Mark Moss

AROMAS OF ROSEMARY AND LAVENDER ESSENTIAL OILS DIFFERENTIALLY AFFECT COGNITION AND MOOD IN HEALTHY ADULTS

This study was designed to assess the olfactory impact of the essential oils of lavender (Lavandula angustifolia) and rosemary (Rosmarlnus officinalis) on cognitive performance and mood in healthy volunteers. One hundred and forty-four participants were randomly assigned to one of three independent groups, and subsequently performed the Cognitive Drug Research (CDR) computerized cognitive assessment battery in a cubicle containing either one of the two odors or no odor (control). Visual analogue mood questionnaires were completed prior to exposure to the odor, and subsequently after completion of the test battery. The participants were deceived as to the genuine aim of the study until the completion of testing to prevent expectancy effects from possibly influencing the data. The outcome variables from the nine tasks that constitute the CDR core battery feed into six factors that represent different aspects of cognitive functioning. Analysis of performance revealed that lavender produced a significant decrement in performance of working memory, and impaired reaction times for both memory and attention based tasks compared to controls. In contrast, rosemary produced a significant enhancement of performance for overall quality of memory and secondary memory factors, but also produced an impairment of speed of memory compared to controls. With regard to mood, comparisons of the change in ratings from baseline to post-test revealed that following the completion of the cognitive assessment battery, both the control and lavender groups were significantly less alert than the rosemary condition; however, the control group was significantly less content than both rosemary and lavender conditions. These findings indicate that the olfactory properties of these essential oils can produce objective effects on cognitive performance, as well as subjective effects on mood.

Oxygen administration selectively enhances cognitive performance in healthy young adults: a placebo-controlled double-blind crossover study

Abstract It was recently demonstrated that oxygen administration can improve performance on a simple word recall task in healthy young adults. This study was aimed at determining the impact of various durations of oxygen administration on a wider range of cognitive measures. This was achieved using the Cognitive Drug Research computerised test battery, and employing a double-blind, placebo-controlled crossover design. Over a period of 7 weeks, 20 participants were trained and subsequently assessed on the test battery under several durations of oxygen inhalation; air administered in an identical fashion served as a control. The results provided support for our earlier work in that increases were found in both immediate and delayed word recall. In addition, oxygen administration significantly improved performance on several measures of attention and vigilance. Simple reaction time, choice reaction time, digit vigilance reaction time and picture recognition reaction time were improved in a manner which depended on the duration of oxygen inspired. With the exception of word recall, no significant improvements were found for any measure of accuracy, nor were word recognition, digit memory scanning, or spatial memory improved. These results are discussed in the context of stages of information processing and are consistent with the hypothesis that cognitive performance is “fuel-limited” and can be differentially augmented by increasing the availability of the brain’s metabolic resources.

MODULATION OF COGNITIVE PERFORMANCE AND MOOD BY AROMAS OF PEPPERMINT AND YLANG-YLANG

This study provides further evidence for the impact of the aromas of plant essential oils on aspects of cognition and mood in healthy participants. One hundred and forty-four volunteers were randomly assigned to conditions of ylang-ylang aroma, peppermint aroma, or no aroma control. Cognitive performance was assessed using the Cognitive Drug Research computerized assessment battery, with mood scales completed before and after cognitive testing. The analysis of the data revealed significant differences between conditions on a number of the factors underpinning the tests that constitute the battery. Peppermint was found to enhance memory whereas ylang-ylang impaired it, and lengthened processing speed. In terms of subjective mood peppermint increased alertness and ylang-ylang decreased it, but significantly increased calmness. These results provide support for the contention that the aromas of essential oils can produce significant and idiosyncratic effects on both subjective and objective assessments of aspects of human behavior. They are discussed with reference to possible pharmacological and psychological modes of influence.

Oxygen administration enhances memory formation in healthy young adults

Despite numerous studies indicating that transient cerebral oxygen depletion has a detrimental effect on cognition, surprisingly little research has examined the possibility of cognitive enhancement following elevated oxygen levels in healthy adults. Here, we present evidence demonstrating that oxygen administration improves memory formation. Inhalation of oxygen immediately prior to learning a word list resulted in a significant increase in mean number of words recalled 10 min later, compared to subjects who inhaled oxygen immediately prior to recall or to controls who underwent no intervention. In a second experiment, the learning-test interval was increased to 24 h and, again, only pre-learning (but not pre-test) oxygen administration resulted in significant memory facilitation. In experiment 3, inhalation of oxygen prior to learning was compared to inhalation of compressed air, oxygen (but not compressed air) resulted in a significant increase in word recall 24 h later. In no experiment did oxygen have a significant effect on any mood item measured. We interpret these data as indicating that increased availability of cerebral oxygen facilitates cognition, including memory consolidation. The implications for the psychopharmacology of cognitive enhancement are considered in the context of cholinergic systems and neural metabolism.

The psychosocial, endocrine and immune consequences of caring for a child with autism or ADHD

Research that has assessed the psychophysiological consequences of caregiver stress in young and middle aged caregivers, that is, in populations not contending with age associated decline of the endocrine and immune systems, has been scarce and yielded inconsistent findings. To extend work in this area, this study assessed the psychosocial, endocrine and immune consequences of caregiver stress in a cross sectional sample of young and middle aged caregivers of children with autism and attention deficit hyperactivity disorder (ADHD) compared against parents of typically developing children. Caregivers (n=56) and parent controls (n=22) completed measures of psychological distress (perceived stress, anxiety/depression), social support and physical health complaints. To capture important indices of the diurnal cortisol pattern, cortisol was measured at waking, 30 min post waking, 1200 h and 2200 h on two consecutive weekdays. Venous blood was taken to assess systemic concentrations of proinflammatory biomarkers, interleukin-6 (IL-6) and C-reactive protein (CRP). Caregivers scored markedly higher on all measures of psychological distress; scores on social support subscales, however, were significantly lower in this group. Diurnal patterns of cortisol secretion did not differentiate between the groups; however, caregivers displayed elevated systemic concentrations of the proinflammatory biomarker, CRP and reported more frequent episodes of physical ill health. The stress of caregiving exacts a significant psychophysiological toll, that is, even in the absence of HPA dysregulation, caregivers demonstrated elevated concentrations of proinflammatory biomarkers and, therefore, might be at greater risk for diseases fostered by disinhibition of the inflammatory response.

Cognitive properties of sedation agents: Comparison of the effects of nitrous oxide and midazolam on memory and mood

Objectives To compare the effects of nitrous oxide and midazolam on cognition and mood.Design A three-way, counterbalanced, cross-over study, using patients receiving conscious sedation for routine dental treatment.Methods On each of three separate visits, patients performed a computerised test battery to determine baseline cognitive performance. Then, following administration of either midazolam, nitrous oxide, or no drug, patients re-performed the test battery. Finally, patients completed visual analogue scales assessing their subjective mood state.Results Relative to baseline performance, midazolam administration produced significantly slower reaction times compared with nitrous oxide and no-drug conditions. Furthermore, patients receiving midazolam were impaired in accuracy relative to the other conditions on many of the cognitive tasks, particularly those assessing the recall of information. Patient performance in nitrous oxide and control conditions did not significantly differ. These results could not be explained by differences in mood between the conditions, as subjective mood ratings during midazolam or nitrous oxide administration were very similar.Conclusions It is important for clinicians to be aware that peri-operative recall of information is reduced in patients who have undergone midazolam sedation. This is an advantage for patients who are anxious, and do not wish to be aware of the operative treatment being performed. However, as the cognitive impairment is enduring, an adult escort and written post-operative instructions should be mandatory for midazolam sedation patients. In contrast, the use of nitrous oxide sedation does not significantly impair higher cognitive tasks and thus patients receiving nitrous oxide sedation can resume normal activities in the post-operative period.

Dose-dependent effects of flumazenil on cognition, mood, and cardio-respiratory physiology in healthy volunteers

Objectives To assess the possible effects of flumazenil on cognitive processing, physiology, and mood.Design A double-blind, placebo controlled, four-way cross-over study, using healthy volunteers.Methods On each of 4 separate visits, 16 participants received 0.5mg, 2.5mg, 5.0mg of flumazenil, or normal saline. They then performed a computerised test battery assessing cognitive function. Measures of pulse rate, arterial oxygen saturation and mean arterial pressure were also taken. Finally, participants completed visual analogue scales assessing their subjective mood state.Results The majority of cognitive tasks showed dose-dependent declines in performance. Mean arterial pressure was significantly reduced, as was pulse rate. Subjective alertness showed a similar decline.Conclusions Flumazenil has been clinically described as an agent with few intrinsic properties, whose primary effect lies in its ability to reverse benzodiazepine-induced states. This study has shown that flumazenil does possess intrinsic activity which have a significant effect on cognition, cardiovascular physiology and mood. Clinicians need to be aware of these effects.

Oxygen and cognitive performance: the temporal relationship between hyperoxia and enhanced memory.

Abstract Oxygen administration coinciding with word presentation enhances word recall in humans, suggesting that elevated levels of circulating blood oxygen may be available to neural memory consolidation processes. This double-blind experiment examined the relationship between blood oxygen levels and cognitive performance when oxygen was inspired for 2 min at different times relative to a simple word recall task, forward digit span and backward digit span. Transient hyperoxia, measured by haemoglobin-bound oxygen, was evident following oxygen inspiration. Neither forward nor backward digit span was affected by oxygen administration. Word recall (12 min following word presentation) was enhanced when oxygen was administered 5 min prior to, immediately before or immediately following word presentation; but not 10 min prior to, 5 min following nor 10 min following, word presentation. These data suggest that oxygen administration can selectively enhance aspects of cognitive performance and support a hypothesis whereby supplemental blood oxygen is sequestered by neural mechanisms involved in memory consolidation.

Perceived stress, common health complaints and diurnal patterns of cortisol secretion in young, otherwise healthy individuals

Research has frequently linked perceived stress with changes in subjective and objective measures of ill health; however, additional assessment should consider the physiological mechanisms mediating these effects. This study investigated whether differential patterns of cortisol secretion might partially mediate perceived stress related disparities in common health complaints in young, otherwise healthy individuals. To capture the kinds of health complaints commonly reported in this population, the Pennebaker Inventory of Limbic Languidness (PILL) was selected. To capture important parameters of the diurnal profile, cortisol was sampled at waking, 30 minutes post waking, 1200 h and 2200 h on three consecutive weekdays. Results revealed flatter diurnal cortisol slopes and elevated mean diurnal output (characterised by HPA hyperactivity in the evening) for participants in the higher stress group. Participants that reported higher perceived levels of stress also reported experiencing common health complaints with markedly greater frequency; however, these disparities were abolished when mean diurnal output of cortisol was statistically controlled. While dysregulation of basal HPA activity has been implicated in the aetiologies of chronic illness, findings reported here implicated hypersecretion of cortisol as one physiological pathway, partially mediating perceived stress related disparities in the kinds of common health complaints that typically affect young, otherwise healthy individuals.

Differential effects of the aromas of Salvia species on memory and mood.

This study investigated the potential for the aromas of the essential oils of Salvia species to affect cognition and mood in healthy adults. Research has demonstrated that orally administered Salvia officinalis and Salvia lavandulaefolia are capable of modulating cognition and mood. The active compounds in the herbal products might also be present in the aromas and so produce similar effects. In an independent groups design, three conditions, S. officinalis aroma, S. lavandulaefolia aroma and no aroma were employed. One hundred and thirty‐five healthy volunteers acted as participants, with 45 in each condition. Cognitive performance was assessed via the Cognitive Drug Research (CDR) System. Bond–Lader mood scales measured the participants’ mood on three dimensions before and after the cognitive tasks. Data analysis revealed that the S. officinalis aroma group performed significantly better than the control group on the quality of memory and secondary memory primary outcome factors from the test battery. The Alert mood measure displayed significant differences between both aromas and the control condition. These findings suggest that the aromas of essential oils of Salvia species reproduce some but not all of the effects found following oral herb administration, and that interesting dissociations occur between subjective and objective responses. Copyright