A note on multiple and canonical correlation for a singular covariance matrix

A weaker generalized inverse (Rao's g-inverse; Graybill's c-inverse) can be used in place of the Moore-Penrose generalized inverse to obtain multiple and canonical correlations from singular covariance matrices.The author expresses his gratitude to a referee for his suggestions.     

Retrieving the correlation matrix from a truncated PCA solution: The inverse principal component problem

Whenr Principal Components are available fork variables, the correlation matrix is approximated in the least squares sense by the loading matrix times its transpose. The approximation is generally not perfect unlessr =k. In the present paper it is shown that, whenr is at or above the Ledermann bound,r principal components are enough to perfectly reconstruct the correlation matrix, albeit in a way more involved than taking the loading matrix times its transpose. In certain cases just below the Ledermann bound, recovery of the correlation matrix is still possible when the set of all eigenvalues of the correlation matrix is available as additional information.     

Adaptation to Reversal of Retinal Feedback of Eyemovements

Both optical and hybrid-computer methods were devised to reverse the visual feedback which the eye gets of its own movements. Optical reversal by a contact lens device caused persisting, unstable, skittered, blurred vision, to which the subject made no effective adaptation. Using a hybrid analog-digital-analog computer, eyemovement-retinal feedback was reversed by yoking oscilloscope targets to the transduced electrical signals of ocular movements and reversing the sign of input-output control of the computer system. Vision with such computer-reversed feedback from ocular movements duplicated the experiences with the contact-lens method. Practice over five sessions of 50 trials indicated that three Ss showed no significant improvement in eye-tracking accuracy with the reversed vision. Perception of direction in vision and the basic signal processes of vision were thus found to be dependent on built-in direction specificity of eyemovement-retinal feedback interactions which also govern dynamic specialization and control of pursuit, saccadic, and fixation movements.     

Notes and Comments the Role of Action Feedback in the Acquisition of Simple Motor Responses

The use of visual action feedback (AIF) in learning a simple motor response can sometimes be as effective as the more conventional terminal feedback (TIF) but sometimes leads to gross overshooting errors when AIF is removed. Both the amplitude of movement and the gain of the AIF have strong and systematic effects on the error in attempted reproductions. Percent overestimation increases linearly with fog. gain and decreases linearly with log. amplitude. This may be due to an intersensory effect in which visual and kinesthetic feedback sum to form a unitary impression of the movement on which subsequent attempts at reproduction are based.     

群体印象形成与个体印象形成：反基准比率效应

采用 “反基准比率效应”范式考察在群体印象形成与个体印象形成两种认知加工过程中, 基准比率对印象形成过程及其结果的影响。被试分别为39名19~25岁大学生(实验1：男生17名, 女生22名, 均为右利手)以及46名19~25岁大学生(实验2：男生21名, 女生25名, 均为右利手)。结果发现：无论是群体印象形成还是个体印象形成, 在学习阶段, 知觉者都能准确认知各类事件间的关系, 但会优先建构高频事件间的联结。而在测试阶段, 当低频事件与高频事件同时出现时, 知觉者发生明显关系误判, 即以反基准比率的倾向高估低频事件间的联结强度。实验表明群体与个体印象形成过程中都会产生反基准比率效应这样的加工偏差, 进而初步揭示反基准比率现象在社会信息加工领域具有一定的普遍性。     

概率判断中的合取谬误

概率判断中的合取谬误是指违反事件发生概率的合取规则而认为包含多个独立事件的复合事件的发生可能性大于其中某些事件的发生可能性的一种概率判断偏差现象。合取谬误的界定存在一定争议, 相关的解释机制有因果模型理论、确认理论、惊奇理论等, 影响合取谬误的因素有频率效应、训练效应以及个体差异等等。未来研究应联系逆转合取谬误的心理机制来完善已有的理论, 同时注意应用研究以及其非理性的探讨。     

A generalized method of image analysis from an intercorrelation matrix which may be singular

Following the works of Guttman (1953) and Kaiser (1976), we show that the image and anti-image covariance matrices can be derived from a singular correlation matrix, by making use of the orthogonal projector and a weaker generalized inverse matrix.     

Estimating the effect of gang membership on nonviolent and violent delinquency: a counterfactual analysis

This study reconsiders the well‐known link between gang membership and criminal involvement. Recently developed analytical techniques enabled the approximation of an experimental design to determine whether gang members, after being matched with similarly situated nongang members, exhibited greater involvement in nonviolent and violent delinquency. Findings indicated that while gang membership is a function of self‐selection, selection effects alone do not account for the greater involvement in delinquency exhibited by gang members. After propensity score matching was employed, gang members maintained a greater involvement in both nonviolent and violent delinquency when measured cross‐sectionally, but only violent delinquency when measured longitudinally. Additional analyses using inverse probability of treatment weights reaffirmed these conclusions. Aggr. Behav. 36:437–451, 2010. © 2010 Wiley‐Liss, Inc.