Explicit candecomp/parafac solutions for a contrived 2 × 2 × 2 array of rank three

Kruskal, Harshman and Lundy have contrived a special 2 × 2 × 2 array to examine formal properties of degenerate Candecomp/Parafac solutions. It is shown that for this array the Candecomp/Parafac loss has an infimum of 1. In addition, the array will be used to challenge the tradition of fitting Indscal and related models by means of the Candecomp/Parafac process.     

Medicine and the Cartesian image of man

The contemporary philosophy of medicine may be characterized as a continuous struggle with the Cartesian heritage, in order to reach a more satisfying image of man. This paper outlines the influence of Cartesian dualism on the foundations of medicine. The notion of a real distinction between the mental and physical, particularly the mechanistic conception of the human body, made possible the development of the natural sciences as well as scientific medicine, not hampered any longer by the risk of colliding with religion or Church. The Cartesian machine model of man immediately appealed to seventeenth century physicians: Dutch Cartesians (Regius, Craanen) and followers of the iatrophysical school (Santorio, Borelli). Dichotomizing between mind and body, subject and object, self and world, self and other, knower and knowledge is constitutive for modern medicine conceiving itself as a natural science.     

An alternating least squares algorithm for fitting the two- and three-way dedicom model and the idioscal model

The DEDICOM model is a model for representing asymmetric relations among a set of objects by means of a set of coordinates for the objects on a limited number of dimensions. The present paper offers an alternating least squares algorithm for fitting the DEDICOM model. The model can be generalized to represent any number of sets of relations among the same set of objects. An algorithm for fitting this three-way DEDICOM model is provided as well. Based on the algorithm for the three-way DEDICOM model an algorithm is developed for fitting the IDIOSCAL model in the least squares sense.The author is obliged to Jos ten Berge and Richard Harshman.     

Convergence properties of an iterative procedure of ipsatizing and standardizing a data matrix,with applications to parafac/candecomp preprocessing

Centering a matrix row-wise and rescaling it column-wise to a unit sum of squares requires an iterative procedure. It is shown that this procedure converges to a stable solution. This solution need not be centered row-wise if the limiting point of the interations is a matrix of rank one. The results of the present paper bear directly on several types of preprocessing methods in Parafac/Candecomp.     

Fitting the off-diagonal dedicom model in the least-squares sense by a generalization of the harman and jones minres procedure of factor analysis

Harshman's DEDICOM model providesa framework for analyzing square but asymmetric materices of directional relationships amongn objects or persons in terms of a small number of components. One version of DEDICOM ignores the diagonal entries of the matrices. A straight-forward computational solution for this model is offered in the present paper. The solution can be interpreted as a generalized Minres procedure suitable for handing asymmetric matrices.     

Reciprocity: Choice shift in a social trap

In the present study it was investigated if choice behaviour in a social trap situation was affected by feedback about the choice of others. On top of the social trap reward structure investigated by Schroeder, Jensen, Reed, Sullivan and Schwab (1983) a bonus was added. In the individual bonus condition subjects were promised an unspecified bonus if they would obtain more points than any other group member of one's group. In the group bonus condition subjects would obtain a bonus if the own group acquired more points than the other group. As expected, in the group bonus condition one took fewer points than in the individual bonus condition. As suggested by the reciprocity explanation of choice behaviour (Liebrand, Wilke, Vogel and Wolters 1986; Liebrand, Jansen and Rijken 1986) it appeared that first choice corresponded strongly with one's expectations about the choices of others. Before the second choice and also before the third choice one received purported feedback about the choices of other members of one's group. In the conserving condition one learned that all others made a conserving choice, whereas in the consuming condition one learned that all others made a consuming choice. According to the reciprocity explanation it was found that when choice behaviour was in agreement with own previous expectations and previous choice, no choice change did occur. Shifts took place in conditions in which own previous expectations about the choices of others and own choice were disconfirmed by information about choices of others.     

Individual risk taking for self and others

In this experimental study, individual risk taking for self and others was observed for three experimental situations (the choice dilemma situations of Kogan and Wallach, 1964, the Pruitt and Teger gambling situation, 1969, and a simple one-trial gamble game). The results of the present study suggest that one takes as much risk for oneself as for somebody else. An attempt was made to determine to what degree the results could be explained by properties of the experimental situations.     

The Impact of Home Ownership on Life Satisfaction in Urban China: A Propensity Score Matching Analysis

China has implemented a series of socioeconomic reforms since 1978. One of the reforms allows urban residents to purchase their own houses rather than renting houses from state institutions which has resulted in a rapid increase in home ownership. This paper estimates the impact of home ownership on life satisfaction in urban China on the basis of the 2010 wave of the China General Social Survey. Special attention is paid to the methodological problem of confoundedness between the determinants of home ownership and life satisfaction. Propensity score matching (PSM) is applied to control it. The results show that PSM reduces upward estimation bias caused by confoundedness and that it is more appropriate to control confoundedness than ordered probit regression. The estimates furthermore indicate that home ownership has a significant positive impact on life satisfaction of medium- and high income urban residents. For low income urban residents, the impact is also positive, though insignificant. The outcomes connect to the objectives of national development policy and thus have several important policy implications. First, the central and local governments, especially in provinces where it is still low, may want to continue stimulating home ownership as it enhances life satisfaction. Secondly, specific programs may be designed to make home ownership financially affordable for low income groups. Thirdly, local governments may want to initiate or intensify urban (renewal) programs to improve poor public facilities including public transportation, green space and sports accommodations in the immediate vicinity of depressing low income neighborhoods.     

Tuning down the hedonic brain: Cognitive load reduces neural responses to high-calorie food pictures in the nucleus accumbens

The present research examined whether cognitive load modulates the neural processing of appetitive, high-calorie food stimuli. In a functional magnetic resonance imaging (fMRI) study, participants quickly categorized high-calorie and low-calorie food pictures versus object pictures as edible or inedible while they concurrently performed a digit-span task that varied between low and high cognitive load (memorizing six digits vs. one digit). In line with predictions, the digit-span task engaged the dorsolateral prefrontal cortex (DLPFC) when cognitive load was high compared to low. Moreover, exposure to high-calorie compared to low-calorie food pictures led to increased activation in the nucleus accumbens (NAcc), but only when cognitive load was low and not when it was high. In addition, connectivity analyses showed that load altered the functional coupling between NAcc and right DLPFC during presentation of the high-calorie versus low-calorie food pictures. Together, these findings indicate that loading the cognitive system moderates hedonic brain responses to high-calorie food pictures via interactions between NAcc and DLPFC. Our findings are consistent with the putative cognitive nature of food motivation. Implications for future research are discussed.