Depressive symptoms in Friedreich ataxiaSíntomas depresivos en la ataxia de Friedreich

Background/Objective: Almost no attention has been paid to depression in Friedreich ataxia (FRDA), a highly disabling cerebellar degenerative disease. Our aim was to study the presence and the profile of depressive symptoms in FRDA and their relationship with demographic-disease variables and cognitive processing speed. Method: The study groups consisted of 57 patients with a diagnosis of FRDA. The Beck Depression Inventory-II was used to assess symptoms of depression. Speed of information processing was measured with a Choice Reaction time task. Results: The mean BDI score for patients was significantly higher than the mean score in the general population. Twenty one percent of participants scored in the moderate/severe range. A Cognitive-Affective score and a Somatic-Motivational score was calculated for each patient. Patients’ scores in both dimensions were significantly higher than the scores in the general population. Demographic and disease variables were not related with symptoms of depression, except for severity of ataxia. Depressive symptoms predict cognitive reaction times. The greater proportion of variance was explained by the Cognitive-Affective dimension. Conclusions: Our data show that both somatic-motivational and cognitive affective symptoms of depression are frequent in individuals with FRDA. In addition, depressive symptoms may influence cognition, especially, the cognitive and affective symptoms.     

Role of amygdala-prefrontal cortex circuitry in regulating the expression of contextual fear memory

The basolateral amygdala (BLA) and medial prefrontal cortex (mPFC) are inter-connected regions involved in fear memory expression. The reciprocal nature of projections between these areas differs along the rostrocaudal extent of BLA. This study investigated the role of functional interactions between BLA and the prelimbic (PL) subregion of mPFC in mediating contextual fear memory. Freezing served as the measure of conditioned fear. Experiments 1–3 examined the effects of left, right or bilateral infusion of bupivacaine into anterior BLA (aBLA), posterior BLA (pBLA) or PL on fear memory expression. Reversible inactivation of left, right or bilateral aBLA impaired fear memory expression. Bilateral inactivation of pBLA or PL also disrupted the expression of fear memory, although left or right inactivation alone had no significant effects in either region. Experiment 4 examined the effects of functionally disconnecting pBLA and PL on contextual fear memory by infusing bupivacaine unilaterally into pBLA and PL in the ipsilateral or contralateral hemisphere. Fear memory expression was impaired by asymmetric inactivation of pBLA and PL; however, a similar effect was also observed with symmetric inactivation of these regions. Bupivacaine infusion did not affect behavior in the open field, likely ruling out non-specific effects of inactivation on innate fear and locomotor activity. These results demonstrate different roles for rostral and caudal BLA in mediating the expression of contextual fear memory. They also raise the possibility that pBLA–PL circuitry is involved in subserving fear memory expression via complex processing mechanisms, although further research is needed to confirm this preliminary finding.     

Un regard structural sur l’inégalité des genres au travail : La causalité des différences « genrées » dans les caractéristiques de réseau de l’employé

This study aims at identifying gender differences in network structure and, hence, at understanding the underlying nature of gender inequalities in organisations. The hypotheses address four ego-network characteristics: network size and density, and ego’s centrality and brokerage. Contrary to the existing body of literature, none significant isolated gender difference in network structure is identified. Instead, those gender differences are triggered exclusively by organisational status, that is to say, they are due to the increased level of power. Thus, organisational status is considered as moderating the relationship between gender and network structure’s characteristics. Some further perspectives are suggested to clarify and generalise the phenomena observed.     

对恐怖情绪的调节：认知重评优于表达抑制 ——一样ERP研究

摘要 本研究采用事件相关电位（ERP）技术,通过测量由视觉诱发的脑电成分晚正波（LPP）来比较情绪调节策略在生理电特征上的差异,进一步探讨认知重评和表达抑制的优劣。实验结果表明：（1）从波幅的角度来比较：在400-600ms时间窗口内,认知重评条件下恐怖图片诱发的LPP波幅显著小于在自由观看条件下的波幅,而表达抑制和自由观看组所诱发的LPP波幅差异较小。（2）从时间进程的角度来比较：认知重评与自由观看组的差异发生在400ms并持续到600ms,甚至以后;而表达抑制和自由观看之间的差异发生在450ms但是只持续到550ms。这表明认知重评相较于表达抑制,对负性情绪起调节作用开始较早,并且持续时间较长。这为认知重评优于表达抑制策略提供了神经生理学上的证据。     

The fate of being forgotten: Information that is initially forgotten is judged as less important

Is forgotten information deemed less important than remembered information? The present study examined potential biases regarding the importance of information that was initially forgotten. In Experiment 1 participants studied words paired with varying point values that denoted their importance and were encouraged to recall higher value words. Participants recalled more high-value words on an initial test. However, on a later cued recall test for the values, initially forgotten words were rated as less valuable than remembered words. Experiment 2 used a similar procedure with the exception that participants rated the importance of traits when evaluating a significant other (e.g., honest, intelligent). Participants were more likely to recall highly valued traits but regarded forgotten traits as less valuable than remembered traits. These results suggest that a forgetting bias exists: If information is initially forgotten, it is later deemed as less important.     

Right hemisphere semantic processing of visual words in an aphasic patient: an fMRI study

This study was designed to identify the neural network supporting the semantic processing of visual words in a patient with large-scale damage to left-hemisphere (LH) language structures. Patient GP, and a control subject, RT, performed semantic and orthographic tasks while brain-activation patterns were recorded using functional magnetic resonance imaging. In RT, the semantic-orthographic comparison activated LH perisylvian and extrasylvian temporal regions comparable to the network of areas activated by non-brain-damaged subjects in other neuroimaging studies of semantic discrimination. In GP, the same comparison activated homologous right-hemisphere regions, demonstrating the ability of the right hemisphere to subserve visual lexicosemantic processes. The results are discussed within the context of the normal right hemisphere's capacity for semantic processing of visual words. Examining results from functional neuroimaging studies on recovery in the context of innate hemispheric abilities may enable reconciliation of disparate claims about mechanisms supporting recovery from aphasia.     

An aphasia database on the internet: a model for computer-assisted analysis in aphasiology

A web-based software model was developed as an example for data mining in aphasiology. It is used for educating medical and engineering students. It is based upon a database of 254 aphasic patients which contains the diagnosis of the aphasia type, profiles of an aphasia test battery (Aachen Aphasia Test), and some further clinical information. In addition, the cerebral lesion profiles of 147 of these cases were standardized by transferring the coordinates of the lesions to a 3D reference brain based upon the ACPC coordinate system. Two artificial neural networks were used to perform a classification of the aphasia type. First, a coarse classification was achieved by using an assessment of spontaneous speech of the patient which produced correct results in 87% of the test cases. Data analysis tools were used to select four features of the 30 available test features to yield a more accurate diagnosis. This classifier produced correct results in 92% of the test cases. The neural network approach is similar to grouping performed in group studies, while the nearest-neighbor method shows a design more similar to case studies. It finds the neurolinguistic and the lesion data of patients whose AAT profiles are most similar to the user's input. This way lesion profiles can be compared to each other interindividually. The Aphasia Diagnoser is available on the Web address http://fuzzy.iau.dtu.dk/aphasia.nsf and thus should facilitate a discussion about the reliability and possibilities of data-mining techniques in aphasiology.     

Influence of the movement parameter to be controlled on manual RT asymmetries in right-handers

In this experiment we test whether the effects of manual asymmetries on movement preparation depend on the parameter (amplitude or direction) to be programmed. In two experiments, only the amplitude, or the direction, of aiming movements was constrained. Reaction and movement times were measured. Results show that RTs are always shorter for left-hand than for right-hand movements. There is an effect of target extent in the amplitude condition, but not in the direction one. RTs for ipsilateral movements are shorter than RTs for contralateral movements. These results are discussed in the light of the processes involved in setting the amplitude or direction of the movement and with regard to the competency of the two hemispheres regarding these processes.