Involuntary Changes Research Articles

Action–perception coupling in kinesthesia: A new approach

According to recent findings, intentional motor actions are controlled by resetting the referent position, R, at which neuromuscular elements, including reflexes, begin to act. It is suggested that somatosensory afferents inform the brain about the deviation (P) of body segments from the centrally set referent position. To perceive the actual position (Q) of body segments and form the position sense (PS), the central and afferent signals are combined: Q=R+P. In previous studies, the R has been shown to remain invariant during involuntary changes in the wrist position elicited by sudden unloading of muscles, suggesting that only the afferent component is responsible for the PS during this reflex. In contrast, the central PS component, R, is predominantly responsible for PS during intentional motion in isotonic conditions. We tested the hypothesis that the R and P are interchangeable PS components such that involuntary changes in wrist position elicited by the unloading reflex can easily be reproduced by making intentional changes in wrist position in isotonic conditions, in the absence of vision. The PS rule also suggests that PS is independent of sense of effort, which was tested by asking subjects to reproduce elbow joint angles under different constant loads. We also tested the hypothesis that tendon vibration may elicit motion that may not be perceived by subjects (no-motion illusion). These hypotheses were confirmed in three experiments. It is concluded that the R and P are additive components of PS and that, contrary to the conventional view, PS is independent of the sense of effort or efference copy. The PS rule also explains kinesthetic illusions and the phantom limb phenomenon. This study advances the understanding of action–perception coupling in kinesthesia.

Sensory ERP effects in auditory distraction: did we miss the main event?

Event-related potentials (ERPs) offer unique insights into processes related to involuntary attention changes triggered by rare, unpredictably occurring sensory events, that is, distraction. Contrasting ERPs elicited by distracters and frequent standard stimuli in oddball paradigms allowed the formulation of a three-stage model describing distraction-related processing: first, the distracting event is highlighted by a sensory filter. Second, attention is oriented towards the event, and finally, the task-optimal attention set is restored, or task priorities are changed. Although this model summarizes how distracting stimulus information is processed, not much is known about the cost of taking this exceptional route of processing. The present study demonstrates the impact of distraction on sensory processing. Participants performed a Go/NoGo tone-duration discrimination task, with infrequent pitch distracters. In the two parts of the experiment the duration-response mapping was reversed. Contrasts of distracter and standard ERPs revealed higher P3a- and reorienting negativity amplitudes for short than for long tones, independently from response type. To understand the cause of these asymmetries, short vs. long ERP contrasts were calculated. The ERP pattern showed that short standards elicited an attention-dependent offset response, which was abolished for short distracters. That is, the apparent P3a- and RON enhancements were caused by the removal of a task-related attentional sensory enhancement. This shows that the disruption of task-optimal attention set precedes the elicitation of the P3a, which suggests that P3a does not reflect a process driving the initial distraction-related attention change.

A New Device for Simultaneous Measurement of Pelvic Floor Muscle Activity and Vaginal Blood Flow: A Test in a Nonclinical Sample

Dyspareunia in women, defined as persistent or recurrent genital pain associated with sexual intercourse, is hypothesized to be related to (fear associated) pelvic floor hyperactivity and to diminished sexual arousal. Psychophysiological research to support these hypotheses is scarce and concentrates mostly on the role of either pelvic floor activity or sexual arousal. To investigate both factors, a measurement device that enables simultaneous assessment of pelvic floor muscle activity and genital sexual arousal would be most optimal. The aim of this study was to test a new vaginal device0-a vaginal photoplethysmograph with build-in surface electromyography (EMG)--that allows simultaneous assessment of pelvic floor muscle activity and vaginal blood flow. Genital arousal measured as vaginal pulse amplitude (VPA) and vaginal surface EMG. Thirty-six sexually functional women participated. To investigate the sensitivity of the device for changes in genital blood flow and involuntary changes in pelvic floor activity, VPA and vaginal surface EMG were monitored during exposure to sexual and anxiety-evoking film clips. In addition, vaginal surface EMG was monitored during voluntary flick and hold contractions. VPA increased in response to the sexual film, and EMG values were significantly higher in response to the anxiety-evoking film. Higher EMG values in response to the anxiety film were associated with lower VPA. EMG during the instructed 3-second hold pelvic floor contractions showed, as expected, higher values during pelvic floor contractions with support of surrounding muscle groups, compared with pelvic floor muscles alone. The device is sensitive to changes in vaginal blood flow in response to sexual stimuli, and it is able to pick up small, involuntary changes in pelvic floor activity associated with anxiety. Also, the device is able to record changes in pelvic floor activity during voluntary pelvic floor contractions. This new device will be a valuable tool in further research on superficial dyspareunia.

Neuromuscular Involvement in Choreoacanthocytosis (P07.204)

Objective: To further describe the peripheral nervous system involvement in choreoacanthocytosis (ChAc) by reporting the findings in 7 patients. Background ChAc is characterized by involuntary movements, behavioral changes, seizures, and hyperCKmia together with peripheral blood acanthocitosis, caused by mutations in the VPS13A gene. Little is known so far about the neuromuscular involvement in these patients, although myopathic or neurogenic changes have been reported in single cases. Design/Methods: We studied 7 patients from 4 unrelated families. Three patients were referred to role out mitochondrial myopathy. ChAc diagnosis was made according to clinical criteria, chorein western-blot and expression of Kell antigen. Clinical examination, conduction nerve studies, electromyography, muscle magnetic resonance imaging (MRI) T1/ STIR sequences of lower limbs and biopsy of distal (gastrocnemius/tibialis anterior) and proximal (biceps braquii) muscles were performed. Informed consent was obtained for inclusion in the study. Results: Clinical examination showed asymmetric calf atrophy in two patients, but was otherwise unremarkable. The serum CK level was elevated and fluctuating (range 275-4050 UI/l). The conduction studies showed decrease in the amplitude of sensory sural nerve potential. Electromyography revealed a mild neurogenic pattern. Western-blot for chorein in peripheral blood showed absence or severe decreased of protein level. T1-sequences MRI showed symmetric increased signal in both gastrocnemius. STIR-sequences were normal. Biopsies of proximal muscles showed subtle changes, while biopsies of distal muscles showed striking neurogenic atrophy together with necrosis and regeneration. Focal areas of myofibrillar disorganization were noted. Conclusions: The selective radiological involvement of gastrocnemius and the coexistence of neurogenic and myopathic features in gastrocnemius biopsy seem to be characteristic features of ChAc which could be helpful for diagnosis. In our study population, neuromuscular involvement was clinically irrelevant. The complexity of this syndrome usually delays the diagnosis of ChAc. Disclosure: Dr. Paradas Lopez has nothing to disclose. Dr. Cabrera Serrano has nothing to disclose. Dr. Rivas Infante has nothing to disclose. Dr. Morales has nothing to disclose. Dr. Marquez has nothing to disclose. Dr. Bader has nothing to disclose. Dr. Mir has nothing to disclose.

Struggling in an inescapable life situation: being a close relative of a person dependent on home enteral tube feeding

To explore what it means to be a close relative of a person dependent on home enteral tube feeding (HETF) and how they can manage this situation. Previous studies have shown that the situation of close relatives in home care in general can be burdensome and difficult. Research is scarce about experiences of close relatives when patients are treated with HETF. A qualitative design was used, in accordance with grounded theory (GT). Twelve close relatives were interviewed twice, using open-ended questions. Five were relatives of patients supported by home care services or advanced home care teams. Using the GT method, sampling, data collection and data analysis were carried out simultaneously. One core category, 'Struggling in an inescapable life situation' and eight categories were found. The situation led to involuntary changes in the lives of the close relatives, something they could do little about. Their lives had become completely upturned and restricted by the HETF. Togetherness and pleasure was lost and they felt lonely. The relatives faced a new role of being informal caregivers and they had to adjust their daily life accordingly. They felt forced to take on a heavy responsibility for which they lacked support. The close relatives struggled to manage and to make the best of their new situation. This study highlighted the demands and vulnerability which is embedded in the role of being a close relative of a patient with HETF. It also pointed out their need for comprehensive support from the health care system. Support to facilitate the situation of close relatives should be given from the health care. One way to organise the care could be through a nurse-led clinic, which provides continuous support, information and counseling.

Audit Report Lags after Voluntary and Involuntary Auditor Changes

SYNOPSIS: We find that the audit report lag is significantly higher for former Andersen clients (that did not follow their Andersen partner to the new audit firm) than for clients voluntarily changing auditors from another Big 5 predecessor for the fiscal year ended December 31, 2002 (the first year with the new auditor for ex-Andersen clients). The differences in audit reporting lags between the two groups are not significant for fiscal years ended December 31, 2000 (the last year before Andersen’s Enron related problems surfaced), or 2003 (the second year with the successor auditor). We also find that clients with voluntary (i.e., non-Andersen) auditor changes have only marginally higher audit reporting lags compared to clients without auditor changes. Our results, focusing on a cost component of involuntary auditor changes, thus provide relevant empirical evidence for debates surrounding mandatory auditor rotation. We also find that ex-Andersen clients that followed the Andersen partner to the new audit firm had shorter audit report lags than ex-Andersen clients that did not follow their Andersen partner. Our findings highlight the importance of individual relationships in the auditing process, and suggest new avenues for future research.

Multi-finger interaction during involuntary and voluntary single finger force changes

Two types of finger interaction are characterized by positive co-variation (enslaving) or negative co-variation (error compensation) of finger forces. Enslaving reflects mechanical and neural connections among fingers, while error compensation results from synergic control of fingers to stabilize their net output. Involuntary and voluntary force changes by a finger were used to explore these patterns. We hypothesized that synergic mechanisms will dominate during involuntary force changes, while enslaving will dominate during voluntary finger force changes. Subjects pressed with all four fingers to match a target force that was 10% of their maximum voluntary contraction (MVC). One of the fingers was unexpectedly raised 5.0 mm at a speed of 30.0 mm/s. During finger raising the subject was instructed "not to intervene voluntarily". After the finger was passively lifted and a new steady-state achieved, subjects pressed down with the lifted finger, producing a pulse of force voluntarily. The data were analyzed in terms of finger forces and finger modes (hypothetical commands to fingers reflecting their intended involvement). The target finger showed an increase in force during both phases. In the involuntary phase, the target finger force changes ranged between 10.71 ± 1.89% MVC (I-finger) and 16.60 ± 2.26% MVC (L-finger). Generally, non-target fingers displayed a force decrease with a maximum amplitude of -1.49 ± 0.43% MVC (L-finger). Thus, during the involuntary phase, error compensation was observed--non-lifted fingers showed a decrease in force (as well as in mode magnitude). During the voluntary phase, enslaving was observed--non-target fingers showed an increase in force and only minor changes in mode magnitude. The average change in force of non-target fingers ranged from 21.83 ± 4.47% MVC for R-finger (M-finger task) to 0.71 ± 1.10% MVC for L-finger (I-finger task). The average change in mode of non-target fingers was between -7.34 ± 19.27% MVC for R-finger (L-finger task) and 7.10 ± 1.38% MVC for M-finger (I-finger task). We discuss a range of factors affecting force changes, from purely mechanical effects of finger passive lifting to neural synergic adjustments of commands to individual fingers. The data fit a recently suggested scheme that merges the equilibrium-point hypothesis (control with referent configurations) with the idea of hierarchical synergic control of multi-element systems.

PET Scan and Autoimmune Focal Encephalitis

The value of the PET scan in the diagnosis of autoimmune focal encephalitis is reported in a 22-month-old girl who presented with involuntary movements, hemiparesis, and behavioral changes at Juntendo University School of Medicine, Tokyo Metropolitan Institute for Neuroscience, Japan.

Phenomenology of abnormal movements in stuttering

Background Stuttering is often accompanied by involuntary movements, abnormal gestures or changes in facial expression. Objective To describe the incidence and phenomenology of abnormal movements (AMs) in stuttering patients. Materials and methods Eighty-five consecutive patients with stuttering and 119 normal controls videotaped and subsequently reviewed, in which AMs were classified as voluntary or involuntary, and as concurrent or unrelated to speech. Movement phenomenology was correlated with disease severity. Results Of 85 stuttering patients studied, 51.7% had AMs and 22 more than one AM. Sixty-six different AMs were identified, of which 83.3% occurred during speech, 72.7% were classified as involuntary, and 27.2% as voluntary. Of 38 involuntary movements concurrent to speech, 25 were originally perceived as voluntary, but had since become involuntary through repeated use during stuttering. All involuntary movements not concurrent to speech fulfilled criteria for tics. Conclusion AMs occurring during stuttering were not always involuntary; movements not concurrent with speech clearly fulfilled clinical criteria for tics and were similar in incidence to normal controls. Inverse correlation was found between conscious control of movement during speech and stuttering severity. Many involuntary movements occurring during speech were clearly referred by patients as initially voluntary early on in the development of their speech disorder (starters or unblockers), underlining the importance of repetitive use of complex motor sequences as a source for putative involuntary movement genesis.

Simultaneous Measurement of Pelvic Floor Muscle Activity and Vaginal Blood Flow: A Pilot Study

Dyspareunia, defined as persistent or recurrent genital pain associated with sexual intercourse, is hypothesized to be related to pelvic floor hyperactivity and to diminished sexual arousal. Empirical research to support these hypotheses is scarce and concentrates mostly on the role of either pelvic floor activity or genital arousal in female dyspareunia. Currently, however, there is no measurement device to assess pelvic floor activity and genital response simultaneously. The aim of this study was to investigate the validity of a new device that enables simultaneous measurement of pelvic floor activity and genital response in women. Genital arousal measured as vaginal pulse amplitude, and vaginal surface electromyogram (EMG). Thirty sexually functional women participated. To investigate the accuracy of genital response measurement with the adapted photoplethysmograph, and the sensitivity of the device for involuntary changes in pelvic floor activity, vaginal pulse amplitude and vaginal surface EMG were monitored during exposure to emotional, including erotic, films. In addition, vaginal surface EMG was monitored during instructed pelvic floor contractions. The genital data obtained during emotional films proved accurate measurement of genital response. EMG values during the emotional films indicated limited sensitivity of the device for small, involuntary changes in pelvic floor activity due to emotional state. The EMG measurements during the instructed pelvic floor contractions proved sensitivity of the new probe to voluntary pelvic floor activity. It is concluded that following improvement of the sensitivity of the EMG measurement for small, involuntary changes in pelvic floor activity, the device will be a valuable tool in research on superficial dyspareunia.

A Process Analytical Technology approach to near-infrared process control of pharmaceutical powder blending: Part II: Qualitative near-infrared models for prediction of blend homogeneity

The successful implementation of near-infrared spectroscopy (NIRS) in process control of powder blending requires constructing an inclusive spectral database that reflects the anticipated voluntary or involuntary changes in processing conditions, thereby minimizing bias in prediction of blending behavior. In this study, experimental design was utilized as an efficient way of generating blend experiments conducted under varying processing conditions such as humidity, blender speed and component concentration. NIR spectral data, collected from different blending experiments, was used to build qualitative models for prediction of blend homogeneity. Two pattern recognition algorithms: Soft Independent Modeling of Class Analogies (SIMCA) and Principal Component Modified Bootstrap Error-adjusted Single-sample Technique (PC-MBEST) were evaluated for qualitative analysis of NIR blending data. Optimization of NIR models, for the two algorithms, was achieved by proper selection of spectral processing, and training set samples. The models developed were successful in predicting blend homogeneity of independent blend samples under different processing conditions. © 2005 Wiley-Liss, Inc. and the American Pharmacists Association

Client Industry Competition and Auditor Industry Concentration

Prior studies examining the association between auditor concentration and intra-industry competition in the client industry have yielded opposite results. I attempt to reconcile these findings by using an additional measure of intra-industry competition (the speed of adjustment of abnormal profits) and controlling for industry size. I document a negative association between auditor industry concentration and intra-industry competition, regardless of the measure of auditor concentration used. Thus, although the average level of auditor industry concentration is generally high, there is some evidence that a more competitive industry has lower auditor concentration. Therefore, involuntary audit market changes that reduce the number of audit firms available, may counter the effect of client industry competition in limiting auditor industry concentration.

Pollutants emission from building materials and their influence on indoor air quality and people performance in offices

Abstract New technologies and materials have introduced a large quantity of new pollutants emitted to the indoor air. Energy conservation for economical reasons, resulting in low outdoor air supply rates, can become the reason of a poor indoor air quality. The cost of the deteriorated indoor climate, resulting in reduced comfort and losses in productivity, for the society is higher than the costs for the heating energy or ventilation systems in the same building. An experiment was conducted to determine how poor indoor air quality could cause involuntary changes in performance and occurring sick building syndrome symptoms. Twenty‐four female subjects were exposed to three environmental conditions, while performing normal office tasks in a low‐polluting room. Sick building syndrome symptoms, the perceived air quality and performance data were obtained. The acceptability of air quality was significantly better and the odour intensity was much lower under the conditions of high ventilation. The performance o...

Work Situation After Breast Cancer: Results From a Population-Based Study

Breast cancer may adversely affect work experience. We assessed whether there was evidence of discrimination at work, defined as negative or involuntary changes in employment situation (including changes in position, wages, and other conditions), associated with a breast cancer diagnosis in a population-based retrospective cohort study conducted in Quebec, Canada. The study was based on the consecutive series of women aged less then 60 years when first treated for breast cancer (identified through the Quebec Tumor Registry) and a random sample of frequency-matched women living in Quebec (identified from provincial health care files) who had never been diagnosed with cancer. Eligibility for the study was restricted to women who were employed at the time of diagnosis (for breast cancer survivors) or the same calendar period (for women in the comparison group). We conducted telephone interviews of eligible women 3 years after diagnosis for 646 survivors or after the matched calendar period for 890 women in the comparison group. Binomial regression was used to evaluate the relationship between having breast cancer and work situation. All statistical tests were two-sided. Working conditions were similar between the two groups at the beginning of follow-up. After 3 years, slightly more survivors (21%) than women in the comparison group (15%) were unemployed (adjusted relative risk for being unemployed = 1.29, 95% confidence interval = 1.05 to 1.59), although most women who were not working (84% of unemployed survivors and 76% of unemployed women in the comparison group) said that the decision to stop working was their own. Among women still employed, no deterioration in working conditions was observed in either group. We found little evidence that women diagnosed with breast cancer experience discrimination at work. This information may be helpful for working women concerned about employment after breast cancer.

Deadlock-free dynamic reconfiguration schemes for increased network dependability

Network-based parallel computing systems often require the ability to reconfigure the routing algorithm to reflect changes in network topology if and when voluntary or involuntary changes occur. The process of reconfiguring a network's routing capabilities may be very inefficient and/or deadlock-prone if not handled properly. We propose efficient and deadlock-free dynamic reconfiguration schemes that are applicable to routing algorithms and networks which use wormhole, virtual cut-through, or store-and-forward switching, combined with hard link-level flow control. One requirement is that the network architecture use virtual channels or duplicate physical channels for deadlock-handling as well as performance purposes. The proposed schemes do not impede the injection, transmission, or delivery of user packets during the reconfiguration process. Instead, they provide uninterrupted service, increased availability/reliability, and improved overall quality-of-service support as compared to traditional techniques based on static reconfiguration.

Emotion and its disorders.

Emotional processes are crucial to the control of human behaviour and anchored to a common foundation in motivational mechanisms where emotional cues have intrinsic re-inforcement values. Emotions per se are transient events, produced in response to external or self-generated emotive stimuli, and typically characterized by attention to the stimulus, involuntary arousal reactions and changes in motor behaviour, subjective feeling states and subsequent biasing of behaviour. Primary emotions, such as happiness and fear, correspond motivationally with approach or withdrawal responses. In humans, feeling-states and subjective emotional experiences reflect cognitive contextual awareness of emotional responses and may be embellished into secondary emotions, such as guilt or relief. This review addresses the application of neuroimaging techniques to understanding the neural mechanisms supporting these aspects of emotional experience.

A Note on Job Mobility Among Workers with Disabilities

This article uses data from the 1990 and 1993 panels of the Survey of Income and Program Participation to analyze relationships between disability status and job mobility. We identify individuals who experienced voluntary or involuntary job separations over a 20‐month period and examine the effect of disability status on rates of job change and wage growth following a job change. The results show that disabled workers are more likely to experience involuntary job changes than are nondisabled workers, but there is little difference in the wage effects of job changes by disability status.

EFFECT OF MUSCLE TENSION ON NON-LINEARITIES IN THE APPARENT MASSES OF SEATED SUBJECTS EXPOSED TO VERTICAL WHOLE-BODY VIBRATION

In subjects exposed to whole-body vibration, the cause of non-linear dynamic characteristics with changes in vibration magnitude is not understood. The effect of muscle tension on the non-linearity in apparent mass has been investigated in this study. Eight seated male subjects were exposed to random and sinusoidal vertical vibration at five magnitudes (0·35–1·4 m/s2 r.m.s.). The random vibration was presented for 60 s over the frequency range 2·0–20 Hz; the sinusoidal vibration was presented for 10 s at five frequencies (3·15, 4·0, 5·0, 6·3 and 8·0 Hz). Three sitting conditions were adopted such that, in two conditions, muscle tension in the buttocks and the abdomen was controlled. It was assumed that, in these two conditions, involuntary changes in muscle tension would be minimized. The force and acceleration at the seat surface were used to obtain apparent masses of subjects. With both sinusoidal and random vibration, there was statistical support for the hypothesis that non-linear characteristics were less clear when muscle tension in the buttocks and the abdomen was controlled. With increases in the magnitude of random vibration from 0·35 to 1·4 m/s2 r.m.s., the apparent mass resonance frequency decreased from 5·25 to 4·25 Hz with normal muscle tension, from 5·0 to 4·38 Hz with the buttocks muscles tensed, and from 5·13 to 4·5 Hz with the abdominal muscles tensed. Involuntary changes in muscle tension during whole-body vibration may be partly responsible for non-linear biodynamic responses.

Personnel Management

After almost a quarter century since graduation from veterinary school, it is somewhat of a challenge to offer valuable information to an audience that does the same work that I do in a very similar work environment. The progression from employee to solo practitioner to partnership to multi- person practice is very familiar to many. We often advise the producers we serve to concentrate a lot of effort on managing feed costs because it is a significant cost of production. We should take our own advice and apply it to our own significant cost of doing business-payroll and personnel. I would like to share with you some ideas that I've done (some regrettably), ideas that are presently employed, and things I will do in the future (hopefully).
 As with any large task, breaking it into manageable, smaller parts makes the whole project easier to deal with. These parts come in the form of questions that we must answer in order for present and prospective associates to understand the employers and the practice setting and mission more fully. Truthfully analyzing and answering these questions, then clearly conveying the answers to personnel, present and future, will save the practice management the drudgery of revolving door associates and spare the employees the unhappiness of involuntary career changes.

Change in thinking about old age among male guardians

What factors differentiate between individuals who change their thinking about a life stage and those whose ideas remain the same? Based on questionnaires from 149 male guardians of older persons, this research investigated the extent to which guardianship and characteristics of wards and guardians influenced involuntary changes in views of old age. Although greater age, poorer health, female sex and limited finances are used to label old age negatively, these characteristics of wards were not linked directly to changes in guardians' views of old age. Guardians' income, frequency of contact with the ward, family disagreement about guardianships and a preference for more support differentiated between change and stability in attitudes toward old age. The types of changes in thinking are examined and implications of the research are noted.