Mental Arousal Research Articles

Global link between heart rate and blood pressure oscillations at rest and during mental arousal in normotensive and hypertensive subjects

Complex phenomena modulate the interplay between heart rate and blood pressure variability, in particular after adjustments induced by stimuli or in pathophysiological conditions. This study sought to investigate in 25 hypertensive and 16 normotensive male subjects whether relationships operating at rest may be preserved after a central nervous system arousal induced by a mental stress test. As a secondary endpoint, we evaluated the potential changes of the components of heart rate and blood pressure variability during stress. Results A significant correlation was observed between components of RR and systolic blood pressure (SBP) variability ( p < 0.0001), after controlling for the subject's status (normotensive vs. hypertensive) and for stress-steps (baseline condition, during stress test and recovery). Moreover, the multiple regression model accounted for the potential effects of the baseline alpha LF value and for the baseline heart rate and systolic blood pressure. The relationship operating between the LF/HF RR ratio and LF/HF SBP ratio was not different either at the different steps of stress test (interaction: p = 0.87) or in the two groups of normotensive and hypertensive subjects (interaction: p = 0.76). The variables of RR and SBP variabilities were modified during stress and recovery. In particular, the LF/HF RR ratio and LF/HF SBP ratio increased during stress and decreased during recovery. Conclusions The association between heart rate and blood pressure oscillations was preserved during central nervous system arousal by mental stress both in normotensives and hypertensives. A central integration may account for this constant relationship, the correlation being independent from baseline heart rate, blood pressure and baroreflex sensitivity.

Cognitive Processes in the Maintenance of Insomnia and Co-Morbid Anxiety

Harvey (2002) developed a model of insomnia that has advanced the understanding of cognitive processes involved in the maintenance of this problem. Despite the high co-morbidity of insomnia with mental health problems, such as anxiety, the relevance of the cognitive processes specified in the model to people with insomnia as well as other mental health problems is yet to be established. This was the subject of investigation in the present study. A between-subjects design was used to compare people with insomnia and co-morbid anxiety (insomnia plus anxiety) with people with insomnia only (insomnia only), and with good sleepers on measures of mental arousal prior to sleep, thought control strategies employed, and unhelpful beliefs about sleep. Results showed that participants with insomnia plus anxiety were comparable to participants with insomnia only, and significantly different from good sleepers on all measures. The research suggests that the cognitive processes thought to maintain insomnia in people without other co-morbid mental health problems may also maintain insomnia in people with co-morbid anxiety disorders.

Sensitivity and Specificity of Measures of the Insomnia Experience: a Comparative Study of Psychophysiologic Insomnia, Insomnia Associated with Mental Disorder and Good Sleepers

To explore proposed explanatory mechanisms in psychophysiologic insomnia by investigating the sensitivity and specificity of commonly used insomnia research tools in discriminating psychophysiologic insomnia, insomnia associated with mental disorder, and good sleepers. Cross-sectional, between-group comparison of responses from subjects with psychophysiologic insomnia, those with insomnia associated with mental disorder, and good sleepers to psychometrically robust self-report instruments. Attendees at adult community outpatient clinics. Fifty-four adults (36 women, 18 men; average age 40 years) across 3 groups (n = 18 per group). Participants with psychophysiologic insomnia met combined Inteernational Classification of Sleep Disorders, Revised and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria and had no history of mental disorder. Participants with insomnia associated with mental disorder satisfied the same criteria for sleep disturbance and met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (Structured Clinical Interview for DSM-IV axis-I Disorders) criteria for depressive disorder. The majority had comorbid anxiety disorder. Insomnia duration in the groups with psychophysiologic insomnia and insomnia associated with mental disorder was around 10 years. Good sleepers served as a control group and included self-reported good sleepers with no history of sleep problems or psychiatric disorder. N/A. Analyses of variance, adjusted for multiple comparisons, indicated no between-group differences on a measure of sleep-related stimulus control, and self-reported somatic arousal was higher in subjects with insomnia associated with mental disorder than in good sleepers or those with psychophysiologic insomnia. Subjects with insomnia associated with mental disorder and psychophysiologic insomnia had poorer sleep hygiene and were characterized by heightened mental arousal. Logistic regression indicated that "effortful preoccupation with sleep" discriminated subjects with both psychophysiologic insomnia (100% sensitivity, 94% specificity) and insomnia associated with mental disorder (100%, 100%) from good sleepers and that only depressive symptomatology discriminated insomnia associated with mental disorder from psychophysiologic insomnia. Psychophysiologic insomnia and insomnia associated with mental disorder may be on a continuum of insomnia severity, rather than categorically distinct. Insomnia associated with mental disorder may respond to psychological intervention. Factors specifically discriminating insomniacs from good sleepers require further investigation.

The processing of music notation: some implications for piano sight-reading

Most piano pupils and many professional pianists find it difficult to sight-read music fluently. A major reason for this phenomenon is the complexity of the piano sight-reading process. Cognitive research reveals an intricate system of neural networks spread over all four cortical lobes of the brain, which are involved in processing musical sound and notation in particular. When sight-reading a piece of music that is seen for the first time (a prima vista) there are no context-specific memory maps to depend on, as is the case in performance study. The weak reader's biggest problem, therefore, is to form adequate motor responses to perceived notation. Specific challenges include dealing with pitch and rhythm separately while maintaining structural coherence, developing the ability of notational audiation or 'inner hearing', and coping with stress caused by high levels of mental arousal. These problems can be overcome if sight-readers develop an awareness of the mental processes that underlie their actions at the keyboard, and if they strengthen both the analytical and holistic strategies of the brain. Current teaching and learning practices need to be overhauled to utilise fully the insights provided by cognitive research.

Editor's Choice

Editor's Choice

Effects of mental stress on coronary epicardial vasomotion and flow velocity in coronary artery disease: relationship with hemodynamic stress responses

OBJECTIVESThis study examines the prevalence and hemodynamic determinants of mental stress-induced coronary vasoconstriction in patients undergoing diagnostic coronary angiography.BACKGROUNDDecreased myocardial supply is involved in myocardial ischemia triggered by mental stress, but the determinants of stress-induced coronary constriction and flow velocity responses are not well understood.METHODSCoronary vasomotion was assessed in 76 patients (average age 59.9 ± 10.4 years; eight women). Coronary flow velocity responses were assessed in 20 of the 76 patients using intracoronary Doppler flow. Repeated angiograms were obtained after a baseline control period, a 3-min mental arithmetic task and administration of 200 μg intracoronary nitroglycerin. Arterial blood pressure (BP) and heart rate assessments were made throughout the procedure.RESULTSMental stress resulted in significant BP and heart rate increases (p < 0.001). Coronary constriction (>0.15 mm) was observed in 11 of 59 patients with coronary artery disease (CAD) (18.6%). Higher mental stress pressor responses were associated with more constriction in diseased segments (rΔSBP = −0.26, rΔDBP = −0.30, rΔMAP = −0.29; p’s < 0.05) but not with responses in nonstenotic segments. The overall constriction of diseased segments was not significant (p > 0.10), whereas a small but significant constriction occurred in nonstenotic segments (p = 0.04). Coronary flow velocity increased in patients without CAD (32.2%; p = 0.008), but not in patients with CAD (6.4%; p = ns). Cardiovascular risk factors were not predictive of stress-induced vasomotion in patients with CAD.CONCLUSIONSCoronary vasoconstriction in angiographically diseased arteries varies with hemodynamic responses to mental arousal. Coronary flow responses are attenuated in CAD patients. Thus, combined increases in cardiac demand and concomitant reduced myocardial blood supply may contribute to myocardial ischemia with mental stress.

A Comparison of Subjective and Physiological Measures of Mechanically Produced and Erotically Produced Erections (Or, Is an Erection an Erection?)

The current investigation explores possible reasons for the poor overall success rates of medical techniques used in the treatment of erectile dysfunction. This is the first study to compare directly the psychological impact of a mechanically produced versus an erotically produced erection. Subjective and objective parameters of sexual arousal were used to compare the experience of a mechanically attained erection versus an erotically stimulated erection. Twenty-eight (28) men without sexual dysfunction were asked to reach a full erection during each of the following two conditions: (a) by using an ErecAid System and (b) by self-stimulating while watching an erotic video. The results of this study suggest that the penile vacuum device was a successful method for attaining penile tumescence; however, the presence of penile tumescence was not accompanied by a subjective state of physical or mental sexual arousal. Thus, the mere physical presence of an erection does not seem to evoke bodily or mental feelings of sexual arousal. It is important to note that these findings suggest that attention to the psychosexual components of the individual's sexual experience are critical to the subjective experience of sexual arousal and reflect once againthe multimodal response systems involved insexual arousal. These results suggest that more effective treatment approaches would be based on a clinical strategy that provides instruction both on the technical use of a mechanical device as well as on the importance of creating an appropriate psychosexual environment.

Destabilizing effects of mental stress on ventricular arrhythmias in patients with implantable cardioverter-defibrillators.

The incidence of sudden cardiac death increases in populations who experience disasters such as earthquakes. The physiological link between psychological stress and sudden death is unknown; one mechanism may be the direct effects of sympathetic arousal on arrhythmias. To determine whether mental stress alters the induction, rate, or termination of ventricular arrhythmias, we performed noninvasive programmed stimulation (NIPS) in patients with defibrillators and ventricular tachycardia (VT), which is known to be inducible and terminated by antitachycardia pacing, at rest and during varying states of mental arousal. Eighteen patients underwent NIPS in the resting-awake state (nonsedated). Ten underwent repeat testing during mental stress (mental arithmetic and anger recall). Induced VT was faster in 5 patients (P=0.03). VT became more difficult to terminate in 5 patients during mental stress; 4 required a shock (P=0.03). There was no change in ease of induction with mental stress. There was no evidence of ischemia on ECG or continuous ejection fraction monitoring. Eight patients received a shock in the resting-awake state and did not perform mental stress. Four underwent repeat NIPS after sedation; 3 then had induced VT terminated with antitachycardia pacing. All patients with an increase in norepinephrine of >50% had alterations in VT that required shock for termination (P<0.01). Mental stress alters VT cycle length and termination without evidence of ischemia. This suggests that mental stress may lead to sudden death through the facilitation of lethal ventricular arrhythmias.

Neurological function during long-term therapy with recombinant interferon alpha.

In 14 patients with myeloproliferative disorders associated with thrombocytosis, neurological and neuropsychological function were monitored prior to therapy with recombinant human interferon alpha (rIFN; dose 25 mU/week; range 10-35 mU/week) and after 3, 6, 9, and 12 months of treatment. No overt neurological side effects were observed except 1 case of cerebral insult, probably not treatment-related. Attention, memory function, and tapping improved significantly. The P2-N3 amplitudes of visually evoked potentials increased during normalization of platelet counts. Muscular strength and the amplitude of the compound muscle action potential of the median and peroneal nerves increased significantly in an inversely dose-related fashion. In patients with myeloproliferative disorders, long-term therapy with low to intermediate doses of rIFN does not seem to impair neurological function, but rather is associated with enhanced muscle power and the level of mental arousal.

Pupil noise is a discriminator between narcoleptics and controls

The pupil light reflex has a long history of being able to indicate states of mental arousal, ranging from sleepiness to concentrated cognitive effort. Such mental states have usually been inferred from pupil diameter or pupil area movements relative to some reference; sleepiness, for example, is characterized by a smaller than average pupil while mental effort brings on a slightly larger pupil. But all pupil movements and associated states of arousal are accompanied by a persistent random pupil diameter motion which has previously been attributed to neurological noise, the noise apparently arising in the neurological controller of the pupil reflex control system. Our experiments and signal processing methods show that the amplitude of this pupil noise is an indicator of the sleeping disorder narcolepsy. Narcoleptics are found to have diminished pupil noise amplitudes relative to control subjects. Pupil noise is estimated by statistical procedures which yield unbiased noise measures in the form of six-dimensional Gaussian vectors. Each subject is associated with a Gaussian vector which is optimally projected onto a scalar axis so as to maximize the mean square distance between the narcoleptic and control samples. The Kullback-Leibler discrimination function is estimated and then evaluated for each projection as a means of discriminating narcoleptics from controls. The projected noise measures correctly classify 18 out of 20 subjects. The projected values also form the basis for supporting or rejecting a hypothesis of narcoleptic or control class membership. Parametric and nonparametric hypothesis tests suggest that, with probabilities close to one, narcoleptics and controls are distinguishable classes. To emphasize the importance of pupil noise as a diagnostic tool we present evidence from the neurophysiology literature indicating that Alzheimer's disease and narcolepsy have some of the same brainstem nuclei implicated. Further, Alzheimer patients and narcoleptics share some of the same disturbed sleep patterns.

Effects of anxiety arousal and mental stress on the vestibulo-ocular reflex.

Although the subjective reports of patients suggest that anxiety may aggravate vertigo and imbalance, there has been little research into how anxiety might directly affect balance system functioning. We conducted two studies to examine the effect of anxiety and arousal on the vestibulo-ocular reflex (VOR). In the first study, pre-lest fear ratings were obtained from 20 normal subjects and 36 anxious subjects immediately prior to rotation and caloric testing. Fear ratings were significantly correlated with the maximum slow-phase velocity (SPV) of nystagmus induced by caloric testing. In the second study, we assessed the VOR response to rotation of 36 normal subjects under 3 task conditions: a) minimal alerting (counting backwards during rotation), b) physical arousal (induced by exertion prior to rotation); c) mental arousal (induced by performance of stressful mental tasks during rotation). Both the physical and mental tasks induced a significant increase in heart rate compared with the alerting condition. The maximum SPV of the nystagmus induced by rotation was significantly greater during performance of the mental task than in the other two conditions. These combined results indicate that anxiety may influence the gain of the VOR.

Mental stress and cognitive performance do not increase overall level of cerebral O2 uptake in humans.

We measured cerebral metabolic rate of oxygen (CMRO2), cerebral blood flow (CBF), and cerebral lactate output during rest, during the execution of mental arithmetic, and during mental stress induced by physical and psychological annoyance. Measurements were performed in healthy volunteers by use of the Kety-Schmidt technique with 133Xe as the inert gas. Electroencephalographic desynchronization and highly significant increases in plasma catecholamines and heart rate verified that the test measurements were performed during conditions differing distinctly from the resting state. In accordance with an earlier study (Sokoloff et al. J. Clin. Invest. 34: 1101-1108, 1985), a minimal and nonsignificant 1% reduction of global CMRO2 during mental arithmetic was observed, signifying that this form of mental activation was unassociated with any detectable increase in overall cerebral synaptic activity. Mental stress induced a slight but highly significant (P less than 0.002) 6% reduction in global CMRO2. This finding is in contrast to results from earlier investigations and contradicts the generally accepted notion of an association between mental arousal and a diffuse upregulation of cerebral synaptic activity. During mental arithmetic and mental stress, cerebral lactate output increased by 207 and 344%, respectively, but because of large individual variations in the measured responses, the elevations reached statistical significance only during mental arithmetic.

Silent ischemia induced by mental arousal is not predicted by ambulatory ST segment monitoring

Silent ischemia induced by mental arousal is not predicted by ambulatory ST segment monitoring

Comparison of verapamil versus propranolol therapy in syndrome X

The effects of oral verapamil, 320 mg daily, propranolol, 120 to 160 mg daily, and placebo were compared in 16 patients presenting with transient myocardial ischemia without evidence of coronary atherosclerosis or vasospasm on angiography (syndrome X). Testing was done according to a randomized double-blind crossover placebo-controlled trial consisting of 3 consecutive 7-day treatment periods with verapamil or propranolol or placebo. Patients underwent continuous 48-hour electrocardiographic monitoring before therapy (run-in phase) and during the last 2 days of each treatment period. A total of 391 episodes of diagnostic (≥0.15 mV) ST depression was recorded during the trial. Of these, 23 were symptomatic. None of the episodes occurred while the patients were asleep, 25% during exercise, 35% during minimal physical activity and 40% at rest. Rest included activities demanding mental arousal (conversation, reading or watching television). Heart rate at the onset of ST depression was higher (≥10 beats/min) than that observed in the 5 minutes preceding ischemia in 95% of the episodes. In the group as a whole, the average number of ischemic episodes per 24 hours was significantly reduced during propranolol therapy compared with placebo (0.7 ± 0.6 vs 3.9 ± 1.8; p < 0.0005). No significant differences were seen during verapamil treatment (3.4 ± 1.7 vs 3.9 ± 1.8). It is concluded that transient myocardial ischemia in syndrome X is mostly precipitated by an increase in oxygen consumption, presumably due to a heightened sympathetic activity. Accordingly, β blockers may represent the first line of treatment.

Factors determining the activity of ischemic heart disease

Transient regional myocardial ischemia appears to underlie symptoms such as angina pectoris and represents a key pathophysiologic step, since it is an objective marker of disease activity and is capable of causing disabling symptoms and damage to left ventricular myocardium. A study of the characteristics of transient ischemia in and out of the hospital has shown that symptoms are an inconsistent underestimation of these events. Ischemia is generally prolonged, mostly asymptomatic, and usually accompanied by a regional decrease in myocardial perfusion. Studies out of the hospital have also shown that these episodes are frequently triggered by a wide range of ordinary everyday activities. These new features of transient ischemia are worth noting when searching for relevant causes that are present during everyday life and when trying to choose more rational therapy. More detailed studies of patient activity have shown that different levels of mental arousal are the most common triggering mechanism causing ischemia out of the hospital. In addition, the occurrence of transient ischemia during everyday life displays a circadian rhythm, with an increase and peak occurrence between 6:00 A.M. and 12 noon each day. The day-to-day variability of ischemia is marked, indicating functional disturbances of coronary stenoses against a background of a severe reduction in cross-sectional area. The examination of proximal stenoses has shown that (1) the reduction in cross-sectional area is usually underestimated by conventional angiography; (2) pressure gradients across coronary stenoses are common and, with reduced poststenotic blood pressure, can jeopardize perfusion; (3) disturbances of vessel caliber and antegrade flow can accompany many of the ordinary everyday activities known to trigger ischemia detected in Holter tapes studied out of the hospital; and (4) there is clear-cut evidence of endothelial dysfunction in these patients, with reversal of the normal dilator response to acetylcholine and paradoxical constriction of stenoses. This evidence of endothelial dysfunction in humans could be central to the problems of atheromatous narrowing, thrombus, and disturbed vasomotion.

Clinical problems in coronary disease are caused by wide variety of ischemic episodes that affect patients out of hospital

Transient ischemia arising from proximal events in epicardial coronary arteries causes important symptoms, such as angina pectoris, and is usually studied in the hospital with provocative tests. However, Holter monitoring of ST-segment disturbances in patients out of the hospital has shown frequent asymptomatic evidence of ischemia that is surprisingly prolonged and that is not associated with the obvious tachycardia of exercise or stress. Positron emission tomography has been developed to measure the regional myocardial uptake of a cation (rubidium-82) in order to assess repeatedly the directional changes in regional coronary blood flow during these events. This method has been used to show that both symptomatic and asymptomatic episodes of ST depression are reliably associated with disturbances in regional myocardial perfusion. The daily activities of patients have been analyzed and reproduced in the hospital to assess the effects of cold stimulation, mental arithmetic, cigarette smoking, and exercise. Physical exercise was associated with angina, ST-segment change, and regional abnormalities of myocardial perfusion, including decreased perfusion in poststenotic segments. The other tests caused the same disturbances in myocardial perfusion; these perfusion disturbances were mostly asymptomatic and surprisingly prolonged, with periods of recovery that were two to five times longer than the ST-segment disturbance and the pain. Current studies using a structured diary indicate that the episodes of transient ischemia occurring out of the hospital are more frequently associated with different levels of mental arousal than with any other activity. Physical exercise is a relatively infrequent cause of transient ischemia. The examination of coronary blood flow using provocative tests derived from the patients' own activities out of the hospital have confirmed that, irrespective of the pattern of angina, patients have frequent episodes of asymptomatic transient ischemia that are surprisingly prolonged and that these episodes occur in response to previously unsuspected ordinary daily activities. The disturbances in coronary blood flow usually include a regional decrease in myocardial perfusion that can only be explained by pathophysiologic events in the proximal epicardial coronary arteries.

Involvement of the baroreceptor reflexes in the changes in blood pressure with sleep and mental arousal.

We have measured baroreflex sensitivity and blood pressure in 13 subjects during sleep and three stages of progressive mental arousal after waking. Baroreflex sensitivity was measured by correlating the increase in pulse interval with the increase in systolic pressure produced by an intravenous injection of 80 micrograms of phenylephrine. Blood pressure was measured directly from the brachial artery. During sleep, blood pressure fell and baroreflex sensitivity increased; with increasing mental arousal, blood pressure rose and baroreflex sensitivity decreased. These results suggest that baroreflex activity may be involved in the medium-term regulation of blood pressure during the day and night in addition to its recognized role in buffering acute changes in blood pressure.

Sex differences in behaviour pattern and catecholamine and cortisol excretion in 3–6 year old day-care children

Fifteen boys and eleven girls between three and six years of age were examined at a day-care center and at home as regards their catecholamine and cortisol excretion. Behaviour pattern was assessed by the MYTH-scale, which measures the competitiveness, impatience-anger and aggression components of the type A behaviour pattern in children (Matthews and Angulo, 1980). The boys obtained higher type A scores and excreted more adrenaline and noradrenaline than the girls, while cortisol excretion did not differ between the sexes. In view of previous findings, the results suggest that sex differences in catecholamine excretion in children are induced by sex related differences in behaviour. This relationship in childhood could be of relevance for sex differences in catecholamine responses observed in adulthood. In both sexes, adrenaline excretion was significantly elevated at the day-care center compared with the at-home levels, indicating that mental arousal was greater at the center. In a separate part of the study, eleven new children were tested while they were adjusting to the day-care situation; it was found that only noradrenaline levels during the first week at the center were significantly elevated.

Flicker fusion thresholds and mental arousal.

Investigated the finding of Busch and Wachholder that flicker fusion thresholds increase under conditions of mental activity and decrease during inactivity. Flicker fusion thresholds for each eye of 21 undergraduates were measured after 2-min. rests, then after the performance of a mathematical counting exercise, and then after another 2-min. rest. The average thresholds for both the right and left eyes were significantly higher following the counting exercise than after the rests. Features of the experiment included a training/screening session for the subjects to detect and correct “pseudothreshold” problems, and an automatic adjustment of the light frequency to minimize possible experimenter effects.

Short‐term adaptive changes in the human vestibulo‐ocular reflex arc

1. Two sets of experiments have examined the vestibulo-ocular response (VOR) to repeated sinusoidal rotation (A) in the dark and (B) after attempting visual tracking of a mirror-reversed image of the visual surround.2. In both A and B a horizontal sinusoidal rotational stimulus of 1/6 Hz and 60 degrees /sec angular velocity amplitude was employed, specifically chosen to lie within the presumed range of natural stimulation of the semicircular canals.3. In A each of seven subjects underwent ten 2-min runs of the standard stimulus in the dark on each of three consecutive days, with 3-min rest periods between runs. Using d.c. electro-oculography (EOG) the VOR gain was measured throughout as eye velocity/head velocity. Mental arousal was maintained by competitive mental arithmetic. Constancy of EOG gain was assured by 50 min dark adaptation before experimentation.4. The results of A showed no consistent change of VOR gain over the three times scales of a run, a day and the 3-day experiment.5. In B the same subjects underwent a similar pattern of vestibular stimulation, but during eight of the 2-min daily runs they attempted the reversed visual tracking task. VOR gain was measured during the 1st, 6th and last runs which were conducted in the dark for this purpose. Constancy of EOG gain was maintained by using red light throughout.6. The results of B showed a substantial (approx. 25%) and highly significant (P << 0.001) reduction of VOR gain attributable solely to the 16 min of reversed visual tracking attempted during the 50 min daily experiment. In addition the pre-test control gain was lower on day 3 than on day 1 (approx. 10% attenuation, P < 0.01) indicating a small cumulative effect from beginning to end of the 3-day experiment.7. It is concluded (A) that the repeated vestibular stimulus did not itself cause significant attenuation of VOR gain, but (B) that superposition of a reversed visual tracking task did induce retained VOR attenuation which was solely due to the antagonistic visual stimulus.8. In conjunction with other experimental evidence it is inferred that this attenuation probably represents an adaptive change in the VOR induced at least in part by retinal image slip.