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At least 19 recordsLinked to original sources
PubMed1991

Modulation of the stretch reflex during volitional sinusoidal tracking in Parkinson's disease.

Sinusoidal visually-guided wrist tracking, in normal and parkinsonian subjects, was perturbed by torque transients every 90 degrees throughout the movement. Long-latency stretch reflex and volitional EMG amplitude modulations were assessed as functions of the tracking phase. Reflex modulation during tracking, both in wrist flexor and extensor muscles, was found to differ significantly between parkinsonian and normal subjects. In the parkinsonian group, the abnormality consisted of an increased reflex activity during tracking phases in which the muscle was lengthening. At these phases the reflex generated torque is opposite in direction to the volitionally generated torque and the tracking movement. No differences in the unperturbed volitional EMG modulation were observed between groups for this error constrained tracking paradigm. Significant correlations were found between ratings of bradykinesia and the amount of abnormal reflex modulation in the wrist flexor. These data suggest that a component of bradykinesia results from a defective coordination of supraspinal reflex and volitional control systems.

Aged↗
PubMed1991

Regional cerebral blood flow during volitional breathing in man.

1. Positron emission tomographic imaging of brain blood flow was used to identify areas of motor activation associated with volitional inspiration in six normal male subjects. 2. Scans were performed using intravenous infusion of H2(15)O during voluntary targeted breathing and positive pressure passive ventilation at the same level. 3. Regional increases in brain blood flow, due to active inspiration, were derived using a pixel by pixel comparison of images obtained during the voluntary and passive ventilation phases. 4. Pooling data from all subjects revealed statistically significant increases in blood flow bilaterally in the primary motor cortex (left, 5.4%; right, 4.3%), in the right pre-motor cortex (7.6%), in the supplementary motor area (SMA; 3.1%) and in the cerebellum (4.9%). 5. The site of increased neural activation in the motor cortex, associated with volitional inspiration, is consistent with an area which when stimulated, either directly during neurosurgery or transcranially with a magnetic stimulus, results in activation of the diaphragm. 6. The presence of additional sites of neural activation in the pre-motor cortex and SMA appears analogous to the results of studies on voluntary limb movement. The site of the increase in the SMA was posterior to that previously reported for arm movements. These areas are believed to have a role 'upstream' of the motor cortex in the planning and organization of movement. 7. This technique provides a means of studying the volitional motor control of respiratory related tasks in man.

Adult↗
PubMedDate not supplied

Volitional collapse (loss of the will to live) in patients with burn injuries. Treatment strategy.

Volitional collapse, or loss of the will to live, remains one of the most vexing of the various system failures complicating serious illness or injury. It resembles, but is distinguishable from, major depression. Two features of volitional collapse may sometimes be turned to therapeutic advantage: it releases the patient from a struggle that may be dissipating already depleted energy reserves, and it transfers survival responsibility from one who has given up to others who have not. Preferred treatment involves carefully orchestrated initiatives from the patient's physician, closest friend, and spouse; their leverage derives from traditional sources, most importantly psychologic transference, bonding, and conjugal commitment. A burn unit provides an ideal environment in which to study the disorder and its response to treatment.

Adult↗
PubMed1991

Volition, deception, and the evolution of justice.

Criminal justice is inextricably associated with the attributive concept of volition. Although the voluntary-involuntary distinction is subjectively vivid, causal research shows its poles to be inseparable, i.e., the dichotomy is deceptive. Why a bulwark of civilization should be founded on paradox, may be clarified by examining the role of self-deception in man's evolutionary heritage. Natural selection for an optimal degree of self-deception probably occurred, both to facilitate deception of others and to foster human cooperation. This contributed to the evolution of psychiatric disorders, the voluntary-involuntary continuum, and large scale social systems. Society and its members reach an equilibrium within the truth-deception continuum, manifest in individuals by conscious versus unconscious and voluntary versus involuntary, and in society by tension between what actually occurs (realism) and its organizing ideals (idealism). Three legal models of criminal justice are understood in this context: The (1) utilitarian, most realistic, is essential to social survival but vulnerable to abuse; (2) rehabilitative, at an opposite idealistic pole, better supports the image of social beneficence that helps to bind society's members; (3) retributive, most heavily grounded in volition, puts greater emphasis on individual autonomy, and reciprocally modulates the other models. All are legitimized by evolutionary traditions that antedate homo sapiens, and none is sufficient in itself. Elements of all three models necessarily coexist within any existing society, their relative strength varying with its collective values, prosperity, and perceived safety.

Criminal Law↗
PubMed1988

Responses of myopes to volitional control training of accommodation.

Twelve young, low myopes were trained to control volitionally their accommodation responses and to achieve clear focus on visual targets moved progressively outward in optical distance. The trainees participated in from 15 to 40 daily training sessions (mean = 28 sessions). All demonstrated volitional control with varying degrees of control authority. Though three of the trainees were unsuccessful, the group achieved a statistically reliable extension of their far points. Post-training optometric examinations were reliably improved over pre-training examinations, but did not appear to be commensurate with the large gains in far-point extension. It was hypothesized that the learned skill may have been 'instrument-specific', i.e. it might not fully generalize to significantly improved post-training binocular performance unless it were accompanied by clinical assistance to transfer the training.

Accommodation, Ocular↗
PubMed1990

Changes in the discharge patterns of motor cortical neurones associated with volitional changes in stepping in the cat.

Extracellular recordings have been obtained from motor cortical neurones of cats walking along a horizontal ladder. We present responses obtained when the animal produced defined volitional changes in limb trajectory, and during different conditions of locomotion. Our results show substantial changes in discharge pattern of some cells under these different conditions. Encounters with displaced rungs produce marked changes in discharge pattern including some which precede foot contact and others graded to the magnitude and direction of displacement.

Animals↗
PubMed1992

Localization of emotional and volitional facial paresis.

Emotional facial paresis is characterized by impaired activation of face muscles with emotion but normal voluntary activation. We report seven patients with this sign. Their lesions involved the frontal lobe white matter, the striatocapsular territory, the anterolateral thalamus and insula, the posterior thalamus and operculum, and the mesial temporal lobe and insula each in one patient, and the posterior thalamus in two patients. Volitional facial paresis affects facial movements with voluntary effort, sparing activation on emotion. We report four such patients, with lesions involving the motor cortex in one and the pyramidal tract in the cerebral hemisphere in three.

Adult↗
PubMed1990

[Emotional-volitional training in the combined treatment of patients with rheumatoid arthritis].

The development of placebo effect was found to be related to the psychological status and neurophysiological features of the body. This made it possible to elaborate the disadaptation hypothesis of the disease development and a total systems approach to its treatment, characterized by the necessity of conducting both conventional (aimed at suppression of the autoimmune process and inflammation) and activation therapy. The method of emotional volitional training (EVT) designed by the authors is advanced as one of the components of the activation therapy lying in the use of music therapy, auto- and heteropsychic actions together with application of an optimal variety of group physical training. Application of the EVT to the treatment of 86 patients with rheumatoid arthritis enabled the drug dosage to be reduced by as many as 50%, to improve the patients' mental status and to enhance work fitness, promoting the decrease of the hospital treatment by 4-5 days and prolongation of the remission from 6 months to 1.5 years.

Adolescent↗
PubMed1988

The development of volitional behavior in the toddler years.

In order to generate a description of early volitional skills, toddlers' abilities to match their activities to externally defined task standards and to monitor and control activities with respect to outcomes were studied. Children between 15 and 35 months were observed as they engaged in a series of play and clean-up tasks. The results showed that there is a consistent developmental pattern in the extent to which children focus on producing outcomes (rather than on acting for its own sake), the extent to which they monitor, correct, and control activities, and the frequency with which they react to their outcomes with positive affect. These patterns are interpreted in terms of changes in the representation of actions, self-regulation abilities, and the active involvement of the self in actions.

Affect↗
PubMed1988

Naloxone, but not Tyr-MIF-1, reduces volitional ethanol drinking in rats: correlation with degree of spontaneous preference.

The possible relationship between the actions of ethanol and opiates led us to examine the effect of opiate antagonists on ethanol intake in rats with a free choice of water. Naloxone (NAL) significantly reduced intake of ethanol. This effect was much greater in "high-preferring" (ethanol/total fluid intake greater than 60%) than in "low-preferring" (ethanol/total fluid intake less than 30%) rats. Furthermore, a correlation was found between the degree of spontaneous preference (ethanol/total fluid intake ratio) and the reduction of ethanol drinking by NAL. Sensitivity to NAL increased with increased preference for ethanol. Neither Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2) nor MIF-1 (Pro-Leu-Gly-NH2) caused a significant modification of ethanol intake. This study shows that NAL can reduce volitional ethanol intake in rats and provides further evidence that Tyr-MIF-1 does not always act like NAL.

Alcohol Drinking↗
PubMed1990

Automatic and volitional semantic processing in aphasia.

The present study investigated the status of semantic information in aphasia by comparing the performances of aphasic and nonaphasic subjects on two tasks: an automatic semantic facilitation task and a volitional task of relatedness judgment. Both the aphasic and nonaphasic groups evidenced a semantic facilitation effect, in an on-line task of semantic processing. However, those aphasics with severe comprehension and naming disturbances (termed low comprehension aphasics) demonstrated considerable difficulty in judging the relatedness between a pictured object and members of that object's semantic field, the severity of the impairment being greater for those pictures that the low comprehension aphasics were unable to name. The pattern of results can best be explained by supposing the structural integrity of the store of semantic information in aphasia, and in particular in low comprehension aphasia: information that is retrieved and manipulated in judgment-mediated tasks with considerable difficulty.

Adult↗
PubMed1988

Volitional oral intake of nicotine in tupaias: drug-induced alterations.

Non-deprived, unstressed tree shrews (Tupaia belangeri) preferred nicotine solution (10 mg/l nicotine tartrate) over water in a free-choice situation. This drug-taking behaviour was stable over 14 months. Several drugs, most of which known to attenuate ethanol consumption in other species, in doses that did not alter locomotive behavior, significantly reduced the volitional nicotine intake in tupaias.

5-Hydroxytryptophan↗
PubMed1989

The anatomy of mental unity and volition: an alternate view.

The preceding paper, by Louis Tinnin, challenges us to consider that there is a brain agency responsible for mental unity, volition and consciousness, which the author labels a "governing mental system" (GMS), or "ego," and that the neural substrate for this GMS is Wernicke's Area. The primary evidence in support of this position comes from three sources: a review of brain and language development in normal and abnormal individuals (e.g., deaf children); studies of patients who have undergone corpus callosum section for intractable epilepsy; and some observations of memory processing during the intracarotid sodium amytal (Wada) procedure. Our comments address two issues. The first is an analysis of the adequacy of these three sources as evidence for Tinnin's position. The second is a description of an alternative model to account for the mental system we agree exists but do not yet understand.

Cerebral Cortex↗
PubMed1991

Volitional augmentation of upper esophageal sphincter opening during swallowing.

Studies were done on eight normal subjects with synchronized videofluoroscopy and manometry to facilitate a biomechanical analysis of the extent and mechanism of voluntary augmentation of upper esophageal sphincter (UES) opening during swallowing. Movements of the hyoid and larynx, dimensions of sphincter opening, and intraluminal pressure events were determined at 1/30-s intervals during swallows of 1 and 10 ml of liquid barium. Swallows of each volume were obtained both before and after subjects were taught a maneuver designed to augment UES opening, the Mendelsohn maneuver (voluntary prolongation of laryngeal excursion at the midpoint of the swallow). At either volume, use of the maneuver increased the duration of the anterior-superior excursion of the larynx and hyoid and consequently delayed sphincter closure by maintaining traction on the anterior sphincter wall. The onset of the pharyngeal contraction (the event normally culminating in sphincter closure) was not affected by the maneuver. We conclude that swallow-related hyoid motion, laryngeal motion, and UES opening are subject to volitional augmentation, supporting the notion that biofeedback techniques can be used to modify impaired swallowing.

Adult↗
PubMed1991

Motor, volitional and behavioural disorders in schizophrenia. 1: Assessment using the Modified Rogers Scale.

The assessment of catatonic symptoms, unlike that of other schizophrenia symptoms, has not acquired accuracy and phenomenological rigour, and their distinction from extrapyramidal side-effects is not always easy. The Modified Rogers Scale can rate abnormalities in movement, volition, speech, and overall behaviour in schizophrenia. It is detailed, reliable and valid, and permits the isolation of a score for non-extrapyramidal and hence presumably catatonic phenomena.

Arousal↗
PubMed1990

Restoration of volitional limb movement of hemiplegics following patterned functional electrical stimulation.

24 hemiplegic patients completed patterned functional electrical stimulation (PFES) upon the afflicted arm and leg. The multichannel PFES program was mathematically derived from the EMG agonist/antagonist pattern recorded from each subject's unaffected limbs during a series of monitored, voluntary movements. The average improvement in volitional range of motion for the group's paralyzed limbs was 90% for the upper extremities and 69% for the lower extremities. For partially paralyzed limbs, there was an average increase in range of movement of 68% for the upper extremities and 26% for the lower extremities. These findings support the relearning-based, PFES open-loop theory which uses individualized therapeutic PFES-derived from EMG coordination patterns modeled from specific, ballistic limb movements to rehabilitate patients who have been immobilized after stroke.

Cerebrovascular Disorders↗