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Biomedical subjects

R D Ogilvie

Publications and source records attributed to R D Ogilvie.

At least 19 recordsLinked to original sources
PubMed2001

The Dream Property Scale: an exploratory English version.

Our goal is to develop an English version of the Dream Property Scale (DPS-E) based on the original normed scale in Japan (DPS-J). Factor analyses extracted four factors (Emotionality, Rationality, Activity, and Impression) and its factor structure was apparently similar to the DPS-J. The DPS-E was also shown to be related to EEG power spectral values. These results indicate that the DPS-E may provide an exploratory basis for a reliable and valid tool for capturing and quantifying the properties of dream experiences that could reflect physiological activities without the intervention of experimenters. We suggest that the DPS-E will develop into a useful tool to help clarify dream production mechanisms by further investigation.

Affect↗
PubMed2000

Recognition of sleep paralysis among normal adults in Canada and in Japan.

There were no differences between Canada and Japan in the prevalence and symptoms of sleep paralysis (SP), but many more Canadians considered SP to be a dream. The difference was considered to be derived from the fact that there is a common expression for SP in Japan but there is not one in Canada. Then, we investigated why there are individuals who consider SP to be a dream and others who do not, and found that many Japanese who regarded it as a dream did not report the symptom of 'unable to move', while in Canada, self-evaluation of spirituality was different between the two groups.

Adult↗
PubMed1999

EEG spectral analysis of the sleep-onset period in narcoleptics and normal sleepers.

The sleep-onset period of 10 drug-free patients with narcolepsy-cataplexy and 10 normals matched for age and gender was investigated using the multiple sleep latency test to elicit episodes of intentional sleep onset. Spectral analyses were calculated for delta, theta, alpha, sigma, and beta frequencies using 5-second epochs beginning at lights-out and continuing until the first 2 minutes of stage 2 or REM sleep were reached, or until 20 minutes had elapsed. The sleep-onset period was divided into quartiles, and mean root mean square (RMS) amplitude within each quartile was calculated. Mean delta amplitude was significantly higher across the sleep-onset period of narcoleptic REM naps and narcoleptic stage 2 naps compared to the sleep-onset period of normal stage 2 naps or normal stage 1 naps. Mean theta amplitude was significantly higher for narcoleptic REM naps compared to normal stage 1 naps, and tended to be higher for narcoleptic stage 2 naps compared to normal stage 1 naps. Mean alpha amplitude was significantly lower for narcoleptic REM naps and narcoleptic stage 2 naps compared to normal naps containing just stage 1. Mean sigma amplitude was significantly lower for narcoleptic REM naps compared to normal stage 1 naps, and tended to be lower for narcoleptic REM naps compared to normal stage 2 naps. Mean beta amplitude did not differ between the narcoleptic and normal sleep-onset process. These findings support the existence of electrophysiologic differences within the microstructure of the process of sleep entry in narcoleptics and normals.

Adult↗
PubMed1997

FFT analysis of EEG during stage 2-to-REM transitions in narcoleptic patients and normal sleepers.

The EEG in REM sleep is markedly different from the EEG in non-REM sleep; however, very little research has been conducted analyzing the transition from NREM to REM sleep. The purpose of this study was to describe the changes in EEG power spectra that coincide with significant physiological events throughout the transition from stage 2 to REM sleep. Furthermore, a comparison of the stage 2 to REM transition between narcoleptic patients and normal sleepers was conducted. Five female and five male patients diagnosed with narcolepsy-cataplexy and 10 normal sleepers matched for age and gender participated. Analyses were based on the consecutive appearance of 3 common physiological indicators of REM sleep: First, a decrease in tonic submental EMG activity; second, the appearance of saw tooth waves; and third, the appearance of rapid eye movements. Systematic changes in EEG power density were evident for delta, theta, alpha and sigma frequencies, across the stage 2-REM transition. These changes appeared to be relatively continuous throughout this transition rather than changing dramatically following the onset of any one of the 3 primary physiological indicators of REM sleep. Furthermore, the transition from stage 2 to stage REM appeared to be similar for narcoleptic patients and normal sleepers.

Adult↗
PubMed1997

The alpha attenuation test: assessing excessive daytime sleepiness in narcolepsy-cataplexy.

Daytime sleep tendency was assessed in 10 drug-free patients with narcolepsy-cataplexy and 10 normals matched for age and gender. Following nocturnal polysomnography, the alpha attenuation test (AAT) and the multiple sleep latency test (MSLT) were administered during five sessions occurring at 2-hour intervals beginning at 0900 and 1000 hours, respectively. For the AAT, participants were polysomnographically recorded for 8 minutes while seated in an illuminated room with their eyes alternately opened and closed. Power spectral analyses of electroencephalograph (EEG) activity at 02-A1 (10 second epochs) were calculated using fast Fourier transformations (FFT) within the alpha frequency range (8-12 Hz) to obtain ratios of mean eyes-closed to mean eyes-open alpha power (i.e. the alpha attenuation coefficient, AAC). The narcoleptics were sleepier than the normals as indicated by a significantly smaller mean AAC and a significantly shorter mean latency to stage 1 on the MSLT. These findings suggest that the AAT may provide a quick and practical objective assessment of the excessive daytime sleepiness (EDS) associated with narcolepsy.

Adult↗
PubMed1997

Electrophysiological changes during the sleep onset period of psychophysiological insomniacs, psychiatric insomniacs, and normal sleepers.

The electroencephalograms (EEGs) of the sleep onset period (SOP) of psychophysiogical insomniacs. psychiatric insomniacs, and controls were compared using power spectral analysis. We predicted that psychophysiological insomniacs would show elevated cortical arousal throughout their entry into sleep. Electroencephalograms, electrooculograms (EOGs), and electromyograms (EMGs) were recorded for two consecutive nights. Power spectral analysis of EEG from the sleep onset period was performed on all standard frequency bands. Psychophysiological insomniacs had less alpha during the first part of the SOP and did not show the dramatic drop in alpha across the SOP that characterizes normal sleep. They showed less delta in the last quartile of the chronological analysis of the SOP. Psychiatric insomniacs showed lower relative beta power values overall, while psychophysiological insomniacs showed higher relative beta power values during wakefulness. This microanalysis indicates that the SOP is generally similar for psychiatric insomniacs and normal sleepers but that clear differences in the SOP of psychophysiological insomniacs exist. They have higher cortical arousal during the SOP than do psychiatric insomniacs and controls. The dramatic changes in power values in the latter two groups as sleep begins are not seen in the psychophysiological insomniacs, which may help explain the difficulty that psychophysiological insomniacs have discriminating between wakefulness and sleep.

Adult↗
PubMed1995

Waking effectiveness of visual alerting signals.

People who are unable to hear acoustic alarm signals because they have a complete or partial hearing loss must rely on visual or tactile signals to warn them in the event of an emergency. However, consumers report that personal smoke detector devices which provide a visual alarm do not wake people reliably. We examined the ability of visual alerting devices to wake people from the deepest stages of sleep: slow wave sleep (SWS) and rapid-eye-movement sleep (REM). These results were related to the physical (optical) characteristics of devices currently on the market. In Experiment 1, a range of strobe intensities and locations were investigated. Experiment 2 confirmed the results of this pilot study on an independent set of subjects. On each trial, the strobe was allowed to run at a constant intensity until the subject awoke, or a maximum of 5 min had elapsed. Even though a diffuse light remained directly over the subject's face for each trial, subjects did not wake consistently. Under the favorable optical (smoke-free) conditions of the present study, the most intense of the devices presently offered for sale in Canada cannot be relied on to wake a sleeping person in the event of a fire. It remains unclear whether any visual alerting device can be expected to safely wake a sleeper in an emergency situation.

Adult↗
PubMed1991

Behavioural response home monitoring of good and insomniac sleepers.

Can the fundamental differences in sleep structure known to differentiate good from insomniac sleepers (e.g., sleep length, sleep onset latency [SOL], number of sleep disruptions, etc.) be identified using a behavioural sleep/wake (S/W) monitor in the home? Sixteen women (8 good and 8 insomniac sleepers) enrolled in an introductory psychology course participated in a study of S/W patterns. They used a portable version of the Ogilvie and Wilkinson (1988) behavioural response (BR) system in their homes for 4 consecutive nights. Insomniacs had greater SOLs, less efficient sleep, and tended to have a greater number of arousals as compared with good sleepers. The data indicate that the behavioural system could be used as a diagnostic tool for in-home evaluations of disorders of initiating and maintaining sleep.

Adult↗
PubMed1991

Behavioral, event-related potential, and EEG/FFT changes at sleep onset.

Behavioral, event-related potential (ERP), and EEG measures were obtained to describe more fully the relationship between brain activity and arousal level during the process of falling asleep. In addition to standard polysomnographic measures, tones were presented at random intervals throughout two nights to each of nine subjects. Subjects were instructed to respond to the tones whenever they heard them. Initial sleep onset was disrupted five times following zero through four successive response failures. Sampling of EEG was initiated 5 s prior to tone onset (EEG analyses) and continued for 5 s following tone onset (ERP data). With EEG ordered as a function of response rate, significant increases in power were found across all standard frequency bands for the pretone data at sleep onset. Significant changes in amplitude were related to decreasing responsivity for all late ERP components except P2. Inasmuch as virtually all EEG frequencies and ERP components were strongly influenced by momentary changes in arousal, arousal must be considered a (possibly the) primary determinant of the characteristics of the overall electrical output of the brain. Response cessation coupled with sharp increases in EEG synchronization mark the point of sleep onset.

Adolescent↗
PubMed1989

The detection of sleep onset: behavioral, physiological, and subjective convergence.

In this report, a sleep deprivation/multiple arousal paradigm was used in which response time (RT) and respiratory and electroencephalographic (EEG) measures were combined with a continuous behavioral index of arousal (a deadman switch) and frequently repeated Stanford Sleepiness Scale ratings to examine the process of falling asleep. Sleep was defined behaviorally as failure to respond to the faint auditory RT cue. Although response rates decreased significantly as EEG stages passed from W through 1 to 2, responding continued in both light "sleep" stages. Respiratory, subjective, and DM changes were more pronounced between Stages W and 1 than between Stages 1 and 2. If the criterion for wakefulness is cognitive response to external stimulation, accurate distinctions between sleep and wakefulness can only be made in EEG Stages 3, 4, and rapid eye movement sleep. If EEG is the criterion, then the data suggest that cognitive response is possible during Stages 1 and 2 "sleep". The concept of a Sleep Onset Period, characterized by lengthening response times and intermittent response failure (thereby reflecting neither true sleep nor wakefulness), may provide a useful resolution to this definitional dilemma.

Adult↗
PubMed1989

A home evaluation of a behavioral response measure of sleep/wakefulness.

15 women and 3 men enrolled in a first-year undergraduate psychology course participated in a study concerned with evaluating the home use of a behavioral response monitor of sleep/wakefulness. The subjects, representing a range of fairly poor to good sleepers, used the device for three consecutive nights in their own homes. The 1967 Monroe Questionnaire was used to differentiate "good" sleepers from "poorer" sleepers. The behavioral response system indicated that subjects could adequately report how long they slept but consistently underestimated their number of arousals and could not reliably specify sleep-onset latency. The behavioral response measure was an effective and economical means of obtaining in-home objective sleep data and holds potential for clinical evaluation of disorders of initiating and maintaining sleep.

Adolescent↗
PubMed1988

Behavioral versus EEG-based monitoring of all-night sleep/wake patterns.

Faint tones were presented at intervals (average 16 s) throughout a night's sleep; whenever they heard them, subjects pressed a palm-mounted button to switch them off. At the same time, electroencephalogram (EEG) was recorded. Button-press responses occurred in all EEG stages of sleep except Stage 4, although there was only one behavioral response (BR) in Stage 3 and one in REM. The mean probability of response (PR)/Stage was Stage 1 = 0.235, Stage 2 = 0.016, Stage 3 = 0.001, Stage 4 = 0.000, Stage REM = 0.0004. Also, responses sometimes failed to occur in EEG Stage wake (PR = 0.94), particularly near sleep onset. If the criterion for wakefulness is cognitive response to external stimulation, only in EEG Stages 3, 4, and REM can accurate distinctions between sleep and wakefulness be made. If EEG is the criterion, then the data suggest that cognitive response is possible during Stages 1 and 2 "sleep." The concept of a sleep onset period (SOP), characterized by lengthening response times and intermittent response failure (thereby reflecting neither true sleep or wakefulness), may provide a useful resolution of this definitional dilemma.

Acoustic Stimulation↗
PubMed1982

Psychological correlates of spontaneous middle ear muscle activity during sleep.

Nine subjects each spent four nights in the sleep lab during which middle ear muscle activity (MEMA) was recorded in addition to standard sleep monitoring. After an adaptation night, subjects were awakened four times on each experimental night: twice from rapid eye movement sleep and twice from stage 2: once from each stage in the presence or absence of MEMA. Detailed mentation reports were obtained, coded, and rated on scales of auditory involvement, emotional activity, bizarreness, hallucinosis, and clouding. Sleep stage was a better predictor of the mental activity of the sleeper than was the presence or absence of phasic activity on the above measures. Auditory ratings were no higher following MEMA than following non-MEMA arousals, but MEMA was associated with bizarre, discontinuous sleep mentation. Theoretical implications were discussed.

Acoustic Impedance Tests↗
PubMed1982

Lucid dreaming and alpha activity: a preliminary report.

10 good dream recallers spent 2 nights in the sleep lab during which they were awakened 4 times per night from REM sleep, twice during their highest alpha activity in REM, and twice during low REM alpha. 5 were given alpha feedback training prior to sleep onset. Arousals from high alpha REM sleep yielded significantly higher lucidity ratings. Alpha feedback had no effect upon lucidity or REM alpha levels. Similarities between lucid dreams and meditative phenomena are discussed.

Adult↗