Differential effects of muscarinic receptor blockade in prelimbic cortex on acquisition and memory formation of an odor-reward task

The present experiments determined the consequences of blocking muscarinic cholinergic receptors of the prelimbic (PL) cortex in the acquisition and retention of an odor-reward associative task. Rats underwent a training test (five trials) and a 24-h retention test (two retention trials and two relearning trials). In the first experiment, rats were bilaterally infused with scopolamine (20 or 5 microg/site) prior to training. Although scopolamine rats showed acquisition equivalent to PBS-injected controls, they exhibited weakened performance in the 24-h retention test measured by number of errors. In the second experiment, rats were injected with scopolamine (20 microg/site) immediately or 1 h after training and tested 24 h later. Scopolamine rats injected immediately showed severe amnesia detected in two performance measures (errors and latencies), demonstrating deficits in retention and relearning, whereas those injected 1 h later showed good 24-h test performance, similar to controls. These results suggest that muscarinic transmission in the PL cortex is essential for early memory formation, but not for acquisition, of a rapidly learned odor discrimination task. Findings corroborate the role of acetylcholine in consolidation processes and the participation of muscarinic receptors in olfactory associative tasks.     

Mood and fluency: The case of pronunciation ease,liking and trust

We explored the impact of mood on the judgemental consequences of word pronounceability in six Experiments (1 preregistered, total N = 1183). Positive and negative mood was induced via video clips (all but Experiment 4) and subliminal affective primes (Experiment 4). Additionally, participants were presented with easy- and difficult-to-pronounce letter strings. These were framed as target words to be judged for liking (Experiments 1–2), as names of eBay sellers to be judged for trustworthiness (Experiments 3–5), or as either seller names or passwords to provoke opposing interpretations of pronunciation fluency (Experiment 6). While pronounceability showed a robust effect across experiments, mood did not modulate the judgemental use of (Experiments 1–4), the correction for (Experiment 5) and the interpretation (Experiment 6) of word pronounceability. In conclusion, the judgemental effects of pronounceability persist despite the presence of more objective and task-pertinent cues, resist judgemental correction and remain unaffected by affective states.     

An experimental analysis of task refusal: A comparison of negative reinforcement contingencies and transitions between academic tasks

The purpose of the study was to do an experimental analysis of academic task refusal for one girl with a developmental disability. Task refusal was analyzed in two experimental analyses. First, an analysis testing if the behavior was maintained by negative reinforcement, and the second, an analysis testing if the behavior was the result of transitioning between academic tasks differing in preference. Task refusal did not occur in the demand condition of the functional analysis, indicating that the behavior was not maintained by escape from demands. Conversely, task refusal occurred solely in the second experimental analysis when transitioning from a high-preferred to a low-preferred academic task. In this case, the context of terminating a preferred academic task and transitioning to a less preferred academic task was aversive but not the demand itself. In addition, when an embedded break condition was compared to a no break condition in a multielement design, task refusal was reduced to zero levels.     

Total spin in the density matrix renormalization group algorithm

A new density matrix renormalization group (DMRG) algorithm is presented which conserves the total spin. This is the first time that standard DMRG is extended to exploit fully the symmetries of the Hamiltonian. The obtained general procedure works for any operator, even operators that do not commute with the Hamiltonian. The new method gives substantial improvements over the standard DMRG.     

Catching up with wonderful women: The women‐are‐wonderful effect is smaller in more gender egalitarian societies

Inequalities between men and women are common and well‐documented. Objective indexes show that men are better positioned than women in societal hierarchies—there is no single country in the world without a gender gap. In contrast, researchers have found that the women‐are‐wonderful effect—that women are evaluated more positively than men overall—is also common. Cross‐cultural studies on gender equality reveal that the more gender egalitarian the society is, the less prevalent explicit gender stereotypes are. Yet, because self‐reported gender stereotypes may differ from implicit attitudes towards each gender, we reanalysed data collected across 44 cultures, and (a) confirmed that societal gender egalitarianism reduces the women‐are‐wonderful effect when it is measured more implicitly (i.e. rating the personality of men and women presented in images) and (b) documented that the social perception of men benefits more from gender egalitarianism than that of women.     

Familial multiple sclerosis with repetitive relapses of manic psychosis in two patients (mother and daughter)

The clinical presentation of multiple sclerosis (MS) with psychiatric symptoms is uncommon but it is believed that MS patients are twice as likely to be afflicted with bipolar disorder as the general population. We report two cases (mother and daughter) of MS presenting with bipolar disorder in the form of recurrent manic psychosis and whose outcome was favourable with neuroleptics and corticosteroids. In both cases we found multiple hypersignal lesions on brain magnetic resonance imaging (MRI), especially in the right frontal lobe where we observed signs of activity. Apart from clinical and radiological concordance, the patients exhibited similar class I HLA alleles and identical class II HLA alleles. We focused discussion on whether there may be a common genetic susceptibility to both illnesses or whether MS caused psychiatric manifestations. The coincidence of psychiatric and neurological symptoms in most relapses supports the second hypothesis.