A Mathematical Model For Body Image And Body Schema System And Its Application Prospect In Rehabilitation Medicine

Aims:To explore the effect of repeated peripheral magnetic stimulation on the three aspects of body image and body schema system:attention,perceived area of hand,angle reproduction of the wrist;and to establish a mathematical model of the plasticity of body image and body schema system for evaluating the stroke and relevant diseases,as a novel tool.Methods:We recruited 40 healthy participants(aged 20 to 40 years old)to and divide them into sham stimulation group(20 participants)and real stimulation group(19 participants,1 dropped out)by Random Function in Excel.Visual detection task and hand perception task were combined together.Participants were required to take visual detection task in two conditions:body condition and control condition,and right before each of them a hand perception task was performed.There are touch condition and no touch condition in each hand perception task.The sequence of body condition and control condition was randomized by Excel,so is the sequence of touch condition and no touch condition in each hand perception task.The above combined visual detection task and hand perception task were taken 5 times in total,and there was 5 minutes break between every two of them.After 10-minute rest,angle reproduction task of the wrist was taken to test the reproduction ability of 10°?20°?30°?40°?50° and 60°?Then the same stimulation was exerted to observe its effect on those 6 angles above.Sequence of the 6 angles were randomized by Excel in each trial.We adopted the response time data in visual detection task to build a mathematical model for body image and body schema system and confirmed its validity in hand perception task and angle reproduction task.In addition,we used previously collected stroke patients' data of visual detection task to test this model's applicability and expanded it to spinal cord injury patients and amputee patients by reasoning.Results:visual detection task showed that repeated magnetic stimulation has a facilitative effect on body-specific attention in general,the difference has statisticalsignificance(P<0.05).The possible law was inhibition first then enhancement,so was the total amount of attention with smaller amplitude.Hand perception task showed that hand perception area increased after repeated magnetic stimulation with statistical significance(P<0.05).Angle reproduction task showed that wrist angle reproduction ability in 10°?20°?30°and 40°declined while in 50°and 60°increased,all of them were of no statistical significance(P>0.05).Body-specific attention and the total amount of attention in chronic stroke patients compared to the normal counterpart both were declined with statistical significance(P<0.05).Conclusions:The mathematical model made of body-specific attention and the total amount of attention can reflect the plasticity of body image and body schema system accurately,thus might be a potential evaluation tool for stroke and other relevant diseases in clinical practice.