Effect of Force Sense to Active Joint Position Sense and Relationships between Active Joint Position Sense,Force Sense,Jumping and Muscle Strength

Abstract

We aimed to investigate the effect of external load on the joint position sense (JPS) accuracy and its relation to the target jump height. The present study also aimed to explore the relationship between force sense (FS) and maximum voluntary isometric contraction (MVIC). Participants’ MVIC levels were determined during the 45-degree knee extension task. Then, participants were asked to execute a knee JPS task with external load (EL-JPS) and with no-load (EL-JPS). To assess jumping accuracy participants were instructed to jump with their 50% of maximum jump height. Results indicated that EL-JPS error values were lower than NL-JPS. EL-JPS was correlated to jumping errors. However, the relationship between NL-JPS and jumping errors was not significant. A significant correlation was found between MVIC and FS errors.     

How trunk turns affect locomotion when you are not looking where you go

How well do we maintain heading direction during walking while we look at objects beside our path by rotating our eyes, head, or trunk? Common experience indicates that it may be fairly hazardous not to look where you are going. In the present study, 12 young adults walked on a treadmill while they followed a moving dot along a horizontal line with their gaze by rotating primarily either their eyes, head, or trunk for amplitudes of up to 25 degrees . During walking the movement of the center of pressure (COP) was monitored using force transducers under a treadmill. Under normal light conditions, the participants showed little lateral deviation of the COP from the heading direction when they performed the eye or head movement task during walking, even when optic flow information was limited. In contrast, trunk rotations led to a doubling of the COP deviation in the mediolateral direction. Some of this deviation was attributed to foot rotation. Participants tended to point their feet in the gaze direction when making trunk turns. The tendency of the feet to be aligned with the trunk is likely to be due to a preference to have feet and body in the same orientation. Such alignment is weaker for the feet with respect to head position and it is absent with respect to eye position. It is argued that feet and trunk orientation are normally tightly coupled during gait and that it requires special abilities to move both segments independently when walking.     

Musical Memory in Alzheimer Disease

ABSTRACT

This study examines musical memory in 12 patients with moderate or severe AD and 12 healthy, older adult controls. Participants were asked to distinguish familiar from novel tunes, to identify distortions in melodies, and to sing familiar tunes. Comparison of the AD and control groups showed significant impairment of the AD participants. However, a more complex picture emerged as we compared each individual case to the control group. Five of the AD group performed within the control group range on most tasks. An additional four participants showed partial sparing in that they performed below the range of control participants, but their scores were above the level of chance. The final three participants showed near complete loss of musical memory, as their performance was consistently at or near the level of chance. These results are discussed in terms of the literature on the heterogeneity of cognitive presentation in AD.     

People believe that they are prototypically good or bad

People have been shown to view their beliefs as being prototypical (modal) but their abilities as (falsely) unique (above or below average). It is possible that these two viewpoints – self as prototypical and self as unique – can be reconciled. If the distribution of ability for a given skill is skewed such that many others have high (low) ability and few others have low (high) ability, it is possible that a majority of peoples’ self-assessments can be above (below) average. Participants in 5 studies demonstrated an understanding that various skills have skewed ability distributions and their self-assessments were related to distribution shape: high when negatively skewed and low when positively skewed. Further, participants tended to place themselves near the mode of their perceived skill distribution. Participants were most likely to think that they were good at skills for which they thought that most others were also good.     

A novel approach to mechanical foot stimulation during human locomotion under body weight support

Input from the foot plays an essential part in perceiving support surfaces and determining kinematic events in human walking. To simulate adequate tactile pressure inputs under body weight support (BWS) conditions that represent an effective form of locomotion training, we here developed a new method of phasic mechanical foot stimulation using light-weight pneumatic insoles placed inside the shoes (under the heel and metatarsus). To test the system, we asked healthy participants to walk on a treadmill with different levels of BWS. The pressure under the stimulated areas of the feet and subjective sensations were higher at high levels of BWS and when applied to the ball and toes rather than heels. Foot stimulation did not disturb significantly the normal motor pattern, and in all participants we evoked a reliable step-synchronized triggering of stimuli for each leg separately. This approach has been performed in a general framework looking for “afferent templates” of human locomotion that could be used for functional sensory stimulation. The proposed technique can be used to imitate or partially restore surrogate contact forces under body weight support conditions.     

How do supporters perceive positive and negative psychological momentum changes during a simulated cycling competition?

ObjectiveThe present study examined changes in sport supporters' psychological momentum (PM) during a simulated cycling competition through the lens of the dynamical systems approach.DesignParticipants were asked to support one of two competing cyclists involved in a race that was displayed on a screen in a lecture hall.MethodThe race scenario was manipulated so that the image of the supported cyclist underwent either positive or negative momentum. At regular intervals, participants indicated their PM perceptions during the race.ResultsPM perceptions rapidly changed at the onset of both the positive and negative momentum sequences and then remained stable, reflecting negative hysteresis. Supporters tended to anticipate the future performance of a given athlete on the basis of their current performance. Moreover, this anticipatory tendency was stronger during the positive momentum sequence than during the negative momentum sequence.ConclusionThese results provide initial insights into how PM perceptions of sport supporters change during a competition.     

Textured Foot Orthotics on Dynamic Stability and Turning Performance in Parkinson’s Disease

Abstract

The purpose of this study was to facilitate sensory feedback, with textured foot orthotics, to evaluate dynamic stability and turning behavior in Parkinson’s disease individuals. Seven participants with a diagnosis of idiopathic Parkinson’s disease, aged 55–80?years old, participated in this study. Participants completed three testing sessions; baseline, 4?weeks post-baseline, and 5?weeks post-baseline. Three experimental conditions were tested: footwear only (F), footwear?+?non-textured orthotic (FO), and footwear?+?textured orthotic (FOT). Kinematic, kinetic, and video data were collected during the steps preceding a turn task. Variables of interest included dynamic stability (maximum mediolateral (ML), minimum ML, and ML range of the center of mass (COM)-base of support (BOS) relationship) and turning performance (gait velocity and step count). There was a statistically significant increase in maximum ML COM-BOS distance (week 4 [0.1298 m?±?0.054] compared to week 0 [0.1069 m?±?0.050] p = .0076), and a significant decrease in step count (week 0-F [5.52 steps ± 1.08] to week 0-FO [5.23 steps ± 0.87] p = .0296) and (week 4-FO [5.24 steps ± 1.31] to week 4–FOT [4.67 steps ± 0.76] p = .0004). Textured foot orthotics modified dynamic stability and turning performance in Parkinson’s disease individuals completing a 180° degree turn. These preliminary results support this potential treatment option for rehabilitation professionals treating Parkinson’s disease.     

Cognitive Biases In Sales Management Evaluations

Abstract

In a factorial experiment, subjects, most of whom possessed managerial experience, were given information about a salesperson and asked to rate his ability on the job. As predicted, the subjects tended to overutilize effort information and underutilize task difficulty information in making their evaluations. The research reveals that cognitive biases in information processing may influence a crucial sales management responsibility. The results are discussed in terms of their implications for employee promotions and the application of attribution theory to sales personnel evaluations.     

Similarity and Social Interaction: When Similarity Fosters Implicit Behavior Toward a Stranger

ABSTRACT

People interact more readily with someone whom they think they have something in common with. At a pedestrian crossing, confederates asked participants for the time and, in one condition, said she/he had the same watch as the participant. The amount of time that participants lingered near a confederate was used as the dependent variable. Participants in the similarity condition spent significantly more time near the confederate than when no similarity was manipulated. The results showed that similarity fosters implicit behavior, adding to the growing body of data on the positive effects of similarity and its role in social interaction.     

Forcing you to experience wonder: Unconsciously biasing people’s choice through strategic physical positioning

Magicians have developed powerful tools to covertly force a spectator to choose a specific card. We investigate the physical location force, in which four cards (from left to right: 1-2-3-4) are placed face-down on the table in a line, after which participants are asked to push out one card. The force is thought to rely on a behavioural bias in that people are more likely to choose the third card from their left. Participants felt that their choice was extremely free, yet 60% selected the 3rd card. There was no significant difference in estimates and feelings of freedom between those who chose the target card (i.e. 3rd card) and those who selected a different card, and they underestimated the actual proportion of people who selected the target card. These results illustrate that participants’ behaviour was heavily biased towards choosing the third card, but were oblivious to this bias.     

Foot care, ‘spousal’ support and type 2 diabetes: an exploratory qualitative study

Objectives: People with type 2 diabetes (T2DM) should check their feet and protect them against harm, but few do. Living with a spouse contributes to good foot care behaviour. This study explores awareness, perceived susceptibility of, and concern about, foot problems, and reported foot care behaviour, and ways in which a spouse may or may not contribute to foot care in T2DM.

Methods: 1:1 interviews were conducted with 6 individuals with T2DM. Half had a spouse half did not. There was one person at low, medium and high risk in each sample. Each spouse participated in a separate interview, and the dyads were interviewed together. Interviews were analysed using Applied Thematic Analysis.

Results: All participants knew that diabetes was associated with foot problems. Not all people with T2DM thought that they were susceptible; spouses perceived greater susceptibility for the patient. This was unrelated to risk level. Most people with T2DM and all spouses engaged in behaviour to identify problems or protect feet, but rarely both. Spouses’ attitude and behaviour did influence the patients’ own behaviour. At times spouse support was perceived positively, and at times negatively.

Conclusion: Engaging spouses in foot care education may improve foot care behaviour.     

Do motor ability and handwriting kinematic measures predict organizational ability among children with Developmental Coordination Disorders?

Background and aimChildren with Developmental Coordination Disorders (DCD) exhibit deficient daily performance concealed in their perception–action mechanism. The aim of this study was to analyze behavior organization of children with DCD, in varied tasks that require generating and monitoring mental representations related to space and time inputs/requirements, for achieving better insight about their perception–action mechanism.MethodParticipants included 42 children aged 7–10, half of whom were defined with DCD and half were typically developing (TD). The children were matched for age, gender and school. They were evaluated using the Movement–ABC and performed three handwriting tasks on an electronic tablet that is part of a computerized system (ComPET – Computerized Penmanship Evaluation Tool). In addition, their teachers completed the Questionnaire for Assessing Students’ Organizational Abilities-Teachers (QASOA-T) to assess the children’s daily organizational ability.ResultsSignificant group differences (DCD versus controls) were found for all handwriting kinematic measures across the three handwriting tasks and for the children’s organizational abilities. Motor ability predicted a considerable percentage of the variance of the kinematic handwriting measures (30–37%), as well as a high percentage of the variance of their organizational abilities (67%). The coefficient of variance of the pen tilt added an additional 3% to the prediction of their organizational abilities.ConclusionsThe results of this study exhibited deficient ability among children with DCD in organizing their behavior in varied real-world tasks requiring generation and monitoring representation related to space and time. The significance of the results to understanding the performance mechanism and implication to the clinical field are discussed.     

Does translation involve structural priming?

When asked to translate utterances, people might merely make sure that their translations have the same meaning as the source, but they might also maintain aspects of sentence form across languages. We report two experiments in which English–German and German–English bilinguals (without specialist translator training) repeated German ditransitive sentences whose meaning was compatible with more than one grammatical form or translated them into English. Participants almost invariably repeated the sentences accurately, thereby retaining the grammatical structure. Importantly, Experiment 1 found that they tended to repeat grammatical form across languages. Experiment 2 included a condition with sentences that had no grammatical equivalent form in English; here participants tended to persist in the order of thematic roles. We argue that cross-linguistic structural priming plays a major role in the act of translation.     

Preschool children's use of novel predicates to make inductive inferences about people

Preschool children's use of novel predicates to make inferences about people was examined in three studies. In a procedure adapted from Gelman and Markman [Cognition 23 (1986) 183.], participants (ages 3 years 5 months–4 years 11 months) saw line drawings of three different faces. In Study 1 (N=16), the drawings were described as depicting children, and participants were asked to predict whether one of the children would share properties with a child who has the same novel predicate (e.g., “is zav,” which is never defined for participants) but is dissimilar in appearance, or with a child who has a different novel predicate but is similar in appearance. Participants tended to use the novel predicates rather than superficial resemblance to guide their inferences about people. In Study 2 (N=16), in which the line drawings were described as depicting dolls rather than children, participants showed no such emphasis on the novel predicate information. Study 3 (N=38) replicated the results of the first two studies. The results suggest that children have a general assumption that unfamiliar words hold rich inductive potential when applied to people but not when applied to dolls.     

The role of visual information in control of a constrained locomotor task

The nature of visually guided locomotion was examined in an experiment where subjects had to walk to targets under various conditions. Target distance was manipulated so that subjects had to (a) lengthen their paces in order to hit the target; (b) shorten their paces; (c) make no adjustments to their standard pace length at all. They did this under four visual conditions: (a) normal vision; (b) with vision restricted to a "snapshot" each time the foot that was to be placed on the target was on the ground; (c) with a snapshot each time the foot to be placed was in the swing phase; and (d) no vision after departure fro the target. The results show that the subjects succeed in reaching the target in most cases. However, the smoothness and fluidity of their movements vary significantly between conditions. Under normal vision or where visual snapshots are delivered when the pointing foot is on the ground, locomotion is smoothly regulated as the subjects approach the target. where snapshots are delivered when the pointing foot is in the swing phase, regulation becomes clumsy and ill coordinated. Where no vision is available at all during the approach, adjustments are made, but these are least coordinated of all. The results show that well-coordinated visual regulation does not require continuous visual guidance but depends on intermittent information being available at the appropriate times in the action sequence. Such timing is often more important than the total amount of information that is available for guidance.     

Gaze behaviour during walking in young adults with developmental coordination disorder

BackgroundIndividuals with Developmental Coordination Disorder (DCD) experience difficulty with motor coordination and this affects their daily functioning. Research indicated inferior visuospatial processing and oculomotor control in DCD. As visual information is essential for locomotor control, more insight in the gaze behaviour of this population during walking is required and crucial for gaze training interventions as a possible means to improve daily functioning of children and adults with DCD.AimThis study explored differences and similarities in gaze behaviour during walking between typically developing young adults and those with DCD.Methods and proceduresTen young adults with DCD (age: 22.13 ± 0.64) and ten typically developing individuals (age: 22.00 ± 1.05) completed a walking task in which they had to place their feet on irregularly placed targets wearing eye tracking glasses.Outcomes and resultsIndividuals with DCD walked slower and demonstrated a different gaze strategy compared to their neurotypical peers as they fixated almost each and every target sequentially. Typically developing individuals, on the other hand, directed gaze further along the path and often fixated areas around the targets.Conclusions and implicationsDespite adequate walking performance in daily situations in young adults with DCD, fundamental control deficits persist into adulthood.What this paper adds?This paper is the first to demonstrate differences in gaze behaviour between young adults with DCD and typically developing individuals in a task that resembles a task of daily living, as previous research focused on laboratory tasks. This is a valuable finding as DCD has a clear impact on the daily life. Furthermore, this study demonstrated that the fundamental control deficits of DCD persist into adulthood despite frequent performance and practice of these daily tasks. Lastly, these findings might contribute to the therapeutic potential of gaze training interventions to improve the daily functioning of children and adults with DCD.     

Perceptions of wisdom: What is it and who has it?

One hundred fifty-five men and 233 women, aged 20 to 79 years, were asked to name both the most wise and the most interpersonally wise persons they knew personally and to give the age and sex of each. Participants were also asked for the areas in which their nominees were particularly wise. Overall, men and women responded similarly. The subjects tended to nominate individuals who were older than they were; the difference between their own age and their nominees' age decreased with increasing age. Subjects nominated males more often than females as wise and this tendency increased with the subjects' age. With the exception of older women, participants nominated females more often than males as interpersonally wise. When asked to report the areas in which their wise nominees were particularly wise, subjects tended to mention specific skill areas (e.g., business or science) for male nominees and interpersonal skill areas for female nominees.Please note that Nancy W. Denney is deceased.     

Distractor Interference in Selective Reaching: Dissociating Distance and Grouping Effects

In the present experiment, the authors sought to differentiate between a distance and a grouping explanation for the symmetric versus asymmetric patterns of distractor interference in selective reaching. Participants (N = 16) pointed to a green target that appeared either with or without a red distractor. Target-distractor separation was manipulated within an array of 5 closely grouped stimulus boxes, and distractor interference (difference in performance between trials with and trials without a distractor) was measured in reaction time, movement time, percentage errors, and movement endpoints. Small distances (5 mm) between target and distractor yielded a symmetric pattern of interference, whereas large distances (20 mm) yielded an asymmetric pattern, with more interference from near than from far distractors. Those findings support the distance account of distractor interference and refute the grouping account.     

Experiencing the Cross-Sensory Error Signal During Movement Leads to Proprioceptive Recalibration

Abstract

Reaching to targets in a virtual reality environment with misaligned visual feedback of the hand results in changes in movements (visuomotor adaptation) and sense of felt hand position (proprioceptive recalibration). We asked if proprioceptive recalibration arises even when the misalignment between visual and proprioceptive estimates of hand position is only experienced during movement. Participants performed a “shooting task” through the targets with a cursor that was rotated 30° clockwise relative to hand motion. Results revealed that, following training on the shooting task, participants adapted their reaches to all targets by approximately 16° and recalibrated their sense of felt hand position by 8°. Thus, experiencing a sensory misalignment between visual and proprioceptive estimates of hand position during movement leads to proprioceptive recalibration.