Neural substrates of cognitive skill learning in Parkinson's disease

While cognitive skill learning is normally acquired implicitly through frontostriatal circuitry in healthy individuals, neuroimaging studies suggest that patients with Parkinson's disease (PD) do so by activating alternate, intact brain areas associated with explicit memory processing. To further test this hypothesis, 10 patients with PD and 12 healthy controls were tested on a modified, learning version of the Tower of London task while undergoing positron emission tomography at four different time points over the course of learning. Despite having less accurate problem solving abilities than controls, PD patients were able to acquire the skill learning task. However, as compared to controls, they maintained higher levels of cerebral blood flow activity in the dorsolateral prefrontal cortex and hippocampus and showed an increase in activity in the frontopolar cortex and posterior cingulate over the course of learning. These findings reflect a shift to the explicit memory system in PD patients, enabling them to learn this cognitive skill, which is normally acquired by control subjects using implicit learning strategies and frontostriatal circuitry.     

Elucidating the neural correlates of egoistic and moralistic self-enhancement

Self-enhancement is the biasing of one’s view of oneself in a positive direction. The brain correlates of self-enhancement remain unclear though it has been reported that the medial prefrontal cortex (MPFC) may be important for producing self-enhancing responses. Previous studies have not examined whether the neural correlates of self-enhancement depend on the particular domain in which individuals are enhancing themselves. Both moralistic and egoistic words were presented to participants while transcranial magnetic stimulation (TMS) was applied to the MPFC, precuneus or in a sham orientation. Participants were asked to make decisions as to the words describing themselves, some of which were positive and some of which were negative. It was found the MPFC TMS significantly disrupted egoistic self-enhancement when TMS was delivered to the MPFC. Judgments involving moralistic words were not influenced by TMS. These data provide further evidence that MPFC is involved in self-enhancement, and that the role of MPFC may be selective in this regard.     

False recognition of emotional stimuli is lateralised in the brain: An fMRI study

We have investigated whether the left (LH) and right (RH) hemisphere play a different role in eliciting false recognition (FR) and whether their involvement in this memory illusion depends on the emotional content of stimuli. Negative and neutral pictures (taken from IAPS) were presented in the divided-visual field paradigm. Subjects task was to indicate whether the pictures had already been presented or not during the preceding study phase. FR rate was much higher for the RH than the LH presentations. In line, FR resulted in activations mainly in the right prefrontal cortex (PFC) for either RH or LH presentations. Emotional content of stimuli facilitated the formation of false memories and strengthened the involvement of the right PFC in FR induction.     

非语言情境中时间加工与空间距离加工的关系

时间加工与空间距离加工的关系主要有两种, 一种是在空距离–空时距以及动物的研究中, 时间加工影响空间距离加工, 空间距离加工影响时间加工, 两者相互影响, 存在对称的干扰, 这种关系与注意和记忆有关。另一种是在实距离–实时距中, 空间距离加工影响时间加工, 而时间加工不受空间距离加工的影响, 时间加工和空间距离加工之间具有不对称的干扰。时空关系的不对称与隐喻理论、人们的感知运动经验和时空信息的显著性有关。神经机制上, 右顶叶皮质、侧顶内区、左顶叶皮质、小脑、前额等参与时间加工和空间距离加工, 但两种加工涉及到的神经机制也有部分差异。未来可以从时间加工的分段性、不同条件下时间加工和空间距离加工的心理机制以及脑机制进行研究。     

Right hemisphere specialization for color detection

Three experiments were carried out to investigate hemispheric asymmetry in color processing among normal participants. In Experiment 1, it was shown that the reaction times (RTs) of the dominant and non-dominant hands assessed using a visual target presented at the central visual field, were not significantly different. In Experiment 2, RTs of ipsilateral hands to lateralized chromatic stimuli revealed that the processing time was 17 ms shorter in the right hemisphere (RH) than that in the left hemisphere among the right-handed participants, whereas no significant difference was found among the left-handed participants. On the other hand, RTs to lateralized achromatic stimuli showed no such asymmetry among both the right- and left-handed participants (Experiment 3). These findings strongly suggest RH superiority for detection of color among right-handed individuals.     

Right hemispatial neglect: frequency and characterization following acute left hemisphere stroke

The frequency of various types of unilateral spatial neglect and associated areas of neural dysfunction after left hemisphere stroke are not well characterized. Unilateral spatial neglect (USN) in distinct spatial reference frames have been identified after acute right, but not left hemisphere stroke. We studied 47 consecutive right handed patients within 48h of left hemisphere stroke to determine the frequency and distribution of types of right USN using cognitive testing and MRI imaging. The distribution of USN types was different from the previously reported distribution following acute right hemisphere stroke. In this left hemisphere stroke population, allocentric neglect was more frequent than egocentric neglect.     

Action monitoring and perfectionism in anorexia nervosa

To study action monitoring in anorexia nervosa, behavioral and EEG measures were obtained in underweight anorexia nervosa patients (n=17) and matched healthy controls (n=19) while performing a speeded choice-reaction task. Our main measures of interest were questionnaire outcomes, reaction times, error rates, and the error-related negativity ERP component. Questionnaire and behavioral results indicated increased perfectionism in patients with anorexia nervosa. In line with their perfectionism and controlled response style patients made significantly less errors than controls. However, when controlling for this difference in error rates, the EEG results demonstrated a reduced error-related negativity in the patient group. These seemingly contradictory outcomes of improved performance and reduced error monitoring are discussed in relation with indications of anterior cingulate cortex hypoactivity in anorexia nervosa patients.     

后悔的认知机制和神经基础

后悔是基于对不利或相对不利行为结果的反事实思维诱发的一种复杂的负性社会情绪,对我们日常生活的决策和身心健康具有重大的影响。与失望情绪相比,后悔在现象学、产生条件以及评价方式等方面具有明显的差异。后悔不仅会受到个体的行为方式、人格特征、归因等因素的影响,而且还会受到结果信息属性的影响。后悔的预期和体验涉及的功能性脑区主要包括：眶额皮层、扣带前回、海马、杏仁核。研究后悔的实验方法和技术手段有待于进一步拓展,后悔的认知机制和神经基础还有待于进一步探讨和完善     

The Importance of Sound for Cognitive Sequencing Abilities: The Auditory Scaffolding Hypothesis

ABSTRACT— Sound is inherently a temporal and sequential signal. Experience with sound therefore may help bootstrap—that is, provide a kind of "scaffolding" for—the development of general cognitive abilities related to representing temporal or sequential patterns. Accordingly, the absence of sound early in development may result in disturbances to these sequencing skills. In support of this hypothesis, we present two types of findings. First, normal-hearing adults do best on sequencing tasks when the sense of hearing, rather than sight, can be used. Second, recent findings suggest that deaf children have disturbances on exactly these same kinds of tasks that involve learning and manipulation of serial-order information. We suggest that sound provides an "auditory scaffolding" for time and serial-order behavior, possibly mediated through neural connections between the temporal and frontal lobes of the brain. Under conditions of auditory deprivation, auditory scaffolding is absent, resulting in neural reorganization and a disturbance to cognitive sequencing abilities.     

注意缺陷多动障碍的研究与治疗

注意缺陷多动障碍（ADHD）的发病群体多为5岁以后的儿童,主要临床表现是多动、冲动,注意力无法集中,对一项任务不能够有规划进行下去,而且脾气暴躁、易怒。近年来,心理学界、神经科学界和教育学界等对ADHD的研究取得了很多进展。本文概括性地介绍了ADHD病症的基本特征,目前对于患者脑机制损害的研究,并从药理学和行为学等方面讨论了ADHD的治疗方法和手段。