A Domain-General Theory of the Development of Perceptual Discrimination

ABSTRACT— In this article, we posit a domain-general principle that may account for the improvement that is observed in several aspects of perceptual development over the first years of life. Development during this time frame is characterized by a process of perceptual narrowing, whereby the discrimination of perceptual information is broadly tuned at first and then declines to more selective levels with experience. This process appears to cut across both the visual and auditory modalities and may reflect the development of a common neural architecture.     

Learning phonetic categories by tracking movements

We explore in this study how infants may derive phonetic categories from adult input that are highly variable. Neural networks in the form of self-organizing maps (SOMs; ) were used to simulate unsupervised learning of Mandarin tones. In Simulation 1, we trained the SOMs with syllable-sized continuous F(0) contours, produced by multiple speakers in connected speech, and with the corresponding velocity profiles (D1). No attempt was made to reduce the large amount of variability in the input or to add to the input any abstract features such as height and slope of the F(0) contours. In the testing phase, reasonably high categorization rate was achieved with F(0) profiles, but D1 profiles yielded almost perfect categorization of the four tones. Close inspection of the learned prototypical D1 profile clusters revealed that they had effectively eliminated surface variability and directly reflected articulatory movements toward the underlying targets of the four tones as proposed by . Additional simulations indicated that a further learning step was possible through which D1 prototypes with one-to-one correspondence to the tones were derived from the prototype clusters learned in Simulation 1. Implications of these findings for theories of language acquisition, speech perception and speech production are discussed.     

测验情境对错误记忆的影响

本研究采用DRM范式,通过两个实验考察测验情境对错误记忆的影响,结果发现：（1）在两个实验中均产生了错误记忆现象：实验一关键诱饵的错误再认率为M=0．514,SD=0233;实验二关键诱饵的总错误再认率M=0．510,SD=0．215：（2）学习词表的语义关联越大,错误再认率越低：实验一项目语义关联程度主效应显著,F（1,84）=6．145．MSE=0．312．P=0．015;实验二,F（1,84）=5．143,MSE=0．225,P=0．026;（3）关键诱饵的位置造成了不同的情境效应：实验一,关键诱饵出现在第一个位置和第二个位置之间错误再认率差异显著（P=0．024）;实验二,关键诱饵出现第二个位置和第三个位置之间的错误再认率边缘显著（P=0．052）。该研究揭示了情境对错误记忆的影响。     

准备间隔对口吃者言语反应速度的影响

为了考察准备间隔对口吃者言语反应速度的影响,作者采用固定准备间隔下的预备反应时范式,设置了6种准备间隔,通过三个系列实验,检测口吃者的最佳言语准备间隔。结果发现,无论时间压力（项目间隔）怎样变化,口吃被试的问题在于,当准备间隔增加到800ms时,他们无法有效保持或提高反应速度;而且,这一现象只在言语命名任务上表现明显。作者认为,口吃者在言语运动准备过程中的异常,很可能是引起口吃现象的重要原因。     

言语产生的同音词表征：模型争论与再思

言语产生和言语理解都涉及同音词在通达过程的表征。言语产生研究中,Levelt和Caramazza分别从通达的两阶段分离激活和独立网络模型推出了同音词的分享和独立表征模型,并用语言实验的频率效应和病人的语音治疗效应给予检验。本文评述了研究的新进展,探讨了同音词表征模型的分歧,认为同音词词汇表征与语言差异、加工范式、知觉通道等有关。从言语理解（言语知觉和词汇再认）的研究表明,这两种表征模型可能难以概括同音词尤其是汉语同音词的表征。本文根据言语理解研究的新近发现建议了一些可能的表征模型。     

Aided speech-identification performance in single-talker competition by older adults with impaired hearing

This study examined the effects of increased processing load on the closed-set speech-identification performance of young and older adults in a one-talker background. Since the older adults had impaired hearing, speech-identification performance was measured for spectrally shaped stimuli comparable to those experienced when wearing well-fit hearing aids. There were three groups of listeners: (1) 19 older adults with high-frequency sensorineural hearing loss; (2) 10 young adults with normal hearing who were assessed with the same spectrally shaped stimuli as the older adults; (3) 9 young adults with normal hearing who were assessed without spectral shaping and at a poorer target-to-competition ratio in an effort to equate overall performance to that of the older adults. In addition to this group factor, there were three within-participant repeated-measures independent variables designed to increase the demands on processing for the target and competing speech stimuli. These were: (1) competition meaningfulness (played in forward or reverse direction); (2) gender match between target and competing talkers (same or different gender); and (3) talker uncertainty (either the same target/competition talker pair or one of many such pairs on each trial). These three repeated-measures independent variables were examined in a 2 × 2 × 2 factorial design. They showed roughly independent and additive effects on speech-identification such that combinations of these variables decreased performance cumulatively. Older adults performed worse than young adults across the board, but also showed diminished relative improvement as the processing load was decreased. Individual differences in performance among the older adults were also examined.     

Functional analysis and intervention of perseverative speech in students with high-functioning autism and related neurodevelopmental disabilities

Although perseverative speech is a common characteristic of individuals with high-functioning neurodevelopmental disabilities, little is known about the operant functions of these verbalizations. We conducted analogue functional analyses of perseverative speech for 2 students using reinforcement contingencies that included alone, attention, control, escape, and tangible conditions. Results showed the following patterns: attention only (Charlotte) or multiply determined including an attention function (Paul). We then tested an intervention for perseverative speech maintained by social positive reinforcement that included differential reinforcement of alternative behavior and extinction of perseverative speech for 1 participant. The intervention reduced perseverative speech, but did not increase appropriate speech until we added a prompting component. We then replicated this three-component intervention with Paul. The results showed moderate to high decreases in levels of perseverative speech and increased appropriate verbalizations in both cases. The results systematically replicated the interventions of previous studies by adding a prompting component to the intervention.     

言语产生的认知神经机制

从认知神经科学的角度阐述了言语产生中时间进程及其激活脑区的研究进展。首先简单介绍了言语产生中词汇通达的2种理论观点。在此基础上介绍了运用电生理技术指标LRP和N200,采用双重判断任务范式对言语产生的时间进程的研究。最后论述了有关语言产生的神经心理学研究和脑成像研究,重点阐述了言语产生中时间进程相对应的激活脑区,言语产生的脑区表现出左侧化趋势。     

The many facets of speech production and its complex effects on phonological processing

In our commentary, we discuss two additional points about developmental speech production. First, we suggest that more precision is needed to accurately describe ‘speech production’ processes, and we suggest that hierarchical constructs from the adult literatures on articulatory phonology and speech motor control may be applicable to infants as well. Second, we discuss the implications from data that indicate that the effects of production are subject to task‐, attentional‐, linguistic‐, and experience‐related demands.