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发展性阅读障碍的ERP研究 总被引:10,自引:0,他引:10
发展性阅读障碍,ERP,语音缺陷假说,Oddball范式。行为实验已经发现,语音能力的缺损是拼音文字发展性阅读障碍的核心。然而近年来行为研究和神经生理学的研究也发现,发展性阅读障碍与基本知觉障碍有关。事件相关电位(event-related potentials ,简称ERP)作为一种独特的电生理学研究手段,从一个更为直观的角度验证了行为实验的结果,推动了发展性阅读障碍的进展。语言认知水平ERP研究表明,发展性阅读障碍者在存在语音加工和信息整合的缺陷。感知觉加工层次的ERP研究结果则不尽一致,有的研究发现,阅读障碍存在着基本的听觉加工缺陷;有的研究则发现发展性阅读障碍存在言语声音加工的缺陷,而对非言语声音的加工与正常读者没有显著差别;有的研究支持大细胞通路受损假说,发现阅读障碍在低对比度和低空间频率上存在视觉加工的缺陷,有的研究结果则没有发现发展性阅读障碍者与正常读者在不同对比度和空间频率上的差异。 相似文献
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阅读是一个视听加工过程,阅读障碍的产生可能是过程中视听时间敏感性缺陷的结果。视听时间敏感性指个体对视觉和听觉刺激出现时间的感知能力,可通过同时性判断、时间顺序判断和视听整合考察。研究发现,阅读障碍者在这一能力上表现出行为和脑层面异常。而这些研究多是拼音文字背景,汉语文字下该领域研究相当少。未来需要丰富实验设计,扩大对汉语背景下视听时间敏感性研究,并以此开发干预手段,为阅读障碍的机制和治疗提供借鉴。 相似文献
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听觉、时间加工能力与发展性阅读障碍 总被引:1,自引:0,他引:1
近年来阅读障碍者的知觉加工越来越受到重视 ,本文介绍了近期国外关于阅读障碍者的听觉加工能力、时间加工能力的最新研究进展。快速听觉加工能力的缺失在阅读障碍者身上普遍存在 ,并被认为是阅读障碍产生的主要原因 ;有研究者提出“时间控制障碍”假说 ,认为阅读障碍源自一种普遍性的时间知觉障碍 ,不具有通道特异性。除此之外 ,还发现阅读障碍者对声音频率、响度等非时间特征也出现了觉察困难。通过这些研究我们可以看到 ,听觉加工能力、快速时间加工能力与阅读能力之间可能有着密切的关系 ,但这几种能力如何具体作用于阅读发展 ,它们之间如何相互作用、相互影响仍需进一步探讨。 相似文献
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发展性阅读障碍的本质一直是研究者争论的焦点。大量研究发现, 阅读障碍者具有视听时间整合缺陷。然而, 这些研究仅考察了阅读障碍者视听时间整合加工的整体表现, 也就是平均水平的表现, 却对整合加工的变化过程缺乏探讨。视听时间再校准反映了视听时间整合的动态加工过程, 对内部时间表征与感觉输入之间差异的再校准困难则会导致多感觉整合受损, 而阅读障碍者的再校准相关能力存在缺陷。因此, 视听时间再校准能力受损可能是发展性阅读障碍视听时间整合缺陷的根本原因。未来的研究需要进一步考察发展性阅读障碍者视听时间再校准能力的具体表现, 以及这些表现背后的认知神经机制。 相似文献
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发展性阅读障碍与知觉加工 总被引:13,自引:0,他引:13
近年来许多行为实验和神经生理学实验都发现 ,发展性阅读障碍与基本知觉障碍有关。在视觉领域研究者提出了巨细胞障碍假设 ,这种假设认为阅读障碍者视觉神经系统中的巨细胞障碍导致他们对某种类型的视觉刺激加工存在困难 ,进而影响阅读。在听觉领域研究发现阅读障碍者加工快速、系列、短暂呈现的声音刺激存在障碍。研究者认为阅读障碍者加工快速刺激输入障碍反映了普遍的时间知觉障碍。这方面的研究发展非常迅速 ,理论观点非常明确 ,并且直接与内在的神经机制相联系 ,形成了与传统的“语言障碍”理论迥然不同的“知觉障碍”理论。“知觉障碍”理论综合了行为、认知和神经等多个层次的研究 ,反映了神经科学发展所带来的巨大影响和认知加工模块化理论的渐渐衰退。 相似文献
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通过分别以高频汉字(实验1)和图形非言语材料(实验2)为刺激的两个联合视觉注意任务, 并采用基于Budensen视觉注意理论的参数估计方法, 系统地探查小学三~六年级汉语发展性阅读障碍儿童的视觉同时性加工技能缺陷的内在机制。以43名汉语发展性阅读障碍儿童和46名生理年龄匹配典型发展儿童为被试, 每类被试均被分为小学中年级组(三、四年级)和高年级组(五、六年级)。两个实验均发现不同年级组的阅读障碍儿童在知觉加工速度参数上显著小于控制组儿童。在空间注意分布权重参数上, 实验1的结果显示, 不同于控制组儿童向左侧化发展的注意分布模式, 两个年级组的阅读障碍儿童均表现为无偏的注意分布; 而实验2未发现显著组别差异。且这两种同时性加工子技能分别与不同水平的汉语阅读技能密切相关。结果表明, 汉语阅读障碍儿童在同时加工多个视觉刺激时存在持续的知觉加工速度缓慢的问题, 在同时加工言语类刺激时还表现出异常的空间注意分布模式。本研究有助于从基础认知层面揭示汉语发展性阅读障碍儿童的缺陷机理, 为进一步设计相关的提高阅读效率的干预方案提供理论依据。 相似文献
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本研究对汉语阅读障碍的加工缺陷进行探讨,期望有助于揭示语言加工的普遍性与特殊性,以及阅读障碍的成因,并可为后期的干预提供帮助。研究采用改编的言语认知测验对阅读水平匹配组与阅读障碍组和生理年龄匹配组进行比较后发现,阅读障碍组在语音意识和正字法加工任务上的成绩均明显差于生理年龄控制组和阅读水平匹配组;阅读障碍组在快速命名和语音记忆任务上的成绩不如生理年龄匹配组,仅达到阅读水平匹配组水平。因此,汉语发展性阅读障碍儿童存在语音意识和正字法加工缺陷,这两种缺陷可能是阅读障碍儿童面临的最主要的两大缺陷;阅读障碍儿童在快速命名和语音记忆上的不足可能是发展迟滞所致。同时,大多数的汉语阅读障碍儿童存在不止一种的认知缺陷。阅读障碍儿童在语音意识和正字法加工上存在缺陷的比例最高。 相似文献
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This fMRI study investigated phonological vs. auditory temporal processing in developmental dyslexia by means of a German vowel length discrimination paradigm (Groth, Lachmann, Riecker, Muthmann, & Steinbrink, 2011). Behavioral and fMRI data were collected from dyslexics and controls while performing same-different judgments of vowel duration in two experimental conditions. In the temporal, but not in the phonological condition, hemodynamic brain activation was observed bilaterally within the anterior insular cortices in both groups and within the left inferior frontal gyrus (IFG) in controls, indicating that the left IFG and the anterior insular cortices are part of a neural network involved in temporal auditory processing. Group subtraction analyses did not demonstrate significant effects. However, in a subgroup analysis, participants performing low in the temporal condition (all dyslexic) showed decreased activation of the insular cortices and the left IFG, suggesting that this processing network might form the neural basis of temporal auditory processing deficits in dyslexia. 相似文献
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Keith Rayner Alexander Pollatsek Alexander B. Bilsky 《Psychonomic bulletin & review》1995,2(4):501-507
In this comment, we argue that although Farmer and Klein (1995) have provided a valuable review relating deficits in nonreading tasks and dyslexia, their basic claim that a “temporal processing deficit” is one possible cause of dyslexia is somewhat vague. We argue that “temporal processing deficit” is never clearly defined. Furthermore, we question some of their assumptions concerning an auditory temporal processing deficit related to dyslexia, and we present arguments and data that seem inconsistent with their claims regarding how a visual temporal processing deficit would manifest itself in dyslexic readers. While we agree that some dyslexics have visual problems, we conclude that problems with reading caused by the visual mechanisms that Farmer and Klein postulate are quite rare. 相似文献
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发展性阅读障碍是一种特殊的学习障碍,伴有多种认知缺陷并且存在不同的亚类型。依据相关的阅读模型理论,阅读障碍可划分为语音型和表层型。从认知缺陷角度出发,语音加工缺陷是主要的缺陷表现,以此为特征形成一种主要的阅读障碍的亚类型,同时还有以正字法加工缺陷和快速命名缺陷为主的其他亚类型。而以基本感知觉缺陷为标准,主要有以视觉加工缺陷和以听觉加工缺陷为主的两种亚类型。在汉语条件下,依据同样的阅读模型理论,语音型阅读障碍亚类型比例明显低于拼音文字条件下的。汉语阅读障碍也具有分别以语音加工缺陷、快速命名缺陷和正字法加工缺陷为主要认知缺陷的亚类型。未来有必要从神经机制角度进一步明确不同亚类型的神经基础。 相似文献
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This study investigated whether "asynchrony" in speed of processing (SOP) between the visual-orthographic and auditory-phonological modalities contributes to word recognition deficits among adult dyslexics. Male university students with a history of diagnosed dyslexia were compared to age-matched normal readers on a variety of experimental measures while event-related potentials and reaction time data were collected. Measures were designed to evaluate auditory and visual processing for non-linguistic (tones and shapes) and linguistic (phonemes and graphemes) low-level stimuli as well as higher-level orthographic and phonological processing (in a lexical decision task). Data indicated that adult dyslexic readers had significantly slower reaction times and longer P300 latencies than control readers in most of the experimental tasks and delayed P200 latencies for the lexical decision task. Moreover, adult dyslexics revealed a systematic SOP gap in P300 latency between the auditory/phonological and visual/orthographic processing measures. Our data support and extend previous work that found SOP asynchrony to be an underlying factor of childhood dyslexia. The present data suggests, however, that among adult dyslexics the between modalities asynchrony occurs at later processing stages than in children. 相似文献
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Cestnick L 《Brain and cognition》2001,46(3):319-325
Neuroanatomical evidence suggests that poor readers may have abnormal lateral (LGN) and medial (MGN) geniculate nuclei responsible for temporal processing in visual and auditory domains respectively (Livingstone & Galaburda, 1993). Although behavioral evidence does support this neuroanatomical evidence in that poor readers have performed poorly on visual and auditory tasks thought to require the utilization of the LGN and MGN, respectively, appropriate examination of the coexistence of these behavioral abnormalities in the same population of poor readers has yet to take place. The present study examined correlations between visual and auditory temporal processing scores of all readers (collapsed groups), good readers, and poor readers who were isolated into phonological and surface dyslexic subtypes. The same subjects and data from Cestnick and Coltheart (1999) and Cestnick and Jerger (2000) were used to run the analyses. Results demonstrated a multitude of correlations between these tasks for the phonological dyslexic group only. It is contended that cross-modality temporal processing deficits may exist in poor nonlexical (phonological dyslexics) as opposed to poor lexical (surface dyslexics) readers. It is conceivable that phonological dyslexics may also have deficiencies within the LGN and MGN, or perhaps within systems related to these nuclei. The precise cause of these processing patterns and correlations is still unknown. 相似文献
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研究采用知觉学习经典范式中的视觉搜索任务探讨汉语发展性阅读障碍儿童的知觉学习过程。研究考察了阅读障碍儿童与正常儿童在简单搜索任务、复杂搜索任务和限制时间的复杂搜索任务上的知觉学习特点。结果发现,阅读障碍儿童在复杂搜索任务中初始搜索时间显著长于正常控制组;在限制时间的复杂搜索任务中更进一步发现阅读障碍儿童的反应正确率显著低于正常控制组儿童;而且两组儿童视觉搜索任务的正确率与汉语阅读的识字量成绩存在显著相关。上述结果表明,汉语发展性阅读障碍儿童存在复杂搜索的知觉学习缺陷,这种缺陷可能在某种程度上与儿童的阅读技能发展有关。 相似文献
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The evidence of supporting phonological deficit as a cause of developmental dyslexia has been accumulating rapidly over the past 2 decades, yet the exact mechanisms underlying this deficit remain controversial. Some authors assume that a temporal processing deficit is the source of the phonological disorder observed in dyslexic children. Others maintain that the phonological deficit in dyslexia is basically linguistic, not acoustic, in nature. Three experiments were conducted and tested the impact of the temporal alteration and the impact of complex syllabic structure on consonant order judgments. Thirteen phonological dyslexics (age 10-13) and 10 controls matched for chronologial age were compared on a Temporal Order Judgment (TOJ) task using the succession of two consonants (/p/ /s/) within a cluster. In order to test the possible relevance of the temporal deficit hypothesis, the task also included two additional conditions where either the two stimuli were artificially slowed or two phonological structures were opposed (CCV and CVCV). As expected, the TOJ performance was significantly poorer in dyslexics than in controls. Moreover, in the "slowed speech" condition dyslexics' performance improved to reach the normal controls' level, whereas manipulating the phonological structure complexity provided no significant improvement. Finally dyslexics' performances, especially on the slowed condition, were found correlated with several tests of phonological processing. These results lend support to the general temporal deficit theory of dyslexia. 相似文献