Auditory evoked brain responses: Intensity functions from bipolar human scalp recordings

Average evoked brain responses were computed from four simultaneous recordings during binaural tone stimulation at 10 intensity levels. Amplitudes and latencies were measured for the prominent components, and linear regression coefficients were computed. The results indicate that the sensitivity of the evoked response to stimulus intensity is dependent upon the selection of the appropriate measure. Linear amplitude functions were demonstrated. Additional research relating these responses to psychophysical measures is suggested.     

Sleep physiology and psychological aspects of the fibrositis (fibromyalgia) syndrome

Fibrositis (fibromyalgia) patients were compared with normal controls in terms of electrophysiology (EEG), self-report indicants of awakening, quality of sleep, behaviourally signalled awakenings, and Symptom Check List 90R (SCL-90R) scores. The results differentiated fibrositis patients from normal controls in terms of SCL-90R scores, with fibrositis patients showing significantly more psychopathology. Fibrositis patients had more alpha EEG sleep and less REM and Stage 1 sleep. They were better able to recall their behaviourally signalled awakenings the following morning and reported qualitatively less satisfying sleep than the normal controls. The alpha EEG sleep anomaly may reflect a vigilant arousal state during nocturnal sleep and result in the daytime experience of unrefreshing sleep, psychologic distress, that re-enforces the perpetuation of the sleep-related symptoms.     

Behavioral effects of chronic melatonin and pregnenolone injections in a myelin mutant rat (taiep)

The taiep (tremor, ataxia, immobility, epilepsy, and paralysis) myelin mutant displays a number of locomotor deficits. Taiep rat gait is characterized by shorter stride and step lengths as well as by larger stride widths. Thirty-day-old taiep mutants were placed under a regimen of daily hormone injections for 60 days. Animals in Condition 1 received melatonin, those in Condition 2 received pregnenolone sulfate, and those in a third control condition received injections of saline. Following the injections, each taiep mutant's gait was analyzed. The animals that received melatonin and pregnenolone displayed significantly larger stride and step lengths than did the controls. In addition, the animals that received hormones displayed shorter stride widths than did the controls. These experimental effects are consistent with a normalization of gait. Possible cellular mechanisms of this behavioral effect are discussed.     

Clamped Corticosterone (B) Reveals the Effect of Endogenous B on Both Facilitated Responsivity to Acute Restraint and Metabolic Responses to Chronic Stress

To determine the effects of both corticosterone (B) and chronic stressors on acute ACTH responses to restraint, young male rats were exposed to streptozotocin-induced diabetes, cold (5-7 degreesC) or intracerebroventricular (icv) neuropeptide Y (NPY) for 5 d and then exposed to restraint within 2 h after lights on. Two groups of rats were studied: intact and adrenalectomized replaced with B pellets that maintained plasma B in the normal mean 24-h range of intact rats. In addition to ACTH and B responses to restraint on d 5, body weight, food intake, fat depots, glucose and other hormones were measured to determine the role of stress-induced elevations in B on energy balance. ACTH responses to restraint were normal in intact rats subjected to diabetes or cold. By contrast, there was no ACTH or B response to restraint in NPY-infused intact rats. All 3 groups of chronically stimulated adrenalectomized rats with clamped B had facilitated ACTH responses to restraint compared to their treatment controls. Overall food intake increased in all groups of stressed rats; however, augmented intake occurred only during the light in intact rats and equally in the light and dark in B-clamped rats. White adipose depot weights were decreased by both diabetes and cold and increased by NPY in intact rats; the decreases with cold and increases with NPY were both blunted and changes in fat stores were not significant in adrenalectomized, B-clamped rats. We conclude that: 1. diabetes- and cold-induced facilitation of restraint-induced afferent input to hypothalamic control of the hypothalamo-pituitary-adrenal (HPA) axis is opposed in intact rats by the elevated feedback signal of B secretion; 2. NPY does not induce facilitation of afferent stress pathways; 3. chronic stimulation of the HPA axis induces acute hyperresponsiveness of hypothalamic neurons to restraint provided that the afferent input of this acute stimulus is not prevented by B feedback; 4. stimulus-induced elevations in B secretion result in day-time feeding; 5. insensitivity of both caloric efficiency and white fat stores to chronic stress in adrenalectomized, B-clamped rats results from loss of normally variable B levels.     

Locomotor analysis of the taiep rat

Locomotor activity (tremor, ataxia, immobility, epilepsy, and paralysis) in the taiep rat, which suffers from a myelin deficient disorder, has not been previously documented. This study used walking track analysis of footprints to analyze locomotor activity in the taiep rat in comparison to normal, age-matched controls. The results confirmed differences between normal and taiep rats in terms of stride length, step length, and stride width. In addition, we found significant interactions between age and condition for stride and step length. The results suggest that locomotor analysis is a sensitive indicator of myelin deficiency. The results are discussed in terms of the underlying myelin deficiency and possible treatment regimens.     

Sad and happy emotion discrimination in music by children with cochlear implants

Children using cochlear implants (CIs) develop speech perception but have difficulty perceiving complex acoustic signals. Mode and tempo are the two components used to recognize emotion in music. Based on CI limitations, we hypothesized children using CIs would have impaired perception of mode cues relative to their normal hearing peers and would rely more heavily on tempo cues to distinguish happy from sad music. Study participants were children with 13 right CIs and 3 left CIs (M = 12.7, SD = 2.6 years) and 16 normal hearing peers. Participants judged 96 brief piano excerpts from the classical genre as happy or sad in a forced-choice task. Music was randomly presented with alterations of transposed mode, tempo, or both. When music was presented in original form, children using CIs discriminated between happy and sad music with accuracy well above chance levels (87.5%) but significantly below those with normal hearing (98%). The CI group primarily used tempo cues, whereas normal hearing children relied more on mode cues. Transposing both mode and tempo cues in the same musical excerpt obliterated cues to emotion for both groups. Children using CIs showed significantly slower response times across all conditions. Children using CIs use tempo cues to discriminate happy versus sad music reflecting a very different hearing strategy than their normal hearing peers. Slower reaction times by children using CIs indicate that they found the task more difficult and support the possibility that they require different strategies to process emotion in music than normal.     

阅读预期对快速阅读理解的影响的实验研究

探讨阅读预期对快速阅读的理解水平与进程的影响。实验１探讨阅读预期对快速阅读理解水平的影响。阅读文章前分别给予被试正确、中性与误导的标题提示,结果表明,不同类型的标题提示对快速阅读的理解成绩有显著的影响,而对正常速度阅读的理解成绩影响效果不显著。实验２探讨阅读预期对快速阅读过程的词句加工程度的影响。结果表明,对优生来说,正确标题提示组发现文章中锗字的成绩显著低于误导标题提示组,差生的不同标题提示组发现错字的成绩差异不显著。两个实验的结果初步表明,快速阅读文章过程会更多地利用概念推动,较少地需要材料信息。     

Behavioral Effects of Chronic Melatonin and Pregnenolone Injections in a Myelin Mutant Rat (taiep)

The taiep (tremor, ataxia, immobility, epilepsy, and paralysis) myelin mutant displays a number of locomotor deficits. Taiep rat gait is characterized by shorter stride and step lengths as well as by larger stride widths. Thirty-day-old taiep mutants were placed under a regimen of daily hormone injections for 60 days. Animals in Condition 1 received melatonin, those in Condition 2 received pregnenolone sulfate, and those in a third control condition received injections of saline. Following the injections, each taiep mutant's gait was analyzed. The animals that received melatonin and pregnenolone displayed significantly larger stride and step lengths than did the controls. In addition, the animals that received hormones displayed shorter stride widths than did the controls. These experimental effects are consistent with a normalization of gait. Possible cellular mechanisms of this behavioral effect are discussed.     

Locomotor Analysis of the Taiep Rat

Locomotor activity (tremor, ataxia, immobility, epilepsy, and paralysis) in the taiep rat, which suffers from a myelin deficient disorder, has not been previously documented. This study used walking track analysis of footprints to analyze locomotor activity in the taiep rat in comparison to normal, age-matched controls. The results confirmed differences between normal and taiep rats in terms of stride length, step length, and stride width. In addition, we found significant interactions between age and condition for stride and step length. The results suggest that locomotor analysis is a sensitive indicant of myelin deficiency. The results are discussed in terms of the underlying myelin deficiency and possible treatment regimens.