The content of compound conditioning

In three experiments using Pavlovian conditioning of magazine approach, rats were trained with a compound stimulus, AB, and were concurrently trained with stimulus B on its own. The reinforcement rate of B, rB, was either 1/2, 2/3, or 2/5 of rAB. After extended training, the conditioning strength of A was assessed using probe trials in which A was presented alone. Responding during A was compared with that during AB, B, and a third stimulus, C, for which rC = rAB - rB. In each experiment, the rats' response rate during A was almost identical to that during C (and during B, when rB = 1/2rAB). This suggests that, during AB conditioning, the rats had learned about rA as being equal to [rAB - rB], and implies that the content of their learning was a linear function of r. The findings provide strong support for rate-based models of conditioning (e.g., Gallistel & Gibbon, 2000). They are also consistent with the associative account of learning defined in the Rescorla and Wagner (1972) model, but only if the learning rate during reinforcement equals that during nonreinforcement.     

How does cognition evolve? Phylogenetic comparative psychology

Now more than ever animal studies have the potential to test hypotheses regarding how cognition evolves. Comparative psychologists have developed new techniques to probe the cognitive mechanisms underlying animal behavior, and they have become increasingly skillful at adapting methodologies to test multiple species. Meanwhile, evolutionary biologists have generated quantitative approaches to investigate the phylogenetic distribution and function of phenotypic traits, including cognition. In particular, phylogenetic methods can quantitatively (1) test whether specific cognitive abilities are correlated with life history (e.g., lifespan), morphology (e.g., brain size), or socio-ecological variables (e.g., social system), (2) measure how strongly phylogenetic relatedness predicts the distribution of cognitive skills across species, and (3) estimate the ancestral state of a given cognitive trait using measures of cognitive performance from extant species. Phylogenetic methods can also be used to guide the selection of species comparisons that offer the strongest tests of a priori predictions of cognitive evolutionary hypotheses (i.e., phylogenetic targeting). Here, we explain how an integration of comparative psychology and evolutionary biology will answer a host of questions regarding the phylogenetic distribution and history of cognitive traits, as well as the evolutionary processes that drove their evolution.     

Early versus Late Disclosure of Evidence: Effects on Verbal Cues to Deception,Confessions, and Lie Catchers' Accuracy

The strategic use of evidence (SUE)—a method of using case information to elicit different verbal responses from guilty and innocent suspects—has been shown to increase cues to deception and lie detection accuracy. This study manipulated the timing of evidence presentation to determine its effect on cues to deception, lie detection accuracy, and confession rates. Liars were less consistent with the evidence, and SUE was associated with higher lie detection accuracy. Results showed no difference between early and late disclosure of evidence on suspects' confession rates, nor on the diagnosticity of the confessions. Copyright © 2011 John Wiley & Sons, Ltd.     

Integrating the Interpersonal Psychological Theory of Suicide Into the Depression/Suicidal Ideation Relationship: A Short-Term Prospective Study

We examined the hypothesis that depressive symptoms are associated with increased beliefs about perceived burdensomeness and thwarted belongingness identified in the interpersonal psychological theory of suicide and that these beliefs are associated with changes in suicidal ideation. Participants with clinical levels of depressive symptoms (n = 299) were selected from a larger group (n = 508) and completed measures of depressive symptoms, perceived burdensomeness and thwarted belongingness, and suicidal ideation twice over a period of 2 months. Results of a structural equation model found that depressive symptoms were associated with increases in burdensomeness and lack of belonging, which were associated with suicidal ideation. Moreover, this hypothesized integrated model demonstrated a significantly better fit than an alternative model that assumed burdensomeness and lack of belonging were associated with changes in depressive symptoms, which were associated with suicidal ideation. Our findings suggest that the well-established relationship between depressive symptoms and suicidal ideation is associated with changes in beliefs that one is a burden on others and lacks belonging. More generally, these results suggest that it may be fruitful to integrate theories of suicide risk to form a comprehensive model that can inform future research and clinical interventions.     

Implementing Readers Theater in Secondary Classrooms

This article describes how secondary teachers might implement readers theater in their classrooms. In addition to reading fluency, this five-day format also explicitly targets reading comprehension and vocabulary. Each day of the week requires students to engage in various activities aimed to develop diverse components of reading as well as prepare students for the weekly performance. During the process, readers theater provides an opportunity for students to engage in multiple readings with a text in more authentic context.     

The Problem of Enhanced Control

I defend (metaphysical) ground against recent, unanswered objections aiming to dismiss it from serious philosophical inquiry. Interest in ground stems from its role in the venerable metaphysical project of identifying which facts hold in virtue of others. Recent work on ground focuses on regimenting it. But many reject ground itself, seeing regimentation as yet another misguided attempt to regiment a bad idea (like phlogiston or astrology). I defend ground directly against objections that it is confused, incoherent, or fruitless. This vindicates the very attempt to regiment ground. It also refocuses our attention on the genuine open questions about ground and away from the distracting, unpersuasive reasons for dismissing them.