Maximum likelihood estimation of multivariate polyserial and polychoric correlation coefficients

The method of finding the maximum likelihood estimates of the parameters in a multivariate normal model with some of the component variables observable only in polytomous form is developed. The main stratagem used is a reparameterization which converts the corresponding log likelihood function to an easily handled one. The maximum likelihood estimates are found by a Fletcher-Powell algorithm, and their standard error estimates are obtained from the information matrix. When the dimension of the random vector observable only in polytomous form is large, obtaining the maximum likelihood estimates is computationally rather labor expensive. Therefore, a more efficient method, the partition maximum likelihood method, is proposed. These estimation methods are demonstrated by real and simulated data, and are compared by means of a simulation study.     

Maximum likelihood estimation of polyserial correlations

This paper considers a multivariate normal model with one of the component variables observable only in polytomous form. The maximum likelihood approach is used for estimation of the parameters in the model. The Newton-Raphson algorithm is implemented to obtain the solution of the problem. Examples based on real and simulated data are reported.The research of the first author was supported in part by a research grant (DA01070) from the US Public Health Service. We are indebted to the referees and the editor for some very valuable comments and suggestions.     

Estimating the standard errors of rotated factor loadings by jackknifing

The jackknife by groups and modifications of the jackknife by groups are used to estimate standard errors of rotated factor loadings for selected populations in common factor model maximum likelihood factor analysis. Simulations are performed in whicht-statistics based upon these jackknife estimates of the standard errors are computed. The validity of thet-statistics and their associated confidence intervals is assessed. Methods are given through which the computational efficiency of the jackknife may be greatly enhanced in the factor analysis model.Computing assistance was obtained from the Health Sciences Computing Facility, UCLA, sponsored by NIH Special Research Resources Grant RR-3.The author wishes to thank his doctoral committee co-chairmen, Drs James W. Frane and Robert I. Jennrich, UCLA, for their contributions to this research.     

Using an AI creativity system to explore how aesthetic experiences are processed along the brain’s perceptual neural pathways

With the increased sophistication of AI techniques, the application of these systems has been expanding to ever newer fields. Increasingly, these systems are being used in modeling of human aesthetics and creativity, e.g. how humans create artworks and design products. Our lab has developed one such AI creativity deep learning system that can be used to create artworks in the form of images and videos. In this paper, we describe this system and its use in studying the human visual system and the formation of aesthetic experiences. Specifically, we show how time-based AI created media can be used to explore the nature of the dual-pathway neuro-architecture of the human visual system and how this relates to higher cognitive judgments such as aesthetic experiences that rely on these divergent information streams. We propose a theoretical framework for how the movement within percepts such as video clips, causes the engagement of reflexive attention and a subsequent focus on visual information that are primarily processed via the dorsal stream, thereby modulating aesthetic experiences that rely on information relayed via the ventral stream. We outline our recent study in support of our proposed framework, which serves as the first study that investigates the relationship between the two visual streams and aesthetic experiences.     

Jury simulation studies: To exclude or not to exclude participants based on a lack of comprehension of the case?

Jury simulation research has been the subject of longstanding criticism in regards to ecological validity. One additional factor that has received little attention that may also impact the generalizability of this research relates to excluding participants based on their memory of, or their attention paid to, the case. In order to determine how common this exclusion is, the authors conducted a scoping review of jury simulation studies within the last 10 years across three major legal psychology journals. The review revealed variability in if and how studies excluded on the basis of poor attention or for failing manipulation or general memory checks. In addition, studies that did exclude on this basis varied greatly in the proportion of the sample that was excluded. Recommendations are provided in order to assist jury researchers in future with how best to manage exclusions on the basis of juror memory and attention.     

动作理解因境而异:动作加工中情境信息的自动整合

针对动作理解的机制,模拟论主张大脑自发模拟他人的动作,就相同的动作其理解也相同,而理论论则认为人们基于合理性原则对他人动作进行推理,相同的动作发生在不同的情境时会有不同的理解。但以往研究所采用动作材料的运动学特性和发生情境存在共变,其难以区分动作理解是支持模拟论还是理论论。通过两项实验,采用动画制作技术来产生有无约束情境下的追逐动作,以指示动作加工过程的脑电μ抑制为指标,对前述两种观点进行了检验。其中,在约束情境中存在障碍物,追逐者需改变运动方向以绕过障碍物,从后方逐渐趋近目标;而无约束情境中不存在障碍物,但追逐者依然保持与存在约束情景下相同的运动模式。结果发现,当追逐动作发生在存在约束的情境时,其基于合理性原则推测可获得清晰的动作目标,该条件下的μ抑制程度高于不存在约束情境的条件(实验1);而当仅追逐者运动,即趋近的目标不确定时,虽然有约束和无约束情境间的物理差异与实验1相同,但条件间μ抑制的差异消失(实验2);且上述μ抑制并非与注意相关的枕叶α活动的泛化。该结果提示,动作发生的情境信息影响人们对动作的理解,即基于推理过程理解动作,支持理论论观点。     

Mental Rotation in False Belief Understanding

This study examines the spontaneous use of embodied egocentric transformation (EET) in understanding false beliefs in the minds of others. EET involves the participants mentally transforming or rotating themselves into the orientation of an agent when trying to adopt his or her visuospatial perspective. We argue that psychological perspective taking such as false belief reasoning may also involve EET because of what has been widely reported in the embodied cognition literature, showing that our processing of abstract, propositional information is often grounded in concrete bodily sensations which are not apparently linked to higher cognition. In Experiment 1, an agent placed a ball into one of two boxes and left. The ball then rolled out and moved either into the other box (new box) or back into the original one (old box). The participants were to decide from which box they themselves or the agent would try to recover the ball. Results showed that false belief performance was affected by increased orientation disparity between the participants and the agent, suggesting involvement of embodied transformation. In Experiment 2, false belief was similarly induced and the participants were to decide if the agent would try to recover the ball in one specific box. Orientation disparity was again found to affect false belief performance. The present results extend previous findings on EET in visuospatial perspective taking and suggest that false belief reasoning, which is a kind of psychological perspective taking, can also involve embodied rotation, consistent with the embodied cognition view.