The weight of expectation: Implicit,rather than explicit,prior expectations drive the size–weight illusion

In the size–weight illusion, small objects feel heavier than identically weighted larger objects. This illusion is thought to be a consequence of how one's prior expectations can influence conscious perception—lifters expect the large object to outweigh the small object and subsequently experience it as feeling lighter than they expected it to be. Here, we directly examined how a familiar object's identity can affect how heavy someone expects it to be, and how these expectations will influence subsequent perceptions of heaviness. We describe two novel weight illusions induced with familiar objects. In one condition, participants judged the weight of a set of similar-size objects with very different natural weights (a polystyrene sphere, a tennis ball, and a cricket ball), which had all been adjusted to weigh the same amount as one another. In this condition, participants experienced a small, but reliable, weight illusion, with the lightest looking ball feeling heavier than the heaviest looking ball. In the other condition, participants judged the weights of a different set of balls, which were different sizes, but similar natural weights, to one another (a golf ball, a foam soccer ball, and an inflated beach ball). Again, participants experienced a perceptual illusion, but in the opposite direction. Surprisingly, participant's perceptions matched, rather than contrasted with, their explicit expectations such that, even though they expected the golf ball to outweigh the beach ball they perceived the golf ball as feeling heavier than the beach ball. The effect of object mass appeared to dominate the effect of conscious expectations, suggesting that contrasting expectations of heaviness are not necessary to experience weight illusions and that current models of this robust perceptual effect must be revised.     

The Concomitant Effects of Phrase Length and Informational Content in Sentence Comprehension

Recent evidence suggests that phrase length plays a crucial role in modification ambiguities. Using a self-paced reading task, we extended these results by examining the additional pragmatic effects that length manipulations may exert. The results demonstrate that length not only modulates modification preferences directly, but that it also necessarily changes the informational content of a sentence, which itself affects modification preferences. Our findings suggest that the same length manipulation affects multiple sources of constraints, both structural and pragmatic, which can each exert differing effects on processing.     

Orangutans (Pongo abelii) "play the odds": information-seeking strategies in relation to cost, risk, and benefit

Recent research has examined whether animals possess metacognition, or the ability to monitor their knowledge states. However, the extent to which animals actively control their knowledge states is still not well delineated. Although organisms might be capable of seeking information when it is lacking, it does not mean that it is always adaptive to do so. In the present set of experiments, we examined the flexibility of this behavior in captive orangutans (Pongo abelii; two adults and one juvenile) in a foraging task, by varying the necessity of information-seeking, the cost associated with it, the likelihood of error, and the value of the reward. In Experiment 1, subjects searched for information most often when it was "cheapest" energetically. In Experiment 2, subjects searched for information most often when the odds of making an error were the greatest. In Experiment 3, subjects searched for information more when the reward was doubled in value. In Experiment 4, adult subjects adapted to risk/benefit trade-offs in their searching behavior. In every experiment, subjects sought information more often when they needed it than when they already knew the solution to the problem. Therefore, the current research suggests that information-seeking behavior in orangutans shows a sophisticated level of flexibility, comparable to that seen in human children, as they appear to "play the odds" when making the decision to seek information or not.     

A post-genomic view of behavioral development and adaptation to the environment

Recent advances in molecular genetics and epigenetics are reviewed that have major implications for the bio-behavioral sciences and for understanding how organisms adapt to their environments at both phylogenetic and ontogenic levels. From a post-genomics perspective, the environment is as crucial as the DNA sequence for constructing the phenotype, and as a source of information in trying to predict phenotypes. The review is organized with respect to four basic processes by which phenotypes adapt to environmental challenges, with an emphasis on the data for humans: (1) developmental plasticity, (2) epigenetic mechanisms, (3) genotype-environment correlations, and (4) gene × environment interactions.     

Longing for Ex‐Partners out of Fear of Being Single

This research investigated whether people who fear being single have a more difficult time letting go of ex‐partners following a romantic breakup. Data were collected in a cross‐sectional study (N = 209, 64% women, M_age = 30 years old) as well as a 1‐month daily experience study of individuals who just went through a romantic breakup (N = 117, 44% women, M_age = 27 years old). Findings from both studies revealed that those with stronger fear of being single (Spielmann et al., 2013) reported greater longing for their ex‐partners. Pre‐ to post‐breakup analyses revealed that fear of being single increased after a breakup, regardless of who initiated the breakup. Within‐day analyses revealed that longing for an ex‐partner and attempts to renew the relationship were greater on days with stronger fear of being single. Lagged‐day analyses provided support for the conclusion that fear of being single increased longing and renewal attempts over time, but longing and renewal attempts did not influence fear of being single. These findings suggest that fear of being single is a particularly useful construct for understanding the romantic detachment process.     

Using the ideal observer to predict performance in perceptual tasks: An example from the auditory temporal masking domain

This article provides a demonstration of an analytical technique that can be used to investigate the causes of perceptual phenomena. The technique is based on the concept of the ideal observer, an optimal signal classifier that makes decisions that maximize the probability of a correct response. To demonstrate the technique, an analysis was conducted to investigate the role of the auditory periphery in the production of temporal masking effects. The ideal observer classified output from four models of the periphery. Since the ideal observer is the best of all possible observers, if it demonstrates masking effects, then all other observers must as well. If it does not demonstrate masking effects, then nothing about the periphery requires masking to occur, and therefore masking would occur somewhere else. The ideal observer exhibited several forward masking effects but did not exhibit backward masking, implying that the periphery has a causal role in forward but not backward masking. A general discussion of the strengths of the technique and supplementary equations are also included.     

The effect of concurrent semantic categorization on delayed serial recall

The influence of semantic processing on the serial ordering of items in short-term memory was explored using a novel dual-task paradigm. Participants engaged in 2 picture-judgment tasks while simultaneously performing delayed serial recall. List material varied in the presence of phonological overlap (Experiments 1 and 2) and in semantic content (concrete words in Experiment 1 and 3; nonwords in Experiments 2 and 3). Picture judgments varied in the extent to which they required accessing visual semantic information (i.e., semantic categorization and line orientation judgments). Results showed that, relative to line-orientation judgments, engaging in semantic categorization judgments increased the proportion of item-ordering errors for concrete lists but did not affect error proportions for nonword lists. Furthermore, although more ordering errors were observed for phonologically similar relative to dissimilar lists, no interactions were observed between the phonological overlap and picture-judgment task manipulations. These results demonstrate that lexical-semantic representations can affect the serial ordering of items in short-term memory. Furthermore, the dual-task paradigm provides a new method for examining when and how semantic representations affect memory performance.     

Evaluation of a social skills program based on social learning theory, implemented in a school setting

Using a sample of 647 Canadian children in kindergarten to Grade 3 (325 boys, 322 girls), the present study evaluated the perceived effectiveness of Skillstreaming (McGinnis & Goldstein, 2003), a widely known social skills program implemented to target the development of four skill sets, i.e., listening, following directions, problem-solving, and knowing when to tell. Results indicated significant postprogram improvements in all skills as well as in ratings of overall prosociality obtained from both classroom teachers and mental health staff, with medium to large effect sizes obtained from teachers' and mental health professionals' ratings, respectively. Additional analyses yielded significant but weak moderator effects of grade and preprogram prosocial functioning for teacher ratings but no consistent moderator effects for children's sex or school location (i.e., urban versus rural) regardless of rater.