THE EFFECTS OF MATCHED STIMULATION AND RESPONSE INTERRUPTION AND REDIRECTION ON VOCAL STEREOTYPY

Stereotypy has been classified as repetitive behavior that does not serve any apparent function. Two procedures that have been found to reduce rates of vocal stereotypy effectively are response interruption and redirection (RIRD) and noncontingent access to matched stimulation (MS). The purpose of the current study was to evaluate the effects of RIRD alone, MS alone, and MS combined with RIRD. One participant's results suggested similar suppressive effects on vocal stereotypy across treatment conditions. For the second participant, a slightly greater suppression of stereotypy was associated with MS + RIRD. In addition, both participants emitted a greater frequency of appropriate vocalizations in conditions with RIRD. Data suggest that the addition of MS might facilitate the implementation of RIRD in applied settings.     

Resting EEG in alpha and beta bands predicts individual differences in attentional blink magnitude

Accuracy for a second target (T2) is reduced when it is presented within 500 ms of a first target (T1) in a rapid serial visual presentation (RSVP) - an attentional blink (AB). There are reliable individual differences in the magnitude of the AB. Recent evidence has shown that the attentional approach that an individual typically adopts during a task or in anticipation of a task, as indicated by various measures, predicts individual differences in the AB deficit. It has yet to be observed whether indices of attentional approach when not engaged in a goal-directed task are also relevant to individual differences in the AB. The current studies investigated individual differences in the AB by examining their relationship with attention at rest using quantitative measures of EEG. Greater levels of alpha at rest were associated with larger AB magnitudes, where greater levels of beta at rest were associated with smaller AB magnitudes. Furthermore, individuals with more beta than alpha demonstrated a smaller AB effect than individuals with more alpha than beta. Our results suggest that greater attentional engagement at rest, when not engaged in a goal-directed task, is associated with smaller AB magnitudes.     

Effects of motor intention on the perception of somatosensory events: A behavioural and functional magnetic resonance imaging study

The intention to execute a movement can modulate our perception of sensory events, and this modulation is observed ahead of both ocular and upper limb movements. However, theoretical accounts of these effects, and also the empirical data, are often contradictory. Accounts of “active touch”, and the premotor theory of attention, have emphasized how movement intention leads to enhanced perceptual processing at the target of a movement, or on the to-be-moved effector. By contrast, recent theories of motor control emphasize how internal “forward” model (FM) estimates may be used to cancel or attenuate sensory signals that arise as a result of self-generated movements. We used behavioural and functional brain imaging (functional magnetic resonance imaging, fMRI) to investigate how perception of a somatosensory stimulus differed according to whether it was delivered to a hand that was about to execute a reaching movement or the alternative, nonmoving, hand. The results of our study demonstrate that a somatosensory stimulus delivered to a hand that is being prepared for movement is perceived to have occurred later than when that same stimulus is delivered to a nonmoving hand. This result indicates that it takes longer for a tactile stimulus to be detected when it is delivered to a moving limb and may correspond to a change in perceptual threshold. Our behavioural results are paralleled by the results of our fMRI study that demonstrated that there were significantly reduced blood-oxygen-level-dependent (BOLD) responses within the parietal operculum and insula following somatosensory stimulation of the hand being prepared for movement, compared to when an identical stimulus was delivered to a nonmoving hand. These findings are consistent with the prediction of FM accounts of motor control that postulate that central sensory suppression of somatosensation accompanies self-generated limb movements, and with previous reports indicating that effects of sensory suppression are observed in higher order somatosensory regions.     

Recruitment of lateral rostral prefrontal cortex in spontaneous and task-related thoughts

Behavioural and neuroimaging studies suggest that spontaneous and task-related thought processes share common cognitive mechanisms and neural bases. Lateral rostral prefrontal cortex (RPFC) is a brain region that has been implicated both in spontaneous thought and in high-level cognitive control processes, such as goal/subgoal integration and the manipulation of self-generated thoughts. We therefore propose that the recruitment of lateral RPFC may follow a U-shaped function of cognitive demand: relatively high in low-demand situations conducive to the emergence of spontaneous thought, and in high-demand situations depending on processes supported by this brain region. We used functional magnetic resonance imaging to investigate brain activity while healthy participants performed two tasks, each with three levels of cognitive demands, in a block design. The frequency of task-unrelated thoughts, measured by questionnaire, was highest in the low cognitive demand condition. Low and high cognitive demand conditions were each compared to the intermediate level. Lateral RPFC and superior parietal cortex were recruited in both comparisons, with additional activations specific to each contrast. These results suggest that RPFC is involved both when (a) task demands are low, and the mind wanders, and (b) the task requires goal/subgoal integration and manipulation of self-generated thoughts.     

Five weeks of immersive reminiscence therapy improves autobiographical memory in Alzheimer’s disease

ABSTRACT

We examined the effects of a new Immersive Reminiscence Therapy (IRT) programme on cognitive function, including autobiographical memory, in a sample Alzheimer’s disease (AD) patients. A total of 43 AD patients with mild to moderate disease severity were randomly assigned to either an intervention group (n?=?22, MMMSE?=?20.77), or a control group (n?=?21, MMMSE?=?19.24). The intervention group received one weekly group-based session of IRT for five weeks in an authentic 1950s style museum environment, matching the time of the participants’ youth. IRT included semi-structured conversations about the past. The control group received standard care. We assessed performance on cognitive function and autobiographical memory at baseline and post-intervention. Five weeks of IRT enhanced subsequent autobiographical memory performance, when participants were cued by concrete objects dated to their youth. Object-cued memories reported post intervention included a significantly higher degree of episodic details and higher word counts. The intervention showed no effect on the Autobiographical Memory Interview or word-cued recall. Global cognitive function and semantic autobiographical memory performance increased across time for both groups. Our findings demonstrate that immersion into a setting, rich on concrete cues dated to the participants’ youth can improve autobiographical remembering.     

Effect of severe plastic deformation on the coercivity of Co–Cu alloys

Cast Co–5.6 wt% Cu and Co–13.6 wt% Cu alloys were subjected to severe plastic deformation (SPD) by high-pressure torsion (HPT). The HPT treatment drastically decreases the size of the Co grains (from 20 µm to 100 nm) and the Cu precipitates (from 2 µm to 10 nm). As a result, the coercivity H _c of both the alloys radically increases. The saturation magnetization, M _s, remains almost unchanged. Thus, SPD of the bulk samples opens the way for drastic increase in the coercivity for the Co-based alloys.     

Ab initio study of Heusler alloys Co2XY (X = Cr,Mn, Fe; Y = Al,Ga) under high pressure

The structural, electronic, and magnetic properties of ferromagnetic Heusler alloys Co₂XY (X?=?Cr, Mn, Fe; Y?=?Al, Ga) have been investigated by means of the all-electron full-potential linearized augmented plane wave method within the generalized gradient approximation for the exchange and correlation potential. The main focus of this study is to elaborate the changes brought about in the electronic and the magnetic properties by applied pressure. The calculated total spin magnetic moments of all the compounds are found to be in good agreement with experiments. Out of these compounds, Co₂CrAl is found to be perfectly half-metallic (HM) and the other compounds are found to be nearly HM. Thus the HM to metal transition was observed at 75?GPa pressure for Co₂CrAl and the nearly half-metal to half-metal transition was observed at 40?GPa and 18?GPa for Co₂CrGa and Co₂MnAl, respectively, while no transition is observed in other compounds under investigation. It can be clearly seen that pressure affects the minority spin states rather than the majority states, leading to a slight reconstruction of the minority spin states with a shift in the Fermi level driving the above-mentioned transition.     

关于针对最小意识状态患者的促醒综合治疗体系的文献综述

急性脑外伤或非创伤性脑损伤常常导致患者进入一种缺乏意识及思维、对自身及周围的事物缺乏感知的严重意识障碍阶段,过去称之为＂植物状态＂.随着最小意识状态概念的提出,本文在国内外现有参考文献的基础上进行改良并结合自身经验建立了规范的促醒治疗方法,就此促醒治疗方法进行综述,旨在为国内此类患者的评估、诊断、治疗及后续康复提供更多的临床参考.     

诺贝尔生理学或医学奖中的“四大利器”

生物医学原理与高科技结合诞生了心电图仪、CT扫描仪、核磁共振成像及膜片钳等四个仪器,它们还登上了诺贝尔生理学或医学奖的宝座.这些仪器将科学技术通过发明的途径物化成生产工具,对人类进步做出了巨大贡献,犹如开路“利器”,对人类文明的历史产生了深远的影响.挖掘四大“利器”研发历程中的重大进展,对未来相关研究在科学思维层面提供了极好的哲学理念和探索启示.仪器获奖的意义在于将科学仪器赋予人类的强大力量在一定程度上转化为能够按照人类自己的目的和方式去设计和建设自己的未来.