Visual search at different spatial scales

Treisman and Gelade's (1980) feature-integration model claims that the search for separate ("primitive") stimulus features is parallel, but that the conjunctions of those features require serial scan. Recently, evidence has accumulated that parallel processing is not limited to these "primitive" stimulus features, but that combinations of features can also produce parallel search. In the experiments reported here, the processing of feature conjunctions was studied when the stimulus features of a combination were at different spatial scales. The patterns in the search array were composed of three cross-shaped or T-shaped (local) elements, which formed an oblique bar (the global pattern) 45 deg or 135 deg in orientation. When the target and distractors differed from each other at one spatial scale only (either in the bar orientation or in the shape of the local elements), target detection was independent of the number of distractors, i.e., the search was parallel. In the conjunction task, in which the target and distractors were defined as the combinations of the bar orientation and the element shape, i.e., both spatial scales were relevant, the detection of the target required slow serial scrutiny of the search array. It is possible that the conjunction search could not be performed in parallel because switches between the two scales (or spatial frequency channels) are linked to attention and the task required the use of both scales in order to find the target.     

Lexical orthographic knowledge develops from the beginning of literacy acquisition

This study reports two experiments assessing the spelling performance of French first graders after 3 months and after 9 months of literacy instruction. The participants were asked to spell high and low frequency irregular words (Experiment 1) and pseudowords, some of which had lexical neighbours (Experiment 2). The lexical database which children had been exposed to was strictly controlled. Both a frequency effect in word spelling accuracy and an analogy effect in pseudoword spelling were obtained after only 3 months of reading instruction. The results suggest that children establish specific orthographic knowledge from the very beginning of literacy acquisition.     

词汇习得年龄和频率对词汇识别的影响

三个实验考察词汇习得年龄和频率在词汇识别中的作用。实验结果表明：词汇习得年龄是影响汉语双字词词汇识别的重要因素,表现为早期习得的词汇比晚期习得的词汇更具有加工的优势。词汇习得年龄和频率独立地影响汉语双字词的识别过程．它们之间的效应是一种相加的关系。本研究还对词汇习得年龄效应的机制进行了讨论。     

The nature of learned categorical perception effects: a psychophysical approach

Categorical perception is often cited as a striking example of cognitive influences on perception. However, some evidence suggests the term is a misnomer, with effects based on cognitive not perceptual processing. Here, using a psychophysical approach, we provide evidence consistent with a learned categorical perception effect that is dependent on analysis within the visual processing stream. An improvement in participants' discrimination between grating patterns that they had learned to place in different categories was 'tuned' around the orientation of the patterns experienced during category learning. Thus, here, categorical perception may result from attentionally modulated perceptual learning about diagnostic category features, based upon orientation-selective stages of analysis. This argues strongly that category learning can alter our perception of the world.     

《黄帝内经》二十五音和经络调理的再思考

通过古琴的启发,对2000多年传抄文字的考量,根据当代物理声学对声音频率的定律,更正了既往研究的错误,最终发现《黄帝内经》二十五音的排列和经络调理之间存在严谨的客观规律,声学部分与当代物理学完全相同,从而为中医听声辨痛提供了一个坚实的科学基础。     

A theory of the visual system biology underlying development of spatial frequency lateralization

The spatial frequency hypothesis contends that performance differences between the hemispheres on various visuospatial tasks are attributable to lateralized processing of the spatial frequency content of visual stimuli. Hellige has proposed that such lateralization could arise during infant development from the earlier maturation of the right hemisphere combined with the increasing sensitivity of the visual system to high spatial frequencies. This proposal is intuitively appealing but lacks an explicit theory with respect to the underlying visual system biology. In this paper, we develop such a theory based on knowledge of visual system processing and development. We then translate our theory into a computational model that serves as the basis for a series of development simulations. We find that the simulations produce spatial frequency lateralization effects consistent with those observed empirically. We relate the nature of the neural asymmetry implied by our theory to empirical findings on visual pathway bias and the relative spatial frequency lateralization effect.     

Frequency versus magnitude of reinforcement: New data with a different procedure

Two pigeons, with previous exposure to concurrent schedules, were submitted to 29 sessions of 8 hours each with concurrent variable-interval variable-interval schedules in which reinforcement parameters changed from session to session. In the first nine sessions reinforcement durations were equal in both schedules while reinforcement frequencies varied; in Sessions 10 through 18, both frequency and duration of reinforcement were varied; in Sessions 19 through 29, only reinforcement duration was varied. Results with this different procedure confirm previous findings that behavior is more sensitive to changes in reinforcement frequency than to reinforcement magnitude.     

Delayed signal detection, differential reinforcement, and short-term memory in the pigeon.

In two discrete-trial delayed-detection experiments, six pigeons were trained on dependent concurrent variable-interval schedules. Pecking a red side key was reinforced when the brighter of two white lights (S1) had been presented on the center key, and pecking a green side key was reinforced when the duller of two white lights (S2) had been presented on the center key. Incorrect responses were red side-key pecks following S2 presentations and green side-key pecks following S1 presentations; these resulted in three-second blackouts. In Experiment 1, the time between presentation of S1 or S2 on the center key and the onset of the red and green side keys was varied nonsystematically from 0.06 seconds to 19.69 seconds across experimental conditions. Stimulus discriminability decreased as the stimulus-choice delay increased. A rectangular-hyperbolic function better described this decrease in discriminability over time than did a negative-exponential function. In Experiment 2, at each of three stimulus-choice delays (0.06, 3.85, and 10.36 seconds), relative reinforcer frequency for correct responses to the red and green side keys was varied by changing the values of the dependent concurrent variable-interval schedules. The sensitivity of choice to relative reinforcer frequency was independent of the decrease in stimulus discriminability with increasing stimulus-choice delay.     

中文阅读预视加工中的词频和预测性效应及其对词切分的启示:基于眼动的证据

研究采用眼动随动显示技术考察中文阅读预视加工中的词汇加工问题。前三项实验发现,剥夺预视加工的掩蔽条件、正确提示词n+1右侧边界的掩蔽条件以及不能提示词n+1右侧边界的掩蔽条件都不影响词频效应,说明中文读者对词n+1处文字的预视加工达不到词汇水平。实验4考察剥夺预视加工的掩蔽条件、提示词n+1右侧边界的掩蔽条件对预测性效应的影响,结果发现,剥夺预视加工完全消除预测性效应,提示词n+1右侧边界则减少预测性效应,说明对词汇的预期加工是中文读者切分词n+1的参考线索。综合4项实验结果可知,中文读者较难通过自下而上的文字识别切分词n+1,自上而下的词汇预期则是切分词n+1的加工形式。     

影响汉语动词、名词识别因素的回归分析

采用回归分析的方法,考察了6个因素对汉语动词、名词识别的影响。结果表明,各变量间有一定的相关,也有相对的独立性。词频、获得年龄和义符熟悉性对词汇识别有显著影响。情境获得性与具体性相关显著,当回归模型中包含情境获得性时,具体性的作用减弱。获得年龄与义符熟悉性在名词回归方程中的解释量大于在动词中的。汉语动词和名词的回归模式既与拼音文字有明显差异,也有一定的共性。这是由汉字的特殊性和语言的共性共同决定的。