两种呈现速度下整字及声旁命名

问题与方法：探讨在快、慢速两种速度呈现条件下,声旁的组字频率和使用频率在整字和部件识别中的作用。结果表明,命名整字时在两种呈现条件下声旁的两类频率都表现在易化作用;命名声旁则依赖于加工时间：快速呈现刺激时声旁组字频率有抑制作用,慢速呈现刺激时声旁使用频率有易化作用。声旁命名任务中,速示条件下其组字频率作用突出,非束示条件下其使用频率更突出。呈现速度在声旁命名时与声旁两类频率有交互作用,但在数字命名时没有。     

高、低频汉字形音义激活的时间进程

采用基于字形的启动范畴判断任务,通过变化SOA和不同的启动类型,考察高、低频汉字形音义激活的相对时间进程。结果表明,高频汉字形音义激活的时间顺序为字形—字义—字音;低频汉字字形的激活在先,字音、字义的激活时间未能分开。这说明汉字的书面使用频率是影响汉字形、音、义激活时间进程的重要因素。本研究进一步支持了汉字形—音、形—义连接强度受汉字使用频率影响的观点。     

汉字加工的基本单元:来自笔画数效应和部件数效应的证据

用命名作业和真假字判断作业考察了笔画数和部件数对汉字加工的影响,发现,当部件数保持恒定时,笔画数少的汉字较笔画数多的汉字加工快,这种笔画数效应和字频之间不存在交互作用;当笔画数被控制时,部件数效应也存在,但和字频有交互作用,表现在低频少部件汉字的加工要快于低频多部件汉字的加工,而高频汉字中的部件数效应不显著。实验还发现独体字（只有一个部件）的加工和合体字（部件数大于等于二）的加工有差异。作者认为,汉字的加工要经过笔画、部件和整字三个层次,其中单位部件的笔画数和部件数影响着汉字加工时间     

结构对称性汉字视觉识别特点的实验研究

用命名作业通过二个实验考察了结构对称性汉字的视觉识别特点,结果表明,汉字识别具有显著的结构对称性效应,识别结构对称性汉字的加工明显快于非对称性汉字,对称性效应与字频效应,笔画效应具有显著的交互作用,进一步的简单效应的分析表明,这种结构对称性效应在低频字中起作用,而在高频字中不起显著作用;在多笔画字中起作用,而在少毛画字中不起显著作用,这表明,对称性汉字中的具有冗余信息的格式塔部件促进地识别汉字的加     

汉字识别中形音义激活时间进程的研究（Ⅱ）

两个实验分别采用基于语义的和基于语音的启动范畴判断作业,在不同的SOA条件下,考察低频汉字形、音、义信息激活的相对时间进程。实验结果表明,低频汉字字形的激活在先,字音和字义的激活同时进行。低频汉字形、音、义激活的这种顺序不受基于语义还是基于语音的实验任务的影响,但实验任务影响了低频汉字字音、字义激活出现时间的早晚。     

Reliability and validity of mothers' developmental estimates for children between 4 and 41 months

The feasibility of mothers estimating their own children's development is explored in this paper. Construction, reliability and validity of a mothers' developmental inventory for children from 4 months to 41 months is described. The inventory consists of six subtests: Gross Motor, Fine Motor, Language Expression, Language Comprehension, Personal-Social Competence and Self Help. A preliminary version of the inventory was item analyzed on a sample of 105 mothers of 4 to 37 months old children. This reduced the inventory to 164 items with satisfactory reliability and age discrimination on half-year intervals. The list was cross-validated on a sample of 275 mothers, for which medians of alpha coefficients for the six subtests ranged from 0.69 to 0.96, with most (26 out of 36) coefficients being 0.77 or higher. Again, the age discrimination was satisfactory, although floor effects appeared on four subtests for children younger than 12 months and ceiling effects on two subtests for children older than 24 months.     

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.     

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.     

Discriminability of frequency of food or stimulus presentations in variable-time schedules

Pigeons responded in a two-alternative forced-choice task in which reinforcement was dependent upon the frequency of events that occurred in an immediately preceding schedule sample. On a given trial the events were either brief food presentations or brief visual and auditory stimulus changes. High levels of stimulus control were obtained by food-presentation schedules only. Discriminative control by frequency or stimulus change was absent. Stimulus control by food frequency was decreased by the imposition of a delay period between the schedule sample and the choice. Moreover, stimulus control by food frequency was related to the ratio of food-presentation schedule pairs when novel schedules were presented in a transfer test.     

Rank-reducibility of a symmetric matrix and sampling theory of minimum trace factor analysis

One of the intriguing questions of factor analysis is the extent to which one can reduce the rank of a symmetric matrix by only changing its diagonal entries. We show in this paper that the set of matrices, which can be reduced to rankr, has positive (Lebesgue) measure if and only ifr is greater or equal to the Ledermann bound. In other words the Ledermann bound is shown to bealmost surely the greatest lower bound to a reduced rank of the sample covariance matrix. Afterwards an asymptotic sampling theory of so-called minimum trace factor analysis (MTFA) is proposed. The theory is based on continuous and differential properties of functions involved in the MTFA. Convex analysis techniques are utilized to obtain conditions for differentiability of these functions.