Loving styles: relationships with personality and attachment styles

We investigated the ability of the major personality dimensions, some of their underlying facet scales, and attachment styles to predict primary and secondary loving styles, as conceptualized by Lee. Personality was assessed using the International Personality Item Pool, and attachment styles through an inventory devised by Collins and Read. Respondents were 302 undergraduate students (212 females; 90 males) who participated in the study in exchange for course credit. Results of regression path analysis showed that N was the only personality dimension without direct predictive links to loving styles. Instead, the influence of N was through an anxious attachment style. There were no personality predictors of Agape, and similarities were also observed between these results and those obtained in Hong Kong. The results are discussed with reference to previous studies and some suggestions for further research are also noted. Copyright © 2003 John Wiley & Sons, Ltd.     

One night of sleep deprivation affects reaction time, but not interference or facilitation in a Stroop task

The Stroop color-naming task is one of the most widely studied tasks involving the inhibition of a prepotent response, regarded as an executive function. Several studies have examined performance on versions of the Stroop task under conditions of acute sleep deprivation. Though these studies revealed effects on Stroop performance, the results often do not differentiate between general effects of sleep deprivation on performance and effects specifically on interference in the Stroop task. To examine the effect of prolonged wakefulness on performance on the Stroop task, we studied participants in a 40-h "constant routine" protocol during which they remained awake in constant conditions and performed a Stroop color-naming task every two hours. We found that reaction time was slowest when the color and word did not match (incongruent), fastest when the color and word did match (congruent), and intermediate when participants named the color of the non-word stimulus (neutral). Performance on all three trial types degraded significantly as a function of time awake. Extended wakefulness did not significantly change the additional time needed to respond when the color and word did not match (Stroop interference), nor did it change the amount of facilitation when color and word matched. These results indicate that one night of sleep deprivation influences performance on the Stroop task by an overall increase in response time, but does not appear to impact the underlying processes of interference or facilitation. The results suggest that the degree to which an "executive function" is affected by sleep deprivation may depend on the particular executive function studied and the degree to which it is subserved by the prefrontal cortex.     

Koffka's effect is mediated by figure thickness at the joining region

Three-quarters of a century ago Gestalt psychologist Kurt Koffka described a remarkable effect: when a contiguous gray ring is placed on a background half one shade of gray, half another, the ring appears homogeneous. However, if the ring is divided, the two halves of the ring appear different shades of gray, the half of the ring on the darker background appearing lighter than the half of the ring on the lighter background. The Gestalt principle of continuity is used to explain this effect. But what microscopic principles might be mediating this effect? Recently we found sufficiently thin rings (annuli) appear heterogeneous even when geometrically continuous. Here, using crescent-shaped figures instead of the circular annuli used for the traditional Koffka effect, we show that this effect of thickness of the ring is mediated by the thickness at the boundary of the region where the halves of the figure are joined.     

Basolateral amygdala inactivation impairs learned (but not innate) fear response in rats

Numerous studies have suggested that the amygdala is involved in the formation of aversive memories, but the possibility that this structure is merely related to any kind of fear sensation or response could not be ruled out in previous studies. The present study investigated the effects of bilateral inactivation of the amygdaloid complex in rats tested in the plus-maze discriminative avoidance task. This task concomitantly evaluates aversive memory (by discrimination of the two enclosed arms) and innate fear (by open-arm exploration). Wistar rats (3-5 months-old) were implanted with bilateral guide cannulae into basolateral amygdala. After surgery, all subjects were given 1 week to recover before behavioral experiments. Afterwards, in experiment 1, 15 min prior to training, 0.5 μl of saline or muscimol (1 mg/ml) was infused in each side via microinjection needles. In experiment 2 the animals received injections immediately after the training session and in experiment 3 rats were injected prior to testing session (24 h after training). The main results showed that (1) pre-training muscimol prevented memory retention (evaluated by aversive arm exploration in the test session), but did not alter innate fear (evaluated by percent time in open arms); (2) post-training muscimol impaired consolidation, inducing increased percent in aversive arm exploration in the test session and (3) pre-testing muscimol did not affect retrieval (evaluated by aversive enclosed arm exploration in the test session). The results suggest that amygdala inactivation specifically modulated the learning of the aversive task, excluding a possible secondary effect of amygdala inactivation on general fear responses. Additionally, our data corroborate the hypothesis that basolateral amygdala is not the specific site of storage of aversive memories, since retention of the previously learned task was not affected by pre-testing inactivation.     

Pre-training anandamide infusion within the basolateral amygdala impairs plus-maze discriminative avoidance task in rats

Endocannabinoids (eCBs) modulate a variety of brain functions via activation of the widely expressed CB1 receptor. One site of high density of this receptor is the basolateral amygdala (BLA), a structure involved in the formation of aversive memories. The activation and blockade of CB1 receptors by systemic or hippocampal drug administrations have been shown to modify memory processing. However, little is known about the role of the BLA endocannabinoid system in aversive memories. Additionally, BLA endocannabinoid transmission seems to be related to emotional states, but the relevance of these effects to memory formation is still unknown. In this study we investigated the effects of the eCB anandamide (AEA) and the CB1 antagonist/inverse agonist AM251 infused into the BLA on the acquisition of an aversive memory task, concomitantly evaluating basal anxiety levels in rats. Male rats received pre-training micro-injection of AEA, AM251 or vehicle bilaterally into the BLA, and were studied with the plus-maze discriminative avoidance task (a paradigm that allows concomitant and independent evaluation of anxiety-like behavior and the memory of an aversive task). Our results showed that AEA into the BLA before training prevented memory retrieval 24 h later, as evaluated by exploration of the aversive arm of the maze, while AM251 into the BLA did not interfere with animals' performance. In addition, AEA had no effect on anxiety-like behavior (as evaluated by open arm exploration and risk assessment), while AM251 induced an anxiogenic effect. Our data indicate an important role of BLA CB1 receptors in aversive memory formation, and suggest that this involvement is not necessarily related to a possible modulation of anxiety states.     

Competence to be executed: An ethical analysis post Panetti

Competence to be executed evaluations in effect can prevent an execution or remove the last meaningful impediment to it. Forensic psychiatrists have primary duties to the legal system and truth and honesty, but like all other areas of medical consultation also should balance conflicting secondary traditional medical ethical duties. Participation in a legally authorized execution so violates medical roles, that it is ethically prohibited by the American Medical Association and American Psychiatric Association. This prohibition includes treatment intended to restore competence to be executed. However, despite the primary treatment intent otherwise being appropriate ethically, like relieving suffering or fostering prison safety, if competence to be executed almost predictably would be a treatment result, at least the risk of this result should be considered ethically as if it were intended. In contrast, competence to be executed assessments can be ethical. Diamond's approach of performing honest evaluations only for the defense is an ethical option for such assessments. However, it is challenging to persuade judges and juries of the objectivity of such honest legitimate assessments. Most practitioners therefore likely would consider assessing competence to be executed for either side. This ethically hazardous position necessitates sensitivity to potentially seriously conflicting duties and roles. Copyright © 2010 John Wiley & Sons, Ltd.     

Gene knockout of insulin-regulated aminopeptidase: Loss of the specific binding site for angiotensin IV and age-related deficit in spatial memory

The AT₄ ligands, angiotensin IV and LVV-hemorphin 7, elicit robust effects on facilitating memory by binding to a specific site in the brain historically termed the angiotensin AT₄ receptor. The identification of the AT₄ receptor as insulin-regulated aminopeptidase (IRAP) is controversial, with other proteins speculated to be the target(s) of these peptides. In this study we have utilized IRAP knockout mice to investigate IRAP in the brain. We demonstrate that the high-affinity binding site for angiotensin IV is absent in IRAP knockout mice brain sections in parallel with the loss of IRAP immunostaining, providing irrefutable proof that IRAP is the specific high-affinity binding site for AT₄ ligands. However, our characterization of the behavioural phenotype of the IRAP knockout mice revealed a totally unexpected finding. In contrast to the acute effects of IRAP inhibitors in enhancing memory, deletion of the IRAP gene resulted in mice with an accelerated, age-related decline in spatial memory that was only detected in the Y maze paradigm. Moreover, no alterations in behaviour of the IRAP knockout mice were observed that could assist in elucidating the endogenous substrate(s). Our results highlight the importance of analysing the behavioural phenotype of knockout mice across different ages and in distinct memory paradigms.     

Factor structure and behavioural correlates of the Psychopathy Checklist-Revised [PCL-R] in a Brazilian prisoner sample

The present study examines the reliability, factor structure, and criterion-related validity of Hare (2003) Revised Psychopathy Checklist [PCL-R] in a Latin American forensic context. Brazilian male inmates (124) were administered the PCL-R, along with relevant subscales of an inventory of normal personality [Personality Factorial Inventory], an intelligence scale [Standard Progressive Matrices], and a semi-structured interview based in DSM IV. Criminal offence records were obtained from prison files. Several theoretical factorial structures for the PCL-R were tested and compared. A bifactor model with three factors, one general factor reflecting the overlap across all items, and two independent subfactors reflecting the unique covariation among particular groups of items, shows the better fit. Overall scores on the PCL-R correlated with the number of criminal offenses committed by participants. No significant correlations were found between PCL-R scores and personality or intelligence measures. It was concluded that the PCL-R is a reliable and valid instrument for the assessment of psychopathy in the Brazilian male forensic population.     

Olfactory predator recognition in predator-naïve gray mouse lemurs (Microcebus murinus)

Olfactory cues of predators, such as feces, are known to elicit antipredator responses in animals (e.g., avoidance, activity). To date, however, there is little information on olfactory predator recognition in primates. We tested whether the odor of feces of different predator categories (historical Malagasy predators and introduced predators) and of Malagasy nonpredators (control) induces antipredator behavior in captive born, predator-na?ve gray mouse lemurs. In an olfactory predator experiment a mouse lemur was exposed to a particular odor, fixed at a preferred location, where the animal was trained to get a reward. The behavior of the mouse lemur toward the respective stimulus category was videotaped and quantified. Results showed that mouse lemurs avoided the place of odor presentation when the odor belonged to a predator. They reacted with a significantly enhanced activity when exposed to odors of carnivores compared to those of nonpredatory controls. These findings are in favor of a genetic predisposition of olfactory predator recognition that might be based on the perception of metabolites from meat digestion.