Attachement père-cadet et qualité des relations fraternelles cadet-aîné

The aim of this study is to establish a link between the father-child attachment and the quality of the sibling relationships for school-age children, by taking into account the theoretical and methodological evolution of this specific attachment. Fifty-seven fathers answered the Questionnaire of Opening up to the World [Défi jeunesse, 8 (2002) 6–12], which defines the father-child attachment (or activation) on two axes: the stimulation (social, cognitive and emotional) and the paternal control exercised over the child. The Questionnaire “Sibling Relationships in Young Children” [Troupel, O., 2006. Attachement fraternel, styles de relations et des interactions de tutelle au sein des fratries de jeunes enfants : effet modulateur de la représentation des relations fraternelles de l’aîné. Thèse de doctorat nouveau régime, université de Toulouse–Le-Mirail] gives insight into the quality of sibships. Children, with a secure attachment to their father, demonstrate a higher level of cooperation with their elder sibling than the other children, in particular those which receive excessive control and little stimulation from their fathers. The hypothesis that the stimulation of the second-born child by the father on the peer side is directly linked to the quality of the sibships is not confirmed. Other results on father-child attachment and sibships are discussed.     

Le vieillissement cognitif et l’hypothèse de l’exercice mental révisée

Although intuitively plausible, the evidence relevant to the mental exercise hypothesis is currently mixed. One of the main controversial issues concerning the investigation of this hypothesis has to do with how cognitive stimulation is assessed. The mental exercise hypothesis was here tested with a subjective and self-reported measure of cognitive stimulation. Overall, results have supported that a greater engagement in cognitively stimulating activities was associated with higher levels of cognitive functioning. However, the rate of cognitive decline with advancing age was not reduced for people who were more mentally active. Of great interest, the subjective measure of cognitive engagement have supported that cognitive demands assessed by participants on activities varied as a function of participants’ cognitive resources: lower cognitive resources were associated with lower perceived cognitive demands.     

Central executive function in mild cognitive impairment: a PET activation study

Using positron emission tomography (PET), we explored the neural correlates of an executive function, dual tasking, in patients with amnestic mild cognitive impairment (aMCI) and in elderly controls. The experiment employed simple auditory and visual tasks that were presented both in isolation and simultaneously to create a task condition requiring enhanced attentional control. Behaviorally, both groups performed well, albeit the patients made more errors on the visual task. The PET analysis focused at prefrontal regions where group differences in task-related activation patterns were expected. During dual task performance, the patients showed attenuated activity in the left inferior frontal region when compared to the controls. This suggests abnormalities in the neural processes underlying attentional control in aMCI.     

Developmental shifts in fMRI activations during visuospatial relational reasoning

To investigate maturational plasticity of fluid cognition systems, functional brain imaging was undertaken in healthy 8-19 year old participants while completing visuospatial relational reasoning problems similar to Raven's matrices and current elementary grade math textbooks. Analyses revealed that visuospatial relational reasoning across this developmental age range recruited activations in the superior parietal cortices most prominently, the dorsolateral prefrontal, occipital-temporal, and premotor/supplementary cortices, the basal ganglia, and insula. There were comparable activity volumes in left and right hemispheres for nearly all of these regions. Regression analyses indicated increasing activity predominantly in the superior parietal lobes with developmental age. In contrast, multiple anterior neural systems showed significantly less activity with age, including dorsolateral and ventrolateral prefrontal, paracentral, and insula cortices bilaterally, basal ganglia, and particularly large clusters in the midline anterior cingulate/medial frontal cortex, left middle cingulate/supplementary motor cortex, left insula-putamen, and left caudate. Findings suggest that neuromaturational changes associated with visuospatial relational reasoning shift from a more widespread fronto-cingulate-striatal pattern in childhood to predominant parieto-frontal activation pattern in late adolescence.     

Mental rotation of mirrored letters: evidence from event-related brain potentials

Event-related brain potentials (ERPs) were recorded while participants (n=13) were presented with mirrored and normal letters at different orientations and were asked to make mirror-normal letter discriminations. As it has been suggested that a mental rotation out of the plane might be necessary to decide on mirrored letters, we wanted to determine whether this rotation occurs after the plane rotation in mirror rotated letters. The results showed that mirrored letters in the upright position elicited a negative-going waveform over the right hemisphere in the 400-500 ms window. A similar negativity was also present in mirrored letters at 30 degrees, 60 degrees, and 90 degrees, but in these cases it was delayed. Moreover, the well-known orientation effect on the amplitude of the rotation-related negativity was also found, although it was more evident for normal than for mirrored letters. These results indicate that the processing of mirrored letters differs from that of normal letters, and suggest that a rotation out of the plane after the plane rotation may be involved in the processing of mirror rotated letters.     

Long-term ability to interpret facial expression after traumatic brain injury and its relation to social integration

There is considerable evidence that individuals with traumatic brain injury (TBI) experience problems interpreting the emotional state of others. However, the functional implications of these changes have not been fully investigated. A study of 13 individuals with severe TBI and an equal number of matched controls found that TBI participants had significantly more difficulty interpreting facial expression and matching emotions to social situations. A significant relationship was also established between social integration and ability to interpret facial expression for TBI participants. These results support the inclusion of therapy targeting this area within rehabilitation programs for individuals with TBI.     

工作记忆负载对位置干扰子激活加工和抑制加工的影响

针对工作记忆（WM）负载对干扰子加工的影响存在认知控制机制和负载特异机制两种分歧观点的争议及Park等人的负载特异机制研究中存在的不足,文章尝试采用干扰效应和负启动效应双指标考察了三种不同类型的WM负载对位置干扰子加工的影响。结果表明,WM负载对位置干扰子加工的影响存在双重作用机制（认知控制机制和负载特异机制）;目标刺激与干扰子刺激的属性一致时,亦可得出负载特异机制观点,且可将WM任务与选择性注意任务之间竞争的资源锁定为知觉处理资源;导致上述两种观点争议的原因是以往研究未将干扰子加工过程分离为激活加工阶段和抑制加工阶段来考察;用双指标分离干扰子加工阶段的研究思路和方法不但可解决这两种观点的争议且可为两者的统合奠定基础。     

Centrally elicited aggressive behavior: A model system for the study of episodic neurobehavioral pathologies?

Studies in which the predatory-like attack of a cat upon a rat has been elicited by electrical brain stimulation have been briefly reviewed with an emphasis on the question of where within the central nervous system such brain stimulation is producing its behaviorally meaningful effects. Two opposing but by no means mutually exclusive views are considered. The first is that brain stimulation elicits this behavior pattern primarily because it affects a specific motivated behavior system that is organized discretely in the midbrain and pons. The second is that forebrain neural activity is modulated in behaviorally significant ways by brainstem stimulation, which elicits predatory-like aggressive behavior in the cat. The possibility that further research on the altered state of central nervous system activity, induced by brain stimulation which elicits aggressive behavior in the cat, may lead to a further understanding of the altered states of central nervous system activity that underlie the aggressive dyscontrol syndrome and other episodic state disorders is discussed.     

左前额叶参与非相关词对的语义编码过程──来自光学成像的佐证

通过研究左前额叶在非相关同对的语义编码过程中的作用,探讨近红外光学成像技术用于脑高级认知活动检测的可行性。被试在两种实验条件下分别学习视觉呈现的20个汉字非相关词对,要求被试或将词对组成一个有意义的句子(深加工),或判断两个词是否具有相同的结构组合(浅加工)。光学成像器即时记录连续光透过额骨及前额皮层后760nm和850nm的漫射光强变化,以此推测相应脑组织的血容量变化。结果表明,与浅加工相比,左下前额叶在深加工时的血容量增多,尤其是背外侧部分。