Effect of Sensory Deprivation on Maximal Force Abilities from Local to Non-local Digits

Abstract

The present study investigates the effect of sensory deprivation of the index and middle finger on motor function of all digits during maximal voluntary force production tasks. A total of 27 subjects performed maximal isometric pressing tasks by using different instructed finger combinations. Subjects completed the same tasks in two visits: a control visit when they had normal sensory feedback in all fingers, and an anesthesia visit when digital nerve blocks were performed on their right index and middle fingers. We evaluated three aspects of motor adaptation on both local (anesthetized) and non-local (non-anesthetized) digits during maximal force production: (1) task-relevant and overall force magnitude, (2) force directional application, and (3) digital individuation and force sharing. Our results indicate that selective digital anesthesia resulted in decreased maximal force magnitude, changed direction of force production, and significant changes extended to non-local digits. The motor weakness and inefficiency revealed in the non-local digits implies that sensory information from each digit can be shared across the digits to assist motor execution within the same hand.     

相对剥夺感:概念、测量、影响因素及作用

相对剥夺感(relative deprivation,RD)是指个体或群体通过与参照群体比较而感知到自身处于不利地位,进而体验到愤怒和不满等负性情绪的一种主观认知和情绪体验。目前,相对剥夺感的测量模型主要有个体–群体RD与认知–情感RD的二维垂直结构模型、认知–情感RD的双维结构模型、个体–群体RD的双维结构模型以及RD的三维结构模型。影响相对剥夺感的相关因素主要包括人口统计学变量、个体特征变量和社会环境变量。影响效应方面,相对剥夺感与心理健康、个体行为等个体水平变量以及群际态度、集群行为等群体水平变量的关系是当前关注的焦点。今后研究的重点应包括完善相对剥夺感的概念与结构、注重青少年及特殊群体研究、丰富研究内容和视角、强化纵向干预研究以及本土化和跨文化研究等。     

Rats learn to eat more to avoid hunger

Several recent experiments have provided evidence that the ingestion of a distinctive food by rats can be a learnt instrumental act as well as an associatively conditioned reaction. In the previous work, maintenance food was withheld for shorter and longer durations on different days following access to the training food. Extra eating before the longer fast was interpreted as avoidance of hunger. This interpretation was based on the evidence showing that extra eating as a result of classical conditioning comes from pairing food stimuli with the presence of little or no hunger because of repletion with energy nutrients. The theory that the extra eating arose from a response-depletion contingency was tested in the present experiment by training rats on only a long fast or only a short fast. Greater increase in intake was seen before the longer fast. The results also replicated previously seen cycles of increase, decrease, and renewed increase in putative deficit-avoidant eating over about three trials, indicating that the extra eating reduces the response-reinforcing hunger and that the consequent part-extinction restores reinforcement. The shape of the learning curve was consistent with these cycles occurring from the start of training, further supporting the view that the increase in food intake before a long delay in refeeding is hunger-reinforced instrumental behaviour.     

The effects of establishing operations on preferences for tangible items

Researchers have demonstrated that both deprivation and satiation can affect the outcome of preference assessments for food. In the current study, paired-stimulus preference assessments for tangible items were conducted under three conditions: control, deprivation, and satiation. Three persons with developmental disabilities and 3 typically developing preschool children served as participants. The results demonstrated that deprivation and satiation influenced the outcome of preference assessments of leisure items or toys.     

Free birds aren't fat: Weight gain in captured wild pigeons maintained under laboratory conditions

Nine feral pigeons, 5 from an urban setting and 4 from a rural setting, were captured and maintained for 42 days under free-feeding conditions comparable to those arranged for laboratory subjects. On average, birds increased their body weights by 17% over this period. The range of increase across birds was 9 to 30%. These findings suggest that the food deprivation arranged for laboratory pigeons, which is characteristically 80% of free-feeding weights, may in some sense be less severe than it first appears.     

Insomniacs' reported use of CBT components and relationship to long-term clinical outcome.

Although there is considerable evidence for the efficacy of non-pharmacological treatment of insomnia, many of the larger trials have delivered CBT in multicomponent format. This makes it impossible to identify critical ingredients responsible for improvement. Furthermore, compliance with home implementation is difficult to ascertain in psychological therapies, and even more so when trying to differentiate across a range of elements. In the present report, 90 patients who had completed 12 month follow-up after participation in a clinical effectiveness study of CBT in general medical practice, responded to a questionnaire asking them about their use of the ten components of the programme. Reports of home use were then entered as predictors of clinical response to treatment. Results indicated that reported home use of stimulus control/sleep restriction was the best predictor of clinical improvement in sleep latency and nighttime wakefulness. Cognitive restructuring also contributed significantly to reduction in wakefulness. In spite of being the most highly endorsed component (by 79% of respondents) use of relaxation did not predict improvement on any variable. Similarly, sleep hygiene was unrelated to sleep pattern change and use of imagery training was modestly predictive of poor response in terms of sleep latency. There are methodological limitations to this type of post hoc analysis, nevertheless, these results being derived from a large patient outcome series raise important issues both for research and clinical practice.