Biomedical subjects

Chien-Ming Yang

Publications and source records attributed to Chien-Ming Yang.

7 recordsLinked to original sources

PubMed2006

The effects of sleep stages and time of night on NREM sleep ERPs.

Event-related potential (ERP) is one of the best techniques for studying information processing during sleep because it does not require behavioral responses or consciousness awareness. Several ERP components have been identified during non-rapid eye movement (NREM) sleep, but the associated underlying processes of these waveforms remain unclear. The present study examines the effect of sleep stage and time of night on the NREM ERPs to further understand these processes. An oddball paradigm was conducted in 11 healthy subjects to elicit ERPs throughout the night. Polysomnographic recordings were also applied to identify sleep stages. The results showed that P220, N350, and P900 decreased during the second half of the night, when the NREM sleep drive is partially satiated. This finding is consistent with the notion that the NREM ERPs reflect an inhibitory process associated with sleep drive. P220 and P900 were also found to increase as subjects entering deep sleep. However, the N350 was not affected by the deepening of sleep and peaked earlier during stage 1 sleep. Although these components are all related to the process for sleep preservation, the N350 may be more associated with sleep-wake transition and the P220 and P900 with the process of deepening of sleep.

Acoustic Stimulation↗

PubMed2005

The situational fatigue scale: a different approach to measuring fatigue.

Fatigue can be defined as a subjective state of an imbalance in the availability of inner resources needed to perform physical or mental activities. The level of fatigue is determined not only by the availability of inner resources but also by the demands of the activities performed. Most conventional fatigue scales require subjects to rate their level of fatigue without specifying the situation. In the present study, we constructed a subjective rating scale, the Situational Fatigue Scale (SFS), with which subjects estimated their level of fatigue in specific activities of daily life. We administered the SFS, along with the Fatigue Assessment Instrument (FAI) to 96 outpatients in a family-medicine clinic and to 62 college students to assess the psychometric properties of the SFS. Principle component analysis revealed two underlying factors: physical fatigue and mental fatigue. SFS scores were significantly correlated with several FAI scores and differentiated patients complaining of fatigue from those who did not. The SFS also showed good internal consistency and test-retest reliability. These results suggest that the SFS could be a useful tool to measure a different dimension of the broad concept of fatigue.

Activities of Daily Living↗

PubMed2005

Insomnia.

The pathogenesis of insomnia in an individual usually is multifaceted. Effective treatments require a thorough evaluation to determine the factors that need to be addressed. Pharmacologic treatments generally are safe and effective for short-term use. Long-term hypnotic use remains controversial because of the potential risk of tolerance and dependency. Various cognitive and behavioral treatments for insomnia have been shown to be effective in the management of insomnia. For long-term follow-up, multicomponent cognitive behavioral therapy, alone or in combination with hypnotic use, has been shown to be superior to hypnotic use alone.

Journal Article↗

PubMed2004

A standard procedure enhances the correlation between subjective and objective measures of sleepiness.

OBJECTIVE: The goal of this study was to assess whether instituting a standard procedure to minimize transient activation prior to the subjective rating of sleepiness can improve the predictive value of the rating process. METHODS: Thirty young adults, aged 19 to 26 years, participated in the study. Subsequent to sleeping at home with bedtime restricted to 5 hours, they came to the sleep laboratory. They were instructed to rate their level of sleepiness on the Stanford Sleepiness Scale (SSS) and visual analog scales (VAS). A "calm-down" procedure, sitting quietly with eyes closed for 1 minute, was instituted prior to sleepiness ratings for half of the subjects (experimental group) but not for the other half of the subjects (control group). A nap trial with polysomnographic recording was then conducted, followed by a vigilance test. RESULTS: For the experimental group, VAS results of "sleepiness" and "alertness" both correlated significantly with sleep-onset latency during the nap (SOL: r = -.62 and .64, respectively, P values < .05) and with reaction time (RT) on the vigilance test (r = .56 and -.54, P values < .05). The SSS ratings showed significant correlation with nap SOL (r = -.58, P < .05) but not with RT on the vigilance test (r = .19, p = .52). For the control group, none of the subjective ratings showed significant correlation with objective measures. The differences between the resultant correlations for the 2 groups were statistically significant for 2 sets of correlations: the correlation between VAS of "alertness" and nap SOL and the correlation between VAS of "sleepiness" and RT on the vigilance test. CONCLUSION: The results indicate that the subjective ratings of the sleepiness state for individuals with mild sleep restriction more faithfully reflect a physiologic tendency to fall asleep as well as cognitive attentiveness when the ratings are conducted subsequent to sitting still with eyes closed for a sufficient time to minimize transient activation.

Adult↗

PubMed2004

Evidence for a new conceptualization of semantic representation in the left and right cerebral hemispheres.

Two experiments are reported that examined qualitative differences in how semantic information is represented in the two hemispheres. In the first experiment, items that were associatively related but did not share semantic features or membership in semantic categories produced priming when delivered to the LH (RVF) but not to the RH (LVF). In the second experiment items that shared semantic features but were neither associates nor in the same category produced priming in the RH (LVF), but not in the LH (RVF). Together, the two experiments support the theory that, in the right hemisphere, semantic memories are represented within a distributed system, on the basis of semantic features, whereas, in the left hemisphere representations are, as in local models, relatively more holistic, and are connected via associative links.

Adolescent↗

PubMed2004

Physiological evidence that a masked unrelated intervening item disrupts semantic priming: implications for theories of semantic representation and retrieval models of semantic priming.

Event-related potentials were recorded in a paradigm where an unrelated word was interposed between two related words. In one condition, the intervening item was masked and in another condition it was not. The N400 component indicated that priming of the related word was disrupted by the intervening item whether it was masked or not. The data are interpreted to be inconsistent with retrieval models of priming.

Adolescent↗

PubMed2003

Coping with sleep disturbances among young adults: a survey of first-year college students in Taiwan.

Sleep problems are highly prevalent among young adults and affect different aspects of their quality of life. In this study, the authors aimed to investigate the young adults' coping strategies for these sleep disturbances and the effectiveness of the coping strategies upon sleep quality and daytime sleepiness. The subjects included 1,922 first-year college students, 44% of whom reported experiencing sleep problems, with insufficient sleep being the most common complaint (23.9%). Taking naps and adjusting sleep schedules were the coping strategies associated with better sleep quality. On the other hand, subjects who reported attempting a sleep-promoting activity, ignoring their sleep problems altogether, or trying unsuccessfully to find a way of coping with their sleep problems reported a poorer sleep quality. Although some coping strategies were associated with better sleep quality than others, the levels of daytime sleepiness were equally impaired in all coping groups to a degree that is equivalent to the sleepiness in patients with a moderate sleep-related breathing disorder.

Adaptation, Psychological↗