Influences on responsiveness: Interactions between mothers and their premature infants

The responsiveness of mothers to their infants has been found to make an important contribution to children's development. Mothers' cognitive ability, emotional state, and life stresses may influence their responsiveness, as may the medical condition of their infants. The patterns of influence may vary between groups of children with different biological risk conditions and should be examined carefully to determine intervention points for different groups. Forty mothers and their 3-month-old (corrected age) infants with intraventricular hemorrhage (IVH) were observed in free play. Mothers' depressive symptoms, cognitive skills, and the degree of infants' IVH were assessed and expected to be influences on mothers' responsiveness. Results indicated that mothers' depressive symptoms and cognitive skills were associated with their responsiveness, but that depressive symptoms were the stronger predictor. Post hoc analyses suggested that socioeconomic status and depressive symptoms may have related effects on mothers' behavior.     

The optic trajectory is not a lot of use if you want to catch the ball

According to linear optic trajectory (LOT) theory, fielders use the direction of curvature of theoptic trajectory to control the way they run to intercept the ball. Data presented by D. M. Shaffer and M. K. McBeath (2002) as support for LOT theory show that the optic trajectory of balls that will fall behind the fielder provide the cue that LOT theory predicts would send the fielder running forward, not backward. In this article, the authors show that watching these balls would provide the fielder with the cue that the optic acceleration cancellation (OAC) theory of interception predicts would send the fielder running backward. It appears that the fielders studied by Shaffer and McBeath were following the cue predicted by OAC theory, not that predicted by LOT theory.     

Effects of normal aging and Alzheimer's disease on emotional memory

Recall is typically better for emotional than for neutral stimuli. This enhancement is believed to rely on limbic regions. Memory is also better for neutral stimuli embedded in an emotional context. The neural substrate supporting this effect has not been thoroughly investigated but may include frontal lobe, as well as limbic circuits. Alzheimer's disease (AD) results in atrophy of limbic structures, whereas normal aging relatively spares limbic regions but affects prefrontal areas. The authors hypothesized that AD would reduce all enhancement effects, whereas aging would disproportionately affect enhancement based on emotional context. The results confirmed the authors' hypotheses: Young and older adults, but not AD patients, showed better memory for emotional versus neutral pictures and words. Older adults and AD patients showed no benefit from emotional context, whereas young adults remembered more items embedded in an emotional versus neutral context.     

Digital chameleons: automatic assimilation of nonverbal gestures in immersive virtual environments

Previous research demonstrated social influence resulting from mimicry (the chameleon effect); a confederate who mimicked participants was more highly regarded than a confederate who did not, despite the fact that participants did not explicitly notice the mimicry. In the current study, participants interacted with an embodied artificial intelligence agent in immersive virtual reality. The agent either mimicked a participant's head movements at a 4-s delay or utilized prerecorded movements of another participant as it verbally presented an argument. Mimicking agents were more persuasive and received more positive trait ratings than nonmimickers, despite participants' inability to explicitly detect the mimicry. These data are uniquely powerful because they demonstrate the ability to use automatic, indiscriminate mimicking (i.e., a computer algorithm blindly applied to all movements) to gain social influence. Furthermore, this is the first study to demonstrate social influence effects with a nonhuman, nonverbal mimicker.     

Holography does not account for goodness: a critique of van der Helm and Leeuwenberg (1996)

P. A. van der Helm and E. L. J. Leeuwenberg (1996) outlined a holographic account of figural goodness of a perceptual stimulus. The theory is mathematically precise and can be applied to a broad spectrum of empirical data. The authors argue, however, that the account is inadequate on both theoretical and empirical grounds. The theoretical difficulties concern the internal consistency of the account and its reliance on unspecified auxiliary assumptions. The account also makes counterintuitive empirical predictions, which do not fit past data or the results of a series of new experimental studies.     

Switching between tasks of unequal familiarity: the role of stimulus-attribute and response-set selection

It has been reported that it is harder to switch to a strong, well-practiced task from a weaker, less-practiced task than vice versa. Three experiments replicated this surprising asymmetry and investigated how it is affected by a reduction in interference between tasks. Experiment 1 progressively delayed the onset of the stimulus attribute associated with the stronger task. Experiments 2 and 3 separated the response sets of the tasks. Both manipulations reduced, without eliminating, interference of the stronger with the weaker task but reversed the asymmetry of switch costs, resulting in a larger cost of switching to the weaker task. The results are interpreted in terms of a model of the interactions between control input, task strength, and task priming.     

The category test perseveration, loss of set, and memory scales: three new scales and their relationship to executive functioning measures

The Category Test (CT) is a neuropsychological measure that taps into multiple domains of complex reasoning but yields a single error score, limiting the use of the test. In this study, three new CT scales were developed to assess specific aspects of executive dysfunction: Perseveration, Failure to Maintain Cognitive Set, and Inability to Recall and Re-Initiate Past Behavior. The relationship of these scales to well-established neuropsychological measures was examined in head-injured individuals and schizophrenia patients. The CT Perseveration score was correlated with the Wisconsin Card Sorting Test (WCST) Perseverative Responses score, but also with measures from the Wechsler Memory Scale-Revised and the California Verbal Learning Test. The CT Memory score correlated with other memory measures, but also with the WCST Perseveration measure. Although future studies designed to test discriminant and convergent validity are warranted, these scales may be useful in determining specific aspects of impaired CT performance.