Patterns of 4-month-old infant responses to hidden silent and sounding people and objects

Responses of 4-month-old infants to hidden people and objects were investigated with equated task demands. Twenty-one 4-month-old infants were administered a combined task, in which they were shown a sounding stimulus that continued to sound after hiding, an auditory task, in which sound was the only source of information about the position of the object in space, and a vision task, in which a silent stimulus was shown to the infants prior to hiding. Five infant behaviours were coded: reaching, gazing, body movements, vocalizations and smiles. The infants reached significantly more for hidden objects than for people, to whom they vocalized instead. They further smiled, and moved their bodies more towards their invisible mother than to the other stimuli. Thus infants responded differentially to people and objects whether the stimuli were soundless (so that there was no cue to their presence) or not. This suggested that infants appreciated (a) that an object had been hidden; (b) this object was either animate or inanimate; and (c) different procedures were appropriate for the retrieval of, or for interacting with animate and inanimate objects. Discussion centres on the underlying representational system that allows for such appreciation.     

Some uniqueness results for PARAFAC2

Whereas the unique axes properties of PARAFAC1 have been examined extensively, little is known about uniqueness properties for the PARAFAC2 model for covariance matrices. This paper is concerned with uniqueness in the rank two case of PARAFAC2. For this case, Harshman and Lundy have recently shown, subject to mild assumptions, that PARAFAC2 is unique when five (covariance) matrices are analyzed. In the present paper, this result is sharpened. PARAFAC2 is shown to be usually unique with four matrices. With three matrices it is not unique unless a certain additional assumption is introduced. If, for instance, the diagonal matrices of weights are constrained to be non-negative, three matrices are enough to have uniqueness in the rank two case of PARAFAC2. The authors are obliged to Richard Harshman for stimulating this research, and to the Associate Editor and reviewers for suggesting major improvements in the presentation.     

REPEATED EXPOSURE TO SUGGESTION AND THE CREATION OF FALSE MEMORIES

Abstract— The purpose of the present study was to extend research on repetition and illusory truth to the domain of eyewitness suggestibility. Specifically, we assessed whether repeated exposure to suggestion, relative to a single exposure, facilitates the creation of false memory for suggested events. After viewing a video of a burglary, subjects were asked questions containing misleading suggestions, some of which were repeated. Their memory for the source of the suggestions was tested. The results show that following repeated (relative to a single) exposure to suggestion, subjects were more likely to (a) claim with high confidence that they remembered the suggested events from the video (Experiment 1) and (b) claim that they consciously recollected witnessing the suggested events (Experiment 2). The effects of repeated exposure were highly reliable and were observed over retention intervals as long as I week.     

Learning capacities during sleep: A preliminary study in a group of schizophrenic inpatients

The relationship between sleep and learning processes is analysed in a sample of schizophrenic patients, starting from more recent hypotheses about the function of REM sleep in learning and memory processes. This is done by means of two experiments: in the first AA. evaluate the possibility to elicit a simple motor conditional reflex acquired during daytime in different sleep stages. With the second experiment daytime learning performances are evaluated with and without a reinforcement administered during REM sleep. Results for the first experiment underline a qualitative difference between REM and nREM sleep in a reflexological perspective. In nREM sleep the conditional response is better maintained than in REM sleep. The second experiment confirms the possibility to improve daytime learning performances after an additional presentation of learning material in REM. The joint study of sleep abnormalities and learning and cognitive impairment in schizophrenic patients is finally suggested.     

Attention switching is not a fatigable process: methodological comments on Axelrod and Guzy (1972)

Guzy and Axelrod investigated auditory attention switching by means of the click-counting paradigm and concluded that attention switching is a fatigable process. In the present comment it is shown that this conclusion is based on a faulty analysis of the data: The scores subjected to the analysis of variance were transformed such that they were no longer linear combinations of the factorial effects. Reanalyzing the data in the correct way renders perfectly linear conting functions that deviate from theoretical fatigue functions. It is concluded that the attention-switching mechanism is not fatigable.     

Personality Factors Related to Black Teenage Pregnancy and Abortion

Forty-eight pregnant adolescents who applied for therapeutic abortions (TAs) were compared with 55 adolescents who planned to have their babies (Terms) and 67 adolescents who were not pregnant (Controls) on the California Psychological Inventory (CPI). All the subjects were single, Black, and aged 15 or 16. CPI results point to psychological differences with the Controls being most socialized, followed by the TAs, and then the Terms. Term girls seem to be experiencing a void and appear to be trying to fill it and assume an adult role by having a baby; the TAs do not seem to have these same needs. In addition, girls who became pregnant and described the relationship with the putative father as casual, appear on the CPI to have more daily problems, lack socialization, be less clear thinking, and have poor self-control. Pregnant girls who have good communication with their mothers showed no differences on the CPI from girls with poor communication with their mothers.     

Some clarifications of the CANDECOMP algorithm applied to INDSCAL

Carroll and Chang have claimed that CANDECOMP applied to symmetric matrices yields equivalent coordinate matrices, as needed for INDSCAL. Although this claim has appeared to be valid for all practical purposes, it has gone without a rigorous mathematical footing. The purpose of the present paper is to clarify CANDECOMP in this respect. It is shown that equivalent coordinate matrices are not granted at global minima when the symmetric matrices are not Gramian, or when these matrices are Gramian but the solution not globally optimal.Part of this research has been supported by The Netherlands Organization for Scientific Research (NWO), PSYCHON-grant (560-267-011).     

Differential effects of identification with family and peers on coping with developmental tasks in adolescence

Adolescents from three Italian cities responded to a questionnaire concerning the particular peer-group with which they were associated and identification with their family, aspects of the process of coping with seven developmental tasks, and demographic characteristics. The participants were 1600 male and female teenagers, with a mean age of 16.28 years, who were approached at schools and various meeting places in three Italian cities. The study shows that effective coping with developmental tasks depends largely on the degree of identification with both family and peer-group. Those who identify with both social groupings show advantages in various critical situations. Adolescents only identifying with either family or peers get emotional and instrumental support from that group but not from the other, thus, they are supported in some critical situations but not in others. Adolescents who are unwilling or unable to identify with their family and/or their peers are less successful in managing the transition to adulthood than others who are close to their parents and peers. Consistent with the findings of previous studies, the type of group adolescents join, be it a formal group or an informal street group, has no significant effect on their coping strategies.     

Repetition,cuing, and state-dependent memory

Two experiments examined the effects of several types of repetition on state-dependent memory for conceptually categorized words. In both experiments, compatibility between pharmacological states at encoding and at retrieval facilitated the uncued recall of nonrepeated categories but had no appreciable effect on the recall of words within recalled categories. In both experiments, compatibility between encoding/retrieval states failed to facilitate the uncued recall of repeated categories li.e., categories whose names and/or exemplars were presented at least twice, in a constant or variable order, and with substantial spacing between successive presentations). And again, in both experiments, the level of uncued recall was higher for repeated than for nonrepeated categories, irrespective of the compatibility or incompatibility of encoding/retrieval states. These findings, together with other relevant observations reported in the literature, suggest that repetition in general, and repetition of category names in particular, influences recall in much the same ways as does explicit cuing with category names: It enhances the accessibility of higher order units, as reflected in uncued category recall, and it diminishes to the extent to which access to these units is state dependent.