Social learning by orangutans (Pongo abelii and Pongo pygmaeus) in a simulated food-processing task

Increasing evidence for behavioral differences between populations of primates has created a resurgence of interest in examining mechanisms of information transfer between individuals. The authors examined the social transmission of information in 15 captive orangutans (Pongo abelii and Pongo pygmaeus) using a simulated food-processing task. Experimental subjects were shown 1 of 2 methods for removing a suite of defenses on an "artificial fruit." Control subjects were given no prior exposure before interacting with the fruit. Observing a model provided a functional advantage in the task, as significantly more experimental than control subjects opened the fruit. Within the experimental groups, the authors found a trend toward differences in the actual behaviors used to remove 1 of the defenses. Results support observations from the wild implying horizontal transfer of information in orangutans and show that a number of social learning processes are likely to be involved in the transfer of knowledge in this species.     

Aging,memory load,and resource allocation during reading

To test the notion that aging brings an inability to self-initiate processing, the authors investigated the effects of memory load on online sentence understanding. Younger and older adults read a series of short passages with or without a simultaneous updating task, which would be expected to deplete resources by consuming memory capacity. Regression analyses of word-by-word reading times onto text variables within each condition were used to decompose reading times into resources allocated to the array of word-level and textbase-level processes needed for comprehension. Among neither the young nor the old were word-level processes disrupted by a simultaneous memory load. However, older readers showed relatively greater levels of resource allocation to conceptual integration than the younger adults when under load, regardless of working-memory span or task priority. These results suggest that the ability to self-initiate the allocation of processing resources during reading is preserved among older readers.     

Hindsight bias in political elections

Two studies on political hindsight bias were conducted on the occasions of the German parliament election in 1998 and the Nordrhein-Westfalen state parliament election in 2000. In both studies, participants predicted the percentage of votes for several political parties and recalled these predictions after the election. The observed hindsight effects were stronger than those found in any prior study on political elections (using percentage of votes as the dependent variable). We argue that the length of the retention interval between original judgement and recollection is mainly responsible for this difference. In our second study, we investigated possible artifacts in political hindsight biases using a control-group design where half of the participants recalled their predictions shortly before or after the election. Hindsight bias was preserved, reinforcing the results of earlier studies with non-control-group designs. Finally, we discuss the possibility that the hindsight experience (in political judgement and in general) actually consists of three different, partly independent components.     

The adaptive user: an investigation into the cognitive and task constraints on the generation of new methods

When people use a computer application, they have the opportunity to adapt the methods or strategies that they deploy to better fit the demands of the task. In Experiment 1, we demonstrated that the generation of methods is limited by, but not entirely prevented by, the reduced opportunity that is associated with the iterative nature of typical computer-based tasks. In Experiment 2, we demonstrated that the cognitive demands associated with task-related problem solving delay, but do not prevent, the generation of more efficient device strategies. We argue that people are rather good at adapting device strategies to task demands and that previously reported arguments to the contrary are premature.     

Functional neuroanatomy of emotions: A meta-analysis

The application of functional neuroimaging to the study of human emotion has yielded valuable data; however, the conclusions that may be drawn from any one study are limited. We applied novel statistical techniques to the meta-analysis of 106 PET and fMRI studies of human emotion and tested predictions made by key neuroscientific models. The results demonstrated partial support for asymmetry accounts. Greater left-sided activity was observed for approach emotions, whereas neural activity associated with negative/withdrawal emotions was symmetrical. Support was also found for affect program emotion accounts. The activation distributions associated with fear, disgust, and anger differed significantly. These emotions were most consistently associated in activity in regions associated with selective processing deficits when damaged: the amygdala, the insula and globus pallidus, and the lateral orbitofrontal cortex, respectively. In contrast, the distributions for happiness and sadness did not differ. These findings are considered in the context of conceptualizations of the neural correlates of human emotion.     

Promoting responsible conduct in research through “survival skills” workshops: Some mentoring is best done in a crowd

For graduate students to succeed as professionals, they must develop a set of general "survival skills". These include writing research articles, making oral presentations, obtaining employment and funding, supervising, and teaching. Traditionally, graduate programs have offered little training in many of these skills. Our educational model provides individuals with formal instruction in each area, including their ethical dimensions. Infusion of research ethics throughout a professional skills curriculum helps to emphasize that responsible conduct is integral to succeeding as a researcher. It also leads to the consideration of ethical dimensions of professional life not covered in traditional ethics courses.     

Category variability, exemplar similarity, and perceptual classification

Experiments were conducted in which observers learned to classify simple perceptual stimuli into low-variability and high-variability categories. Similarities between objects were measured in independent psychological-scaling tasks. The results showed that observers classified transfer stimuli into the high-variability categories with greater probability than was predicted by a baseline version of an exemplar-similarity model. Qualitative evidence for the role of category variability on perceptual classification, which could not be explained in terms of the baseline exemplar-similarity model, was obtained as well. Possible accounts of the effects of category variability are considered in the General Discussion section.     

Probing spatial working memory with the Corsi Blocks task

The Corsi Blocks task (CBT) measures spatial memory span, but methodological differences across previous studies prevent a clear appreciation of perceptual, memory, and motor contributions to spatial span. CBT performance in a standard condition was compared to performance with longer encoding intervals (3 vs 1 s), longer memory intervals (9 vs 1 s), or fewer response alternatives (all nine vs only the relevant positions). All experiments also contrasted ascending vs descending order of item difficulty and recorded response-initiation times. Performance improved with longer encoding and maintenance intervals and with fewer response alternatives. Item order had no reliable effects. Response-initiation times were a useful additional measure of spatial span. Implications of these findings for research using the CBT are discussed.     

Family, personality, and social risk factors impacting the retention rates of first-year Hispanic and Anglo college students

This study investigated familial and behavioral differences between Hispanic and Anglo-American first-year college students. Analyses of variance and chi-square analyses were used to test for ethnic differences in (a) risk factors associated with family dysfunction, family addictions, personality factors, and social experiences, (b) student problem behaviors, namely alcohol use, drug use, and eating disorders, (c) a one-year follow-up of student retention, and (d) specific factors related to retention at the one-year follow-up. The Hispanic freshmen appeared to demonstrate resilience despite a lack of mentoring and greater paternal addiction. However, the one-year follow-up suggested that Hispanic females were at particular risk for leaving school. To improve college retention rates, social policy should focus on Hispanic students' vulnerabilities and strengths in making important developmental transitions.