregaria ◽  
Sensory System ◽  
Outer Region ◽  
Hair Shaft ◽  
Distal Process ◽  
Motor Neurones ◽  
The Central Nervous System ◽  
Tormogen Cell ◽  
Hair Shafts

The hair sense-organs of the head are part of a sensory system affecting the activity of motor neurones to the flight muscles. They possess curved hollow hair shafts inserted in a complex socket. A large neurone is present beneath the socket and is partly surrounded by a large formative cell, the trichogen-tormogen cell. The distal process passes up into the expanded base of the hair shaft. Fine connexions between the outer region of the formative cell and the inner part round the neurone process, possibly limiting angular sensitivity, can be seen in some specimens, although the form and fine structure of the hair shaft is almost certainly important in this respect. The axons from the 5 areas of hair organs are collected together into a dorsal tegumentary nerve, those from area three forming a short subocellar nerve. Electronmicrographs of this nerve show that there are a number of large fibres (1 to 5 µ), and many more smaller fibres (1.0 to 0.1µ.) with no sheaths. There were estimated to be 5,500 fibres in each dorsal tegumentary nerve. Within the central nervous system, the dorsal tegumentary fibres may follow one of 4 routes, as follows. They may (i) pass forward into the protocerebrum, (ii) end in zones of terminals in the deutocerebral region, (iii) a few thick fibres pass down into the suboesophageal ganglion and then cross over to the opposite side giving off collaterals before descending to the pterothoracic ganglia, (iv) most of the fine descending fibres probably end at the suboesophageal level, a proportion of them crossing over here. The motor neurones to the longitudinal indirect muscles M81 and M82 consist of 4 anterior and 1 posterior cell respectively, and possess large and striking cell bodies, whose collaterals could be seen in the dorsal zones of motor terminals. The probable internuncial links between the sensory and motor arcs are outlined.

Auditory Profile of Children With Some Rare Neurodevelopmental Disorders

2019 ◽  
pp. 32-55
Author(s):  
Saransh Jain ◽  
Vijaya Kumar Narne
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Hearing Loss ◽  
Sensory Processing ◽  
Neurodevelopmental Disorders ◽  
Neurodevelopmental Disorder ◽  
Sensory System ◽  
Prevalence Rates ◽  
Human Beings ◽  
The Central Nervous System

Neurodevelopmental disorder is an umbrella term comprising many muscular, skeletal, metabolic, endocrinal, systemic, and immune-related diseases, which are caused due to the improper/inaccurate development of the central nervous system. Most of these disorders are highly prevalent, but some express rarely in human beings. Such disorders with least prevalence rates are known as rare neurodevelopmental disorders. The sensory system is affected in all individuals with these rare neurodevelopmental disorders, although to a varying extent. Sensory processing in terms of hearing loss is reported by many researchers in many rare neurodevelopmental disorders, but the pathophysiology of audiological findings are seldom investigated. In this chapter, the authors highlight the possible relationship between underlying cause and the resultant audiological symptoms in some of the rare neurodevelopmental disorders. Further, the research studies on the audiological profiling in such disorders are discussed.

Monitoring Bicycle Riding Motion with Multiple Inertial Sensors

2014 ◽  
Vol 541-542 ◽  
pp. 1398-1402
Author(s):  
Jae Hoon Lee ◽  
Takashige Yano ◽  
Tomoshi Yamashita ◽  
Shingo Okamoto
Keyword(s):  
Human Body ◽  
Inertial Sensors ◽  
Sensory System ◽  
Measurement Data ◽  
Human Motion ◽  
System Configuration ◽  
Position Information ◽  
Multiple Sensors ◽  
Laser Scanners ◽  
Bicycle Rider

This paper presents a novel sensory system for monitoring situations of riding bicycle. The proposed system can be used to measure and save in real-time not only the motion of bicycle rider but also the situation near the vehicle. Multiple inertial sensors being attached to human body are employed to measure the motion of the rider. Two laser scanners installed in the front of the bicycle and two cameras of wide view angle were used to detect the environmental change including pedestrians and static/dynamic objects. The system configuration was designed for the synchronization of multiple sensors according to the position information of the vehicle. Particularly, the human motion of riding bicycle is captured with the system and analyzed with the measurement data in this paper.

scholarly journals THE IMPACT OF PHYSICAL AND SPORTS REHABILITATION OF PEOPLE WITH CEREBRAL PALSY ON THE PROPRIOCEPTIVE SYSTEM IMPROVEMENT

2019 ◽  
pp. 36-45
Author(s):  
Olha Herus ◽  
Tereza Klymus ◽  
Marta Kozak
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cerebral Palsy ◽  
Motor Skills ◽  
Physical Therapists ◽  
Sensory System ◽  
Fine Motor ◽  
Slow Development ◽  
The Central Nervous System ◽  
The Impact

Introduction: Cerebral palsy occurs as a result of affecting those parts of the central nervous system that control the muscles and are responsible for the balance and movements arbitrariness. It has a number of forms with varying degrees of damage to the central nervous system and impaired physiological functions. And this certainly affects the perception. Due to perception distortion, sensory interpretation is slowed down and incorrectly analyzed in the cerebral cortex. The improvement of the motor sphere implies the development of general and small motor skills, and the improvement of movements coordination. The correction of motor sphere disorders should be done in a comprehensive, systematic manner, with the involvement of specialists (neurologists, physical therapists, rehabilitologists, sensory therapists). This will help to determine the content of motor sphere correction exercises and define the step-by-step measures for physical condition improvement. Aim: to investigate the impact of physical and sports rehabilitation measures of people with cerebral palsy disabilities on improving the proprioceptive system basing on an analysis of the practical application of the bocce game program. Methodology: SIPT (Sensory Integration and Praxis Tests) breach detection study. Bocce game lessons were tested (as a method of physical and sport rehabilitation) in order to improve the sensory system. Object of the study – 10 people aged 28–35 with a clinical diagnosis of "Cerebral palsy" with impaired mobility, who are using a trolley and are undergoing rehabilitation at the rehabilitation center in Lviv. Results: It was found that 9 out of 10 participants had dysarthric disorders. General somatic attenuation and slow development of locomotor functions are accompanied by a lag in the motor sphere development of the people with cerebral palsy. Conclusion: The study found that engaging in sports and exercise leads to increased physical health and improved gross fine motor skills related to the sensorimotor system

Sign in / Sign up

Export Citation Format

Share Document