The effects of prior knowledge on the encoding of episodic contextual details

A positive relationship between prior knowledge and item memory is a consistent finding in the literature. In the present study, we sought to determine whether this relationship extends to episodic details that are present at the time of encoding, namely source memory. Using a novel experimental design, we were able to show both between- and within-subjects effects of prior knowledge on source memory. Specifically, the results revealed that the degree of prior knowledge positively predicted memory for source specifying contextual details. In addition, by including two conditions in which attention was divided either at encoding or retrieval, we were able to show that prior knowledge influences memory by affecting encoding processes. Overall, the data suggest that a priori knowledge within a specific domain allows attentional resources to be allocated toward the encoding of contextual details.     

Seeing What We Know, Knowing What We See: Challenging the Limits of Visual Acuity

Ageism has resulted in overstated expectations regarding the inevitable deterioration in human capabilities, such as visual perception, with age (Rowe and Kahn in Science, 237, 143?C149, 1987; Grant in Health and Social Work, 21, 9?C15, 1996). Human visual perception, however, is of a largely constructive nature, evidenced in the complementary interactions between top-down inputs (e.g., expectations) and bottom-up stimuli (Engel et al. in National Review of Neuroscience, 2(10), 704?C716, 2001; Miller and Cohen in, Annual Review of Neuroscience, 24, 167-202, 2001). Based on this constructive nature, we hypothesized that visual perception may be better than is typically expected. In three experiments, we demonstrated the malleability of visual acuity using a conditioning procedure involving manipulations in bottom-up stimuli. Experimental groups read a book excerpt with one letter in decreased font size, while the control groups read the same book excerpt with all letters in the same font size. Experiment 1 (N?=?112) examined whether visual acuity could be enhanced for a specific letter. Experiment 2 (N?=?70) assessed whether visual acuity could be enhanced for a non-conditioned letter, while Experiment 3 (N?=?108) evaluated whether the visual conditioning effects would transfer to all non-conditioned letters. Visual acuity for experimental groups was significantly better than that in the control groups, speaking to the general malleability of our visual sense.     

The comprehension of sentences involving quantity information affects responses on the up–down axis

We investigated the use of space in the comprehension of the concept of quantity in text. Previous work has suggested that the right-left axis is useful in spatial representations of number and quantity, while linguistic evidence points toward use of the up-down axis. In Experiment 1, participants read sentences containing quantity information and pressed buttons in either (1) an up and a down position or (2) a left and a right position. In Experiment 2, the participants pressed buttons in either (1) up and down positions or (2) left and right positions, but heard the sentences rather than reading them. We found spatial compatibility effects for the up-down axis, but not for the right-left axis. Additionally, the spatial compatibility effect was observed whether or not the participants moved to make their responses. We discussed the results in the context of embodied approaches to the comprehension of quantity information.     

Construct validity of the Anxiety Sensitivity Index-3 in clinical samples

Using two clinical samples of patients, the presented studies examined the construct validity of the recently revised Anxiety Sensitivity Index-3 (ASI-3). Confirmatory factor analyses established a clear three-factor structure that corresponds to the postulated subdivision of the construct into correlated somatic, social, and cognitive components. Participants with different primary clinical diagnoses differed from each other on the ASI-3 subscales in theoretically meaningful ways. Specifically, the ASI-3 successfully discriminated patients with anxiety disorders from patients with nonanxiety disorders. Moreover, patients with panic disorder or agoraphobia manifested more somatic concerns than patients with other anxiety disorders and patients with nonanxiety disorders. Finally, correlations of the ASI-3 scales with other measures of clinical symptoms and negative affect substantiated convergent and discriminant validity. Substantial positive correlations were found between the ASI-3 Somatic Concerns and body vigilance, between Social Concerns and fear of negative evaluation and socially inhibited behavior, and between Cognitive Concerns and depression symptoms, anxiety, fear of negative evaluation, and subjective complaints. Moreover, Social Concerns correlated negatively with dominant and intrusive behavior. Results are discussed with respect to the contribution of the ASI-3 to the assessment of anxiety-related disorders.     

Hungry pigeons make suboptimal choices, less hungry pigeons do not

Hungry animals will often choose suboptimally by being attracted to reliable signals for food that occur infrequently (they gamble) over less reliable signals for food that occur more often. That is, pigeons prefer an option that 50?% of the time provides them with a reliable signal for the appearance of food but 50?% of the time provides them with a reliable signal for the absence of food (overall 50?% reinforcement) over an alternative that always provides them with a signal for the appearance of food 75?% of the time (overall 75?% reinforcement). The pigeons appear to choose impulsively for the possibility of obtaining the reliable signal for reinforcement. There is evidence that greater hunger is associated with greater impulsivity. We tested the hypothesis that if the pigeons were less hungry, they would be less impulsive and, thus, would choose more optimally (i.e., on the basis of the overall probability of reinforcement). We found that hungry pigeons choose the 50?% reinforcement alternative suboptimally but less hungry pigeons prefer the more optimal 75?% reinforcement. Paradoxically, pigeons that needed the food more received less of it. These findings have implications for how level of motivation may also affect human suboptimal choice (e.g., purchase of lottery tickets and playing slot machines).     

Multialternative context effects obtained using an inference task

When decision-makers are faced with a choice among multiple options that have several attributes, preferences are often influenced by how the options are related to one another. For example, consumer preferences can be influenced, and even reversed, by the context defined by available products. This article discusses three standard context effects found in the preferential-choice literature: the attraction, similarity, and compromise effects. While decision theorists have attempted to explain these three effects under single modeling accounts, it has never before been demonstrated that these effects can be obtained within the same experimental paradigm. A set of experiments is described that demonstrate the three effects in an inference task. The paradigm is completely novel, as no previous experimental work has examined the standard context effects in inference. The experiments also add to evidence that the effects are not confined to choices among options with affective value, such as consumer products. The experimental results provide evidence that these effects might be a general property of human choice behavior and bring into question explanations of the effects that are based on the concept of loss-aversion asymmetry.     

Exploratory factor analysis of African Self-Consciousness Scale scores

This study replicates and extends prior studies of the dimensionality, convergent, and external validity of African Self-Consciousness Scale scores with appropriate exploratory factor analysis methods and a large gender balanced sample (N = 348). Viable one- and two-factor solutions were cross-validated. Both first factors overlapped significantly and were labeled "Embracing African Heritage." The second subscale of the two-factor solution was labeled "Refusal to Deny African Heritage." Only the structural validity of the first factor of the two-factor solution was fully consistent with prior findings. Partial evidence of convergent validity was found for all factors, and only the second factor of the two-factor solution received external validity support. Implications for usage of the African Self-Consciousness Scale and recommendations for further investigation are discussed.     

Selecting a linear mixed model for longitudinal data: repeated measures analysis of variance, covariance pattern model, and growth curve approaches

With increasing popularity, growth curve modeling is more and more often considered as the 1st choice for analyzing longitudinal data. Although the growth curve approach is often a good choice, other modeling strategies may more directly answer questions of interest. It is common to see researchers fit growth curve models without considering alterative modeling strategies. In this article we compare 3 approaches for analyzing longitudinal data: repeated measures analysis of variance, covariance pattern models, and growth curve models. As all are members of the general linear mixed model family, they represent somewhat different assumptions about the way individuals change. These assumptions result in different patterns of covariation among the residuals around the fixed effects. In this article, we first indicate the kinds of data that are appropriately modeled by each and use real data examples to demonstrate possible problems associated with the blanket selection of the growth curve model. We then present a simulation that indicates the utility of Akaike information criterion and Bayesian information criterion in the selection of a proper residual covariance structure. The results cast doubt on the popular practice of automatically using growth curve modeling for longitudinal data without comparing the fit of different models. Finally, we provide some practical advice for assessing mean changes in the presence of correlated data.     

A Randomized, Double-Blind, Crossover Comparison of MK-0929 and Placebo in the Treatment of Adults With ADHD

Objective: Preclinical models, receptor localization, and genetic linkage data support the role of D4 receptors in the etiology of ADHD. This proof-of-concept study was designed to evaluate MK-0929, a selective D4 receptor antagonist as treatment for adult ADHD. Method: A randomized, double-blind, placebo-controlled, crossover study was conducted in adults with primary ADHD. The primary end point was changed from baseline in total score on the Adult ADHD Investigator Symptom Rating Scale following a 4-week treatment regimen. Additional measures included Clinical Global Impression-Severity Scale, Hospital Anxiety and Depression Scale, and Brown Attention Deficit Disorder Scale and D4 genotype analysis. Results: No statistically significant treatment differences were found between MK-0929 and placebo in any of the primary or secondary assessments. Conclusion: Results from this study suggest that blockade of the D4 receptor alone is not efficacious in the treatment of adult ADHD.     

Moral Machines?

Wendell Wallach and Colin Allen??s Moral Machines: Teaching Robots Right From Wrong (Oxford University Press, 2009) explores efforts to develop machines that, not only can be employed for good or bad ends, but which themselves can be held morally accountable for what they do??artificial moral agents (AMAs). This essay is a critical response to Wallach and Allen??s conjectures. Although Wallach and Allen do not suggest that we are close to being able to create full-fledged AMAs, they do talk seriously about making incremental progress in the direction of creating them (even if we never fully succeed). However, there are important questions about the moral development of AMAs that Moral Machines does not address. Given the responsibilities entrusted to human moral agents, we take questions about their moral development very seriously. In the case of children, the hope is that eventually they will develop into full-fledged moral agents. How might we expect this to go with less than fully formed AMAs? Will there be a comparable story of moral development and moral education that we can tell?