Prefrontal cortex dysfunction and ‘Jumping to Conclusions’: Bias or deficit?

The 'beads task' is used to measure the cognitive basis of delusions, namely the 'Jumping to Conclusions' (JTC) reasoning bias. However, it is not clear whether the task merely taps executive dysfunction - known to be impaired in patients with schizophrenia - such as planning and resistance to impulse. To study this, 19 individuals with neurosurgical excisions to the prefrontal cortex, 21 unmedicated adults with Attention Deficit Hyperactivity Disorder (ADHD), and 25 healthy controls completed two conditions of the beads task, in addition to tests of memory and executive function as well as control tests of probabilistic reasoning ability. The results indicated that the prefrontal lobe group (in particular, those with left-sided lesions) demonstrated a JTC bias relative to the ADHD and control groups. Further exploratory analyses indicated that JTC on the beads task was associated with poorer performance in certain executive domains. The results are discussed in terms of the executive demands of the beads task and possible implications for the model of psychotic delusions based on the JTC bias.     

Patient and partner correlates of couple relationship functioning in bipolar disorder

Extensive research in unipolar depressed and population-based samples has shown cross-partner associations between depressive symptoms and relationship adjustment. Yet despite evidence that bipolar disorder (BPD) is a more chronic and severe illness than unipolar depression, that individuals with BPD are at risk for interpersonal dysfunction, and that critical, unsupportive relationships are predictive of the course of depressive symptoms in BPD, there have been limited efforts to understand the correlates of relationship functioning within BPD. The current study addresses this gap in the literature by examining the associations between the depressive and manic symptoms of individuals with BPD, their partner's depressive symptoms, and relationship functioning, using a multimethod, multi-informant approach. Results revealed that the depressive symptoms of the individual with BPD were associated with poorer relationship functioning, particularly when the partner without BPD also had elevated depressive symptoms. In addition, an interaction between the individual with BPD's depressive and manic symptoms was observed, such that manic symptoms were associated with increased observed hostility and poorer partner relationship adjustment, but only when depressive symptoms were also elevated. These effects persisted even after overall mental health of both partners was controlled.     

A critical eye: Praise directed toward traits increases children’s eye fixations on errors and decreases motivation

Although there is evidence that praise of different types (i.e., generic vs. nongeneric) influences motivation, it is unclear how this occurs. Generic praise (e.g., ??You are smart??) conveys that a child possesses a trait responsible for their performance, whereas nongeneric praise (e.g., ??You worked hard??) conveys that performance is effort-based. Because praise conveys the basis for success, praise may change the interpretation and salience of errors. Specifically, generic praise may highlight the threatening nature of error (i.e., the child does not possess this trait). Because attention is drawn to threats in the environment, we expected generic praise to increase attention to error. We used eyetracking to measure implicit responses to errors (i.e., visual attention: fixation counts and durations) in order to determine the relation between visual attention and verbal reports of motivation (persistence and self-evaluations) in 30 four- to seven-year-old children. Children first saw pictures attributed to them, for which they received either generic or nongeneric praise. The children then saw pictures attributed to them that contained errors??that is, missing features. As a pretest and posttest, the children saw pictures that were ??drawn by other children,?? half of which contained errors. The results indicated that children who received generic praise (??you are a good drawer??) produced more and longer fixations on errors, both their ??own?? and on ??other children??s,?? than did children who received nongeneric praise (??you did a good job drawing??). More fixations on errors were related to lower persistence and lower self-evaluations. These results suggest that generic praise increases attention to errors because error threatens the possession of a positive trait.     

GSK-3β activity in the hippocampus is required for memory retrieval

Several molecules were recently found to be important for the memory retrieval process in the hippocampus; however, the mechanisms underlying the memory retrieval remain poorly understood. GSK-3β has been implicated in the control of synaptic plasticity and memory formation. Here, we investigated the relationship between hippocampal GSK-3β activity and memory retrieval using behavioral and Western blotting methods. We found that GSK-3β was activated in the hippocampus after a retention session in the passive avoidance task. An intrahippocampal injection of the GSK-3β inhibitor, SB 216763, before the retention session blocked memory retrieval (but not reconsolidation) without affecting locomotor activity. These results suggest that GSK-3β activation would be essential for memory retrieval in the hippocampus.     

Selective lesions of the dentate gyrus produce disruptions in place learning for adjacent spatial locations

The hippocampus (HPP) plays a known role in learning novel spatial information. More specifically, the dentate gyrus (DG) hippocampal subregion is thought to support pattern separation, a mechanism for encoding and separating spatially similar events into distinct representations. Several studies have shown that lesions of the dorsal DG (dDG) in rodents result in inefficient spatial pattern separation for working memory; however, it is unclear whether selective dDG lesions disrupt spatial pattern separation for reference memory. Therefore, the current study investigated the role of the dDG in pattern separation using a spatial reference memory paradigm to determine whether the dDG is necessary for acquiring spatial discriminations for adjacent locations. Male Long-Evans rats were randomly assigned to receive bilateral intracranial infusions of colchicine or saline (control) into the dDG. Following recovery from surgery, each rat was pseudo-randomly assigned to an adjacent arm or separate arm condition and subsequently tested on a place-learning task using an eight-arm radial maze. Rats were trained to discriminate between a rewarded arm and a nonrewarded arm that were either adjacent to one another or separated by a distance of two arm positions. Each rat received 10 trials per day and was tested until the animal reached a criterion of nine correct choices out of 10 consecutive trials across 2 consecutive days of testing. Both groups acquired spatial discriminations for the separate condition at similar rates. However, in the adjacent condition, dDG lesioned animals required significantly more trials to reach the learning criterion than controls. The results suggest that dDG lesions decrease efficiency in pattern separation resulting in impairments in the adjacent condition involving greater overlap among the distal cues. Conversely, in the separate condition, there was less overlap among distal cues during encoding and less need for pattern separation. These findings provide further support for a critical role for the dDG in spatial pattern separation by demonstrating the importance of a processing mechanism that is capable of reducing interference among overlapping spatial inputs across a variety of memory demands.     

Lateralized interference in finger tapping: comparisons of rate and variability measures under speed and consistency tapping instructions

Forty right-handed college subjects tapped with and without a verbal task under two instructional conditions (tap as quickly as possible vs. tap as consistently as possible) and two levels of verbal production (silent vs. aloud). The tapping task consisted of the alternate tapping of two keys with the index finger of the left vs. right hands, while the verbal task was anagram solution. Three rate and four variability measures of tapping performance were evaluated in the identification of lateralized interference. The results indicate that reliable lateralized interference, more right-hand than left-hand tapping disruption, was observed only for variability measures under instructions to tap as consistently as possible. Furthermore, only one of these variability measures was sensitive to an increase in lateralized interference produced by verbal production. Because of the limited demonstration of verbal laterality effects with the two-key tapping procedure in this study, conclusions suggest that the simpler manual task of repetitive tapping of one key should be viewed as the method of choice in future dual-task studies.     

Reason and Emotion in the Ethics of Self‐Restraint

In this essay I argue that Reinhold Niebuhr's ethics of self‐restraint, though promising, is based on an incomplete and imprecise moral psychology. Although Niebuhr claims that reason cannot provide a sufficient grounding to motivate self‐restraint, he does not disclose which human capacity might serve this purpose. I suggest that we can address this oversight by strengthening Niebuhr's tentative embrace of David Hume, and by developing a concept of the emotions in order to explain how human beings can cultivate a stable inclination to self‐restraint. This project is informed by and in the service of feminist critiques of Niebuhr and social concerns.