听力障碍与听力正常群体视觉注意发展及其机制的比较

One of the most important functions in the individual development is the interaction and integration of each sensory input. There exist two competing theories, i.e. the deficiency theory and the compensatory theory, regarding the origin and nature of changes in visual functions observed after auditory deprivation. The deficiency theory proposed that integrative processes are essential for normal development. In contrast, the compensatory theory stated that the loss of one sense may be met by a greater reliance upon, therefore an enhancement of the remaining senses. Given that hearing impaired children’s learning depends primarily on visual information, it is important to recognize the differences of visual attention between them and their hearing age-mates. Differences among age groups could exist in either selectivity or sustained attention. Study 1 and study 2 explored the selective and sustained attention development of hearing impaired and hearing students with average cognitive ability, aged from 7 years to college students. The analysis and discussion of the results are based on the visual attention development as well as deficiency theory and compensatory theory. According to the results of the study 1 and study 2, the spatial distribution and controlling of the visual attention between hearing impaired and hearing students were also investigated in the study 3 and study 4. The present work showed that: Firstly, both hearing impaired and hearing participants had the similar developmental trajectory of the sustained attention. The ability of children’s sustained attention appeared to improve with age, and in adolescence it reached the peak. The hearing impaired participants had the comparable sustained attention skills to the matched hearing ones. Besides, the results of the hearing impaired participants showed that they could maintain their attention and vigilance on the current task over the observation period. Secondly, group differences of visual attention development were found between hearing impaired and hearing participants. In the childhood, the visual attention developmental speed of the hearing impaired children was slower than that of the hearing ones. The selective attention skill of the hearing impaired were not comparable to the hearing ones, however, their selective skill improved with age, so in the adulthood, hearing impaired students showed the slight advantage in the selective attention skill over the hearing ones. Thirdly, hearing impaired and hearing participants showed the similar spatial distribution in the attention resources. In the low perceptual load condition, both participants were suffered great interference of the distrator at the fixation. In contrast, in the high perceptual load condition, hearing impaired adults were suffered more interference of the peripheral distractor, which suggested that they distributed more attention resources to the peripheral field when faced difficult tasks. Fourthly, both groups showed similar processing in the visual attention tasks. That is, they both searched the target with only the color feature in a parallel way, but in a serial way while processing orientation feature and the features with the combination of the color and orientation. Furthermore, the results indicated that two groups show similar ways in the attention controlling. In summary, the present study showed that visual attention development was dependent upon the integration of multimodal sensory information. Because of the interaction and integration of the input from various sensory, it has a negative impact on the intact sensory at the early stage of one sensory loss, however, it can better the functions of other intact sensory gradually with development and practice.

聋童与正常儿童中文阅读信息加工过程的比较研究

Based upon the experiments showing three traits of Chinese characters as stimulus, the comparison has been made between the hearing-impaired and normal children in RT functions for the judgment involved in the verbal recording. The results show that the function of semantic code is more strongly correlated with recognition of Chinese character than the phonetic code and graphic code for both the hearing-impaired and normal children. For hearing-impaired children, a direct access that a semantic code is produced directly from the graphic code is observed. However, for normal children the strategly of grapheme-phoneme conversion rules to interpret the meaning of words is used. It's shown that no significant differences of mental processing has been found between the hearing-impaired and normal children. Perhaps both the direct access and the grapheme-phoneme conversion form a comprehensive information procession activating each other. In reading Chinese character, the hearing-impaired and normal children is significantly effected by stroke under and character frequency. It is found that the normal children have more depth processing in reading Chinese sentences than the hearing-impaired children.

mtDNA mutation C1494T, haplogroup A, and hearing loss in Chinese

Mutation C1494T in mitochondrial 12S rRNA gene was recently reported in two large Chinese families with aminoglycoside-induced and nonsyndromic hearing loss (AINHL) and was claimed to be pathogenic. This mutation, however, was first reported in a sample f

The hearing gene Prestin unites echolocating bats and whales

This work was supported by a grant from Key Disciplines of Zoology in Sowthwest Forestry University (XKX200903).

Enriched environment treatment restores impaired hippocampal synaptic plasticity and cognitive deficits induced by prenatal chronic stress

Prenatal stress can cause long-term effects on cognitive functions in offspring. Hippocampal synaptic plasticity, believed to be the mechanism underlying certain types of learning and memory, and known to be sensitive to behavioral stress, can be changed

Chronic Morphine Treatment Impaired Hippocampal Long-Term Potentiation and Spatial Memory via Accumulation of Extracellular Adenosine Acting on Adenosine A(1) Receptors

Chronic exposure to opiates impairs hippocampal long-term potentiation (LTP) and spatial memory, but the underlying mechanisms remain to be elucidated. Given the well known effects of adenosine, an important neuromodulator, on hippocampal neuronal excitability and synaptic plasticity, we investigated the potential effect of changes in adenosine concentrations on chronic morphine treatment-induced impairment of hippocampal CA1 LTP and spatial memory. We found that chronic treatment in mice with either increasing doses (20-100 mg/kg) of morphine for 7 d or equal daily dose (20 mg/kg) of morphine for 12 d led to a significant increase of hippocampal extracellular adenosine concentrations. Importantly, we found that accumulated adenosine contributed to the inhibition of the hippocampal CA1 LTP and impairment of spatial memory retrieval measured in the Morris water maze. Adenosine A(1) receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine significantly reversed chronic morphine-induced impairment of hippocampal CA1 LTP and spatial memory. Likewise, adenosine deaminase, which converts adenosine into the inactive metabolite inosine, restored impaired hippocampal CA1 LTP. We further found that adenosine accumulation was attributable to the alteration of adenosine uptake but not adenosine metabolisms. Bidirectional nucleoside transporters (ENT2) appeared to play a key role in the reduction of adenosine uptake. Changes in PKC-alpha/beta activity were correlated with the attenuation of the ENT2 function in the short-term (2 h) but not in the long-term (7 d) period after the termination of morphine treatment. This study reveals a potential mechanism by which chronic exposure to morphine leads to impairment of both hippocampal LTP and spatial memory.

A reappraisal of complete mtDNA variation in East Asian families with hearing impairment

In a number of recent studies, we summarized the obvious errors and shortcomings that can be spotted in many (if not most) mitochondrial DNA (mtDNA) data sets published in medical genetics. We have reanalyzed here the complete mtDNA genome data published

汉字阅读中的字形、字音、字义及频率效应的研究

Unlike alphabetic languages, Chinese language is ideographical writing system. Each Chinese character is single-syllable and usually has a direct meaning. So Chinese characters are a kind of valuable experimental material used for research on reading and comparisons of the reading mechanism of different language. In this paper, the normal persons and the patients with semantic dementia were respectively scheduled for two parts of experimental studies on the orthographic, phonologic, semantic and frequency effects of reading of Chinese characters. The Stroop-like character-picture interference experimental paradigm was used to investigate the orthographic, phonologic, semantic and frequency effects of Chinese characters on picture naming when they were presented with pictures to normal persons. The results indicated that the orthographic facilitation effect, phonologic facilitation effect, and semantic interference effect occurred at different SOA values. The orthographic and phonologic facilitation effects were independent. It was for the first time shown that the interaction between orthographic variable and semantic variable occurred when the high-frequency Chinese characters were read. Phonologic representation was activated quicker than semantic representation, by comparison of their SOA. Generally, it means that there is reading without meaning in Chinese character among the normal persons. The orthographic, phonologic, semantic, frequency and concrete effects of Chinese characters were further investigated among the dementia patients with DAT(dementia of Alzheimer's type disease) or CVA or both. They all have an impaired semantic memory. The results showed that patients with dementia could read the names of the pictures aloud while they could not name them or match them with a right character correctly. This is reading impairment without meaning in Chinese among the dementia patients. Meanwhile, they had a selective reading impairment and more LARC(a legitimate alternative reading of components) mistakes especially when reading low-frequency irregular, low-frequency inconsistent and abstract Chinese characters. With the patients' semantic impairment developed, their ability to read the pictures names would remain whereas their ability to read low-frequency irregular and low-frequency inconsistency Chinese characters was reduced. These results indicated that low-frequency irregular Chinese characters can be read correctly only when it is supported by their semantic information. Based on the above results of reading without meaning and of reading of low-frequency irregular Chinese characters supported by their semantic information, it is reasonable to suggest that at least two routes are involved in the process of reading Chinese characters. They are direct phonologic route and indirect semantic route; moreover, the two routes are independent.