Referential understanding of videos in chimpanzees (Pan troglodytes), orangutans (Pongo pygmaeus), and children (Homo sapiens)

Performance on identical search tasks based on cues directly perceived or indirectly perceived through video were compared among a group of 4 adult chimpanzees (Pan troglodytes), a group of 2 adult orangutans (Pongo pygmaeus), and a group of 36 children (between 2 and 3 years of age). Children comprehended directly perceived cues but had difficulty with video cues. In contrast, chimpanzees and 1 orangutan were successful in using video to guide their search for a hidden object. Two follow-up studies with 3-year-old children demonstrated the importance of more distinct perceptual and verbal cues in aiding children's understanding of video as referring to real-world events.     

Nonlinearity in the Epidemiology of Complex Health and Disease Processes

Theoretical Medicine and Bioethics - The challenges posed by chronic illness have pointed out to epidemiologists the multifactorial complex nature of disease causality. This notion has been...     

Lexicographic aggregation of semiorders

It is well known that the lexicographic aggregation of complete preorders gives a complete preorder. Unfortunately, this property is no longer true when the lexicographic rule is applied to semiorders. In this paper we study some ways of defining a lexicographic aggregation of semiorders and the properties of the resulting structures.     

Perceived self in infancy

Research is presented suggesting that an implicit sense of self is developing from birth, long before children begin to manifest explicit (conceptual) self-knowledge by the second year. Implicit self-knowledge in infancy is rooted in intermodal perception and action. Studies are reported showing that at least from 2 months of age, infants become increasingly systematic and deliberate in the exploration of their own body and the perceptual consequences of self-produced action. From such exploration, infants develop a sense of their own body as a differentiated entity, situated and agent in the environment. Based on recent empirical findings, the perceptual determinants of such implicit sense of self are discussed.     

Mother and infant affective involvement states and maternal depression

This study shows two different dimensional types of maternal depression, one dull and slow, the other stressed and irritable. When the quality of the infant attachment to mother is assessed, it is noted that the dimensional aspect of the maternal depression can be of some importance in the quality of the attachment. In fact, children are more inclined to develop an insecure–ambivalent attachment to their stressed depressed mothers, while children of slow depressed mothers are more insecure–avoiding. Thus, the dimensions of maternal depression can be an indicator of the type of insecure attachment of the infant at one year of age. We have also found that insecure children of depressed mothers express very little joy in the course of face-to-face interactions. A parallel can be established between the characteristics of the different affective dimensions of the maternal depression, the affective involvement state level of the partners, their synchrony or non-synchrony, the affective expression of the baby, and the type of insecure attachment to the mother. Thus, affective interaction may be an indicator of the child's development, both to assess the interaction and to evaluate the type of attachment shown by the child, indicating that previous interactive patterns have been internalized. © 1997 Michigan Association for Infant Mental Health     

Preference Structures and Co-comparability Graphs

Order structures such as linear orders, weak orders, semiorders and interval orders are often considered as models of a decision maker's preferences. In this paper we introduce and study new order structures characterized by their symmetric part belonging to certain classes of co-comparability graphs. We outline possible interpretations and suggest special representations of these structures and we point out their potential use for approximating relations obtained through a multicriteria aggregation procedure. We provide various characterizations of the new structures (as well as of older ones) in terms of minimal forbidden configurations and by algebraic conditions.     

Repeated checking really does cause memory distrust

Memory phenomena associated with obsessive-compulsive disorder (OCD) have received increased attention in the recent literature. Some debate remains about whether OCD is characterized by deficits in memory per se, or by poor memory confidence. Following from a recent study that demonstrated memory distrust results from repeated checking of a virtual computerized stove, we asked 50 undergraduate students to repeatedly turn on, turn off and check either a real kitchen stove (relevant checking) or a real kitchen faucet (irrelevant checking) in a standardized, ritualized manner. All participants completed a final check of the stove following these 19 checking trials. Results indicated that following repeated relevant checking, participants reported significantly reduced memory confidence, vividness and detail. Repeated irrelevant checking did not produce these decreases. Results are discussed in terms of cognitive-behavioural formulations of OCD and in terms of the effects of repetition on memory and metamemory.     

Excessive Reassurance Seeking, Hassles, and Depressive Symptoms in Children of Affectively Ill Parents: A Multiwave Longitudinal Study

The current study examined whether excessive reassurance seeking serves as a vulnerability factor to depression in a sample of high-risk youth using a multiwave longitudinal design. At Time 1, 140 children (aged 6-14) of affectively disordered parents completed measures assessing reassurance seeking and depressive symptoms. In addition, every 6 weeks during the following year, children and parents completed measures assessing depressive symptoms and the occurrence of hassles. In line with hypotheses, the results of contemporaneous analyses indicated that children with high levels of reassurance seeking reported greater elevations in depressive symptoms following elevations in either hassles or parental depressive symptoms than children with low levels. At the same time, the results of time-lagged analyses indicated that both these relationships were moderated by age with excessive reassurance seeking being associated with greater elevations in depressive symptoms following elevations in either hassles or parental depressive symptoms in older but not younger children.