Distinct ventral and dorsal hippocampus AP5 anxiolytic effects revealed in the elevated plus-maze task in rats

The hippocampal formation (HPC) mediates processes associated with learning, memory, anxiety and fear. The glutamate N-methyl-d-aspartate (NMDA)-receptor subtype is involved in many HPC functional processes related to learning and memory. Although not tested for the HPC, NMDA-receptor antagonists reduced fear and anxiety related responses when applied to other brain regions mediating defensive behaviour. Consequently, this study evaluated the effects of ventral or dorsal HPC application of the NMDA-receptor antagonist, AP5, in rats submitted to the Trial 1/Trial 2 elevated plus-maze (EPM) task. Ventral, but not dorsal, infusions of AP5 (6 and 24 nmol) before EPM Trial 1 increased open arms exploration and reduced risk assessment behavior, suggesting an anxiolytic-like effect. Furthermore, no interference in the avoidance responses was detected during EPM Trial 2 after AP5 infusion into the ventral or dorsal HPC before Trial 1, post-trial 1, or before Trial 2. These data support the notion of differential involvement of ventral HPC, but not dorsal, in mechanisms associated with anxiety and suggest the participation of the glutamatergic transmission, through NMDA receptor, into the ventral HPC in the mediation of defensive behavior.     

In the name of democracy: The value of democracy explains leniency towards wrongdoings as a function of group political organization

According to the “democracy‐as‐value” hypothesis, democracy has become an ideological belief system providing social value to democratic individuals, groups and institutions, granting legitimacy to their actions (even if dishonest or violent), and protecting them from consecutive punishments. The present research investigates the extent to which this legitimizing process is based on the individual endorsement of democratic principles. Across four experiments, following the misdeed of a (few) group member(s), respondents who valued democratic group organization and democracy in general expressed more lenient retributive justice judgments towards democratic (as compared with nondemocratic) offender groups. These findings shed light on the ways in which democratic ideology infuses justice judgments. Copyright © 2015 John Wiley & Sons, Ltd.     

Methodological naturalism and epistemic internalism

Epistemic naturalism holds that the results or methodologies from the cognitive sciences are relevant to epistemology, and some have maintained that scientific methods are more compatible with externalist theories of justification than with internalist theories. But practically all discussions about naturalized epistemology are framed exclusively in terms of cognitive psychology, which is only one of the cognitive sciences. The question addressed in this essay is whether a commitment to naturalism really does favor externalism over internalism, and we offer reasons for thinking that naturalism in epistemology is compatible with both internalist and externalist conceptions of justification. We also argue that there are some distinctively internalist aims that are currently being studied scientifically and these notions, and others, should be studied by scientific methods. This essay is dedicated to Deborah Mayo, who has long advocated using error statistical techniques to analyze and resolve epistemological puzzles in the philosophy of science. This essay follows the same spirit by advocating that computational concepts and techniques be applied within the heart of traditional, analytic epistemology.     

Hemispheric asymmetry reduction in older adults: the HAROLD model

A model of the effects of aging on brain activity during cognitive performance is introduced. The model is called HAROLD (hemispheric asymmetry reduction in older adults), and it states that, under similar circumstances, prefrontal activity during cognitive performances tends to be less lateralized in older adults than in younger adults. The model is supported by functional neuroimaging and other evidence in the domains of episodic memory, semantic memory, working memory, perception, and inhibitory control. Age-related hemispheric asymmetry reductions may have a compensatory function or they may reflect a dedifferentiation process. They may have a cognitive or neural origin, and they may reflect regional or network mechanisms. The HAROLD model is a cognitive neuroscience model that integrates ideas and findings from psychology and neuroscience of aging.     

Selective influence of second target exposure duration and Task1 load effects in the attentional blink phenomenon

The purpose of the experiments was to constrain the locus of interference in the attentional blink (AB) paradigm. Two visual stimuli, T₁ and T₂, were shown 300 msec apart, and each was followed by a mask. T₁ was an “H,” an “S,” an “ &, ” or a blank field; T₂ consisted of five letters. In Task₁, blank fields and & characters could be ignored, whereas Hs and Ss had to be identified and reported. Task₂ was always to report as many letters as possible from T₂. Task₂ performance was lower when T₁ had to be reported, as expected from the attentional blink phenomenon (AB). The exposure duration of T₂ was also manipulated. More letters could be reported as exposure duration was increased. However, this effect was additive with manipulations of Task₁ processing load that produced the AB effect. Log-linear analyses assuming that effects of T₂ exposure duration and Task₁ load effects occur at functionally distinct stages of processing provided satisfactory fits to the results, suggesting that none of the AB effect occurs as early as those of T₂ exposure duration. The results suggest that the locus of the AB effect is later than the stage(s) of processing affected by exposure duration.     

Response strategies and the Simon effect

The study investigated whether the Simon effect, and its facilitation and interference components, shows up in reaction time (RT) or in movement time (MT), depending on the response strategy. Experiment 1 replicated a study by Hietanen and Rämä. Subjects had to press one of two lateralised keys in response to one of two stimuli. The stimuli were presented in the center (neutral condition) or to the left or right side (corresponding or non-corresponding conditions). To press the response key, a reaching movement was necessary, and both RT and MT were recorded. One group of subjects showed an RT facilitation effect and an MT interference effect. Another group of subjects showed both MT facilitation and MT interference effects. It was hypothesized that the two groups used different response strategies. In Exps. 2 and 3, the subjects were explicitly instructed to use the two strategies that were hypothesized for Exp. 1. The results showed that whether facilitation and interference manifest themselves in RT or MT depends on the response strategy adopted by the subjects.     

The processing of the right-sided accent mark in left neglect dyslexia

Italian polysyllabic words with stress falling on the last syllable are written with a diacritic sign on the last vowel. It allows discrimination between two words with the same orthographic segments (e.g., papa [pope], papà [dad]). The effect of the accent mark in left neglect dyslexia has never been investigated. In the current study, six patients with neglect dyslexia were asked to read aloud homographic words and non-words, with or without the accent mark. The presence of the accent improved reading performance of three patients but only with real words. In contrast, two patients ignored the accent mark, even if it relied on the right ipsilesional space. We conclude that the accent mark is computed separately from letter identity and that it can act as an important cue for lexical access.     

Metarepresentative functions in borderline personality disorder

Many authors consider that patients suffering from Borderline Personality Disorder (BPD) are hampered in their ability to metarepresent, which is the correct ascribing of states of mind to oneself and to others and the reflecting thereon. Although the ability to mentalize is generally described as being uniform, various authors pinpoint problems which appear to be of a diverse psychological nature. Some describe difficulties in identifying emotions or a shortfall in their regulation, others identify a lack of integration between representations of self and those of others, and yet others focus on the failure to distinguish between fantasy and reality. In the present research all sessions during the first year of therapy of four patients suffering from BPD were tape-recorded and transcribed, and then analyzed using the Metacognition Assessment Scale (MAS), which is designed for the evaluation of the ability to metarepresent in clinical reports. The results support the hypothesis that there is a metarepresentation impairment in BPD but that it is more selective than was thought until now. In particular, such patients maintain their ability to identify internal states, whereas they are impaired in the integration of representations of self and others and in the differentiation between fantasy and reality.     

AEDs and psychotropic drugs in children with autism and epilepsy

The efficacy of antiepileptic drugs (AEDs) and psychotropic medications in children with autism is limited to the treatment of seizures or to specific behaviors such as irritability, impulsivity, hyperactivity, repetitive behaviors, or aggression. The reliability and value of the available data--to determine the efficacy of these medications in autism--are limited by lack of controlled clinical trials, the small number of subjects, the heterogeneity of the population studied, and the brief duration of most drug trials. Indeed, few controlled clinical trials using AEDs in autism, with or without seizures, have been conducted. Because some AEDs also have a positive effect on mood, the benefits that children with autism sometimes obtain from these medications may not be due to the treatment of the abnormal electrical activity or the seizures per se but to an effect on common neuronal systems responsible for both behavior and epilepsy. The relationship between epilepsy and autism, and specifically the effects that abnormal electrical activity may have on the developing brain, may provide some valuable insights into the type of studies that are needed to help us understand the pathophysiology of autism.