Anxiolytic-like activity of SB-205384 in the elevated plus-maze test in mice

Recent studies point to a major role for alpha2-containing GABA-A receptors in modulating anxiety. However, the possible implication of GABA-A receptors containing the alpha3 subunit on anxiety is less known. The aim of this study was to examine the effects of SB-205384 (0.5-4 mg/kg, i.p.), an alpha3 subunit positive modulator of GABA-A receptor, on anxiety tested in the elevated plus-maze in male mice, using classical and ethological parameters. Mice treated with SB-205384 showed an increase in the frequency of entries and the time spent in open arms, as well as a reduction in the time spent in closed arms, as compared with the control group. A notable increase of "head-dipping" unprotected and a reduction of "stretched-attend posture" protected was also evident. These findings indicate that SB-205384 exhibits an anxiolytic-like profile in the elevated plus-maze test, suggesting that GABA-A receptors which contain the alpha3 subunit might be involved in regulation of anxiety.     

Selective attention affects implicit and explicit memory for familiar pictures at different delay conditions

Three experiments investigated the effects of two variables -selective attention during encoding and delay between study and test- on implicit (picture fragment completion and object naming) and explicit (free recall and recognition) memory tests. Experiments 1 and 2 consistently indicated that (a) at all delays (immediate to 1 month), picture-fragment identification threshold was lower for the attended than the unattended pictures; (b) the attended pictures were recalled and recognized better than the unattended; and (c) attention and delay interacted in both memory tests. For implicit memory, performance decreased as delay increased for both attended and unattended pictures, but priming was more pronounced and lasted longer for the attended pictures; it was still present after a 1-month delay. For explicit memory, performance decreased as delay increased for attended pictures, but for unattended pictures performance was consistent throughout delay. By using a perceptual object naming task, Experiment 3 showed reliable implicit and explicit memory for attended but not for unattended pictures. This study indicates that picture repetition priming requires attention at the time of study and that neither delay nor attention dissociate performance in explicit and implicit memory tests; both types of memory require attention, but explicit memory does so to a larger degree.     

Pretend play: an application of an intervention program in autism

Methodologically and theoretically based on metarrepresentational deficit hypothesis, we design an intervention to teach the mental state of pretense to an autistic boy. The production and comprehension of symbolic play by means of the use of two specific strategies founded on pictorial analogy of the mental representation and process, was the focus of the learning. The efficiency and efectiveness of the program is reflected in the results that indicated the subject's competence to generate and comprehend the pretense as well as to generalize the acquired knowledge into other areas of mentalistic functioning. We discuss the possibility to develop a metarrepresentational knowledge based on the internalizing of the strategies of conceptual support.     

Task-order coordination in dual-task performance and the lateral prefrontal cortex: an event-related fMRI study

A crucial demand in dual tasks suffering from a capacity limited processing mechanism is task-order scheduling, i.e. the control of the order in which the two component tasks are processed by this limited processing mechanism. The present study aims to test whether the lateral prefrontal cortex (LPFC) is associated with this demand. For this, 15 participants performed a psychological refractory paradigm (PRP) type dual task in an event-related functional magnetic resonance (fMRI) experiment. In detail, two choice reaction tasks, a visual (response with right hand) and an auditory (response with left hand), were presented with a temporal offset of 200 ms, while the participants were required to respond to the tasks in the order of their presentation. Importantly, the presentation order of the tasks changed randomly. Based on previous evidence, we argue that trials in which the present task order changed as compared to the previous trial (different-order trials) impose higher demands on task coordination than same-order trials do. The analyses showed that cortical areas along the posterior part of the left inferior frontal sulcus as well as the right posterior middle frontal gyrus were more strongly activated in different-order than in same-order trials, thus supporting the conclusion that one function of the LPFC for dual-task performance is the temporal coordination of two tasks. Furthermore, it is discussed that the present findings favour the active scheduling over the passive queuing hypothesis of dual-task processing.     

The frontal hypothesis of cognitive aging: factor structure and age effects on four frontal tests among healthy individuals

With 101 healthy aging adult participants, the authors investigated whether executive functions are a unitary concept. The authors established the factor structure of the Wisconsin Card Sorting Test (WCST; E. A. Berg, 1948), the Stroop color and word test (C. J. Golden, 1978), verbal fluency using the Controlled Oral Word Association Test (COWAT; Benton, 1967), and the Digits Backwards subtest of the Wechsler Adult Intelligence Scale-Revised (WAIS-R; D. Wechsler, 1981). The authors also evaluated the extent to which age and other demographic variables predicted common underlying properties of these frontal tests. Results revealed an age-related decline in executive abilities differentially reflected by the selected tasks. These data suggest caution using the COWAT to evaluate executive abilities in older people. The authors interpret findings to support the unitary view of executive abilities and the executive decline proposed by the frontal hypothesis.     

Oral kinesthetic deficit in adults who stutter: a target-accuracy study

The current study was based on the hypothesis that chronic developmental stuttering in adults involves a deficiency in oral kinesthesia. The authors used a target-accuracy task to compare oral kinesthesia in adults who stutter (n = 17) and in normal speakers (n = 17). During the task, participants were instructed to make accurate jaw-opening movements in visual and nonvisual feedback conditions. The authors further contrasted oral movement control in a normal response time condition with that in a reaction time condition. Overall, the adults who stutter consistently made significantly less accurate and more variable movements than the control participants in the nonvisual condition, but particularly in the reaction time condition. In general, the present findings suggest that chronic developmental stuttering involves an oral kinesthetic deficiency, although without direct measures of somatosensory function, one cannot exclude a motor deficit interpretation.     

Work-related stress and well-being: the roles of direct action coping and palliative coping

The purpose of the present study is to analyze the roles of direct action coping and palliative coping in the relationship between work stressors and psychological well-being, as well as their possible interactions, in a sample of 464 bank employees. Hierarchical regression analyses showed main effects of direct action coping on well-being. Palliative coping predicts higher levels of psychological distress. Contrary to what was expected, the interactions between work stressors and direct action coping were not significant. Palliative coping interacted with work stressors when predicting psychosomatic complaints. The interaction between the two types of coping was significant on psychosomatic complaints and psychological distress, but not on job satisfaction. The paper discusses theoretical and practical implications of these results, in order to design intervention strategies to prevent and manage job stress.     

Cortical memory mechanisms and language origins

We have previously proposed that cortical auditory-vocal networks of the monkey brain can be partly homologized with language networks that participate in the phonological loop. In this paper, we suggest that other linguistic phenomena like semantic and syntactic processing also rely on the activation of transient memory networks, which can be compared to active memory networks in the primate. Consequently, short-term cortical memory ensembles that participate in language processing can be phylogenetically tracked to more simple networks present in the primate brain, which became increasingly complex in hominid evolution. This perspective is discussed in the context of two current interpretations of language origins, the "mirror-system hypothesis" and generativist grammar.     

The transition to increased automaticity during finger sequence learning in adult males who stutter

The present study compared the automaticity levels of persons who stutter (PWS) and persons who do not stutter (PNS) on a practiced finger sequencing task under dual task conditions. Automaticity was defined as the amount of attention required for task performance. Twelve PWS and 12 control subjects practiced finger tapping sequences under single and then dual task conditions. Control subjects performed the sequencing task significantly faster and less variably under single versus dual task conditions while PWS' performance was consistently slow and variable (comparable to the dual task performance of control subjects) under both conditions. Control subjects were significantly more accurate on a colour recognition distracter task than PWS under dual task conditions. These results suggested that control subjects transitioned to quick, accurate and increasingly automatic performance on the sequencing task after practice, while PWS did not. Because most stuttering treatment programs for adults include practice and automatization of new motor speech skills, findings of this finger sequencing study and future studies of speech sequence learning may have important implications for how to maximize stuttering treatment effectiveness. Educational objectives: As a result of this activity, the participant will be able to: (1) Define automaticity and explain the importance of dual task paradigms to investigate automaticity; (2) Relate the proposed relationship between motor learning and automaticity as stated by the authors; (3) Summarize the reviewed literature concerning the performance of PWS on dual tasks; and (4) Explain why the ability to transition to automaticity during motor learning may have important clinical implications for stuttering treatment effectiveness.     

Determinants of lexical access in speech production: Role of word frequency and age of acquisition

The main determinants of lexical access in speech are considered to be a word's age of acquisition (AoA) and its frequency of occurrence in a speaker's experience. It is unclear whether and how these variables interact, although they are commonly observed to be correlated, for the few studies that address the issue have reported inconsistent findings. An influential view of AoA in lexical processing (Ellis and Lambon Ralph, 2000) predicts stronger frequency effects for items acquired later in life than for those acquired at an early age. Five experiments were designed to investigate the possible interaction of AoA and frequency effects in speech. We found that the interaction between word frequency and AoA was not robust and that, contrary to expectation, the effect of word frequency was greater for words acquired earlier in life than for those acquired later. The implications of our findings are discussed.