Problems with EM algorithms for ML factor analysis

Rubin and Thayer recently presented equations to implement maximum likelihood (ML) estimation in factor analysis via the EM algorithm. They present an example to demonstrate the efficacy of the algorithm, and propose that their recovery of multiple local maxima of the ML function “certainly should cast doubt on the general utility of second derivatives of the log likelihood as measures of precision of estimation.” It is shown here, in contrast, that these second derivatives verify that Rubin and Thayer did not find multiple local maxima as claimed. The only known maximum remains the one found by Jöreskog over a decade earlier. The standard errors obtained from the second derivatives and the Fisher information matrix thus remain appropriate where ML assumptions are met. The advantages of the EM algorithm over other algorithms for ML factor analysis remain to be demonstrated.     

Model Existence in Non-Compact Modal Logic

Predicate modal logics based on Kwith non-compact extra axioms are discussed and a sufficient condition for the model existence theorem is presented. We deal with various axioms in a general way by an algebraic method, instead of discussing concrete non-compact axioms one by one.     

Thought control strategies as mediators of trauma symptoms in young women with histories of child sexual abuse

The current retrospective study examined thought control strategies, or cognitive techniques individuals use to deal with unpleasant thoughts following stressful events, as potential mediators of adjustment in young women with histories of child sexual abuse (CSA). In a sample of 76 undergraduate women who self-reported on abuse experiences, thought control strategies, and current trauma symptoms, several key findings emerged: (i) Greater severity of the CSA event was associated with greater reported use of worry and punishment strategies and less use of social control strategies; (ii) Increased use of worry and punishment strategies following the CSA event was associated with greater levels of trauma symptoms, while increased use of social control strategies following the CSA event was associated with lower levels of trauma symptoms; and (iii) Worry, punishment, and social control strategies served as mediators between CSA severity and trauma symptoms. The results suggest that thought control strategies, specifically increased worry and punishment, and decreased social control, play a vital role in understanding adjustment after CSA. Future research should examine the roles of these cognitive control strategies as possible avenues of intervention following CSA.     

Understanding of speaker certainty and false‐belief reasoning: a comparison of Japanese and German preschoolers

It has been repeatedly shown that when asked to identify a protagonist's false belief on the basis of his false statement, English‐speaking 3‐year‐olds dismiss the statement and fail to attribute to him a false belief. In the present studies, we tested 3‐year‐old Japanese children in a similar task, using false statements accompanied by grammaticalized particles of speaker (un)certainty, as in everyday Japanese utterances. The Japanese children were directly compared with same‐aged German children, whose native language does not have grammaticalized epistemic concepts. Japanese children profited from the explicit statement of the protagonist's false belief when it was marked with the attitude of certainty in a way that German children did not – presumably because Japanese but not German children must process such marking routinely in their daily discourse. These results are discussed in the broader context of linguistic and theory of mind development.     

Selfish strategies develop in social problem situations in chimpanzee (Pan troglodytes) mother–infant pairs

Humans employ various strategies, including selfish and altruistic strategies, depending on the situation. In order to examine whether non-human animals show such flexibility or not, we analyzed chimpanzees’ selfish and cooperative behavior in two types of social problem situations. In this study, we tested chimpanzee mother–infant pairs in two adjacent booths, each equipped with a vending machine. When a token was inserted into a vending machine, the vending machine delivered food rewards to the adjacent booth. In experiment 1, a partition between the two booths was open. In experiment 2, the partition was closed and a mother and her infant were placed in separate booths, so that reciprocal cooperation was essential for them to receive rewards. The participants did not cooperate reciprocally in either experiment. In experiment 1, the chimpanzees developed selfish tactics to get rewards and changed their tactics flexibly according to the partner’s behaviors. In experiment 2, in which they could not receive rewards without cooperation, they stopped altogether inserting tokens. In both cases, the infants stopped cooperating first. These findings support the idea that chimpanzees are primarily competitive rather than cooperative. Chimpanzees’ high social intelligence might be demonstrated in the flexibility of their selfish tactics, but not in the form of reciprocal cooperation at least when food is involved. We suggest that the failure to establish reciprocal cooperation was due to the social relationship between the mother and her infant, which was characterized by infant’s privilege and mother’s tolerance.     

The neural plasticity of other-race face recognition

Although it is well established that people are better at recognizing own-race faces than at recognizing other-race faces, the neural mechanisms mediating this advantage are not well understood. In this study, Caucasian participants were trained to differentiate African American (or Hispanic) faces at the individual level (e.g., Joe, Bob) and to categorize Hispanic (or African American) faces at the basic level of race (e.g., Hispanic, African American). Behaviorally, subordinate-level individuation training led to improved performance on a posttraining recognition test, relative to basic-level training. As measured by event-related potentials, subordinate- and basic-level training had relatively little effect on the face N170 component. However, as compared with basic-level training, subordinate-level training elicited an increased response in the posterior expert N250 component. These results demonstrate that learning to discriminate other-race faces at the subordinate level of the individual leads to improved recognition and enhanced activation of the expert N250 component.     

Impaired Interpretation of Others’ Behavior is Associated with Difficulties in Recognizing Pragmatic Language in Patients with Schizophrenia

Much attention has been paid to the pragmatic language function in schizophrenia. This study of Japanese patients with schizophrenia examined the relationship between impaired interpretation of the behaviors of other people in social contexts and the ability to recognize metaphor and irony. We assessed 34 patients with schizophrenia and 34 normal subjects using first- and second-order theory of mind tasks, the Metaphor and Sarcasm Scenario Test, and the Dewey Story Test (which tests the ability to judge others’ social behaviors). We compared the performance between the groups and analyzed correlations between the tasks. All tasks revealed significant deficits in the patients compared with the controls. In the patient group, metaphor comprehension was correlated with the ability to judge normal behaviors, and irony comprehension was correlated with the ability to judge abnormal behaviors, suggesting that deficits of social cognition in schizophrenia include these two types of factors associated with pragmatic language.     

On the relationship between the sense of self and the structure of dreams examined through questionnaire research for Japanese university students

In this paper, the author attempts to show some structural changes in the adolescent mind in modern Japan through examination of our quantitative research of the dreams of university students. Two questionnaires, Scale of Anthropophobia Mentality and Scale of Sense of Self, were administered while asking students about the contents of their ‘impressive dreams’ in childhood as well as their recent dreams. By paying attention to the relationship between the sense of self of dream-ego and the structure of dreams, the author demonstrates the subjects’ difficulty, or inability, to ‘have’ anxiety and thereby become active enough both on the surface of their consciousness and in the depth of their unconscious to effect change in their situation. The author concludes with a suggestion regarding the necessity of a cross-cultural study in this field and adds some points of comparison between German and Japanese dreams reported in psychotherapies.     

External source monitoring in a real‐life event: developmental changes in ability to identify source persons

The present study investigated young children's and adults' external source‐monitoring abilities with respect to facial identification accuracy for complex live events. Five‐ to 6‐ year‐olds and adults watched a magic show in which three different female magicians (i.e. source persons) performed three different kinds of magic tricks each. After approximately 1 month, the participants were asked to recognize what kinds of magic tricks had been performed, to make face identifications as to which magician had performed those magic tricks and to recognize those magicians' attributes. Results showed that both young children and adults had more difficulty with identifying source persons than recognizing them in a real‐life event in which a number of persons appeared. Especially for young children, low credibility was shown not only for the source memories but also for the recognition memories of the source person attributes. Copyright © 2007 John Wiley & Sons, Ltd.