Assessing the stability of principal components using regression

This paper presents an analysis, based on simulation, of the stability of principal components. Stability is measured by the expectation of the absolute inner product of the sample principal component with the corresponding population component. A multiple regression model to predict stability is devised, calibrated, and tested using simulated Normal data. Results show that the model can provide useful predictions of individual principal component stability when working with correlation matrices. Further, the predictive validity of the model is tested against data simulated from three non-Normal distributions. The model predicted very well even when the data departed from normality, thus giving robustness to the proposed measure. Used in conjunction with other existing rules this measure will help the user in determining interpretability of principal components.The authors would like to thank the four anonymous reviewers and the two editors for their valuable comments. Atanu R. Sinha gratefully acknowledges the research support received from the Marketing Studies Center, AGSM, UCLA. Send requests for reprints to Atanu R. Sinha, B418 Gold Hall, 110 Westwood Plaza, Los Angeles, CA 90095.     

Infant search tasks reveal early concepts of containment and canonical usage of objects

It is difficult to gain unambiguous evidence on the use of concepts by infants. Many results can be accounted for in terms of action-based strategies. The evidence reported here fulfils the minimal criteria for the operation of working concepts in infants. Search tasks are used with a filled interval which forces memory-search, and the object is hidden in containers which fulfil their customary job or violate it. Infants treat an upright cup as a more reliable location marker than an inverted one. A series of experiments probes the phenomenon. The results indicate that the infants have a working concept of containment which can be triggered by the provision of containers in their canonical orientation. Even “object permanence tasks” lead infants to access their knowledge of the relationships into which things typically enter in the world outside the laboratory.     

Contribution of color to face recognition

One of the key challenges in face perception lies in determining how different facial attributes contribute to judgments of identity. In this study, we focus on the role of color cues. Although color appears to be a salient attribute of faces, past research has suggested that it confers little recognition advantage for identifying people. Here we report experimental results suggesting that color cues do play a role in face recognition and their contribution becomes evident when shape cues are degraded. Under such conditions, recognition performance with color images is significantly better than that with gray-scale images. Our experimental results also indicate that the contribution of color may lie not so much in providing diagnostic cues to identity as in aiding low-level image-analysis processes such as segmentation.     

The role of eyebrows in face recognition

A fundamental challenge in face recognition lies in determining which facial characteristics are important in the identification of faces. Several studies have indicated the significance of certain facial features in this regard, particularly internal ones such as the eyes and mouth. Surprisingly, however, one rather prominent facial feature has received little attention in this domain: the eyebrows. Past work has examined the role of eyebrows in emotional expression and nonverbal communication, as well as in facial aesthetics and sexual dimorphism. However, it has not been made clear whether the eyebrows play an important role in the identification of faces. Here, we report experimental results which suggest that for face recognition the eyebrows may be at least as influential as the eyes. Specifically, we find that the absence of eyebrows in familiar faces leads to a very large and significant disruption in recognition performance. In fact, a significantly greater decrement in face recognition is observed in the absence of eyebrows than in the absence of eyes. These results may have important implications for our understanding of the mechanisms of face recognition in humans as well as for the development of artificial face-recognition systems.     

Prenatal auditory experience and its sequelae

Towards the end of the second trimester of gestation, a human fetus is able to register environmental sounds. This in utero auditory experience is characterized by comprising strongly low-pass-filtered versions of sounds from the external world. Here, we present computational tests of the hypothesis that this early exposure to severely degraded auditory inputs serves an adaptive purpose—it may induce the neural development of extended temporal integration. Such integration can facilitate the detection of information carried by low-frequency variations in the auditory signal, including emotional or other prosodic content. To test this prediction, we characterized the impact of several training regimens, biomimetic and otherwise, on a computational model system trained and tested on the task of emotion recognition. We find that training with an auditory trajectory recapitulating that of a neurotypical infant in the pre-to-postnatal period results in temporally extended receptive field structures and yields the best subsequent accuracy and generalization performance on the task of emotion recognition. This strongly suggests that the progression from low-pass-filtered to full-frequency inputs is likely to be an adaptive feature of our development, conferring significant benefits to later auditory processing abilities relying on temporally extended analyses. Additionally, this finding can help explain some of the auditory impairments associated with preterm births, suggests guidelines for the design of auditory environments in neonatal care units, and points to enhanced training procedures for computational models.     

Defense Mechanisms in Mania,Bipolar Depression and Unipolar Depression

The present study compared the use of defense mechanisms in ten bipolar manic, ten bipolar depressed and ten unipolar depressed patients. The defense mechanisms were assessed by two methods: TAT stories scored by Defense Mechanism Manual and Defense Mechanism Rating Scale ratings of psychodynamic interviews. The severity of symptoms was assessed by Beck Depression Inventory for depressed patients and Young’s Manic Rating Scale for manic patients. Both bipolar manic and depressed groups used the defense mechanism of denial, borderline level defenses and immature defenses significantly more than the unipolar depression group. The manic group showed greater dependence on narcissistic level defenses as compared to the other two groups. Positive relationships were found between severity of manic symptoms and the defense mechanisms of denial as well as the narcissistic level defenses. The bipolar depression group also used more action level defenses as compared to the unipolar depression group. The unipolar depression group scored higher on the defense mechanism of identification and adaptive level defenses as compared to the manic group. A negative correlation was found between the severity of depressive symptoms for unipolar depression group and the defense mechanism of identification. The neurotic level defenses were used most frequently by unipolar depression group, followed by the bipolar depression group and manic group. Some of these findings are in consonance with the psychoanalytic understanding of mania and depression.     

Influence of Personality Traits and Moral Values on Employee Well-Being,Resilience and Performance: A Cross-National Study

Research examining the relationship at the interface of personality, values, moral foundations and its impact on employees’ subjective well-being, resilience, job performance and satisfaction is almost non-existent. This study addresses this Special Issue’s call focusing on the key antecedents and consequences of resilience on individual and/or organisational level outcomes. It does so by analysing data from two different, though comparative cross-national studies in Australia and India. Employing a quantitative survey method, we collected data from 195 respondents in Australia and 257 respondents from India. Employing the core theory of moral foundations in association with its relationships with individual personality, values, well-being and resilience, our findings suggest a significant relationship between personality traits and individual moral foundations, and psychological well-being via values. The study offers distinctive contributions to the literatures on well-being, resilience and moral foundations theory. Specifically, the personality trait of extroversion influences power and achievement or self-enhancement values through individualised moral foundations. Second, the study found that values of benevolence and universalism, or compassionate values, form the basis for biological mechanisms of resilience through individual moral foundations of fairness/harm care. The paper concludes with implications for theory and practice.