The many directions of time

Event duration perception is fundamental to cognitive functioning. Recent research has shown that localized sensory adaptation compresses perceived duration of brief visual events in the adapted location; however, there is disagreement on whether the source of these temporal distortions is cortical or pre-cortical. The current study reveals that spatially localized duration compression can also be direction contingent, in that duration compression is induced when adapting and test stimuli move in the same direction but not when they move in opposite directions. Because of its direction-contingent nature, the induced duration compression reported here is likely to be cortical in origin. A second experiment shows that the adaptation processes driving duration compression can occur at or beyond human cortical area MT+, a specialized motion center located upstream from primary visual cortex. The direction-specificity of these temporal mechanisms, in conjunction with earlier reports of pre-cortical temporal mechanisms driving duration perception, suggests that our encoding of subsecond event duration is driven by activity at multiple levels of processing.     

Neurogenesis interferes with the retrieval of remote memories: Forgetting in neurocomputational terms

In contrast to models and theories that relate adult neurogenesis with the processes of learning and memory, almost no solid hypotheses have been formulated that involve a possible neurocomputational influence of adult neurogenesis on forgetting. Based on data from a previous study that implemented a simple but complete model of the main hippocampal circuitry (Weisz & Argibay, 2009), we now test this model under different situations to better study the case of remote memories. The results of this work show that following neurogenesis, the new, ongoing memories in the hippocampus are better retained than when no neurogenesis occurs at all, while the older memories are affected (to a lesser extent) by a special type of interference that is different from interference that occurs with an increasing number of memories per se. This work adds a new point of analysis in support of the interference view that might lead to the forgetting of memories in the hippocampus as they are transferred to neocortex for long-term storage, consistent with the Complementary Learning Systems models of system-level consolidation. Attention should be directed to the specific causes of interference; the results of this work signal a type of distortion of remote memories that is produced by the birth and the growth of new processing units, which results in a subtly impoverished retrieval as new neurons become active. The proposals of this model fit well with some empirical findings that are related to the issue. In the future, as new evidence emerges, we believe that this biological process, which is largely related to learning and memory, will also help to shape our ideas about normal forgetting and its possible contributions to system consolidation.     

Control networks and neuromodulators of early development

In adults, most cognitive and emotional self-regulation is carried out by a network of brain regions, including the anterior cingulate, insula, and areas of the basal ganglia, related to executive attention. We propose that during infancy, control systems depend primarily upon a brain network involved in orienting to sensory events that includes areas of the parietal lobe and frontal eye fields. Studies of human adults and alert monkeys have shown that the brain network involved in orienting to sensory events is moderated primarily by the nicotinic cholinergic system arising in the nucleus basalis. The executive attention network is primarily moderated by dopaminergic input from the ventral tegmental area. A change from cholinergic to dopaminergic modulation would be a consequence of this switch of control networks and may be important in understanding early development. We trace the attentional, emotional, and behavioral changes in early development related to this developmental change in regulative networks and their modulators.     

Does delaying judgments of learning really improve the efficacy of study decisions? Not so much

A widely held assumption in metamemory is that better, more accurate metamemory monitoring leads to better, more efficacious restudy decisions, reflected in better memory performance--we refer to this causal chain as the restudy selectivity hypothesis. In 3 sets of experiments, we tested this hypothesis by factorially manipulating metamemory monitoring accuracy and self-regulation of study. To manipulate monitoring accuracy, we compared judgments of learning (JOLs) made contemporaneously with a delayed retrieval attempt to JOLs either made at a delay without attempting retrieval or made immediately after study; in previous studies, delayed retrieval-based JOLs have robustly predicted recall with greater relative accuracy than have the other JOL types. To manipulate self-regulation of study, in Experiments 1A-1C and 2A-2C, we compared conditions in which participants' restudy selections were honored with conditions in which they were completely or randomly dishonored; in Experiments 3A-3C, we randomly honored or dishonored half of the restudy selections and half of the nonselections. Results revealed that the benefit of delayed, retrieval-based JOLs for final memory performance was due largely to the selection of more items for restudy rather than to better discriminations between items that would benefit more versus less from restudy. In most cases, gains in recall due to greater self-regulation of study did not increase with better monitoring accuracy; when they did, the effect was extremely small. The surprising conclusion was that restudy decisions were not very much more efficacious under conditions that yield greater monitoring accuracy than under those that do not.     

Re-examining the home disadvantage in professional ice hockey

Occurrence of the home disadvantage in professional ice hockey was examined by analyzing shootout data from 2005 through 2008. Results indicated that teams involved in shootouts playing at their home arenas did not lose significantly more games at home than on the road. Results did not support the hypotheses that emphasize the roles of physical contact and diffusion of responsibility in accounting for past failures to find the home disadvantage in professional ice hockey.     

Real three-dimensional objects: effects on mental rotation

The current experiment investigated real three-dimensional (3D) objects with regard to performance on a mental rotation task and whether the appearance of sex differences may be mediated by experiences with spatially related activities. 40 men and 40 women were presented with alternating timed trials consisting of real-3D objects or two-dimensional illustrations of 3D objects. Sex differences in spatially related activities did not significantly influence the finding that men outperformed women on mental rotation of either stimulus type. However, on measures related to spatial activities, self-reported proficiency using maps correlated positively with performance only on trials with illustrations whereas self-reported proficiency using GPS correlated negatively with performance regardless of stimulus dimensionality. Findings may be interpreted as suggesting that rotating real-3D objects utilizes distinct but overlapping spatial skills compared to rotating two-dimensional representations of 3D objects, and real-3D objects can enhance mental rotation performance.     

Number of players who gain ball possession as a function of basketball mass among 9-11-year-old male players

This study analyzed whether a ball with a higher (540-g) or lower (440-g) mass than the regulation ball (485-g) resulted in a larger number of participants gaining ball possession during games. Prior studies have indicated that ball handling is facilitated by decreasing the mass of the ball. It was assumed that a greater number of children gaining possession of the ball indicated greater ease of use and more control. Thus, the hypothesis was that the number of participants who gained ball possession would increase when using a ball of lower mass. The participants were 54 boys from six youth basketball teams. Participants played four games with each one of the three different balls and the number of possessions was calculated using videos of each game. The hypothesis was only partially supported: the number of participants who gained possession with the regular ball was similar to that with the 440-g ball and with the 540-g ball, but a greater number of participants gained possession with the 440-g ball in comparison to the 540-g ball. This result suggests balls that differ by more than 65 g may affect actual game outcomes.     

Dynamic adaptation to history of trial difficulty explains the effect of congruency proportion on masked priming

In reaction time research, there has been an increasing appreciation that response-initiation processes are sensitive to recent experience and, in particular, the difficulty of previous trials. From this perspective, the authors propose an explanation for a perplexing property of masked priming: Although primes are not consciously identified, facilitation of target processing by a related prime is magnified in a block containing a high proportion of related primes and a low proportion of unrelated primes relative to a block containing the opposite mix (Bodner & Masson, 2001). In the present study, this phenomenon is explored with a parity (even/odd) decision task in which a prime (e.g., 2) precedes a target that can be either congruent (e.g., 4) or incongruent (e.g., 3). It is shown that the effect of congruence proportion with masked primes cannot be explained in terms of the blockwise prime-target contingency. Specifically, with masked primes, there is no congruency disadvantage in a block containing a high proportion of incongruent primes, but there is a congruency advantage when the block contains an equal proportion of congruent and incongruent primes. In qualitative contrast, visible primes are sensitive to the blockwise prime-target contingency. The authors explain the relatedness proportion effect found with masked primes in terms of a model according to which response-initiation processes adapt to the statistical structure of the environment, specifically the difficulty of recent trials. This account is supported with an analysis at the level of individual trials using the linear mixed effects model.     

The bystander-effect: a meta-analytic review on bystander intervention in dangerous and non-dangerous emergencies

Research on bystander intervention has produced a great number of studies showing that the presence of other people in a critical situation reduces the likelihood that an individual will help. As the last systematic review of bystander research was published in 1981 and was not a quantitative meta-analysis in the modern sense, the present meta-analysis updates the knowledge about the bystander effect and its potential moderators. The present work (a) integrates the bystander literature from the 1960s to 2010, (b) provides statistical tests of potential moderators, and (c) presents new theoretical and empirical perspectives on the novel finding of non-negative bystander effects in certain dangerous emergencies as well as situations where bystanders are a source of physical support for the potentially intervening individual. In a fixed effects model, data from over 7,700 participants and 105 independent effect sizes revealed an overall effect size of g = -0.35. The bystander effect was attenuated when situations were perceived as dangerous (compared with non-dangerous), perpetrators were present (compared with non-present), and the costs of intervention were physical (compared with non-physical). This pattern of findings is consistent with the arousal-cost-reward model, which proposes that dangerous emergencies are recognized faster and more clearly as real emergencies, thereby inducing higher levels of arousal and hence more helping. We also identified situations where bystanders provide welcome physical support for the potentially intervening individual and thus reduce the bystander effect, such as when the bystanders were exclusively male, when they were naive rather than passive confederates or only virtually present persons, and when the bystanders were not strangers.