Influence of a scheduled-waiting task on EMG reactivity and oral habits among facial pain patients and no-pain controls.

Recent research has strongly implicated the role of psychological stress in the development of temporomandibular disorders (TMD). It is widely reported that oral habits (e.g., teeth grinding) probably provide a behavioral link between stress and the development of TMD symptomatology. Extrapolation of research in the field of adjunctive behavior to the TMD disorders suggests that oral behaviors may develop conjointly with fixed-time (FT) stimulus presentation. The current experiment extended previous research examining this possibility by assessing the influence of experimental stress on masseter EMG and oral habits among persons who met broadband criteria for TMD and no-pain controls. Oral habit activity was assessed via self-report questionnaire whereas masseter muscle activity was measured continuously via electromyography across four phases (Adaptation, Free-Play, Scheduled-Play, Recovery). The Scheduled-Play phase was designed as a stress-reactivity task that included an FT schedule. Results indicated that, consistent with the stress-reactivity model, the Scheduled-Play phase resulted in a significant increase in masseter EMG levels relative to Free-Play and Adaptation, and that this effect was significantly larger for the TMD group relative to controls. The results suggest an adjunctive behavior effect although the effect was not specific to those with facial pain. Oral habit data showed a significant phase effect with oral habits that was significantly higher during the Scheduled-Play phase relative to Adaptation. The findings are the impetus for further study regarding the mechanisms whereby oral habits are developed and maintained despite their painful consequences.

EMG reactivity and oral habits among facial pain patients in a scheduled-waiting competitive task.

For individuals with temporomandibular disorder (TMD) it has been theorized that stressful events trigger oral habits (e.g., teeth grinding), thereby increasing masticatory muscle tension and subsequent pain. Recent research involving adjunctive behaviors found an increase in masseter surface EMG (sEMG) and oral habits when students with TMD symptomatology were placed on a fixed-time reinforcement schedule. The current study used a treatment-seeking community sample with TMD symptomatology in a competitive task designed to be a more naturalistic Fixed Time task. The experiment consisted of Adaptation, Free-Play, Scheduled-Play, and Recovery phases. During the Scheduled-Play phase participants played, and waited to play, an electronic poker game. Results indicated that masseter muscle tension in the Scheduled-Play phase was significantly higher (p < .001) than in any other phase. Moreover, during the Scheduled-Play phase masseter sEMG was higher (p < .001) when participants waited to play. Self-reported oral habits and overall affect were significantly higher (p's < .05) in the Free-Play and Scheduled-Play phases relative to Adaptation and Recovery. The observation that masseter sEMG was elevated during the Scheduled-Play phase relative to all other phases, and within the Scheduled-Play phase sEMG was highest while waiting, suggests that adjunctive oral habits may lead to TMD symptomatology.

Cognitive factors associated with facial pain.

Most well-accepted etiological models of facial pain (e.g., temporomandibular disorders and headache) implicate emotional distress as an important factor in the development and maintenance of pain. Data exists to support the notion that some facial pain sufferers are more emotionally distressed than no pain controls. However, many of these dependent measures of emotional distress are either lengthy assessment batteries, lack clear cut psychotherapeutic treatment implications, or focus exclusively on pain related sequela. As cognitive-behavioral interventions become more integrated into the treatment of chronic pain conditions, including various facial pain conditions, it becomes more imperative that the tools used to assess psychological functioning provide the clinician with specific cognitive/behavioral targets for change. The purpose of this study was to assess the degree to which symptomatic treatment seeking facial pain sufferers (N = 25), symptomatic non-treatment seeking facial pain sufferers (N = 48), and healthy pain-free controls (N = 70) differed on the Rational Beliefs Inventory (RBI). The RBI is a reliable, valid questionnaire assessing rational beliefs that are operationalized within a Rational Emotive Therapy (RET) framework. RET is a cognitive-behavioral treatment paradigm that focuses on how an individual's maladaptive cognitive errors or distortions exacerbate emotional distress. Group differences were assessed using a oneway Analysis of Covariance (ANCOVA) with the total RBI score serving as the dependent measure, and a Multivariate Analysis of Covariance (MANCOVA) using individual RBI belief subscales as dependent measures. These results indicated that groups differed significantly on the total score and several of the individual belief subscales. These findings indicated that facial pain sufferers generally hold maladaptive beliefs that may be of clinical significance for cognitive/behavioral treatment approaches.

Schedule-induced masseter EMG in facial pain subjects vs. no-pain controls.

Empirical reports suggest that oral habits (e.g., teeth clenching) may be behavioral mediators linking stress to muscle hyperreactivity and the development of facial pain. Another report suggests that excessive behavioral adjuncts develop in conjunction with fixed-time stimulus presentation. The present study assessed the extent to which the oral habits exhibited by facial pain patients are schedule-induced. Subjects with Temporomandibular Disorder (TMD) symptomatology (n = 15) and pain-free controls (n = 15) participated in a 4-phase experiment (adaptation, baseline, task, recovery) designed to elicit schedule-induced behaviors. Self-report of oral habits and negative affect were recorded after each phase. Objective measures of oral habits were obtained via behavioral observation and masseter EMG recordings. Results revealed that negative arousal significantly increased during the fixed-time (FT) task and was also associated with increased oral habits among the TMD subjects. Moreover, 40% of the TMD subjects and none of the controls exhibited a pattern of EMG elevations in the early part of the inter-stimulus interval that met a strict criteria for scheduled-induced behavior per se. Taken together, these results suggest that the TMD subjects were engaging in schedule-induced oral habits. The adjunctive behavior literature seems to provide a plausible explanation as to how oral habits develop and are maintained in TMD patients, despite their painful consequences.

Perceptual and cognitive abnormality model of hypochondriasis: amplification and physiological reactivity in women.

This study investigated the perceptual/cognitive abnormality model of hypochondriasis, which suggests that hypochondriacal patients amplify and misinterpret normal bodily sensations. The hypothesis was evaluated by assessing pain perception and stress reactivity in female hypochondriacal (N = 15) and female nonhypochondriacal control subjects (N = 15). Subjects completed self-report measures and participated in a laboratory stress reactivity assessment consisting of the cold pressor task and an imagery task. Hypochondriacal subjects exhibited a significant increase in heart rate during the cold pressor task and a significant drop in hand temperature relative to controls. Hand temperature remained lower among the hypochondriacal subjects after the cold pressor task was terminated. Hypochondriacal subjects terminated the cold pressor task more frequently, left their feet in the cold water bath a significantly shorter period of time, and rated the cold pressor task as significantly more unpleasant (although not more intense) relative to controls. Group differences were not observed in the imagery task. Of interest, hypochondriacal subjects' baseline heart rate was significantly lower than that of controls. Taken together, these data suggest that hypochondriacal behavior may be mediated, in part, by objective differences in physiological reactivity.

Temporomandibular disorder: efficacy of an oral habit reversal treatment program.

Little attention has been directed at interventions that directly teach facial pain patients to detect, interrupt, and reverse the maladaptive oral habits and cognitions thought to be associated with muscle hyper-reactivity and pain. The present study tested a seven-session structured-group habit reversal treatment intervention for facial pain patients. Nine facial pain subjects participated in treatment groups and seven qualified subjects who did not participate in treatment served as a comparison group. Pre, post, and follow-up assessments included measures of pain and psychological functioning. Subjects in the treatment group improved on all measures of pain relative to those in the comparison group. These improvements were maintained or augmented at four month follow-up assessments suggesting that habit reversal training, particularly in a group format, may provide a cost-effective intervention for facial pain patients.

The influence of life stress, personality, and learning history on illness behavior.

Previous research has suggested that prior learning experiences and current reinforcement contingencies account for a substantial portion of the variance in illness behaviors. The present study examined the role of other variables (e.g., stimulus and organismic variables). Two hundred and sixty four college students completed questionnaires that included the Life Events Survey, Hassles Scale, Hypochondriasis Scale (MMPI), Illness Attitude Scale, and a Medical Problems Survey. It emerged that social learning variables accounted for significant portions of variance in symptom reporting behavior even after other demographic, current stressor, and personality variables were accounted for. The advantages of using behavioral assessment models for conceptualizing influential variables is highlighted and directions for future research discussed.

Efficient pain assessment in clinical settings.

The need for efficient and practical assessment techniques of the multidimensional nature of chronic pain remains paramount in clinical settings. Visual analogue scales (VASs) and simple behavioral observation methods have been proposed as efficient, reliable, and valid measures of the subjective (sensory and affective) and overt behavioral aspects of the pain experience. The relationships among VASs and the UAB Pain Behavior Scale were examined among 48 chronic pain patients. Ratings of overt behavior were significantly related to both the VAS sensory and VAS affective ratings. Regression analysis indicated that the VAS scores accounted for significant amount of the variance (27.7%) in UAB scores. Moreover, the affective dimension of self-reported pain tended to be more strongly related to the visible manifestations of pain than were ratings of pain intensity.

Neuropsychological deficits in symptomatic minor head injury patients after concussion and mild concussion.

Recent studies have concluded that most individuals who sustain minor head injury are free of persistent neuropsychological dysfunction. Nevertheless, a subgroup of patients experience continuing post-concussive difficulties and neuropsychological deficits. This study examined 53 symptomatic minor head injury patients referred for neuropsychological evaluation between one and 22 months after injury. These individuals performed significantly poorer than uninjured controls on four of eight neuropsychological tests. Patients who lost consciousness during injury obtained test scores similar to persons who experienced disorientation or confusion but no loss of consciousness. The results indicate that minor head injury patients who report post-concussive symptoms possess measurable neuropsychological deficits and the severity of these deficits is independent of neurological status immediately following injury.

Perceived barriers to exercise and weight control practices in community women.

A sample of community women was surveyed to determine exercise habits, weight control methods, and perceived barriers to sustaining and initiating exercise and weight management programs. Lack of time was reported to be the most significant factor limiting exercise, while lack of willpower and time constraints were the most frequently reported obstacles to weight management. Suggestions to aid adherence to exercise and weight control programs among women are outlined.

Sleep patterns and aging: comparison of older adults with and without insomnia complaints.

The nature of geriatric insomnia was studied by comparing older adults with (n = 42) and without (n = 30) insomnia complaints on measures of sleep, mood, life-style, health, and sleep-requirement expectations. Elderly persons with insomnia complaints reported longer sleep latency and more frequent and longer awakenings and used sleeping aids more often than those without insomnia complaints. Nocturnal sleep time was not a reliable discriminator. Poor sleepers showed greater discrepancies between their current sleep patterns and sleep-requirement expectations than did good sleepers. Elderly insomniacs acknowledged greater symptomatology of depression and anxiety than did good sleepers. Daytime napping and physical exercise were equivalent in both groups. Medical disorders, pain conditions, and drug usage (other than sleep aids) did not distinguish the two groups. Clinical implications for the treatment of geriatric insomnia are discussed.

Some effects of pimozide on nondeprived rats' lever pressing maintained by a sucrose reward in an anhedonia paradigm.

The present work examined the generalizability of the anhedonia phenomenon (extinction-like responding with repeated neuroleptic treatment) by examining the effects of pimozide (PIM) on nondeprived rats lever pressing for a sucrose solution reward (32%) in an eight day dosing regime. The procedures used replicated the essential features of a previous study (Gramling et al. [10]) wherein the effects of PIM on rats licking directly a sucrose solution were assessed. Thirty nondeprived rats were trained to lever press on a CRF schedule for a 32% sucrose solution reward and then assigned to one of five treatment groups (N = 6). The treatment conditions included a no-reward group (EXT; vehicle injections), two pimozide (PIM) with reward conditions (either PIM 0.25 mg/kg + RWD or PIM 0.5 mg/kg + RWD), and a vehicle control group (RWD; vehicle injections). These four groups each received their respective injections and operant exposure for eight consecutive days. The fifth group was a home cage (HC) control condition wherein the rats were injected with 0.5 mg/kg PIM each test day but did not receive operant exposure until the fourth test day. The PIM treated rats exhibited a significant curvilinear pattern of responding on the rate measure across eight days of testing, whereas rats in the no-reward condition exhibited a significant downward linear trend across eight days of testing. Within-session analysis revealed that rats in the EXT group responded at significantly higher rates during the first five minutes of testing on the first test day compared to rats in the PIM 0.5 + RWD condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of pimozide on emitted force, duration and rate of operant response maintained at low and high levels of required force.

The behavioral effects of pimozide (0.25, 0.5, and 1.0 mg/kg) were assessed in two separate experiments in which session mean peak force, maximum peak force, and response duration served as the dependent variables complementing operant response rate. In the first experiment, two groups of water-deprived rats were trained on a continuous reinforcement (CRF) schedule for reaching out and pressing downward on a force transducer with peak forces of at least 4 g (low-force group) or 40 g (high-force group). In the second experiment a pull-type response topography and fixed ratio 20 were used, and force requirements were 4 g for the low-force group and 100 g for the high-force condition. Under these conditions pimozide decreased response rate and increased response duration irrespective of response topography, required force, or schedule of reinforcement. Neither mean peak force nor maximum peak force were significantly decreased by the drug, and in the low-force CRF condition a small but significant dose-related rise in mean peak force was observed. It was hypothesized that neuroleptics exert their motor-impairing effects primarily in the temporal domain of behavior but do not appreciably affect the force dimension of performance capacity. And these temporal domain effects may be reflected in differences in the kinetic requirements for the overall behavior and not just the response itself. Additionally, the possibility that some of the observed effects could be accounted for by "anhedonia" was addressed.

Some effects of pimozide and of shifts in sucrose concentration on lick rate, duration, and interlick interval.

Multiple dependent measures were employed to characterize the licking behavior of rats exposed to shifts in reward magnitude or injected with pimozide (PIM). Nondeprived rats licked either a 32% (n = 14) or 4% (n = 15) sucrose solution in daily 10 min sessions. Rats in the 32% condition were then down-shifted to either a 16% (n = 7) 4% (n = 7) sucrose solution. Rats in the 4% condition were up-shifted to either 16% (n = 7) or 32% (n = 8) sucrose solution. The response profiles generated by those rats shifted to a lower reward magnitude were contrasted with either rats shifted from a 32% sucrose solution to a no-reward (plain tap water) condition, or with rats maintained on a 32% sucrose solution and administered the neuroleptic PIM (0.5 mg/kg or 1.0 mg/kg). Rats down-shifted from a 32% to 4% sucrose solution generated response profiles more similar to rats shifted to plain tap water than rats maintained on a 32% sucrose solution and administered PIM. These results suggested that PIM treatment is not functionally equivalent to either a shift to no-reward or to a shift to reduced reward conditions.

Effects of neuroleptics on rate and duration of operant versus reflexive licking in rats.

Operant conditioning techniques were used to train one group of nine rats to lick a dry horizontal metal disk on a fixed ratio 15 schedule with water reinforcement delivered at a different location. Another group of seven rats licked reflexively from a water reservoir positioned with the same spatial arrangements as the metal disk. The distance the rats' rongues traversed (10 mm) to contact the licking surface was the same in both the operant and reflexive lick conditions. The effects of three neuroleptics, haloperidol (0.06, 0.12, 0.24, 1.0, 2.0 mg/kg), chlorpromazine (0.5, 1.0, 2.0 mg/kg) and clozapine (2.5, 5.0, 7.5 mg/kg) on average lick rate and median lick duration were assessed for both groups. Dose related decreases in average lick rate were observed in both groups of rats as a function of dose of each of these neuroleptics. Moreover, operant lick rates were proportionately more affected by neuroleptic treatment than were reflexive lick rates. The dose-response effect for the duration variable was different for the two lick conditions in that reflexive lick duration was lengthened as dose increased, whereas operant lick duration was lengthened only at the lower doses of these drugs. The differential effect of these neuroleptics on operant vs. reflexive licking suggests that neuroleptics attenuate selectively those responses that require relatively more conditioning to acquire. These results may be analogous to the initiation deficit that has been suggested to account for neuroleptics' selective attenuation of avoidance, while leaving relatively intact the escape response in escape/avoidance procedures.

Some effects of pimozide on nondeprived rats licking sucrose solutions in an anhedonia paradigm.

The present work examines the generalizability of the anhedonia phenomenon (extinction-like responding with repeated neuroleptic treatment) by examining rats' licking behavior, a response heretofore untested, in the anhedonia paradigm. Nondeprived rats learned to lick a sucrose solution (32%) and were then tested for eight consecutive days in either a no-reward condition (N = 8) or two pimozide (PIM) with reward conditions (N = 8 at each of these two doses: 0.5 and 1.0 mg/kg). PIM treated animals did not exhibit rates or patterns of responding equivalent to animals in the extinction condition. Instead of an across session decline in rate, PIM treated animals showed a trend towards recovery on the rate measure. Within session patterns of responding of PIM treated animals more closely resembled animals in a normally rewarded condition responding at a generally lower rate, than animals in an extinction condition. The experimental procedure included the the use of home cage control animals, replication of the intermittent dosing procedure, and tests for transfer effects; all of these failed to produce patterns of responding typically obtained in the anhedonia paradigm when the response is lever pressing. Median lick duration and median interlick interval (ILI) were both lengthened with PIM treatment relative to injection control and extinction conditions, suggesting that pimozide treatment creates a motoric deficit. Taken together these results emphasize the importance of neuroleptics' motor vis a vis anhedonic effects.

Acute and subchronic effects of neuroleptics on quantitative measures of discriminative motor control in rats.

Operant-conditioning methods were used to train rats to reach through an opening in an operant chamber to exert forces on a silent, nearly isometric force-sensing manipulandum. The reinforcement contingency required the rat to hold forelimb force at 20-50 g for a minimum of 2 s. Once established, this 'hold-in-the-band' behavior yielded three measures of performance (time on task, number of reinforcers, variance of in-band force). Variance of in-band force was presumed to reflect steadiness of forelimb control. Acute drug effects on the three dependent variables were assessed for dose ranges of haloperidol (HAL), chlorpromazine (CPZ), clozapine (CLZ), and chlordiazepoxide (CDP). Moreover, the effects of HAL (0.5 mg/kg) and CLZ (5.0 mg/kg) were examined in a subchronic (28 day) dosing regimen. The acutely administered neuroleptics (HAL, CPZ, CLZ) produced dose-related decreases in time on task and number of reinforcers, but did not significantly affect variance of in-band force. The subchronic paradigm produced similar results. CDP did not significantly affect variance of in-band force and the 5.0 mg/kg dose produced a slight, but non-significant increase in time on task while significantly decreasing number of reinforcers; a trend opposite to that seen for the neuroleptics, which produced parallel effects on these two measures. The results suggest that the neuroleptics impaired performance by affecting the tendency to initiate responding instead of affecting the capacity to maintain steady forelimb force once a response was started.