Erica Harris

REM and NREM sleep mentation.

We review the literature on the neurobiology of rapid eye movement (REM) and non-rapid eye movement (NREM) sleep states and associated dreams. REM is associated with enhanced activation of limbic and amygdalar networks and decreased activation in dorsal prefrontal regions while stage II NREM is associated with greater cortical activation than REM. Not surprisingly, these disparate brain activation patterns tend to be associated with dramatically different dream phenomenologies and dream content. We present two recent studies which content-analyzed hundreds of dream reports from REM and NREM sleep states. These studies demonstrated that dreamer-initiated aggressive social interactions were more characteristic of REM than NREM, and dreamer-initiated friendliness was more characteristic of NREM than REM reports. Both REM and NREM dreams therefore may function to simulate opposing types of social interactions, with the REM state specializing in simulation of aggressive interactions and the NREM state specializing in simulation of friendly interactions. We close our review with a summary of evidence that dream content variables significantly predict daytime mood and social interactions.

The phylogeny of sleep database : a new resource for sleep scientists.

We have constructed a database that describes the sleeping characteristics of 127 different mammalian species representing 46 families across 17 orders. The data were extracted from 178 separate references that were found using standardized search protocols, and for each study includes information on the time spent in REM and NREM sleep, sleep cycle length, the number of animals sampled, their sex and age, and reference citation. Importantly, we also coded nine laboratory condition scores as a way to control for the procedures that were used to collect the data. We created a website that contains the database (http://www.bu.edu/phylogeny/) from which others can both download the data and submit new results. This database is being used to address fundamental questions concerning the evolution of mammalian sleep; similar databases on other groups of organisms will enable sleep biologists to understand patterns of sleep at broader phylogenetic scales.

Life goals of patients with Parkinson’s disease: a pilot study on correlations with mood and cognitive functions

Objective: To identify the life goals of people with Parkinson’s disease, to assess whether patients felt that these goals were ‘on track’, and to assess the relation of these life goals to neuropsychologic and mood function. Design: Cross-sectional descriptive study with an age-matched control group. Setting: Outpatient Movement Disorders Clinics Veterans Hospital. Subjects: Twenty-two patients with mid-stage Parkinson’s disease and 22 age-matched controls. Measures: Rivermead Life Goals Inventory, neuropsychological and mood scales. Results: People with Parkinson’s disease were less likely than age-matched controls to cite religion, social contacts, leisure activities and personal care as ‘extremely important life goals’. People with Parkinson’s disease assigned significantly lower ‘importance’ ratings to leisure activities and religion than did controls. In addition, people with Parkinson’s disease assigned significantly lower ‘on track’ ratings for leisure activities, work, social contacts, religion and financial affairs compared with controls’ rating on the same items. Although people with Parkinson’s disease showed significantly greater levels of cognitive and mood dysfunction than did controls, their mean importance ratings on life goals correlated only with mood function scores. Conclusions: The leisure activities, work, social contacts, religion and financial affairs of people with Parkinson’s disease are less ‘on track’ than are their personal and family relationships. Subjective importance ratings of particular life goals of people with Parkinson’s disease were found to be significantly related to mood function and not to cognitive function. Goal derailment ratings on the other hand were significantly related to both mood and cognitive impairment.

Hallucinations, Dreaming, and Frequent Dozing in Parkinson Disease: Impact of Right-hemisphere Neural Networks

ObjectiveTo relate sleep disturbances in Parkinson disease (PD) to hemispheric asymmetry of initial presentation. BackgroundSleep disturbances are common in PD arising from the neurodegenerative process underlying the disease, which is usually lateralized at onset. Patients with left-side Parkinson disease onset (LPD: right hemisphere dysfunction) exhibit reduced vigilance relative to those with right-side Parkinson disease onset (RPD: left hemisphere dysfunction), leading us to hypothesize that sleep-related disturbances, particularly excessive daytime sleepiness, would be more severe for LPD than for RPD. MethodsThirty-one nondemented participants with PD (17 RPD and 14 LPD) and 17 age-matched control (CO) participants with chronic health conditions were administered the Parkinson Disease Sleep Scale and polysomnography was performed on a subset of the PD participants. ResultsBoth PD subgroups exhibited more nighttime motor symptoms than the CO group, but only LPD endorsed more nocturnal hallucinations and daytime dozing. Controlling for mood additionally revealed more vivid dreaming in LPD than RPD. There were no significant differences between LPD and RPD on measures of sleep architecture. ConclusionsIncreased dreaming, hallucinations, and daytime somnolescence in LPD may be related to changes in right-hemisphere neural networks implicated in the generation and control of visual images, arousal, and vigilance. Our results underscore the need to consider side of onset in regard to sleep disturbances in PD.

“Machiavellianism” and frontal dysfunction: Evidence from Parkinson's disease

Introduction. A number of reports have identified significant personality differences in patients with Parkinsons disease (PD) when compared with age-matched controls. We hypothesised that these differences may be related to impairment in prefrontal inhibitory functions resulting in the expression of new “Machiavellian” personality traits. Methods. Thirty-five patients with PD and 17 age-matched controls were assessed with a set of neuropsychologic, personality and mood tests as well as the Mach IV scale, which measures a set of “Machiavellian” personality characteristics. Results. PD patients with elevated Machiavellian traits (“high Machs”) were selectively impaired on tests of prefrontal function relative to “low Mach” patients. In addition, while high Machs did not differ from low Machs in terms of age, educational level, Hoehn-Yahr stage, mood function, or Mini Mental State Exam score, they indicated greater willingness to affiliate with a fictional Machiavellian character and scored significantly lower on the “cooperativeness” and “self-directedness” subscales of the Cloninger Temperament and Character Inventory. Conclusions. We suggest that (1) PD patients with frontal impairment are vulnerable to dramatic personality change, and (2) the frontal lobes are required for maintenance of prosocial personality traits.

Mood, side of motor symptom onset and pain complaints in Parkinson's disease

Patients with Parkinsons disease (PD) present with a variety of non‐motor symptoms including sensory complaints and mood disturbances. In the current pilot study, we aimed to explore pain complaints and the association between mood and pain in PD. We hypothesized that pain ratings would be elevated in patients with PD relative to controls. As PD is lateralized at onset and studies have found lateralization of some non‐motor symptoms in PD, we also hypothesized that PD patients would exhibit differing pain profiles depending on side of onset of the disease.

Impact of REM sleep on distortions of self-concept, mood and memory in depressed/anxious participants

INTRODUCTION We tested the hypothesis that REM sleep contributes to core features of cognitive dysfunction of anxious depression including negative self-appraisals, biased memory processing and unpleasant dream content. METHODS After a habituation night in a sleep lab, a convenience sample of 35 healthy college students and 20 depressed/anxious students were awakened 10 min into a REM sleep episode and then 10 min into a NREM sleep episode. Awakenings were counterbalanced to control circadian effects. After each awakening participants reported a dream and then completed memory recall, mood and self-appraisal tasks. RESULTS Self-appraisals of depressed/anxious participants were significantly less positive and significantly more negative after awakenings from REM sleep vs NREM sleep. Appraisal of the REM sleep dream self was negative for depressed/anxious subjects only. Recall of negative memories was significantly more frequent after REM vs NREM sleep awakenings for both depress/anxious and healthy participants. REM sleep dreams were associated with greater frequencies of negative emotion, greater aggression and victimization rates than dreams in NREM sleep for depressed/anxious participants. LIMITATIONS Depressed/anxious participants were classified as such on the basis of mood scales rather than clinical interview. All participants were drawn from a volunteer college student population and thus our results may not be applicable to some elderly clinical populations. CONCLUSIONS REM appears to facilitate cognitive distortions of anxious depression.

Sleep architecture and sleep-related mentation in securely and insecurely attached people

Based on REM sleeps brain activation patterns and its participation in consolidation of emotional memories, we tested the hypothesis that measures of REM sleep architecture and REM sleep-related mentation would be associated with attachment orientation. After a habituation night in a sleep lab, a convenience sample of 64 healthy volunteers were awakened 10 minutes into a REM sleep episode and 10 minutes into a control NREM sleep episode in counterbalanced order, then asked to report a dream and to rate themselves and a significant other on a list of trait adjectives. Relative to participants classified as having secure attachment orientations, participants classified as anxious took less time to enter REM sleep and had a higher frequency of REM dreams with aggression and self-denigrating themes. There were no significant differences across attachment groups in other measures of sleep architecture or in post REM-sleep awakening ratings on PANAS subscales reflecting mood and alertness. Selected aspects of REM sleep architecture and mentation appeared to be associated with attachment orientation. We suggest that REM sleep plays a role in processing experiences and emotions related to attachment, and that certain features of sleep and dreaming reflect attachment orientations.

Apathy in patients with Parkinson disease as a function of side of onset.

Background: In previous studies among patients with Parkinson disease (PD) who were administered the Apathy Evaluation Scale (AES), between 12% and 51% evidenced clinically significant apathy. Although apathy is a risk factor for dementia, its causes and clinical correlates have not been adequately studied. In particular, side of onset of disease, though a likely predictor of apathy and dementia, has not been thoroughly investigated. Methods: A total of 30 mid-stage patients with PD and 35 community-dwelling elderly control patients (CPs) were administered the AES (self version) along with a battery of cognitive and neuropsychiatric assessments. Persons close to patients with PD and CPs completed the AES—other (informant) version about the patient or CP. Multiple linear regression analysis examined predictors of apathy severity after controlling for mood, levodopa dosage equivalents (LDEs), gender, age, and disease severity (Hoehn–Yahr [H-Y] stage). Results: Patients with right-onset disease more frequently exhibited apathy and evidenced significantly higher total AES scores than left-onset patients with PD or CPs (P < .03). Of all the patients, 42% with right-onset PD versus 11.1% of the patients with left-onset PD exhibited clinically significant levels of apathy. There were no differences for self versus informant scores for right-onset patients with PD. The AES scores were not correlated with depression, stress, anxiety, LDEs, gender, age, and H-Y stage. There were no gender differences for any AES variables. Conclusion: Clinically significant levels of apathy are much more likely to occur in patients with right-onset disease. These patients may be at greater risk of PD-related dementia.

Novelty seeking in patients with right- versus left-onset Parkinson disease.

Objective and Background: In patients with Parkinson disease, the personality trait “novelty seeking” has been linked to higher-than-normal risk for impulse control disorders. We measured novelty seeking to test whether side of onset of Parkinson disease predicted patients’ risk for impulsivity. Methods: We evaluated 38 patients with Parkinson disease (19 right onset, 19 left onset) and 44 community-dwelling neurotypical controls. All participants completed demographic and mood measures and the Temperament and Character Inventory personality questionnaire. The right- and left-onset groups were nearly the same in background and clinical variables, including use of dopamine agonists. Results: The patients with right-onset disease exhibited significantly higher levels of novelty seeking than the patients with left-onset disease. Conclusions: Our results suggest that patients with right-onset Parkinson disease who are taking dopamine agonists and who exhibit high novelty seeking are at greater risk for developing impulse control disorders than are patients with left onset who are also taking dopamine agonists.