Space and time,not surface features,guide object persistence

Successful visual perception relies on the ability to keep track of distinct entities as the same persisting objects from one moment to the next. This is a computationally difficult process and its underlying nature remains unclear. Here we use the object file framework to explore whether surface feature information (e.g., color, shape) can be used to compute such object persistence. From six experiments we find that spatiotemporal information (location as a function of time) easily determines object files, but surface features do not. The results suggest an unexpectedly strong constraint on the visual system’s ability to compute online object persistence.     

Modeling the Ecological Validity of Neurocognitive Assessment in Adults with Acquired Brain Injury

Neuropsychologists are increasingly asked to make judgments regarding treatment options and rehabilitation strategies in addition to evaluating the degree and scope of neuropsychological impairment following acquired brain injuries. The capacity to make informed clinical decisions relies upon research investigating the relationships between neuropsychological and psychosocial status (i.e., ecological validity). Unfortunately, much of this research employs exploratory analyses, an approach that can lead to theoretical ambiguity and ad-hoc interpretations. The current availability and accessibility of analytical tools, like structural equation modeling (SEM), however, permits the testing of specific hypotheses regarding ecological validity and promotes a-priori theory development. In the current study, a theory-driven model of the ecological validity of a neurocognitive assessment was tested against data obtained from individuals with acquired brain injury using SEM. The results provide confirmatory evidence for the ecological validity of neurocognitive constructs and empirical support for a theory-driven analytical approach to ecological validity research.     

Location serves as a conditional cue when harp seals (Pagophilus groenlandicus) solve object discrimination reversal problems.

We examined the capacity of harp seals (Pagophilus groenlandicus) to use spatial context (i.e., their tank) as a conditional cue to solve a two-choice visual discrimination reversal task. Seals were trained to touch one of two 3D objects. Two of four seals experienced a context shift that coincided with each of five reversals in the reward value of the two stimuli (i.e., a reversal of S+ and S-); these seals solved the six discriminations in significantly fewer trials than did seals that did not experience a context shift with the contingency reversal. Thus, harp seals use contextual cues when encoding information. The findings are discussed in terms of harp seals' adaptations to the pack-ice environment, the constraints of the learning tasks, and the nature of the subjects that were raised in captivity.     

Predicting short-term outcome in well-being following suicidal behaviour: the conjoint effects of social perfectionism and positive future thinking

This study investigated an integrative, psychological model of suicidality involving the relationship between perfectionism and future thinking to predict short-term outcome in well-being following a suicidal episode. Two hundred and sixty-seven adults hospitalized following a self-harm episode completed a range of clinical and psychological measures in hospital and were followed up approximately two months after discharge. Hierarchical regression analyses confirmed that, among the suicidal self-harmers who had a history of repetitive self-harm (n=65), outcome among low social perfectionists changed as a function of positive future thinking such that outcome was better for those high on positive thoughts compared with those low on positive future thoughts. There was no such positive change in outcome among the high social perfectionists. There were also no significant interactive effects evident among the non-repetitive self-harmers (n=61). These findings extend recent research to suggest that socially prescribed perfectionism and positive future thinking (but not negative future thinking) are implicated in outcome following repetitive suicidality. Implications for theory and clinical practice are discussed.     

Young children associate novel words with complex objects rather than salient parts

How do children learn associations between novel words and complex perceptual displays? Using a visual preference procedure, the authors tested 12- and 19-month-olds to see whether the infants would associate a novel word with a complex 2-part object or with either of that object's parts, both of which were potentially objects in their own right and 1 of which was highly salient to infants. At both ages, children's visual fixation times during test were greater to the entire complex object than to the salient part (Experiment 1) or to the less salient part (Experiment 2)--when the original label was requested. Looking times to the objects were equal if a new label was requested or if neutral audio was used during training (Experiment 3). Thus, from 12 months of age, infants associate words with whole objects, even those that could potentially be construed as 2 separate objects and even if 1 of the parts is salient.     

Major life events and major chronic difficulties are differentially associated with history of major depressive episodes

Major life events have been found to precede onsets of a 1st lifetime episode of depression more commonly than subsequent recurrences. Despite general empirical support for this finding, few data directly address how the role of major life events may change over successive recurrences. Further, little research has examined major chronic difficulties in relation to a 1st lifetime episode versus a recurrence of depression. The present study tested the associations between major life events and major difficulties in relation to lifetime history of depressive episodes in a sample of 96 individuals diagnosed with major depression. Using investigator-based measures of life stress, the authors found that, whereas major life events were associated with fewer lifetime episodes, major chronic difficulties were related to more prior episodes. These findings are discussed in terms of underlying mechanisms that may account for the changing role of major life stress over successive recurrences of depression.     

Asking the wrong questions about leadership

Comments on the article by R. J. Hackman and R. Wageman which presented some directions for leadership research. Hackman and Wageman organized their article around their five reject-accept questions suggesting new directions. The current author discusses how each of the questions appears far too timid for real progress in sorting out the chaff from the grain, but points out that the Hackman and Wageman article was a critique of five companion articles and made a substantial contribution to the literature.