Cognitive Neuroscience, Temporal Ordering, and the Human Spirit

Understanding purpose and intent requires attention to our experience of time. Cognitive neuroscientific research into the functional and neural substrates of higher cognitive functions have direct bearing on the experience of temporal ordering. Consciousness, located within the short span of working memory, is made cognitively possible and evolutionarily valuable by biological constraints in time. These constraints, including our longevity, make thought about more extended events both possible and useful. Such cognitive processes, rooted in the neurophysiology of cortical function, are a sine qua non for the construction of meaning, relationship, morality, and purposes that may extend beyond our mortality. Research in the cognitive neurosciences is overviewed, and implications are discussed for questions of mortality, design and intention, the reconstruction of meaning, and the experience of eternity.     

The neural basis of cognitive control: Response selection and inhibition

The functional neuroanatomy of tasks that recruit different forms of response selection and inhibition has to our knowledge, never been directly addressed in a single fMRI study using similar stimulus–response paradigms where differences between scanning time and sequence, stimuli, and experimenter instructions were minimized. Twelve right-handed participants were scanned on two standard cognitive control tasks, a stimulus–response incompatibility task, and a response inhibition task. A compound trial design allowed comparison of preparing to inhibit an upcoming automatic response to wholly inhibiting an automatic response. Furthermore, inhibiting an automatic response to perform an alternative task-relevant response was compared to wholly inhibiting an automatic response. No differences were found in prefrontal activity when preparing to inhibit an automatic response was compared to wholly inhibiting an automatic response, suggesting a mostly common network. The left inferior frontal gyrus was found to be commonly recruited during both tasks when controlled responses were required, likely due to its role in response selection. In contrast, the right inferior frontal gyrus was found to be more involved when task demands were stronger for response inhibition. Our results are largely consistent with models of cognitive control that postulate that separate psychological constructs, such as response selection and inhibition, are related processes largely served by a common prefrontal network. This prefrontal network is recruited to a greater or lesser extent depending on specific task demands.     

Self-referential processing of negative stimuli within the ventral anterior cingulate gyrus and right amygdala

Neural activity associated with self-referential processing of emotional stimuli was investigated using whole brain functional magnetic resonance imaging (fMRI). Fifteen healthy subjects underwent fMRI scanning while making judgments about positive and negative trait words in four conditions (self-reference, other-reference, semantic processing, and letter processing). Significant activity was observed in the right ventral anterior cingulate gyrus and the right amygdala in the negative-word/self-reference condition, and in the left amygdala in the positive-word/self-reference condition. Compared with the semantic-processing condition, the self-reference conditions showed significantly more activity in the medial prefrontal and temporal gyri, posterior cingulate gyrus, and precuneus. These results suggest that the medial prefrontal gyrus, posterior cingulate gyrus, and precuneus are associated with a self-referential processing, and the ventral anterior cingulate gyrus is involved in self-referential processing of negative emotional stimuli. The results also suggest that the amygdala is associated with self-referential processing of both positive and negative emotional stimuli.     

选择扩散效应研究的回顾与前瞻

由失调导致的态度改变一直受到社会心理学的关注,选择扩散效应是态度改变的结果之一。多个理论模型对此做出各种解释,近年来对失调的脑机制研究为行为模型提供了新的证据。文化心理学也涉足了这方面的研究,并多以自我模型为基础,发现东西方人在对失调的体验及随后的态度变化上存在文化差异。总结了选择扩散效应的研究意义后,文章从该效应的研究范式、心理机制和脑机制、文化影响三方面对相关研究进行回顾,在此基础上提出研究范式的区分、模型的整合、脑机制的进一步研究、减缓失调的积极作用是未来的研究趋势,并指出跨文化研究中应注意的问题     

联觉的认知神经机制

联觉是指由一种感官刺激引起其他感官体验的心理过程。近年来的研究将行为实验和脑成像技术结合,发现了联觉的认知神经基础。本文总结了最受关注的字形-颜色联觉的研究成果,认为联觉发生在视知觉加工的早期阶段,与知觉在本质上有许多共同特征,其脑区涉及梭状回（V4）和顶叶。未来联觉的研究将通过综合运用各种方法,进一步拓宽研究范围。     

The expression of c-Fos and colocalisation of c-Fos and glucocorticoid receptors in brain structures of low and high anxiety rats subjected to extinction trials and re-learning of a conditioned fear response

We designed an animal model to examine the mechanisms of differences in individual responses to aversive stimuli. We used the rat freezing response in the context fear test as a discriminating variable: low responders (LR) were defined as rats with a duration of freezing response one standard error or more below the mean value, and high responders (HR) were defined as rats with a duration of freezing response one standard error or more above the mean value. We sought to determine the colocalisation of c-Fos and glucocorticoid receptors-immunoreactivity (GR-ir) in HR and LR rats subjected to conditioned fear training, two extinction sessions and re-learning of a conditioned fear. We found that HR animals showed a marked decrease in conditioned fear in the course of two extinction sessions (16 days) in comparison with the control and LR groups. The LR group exhibited higher activity in the cortical M2 and prelimbic areas (c-Fos) and had an increased number of cells co-expressing c-Fos and GR-ir in the M2 and medial orbital cortex after re-learning a contextual fear. HR rats showed increased expression of c-Fos, GR-ir and c-Fos/GR-ir colocalised neurons in the basolateral amygdala and enhanced c-Fos and GR-ir in the dentate gyrus (DG) in comparison with LR animals. Our data indicate that recovery of a context-related behaviour upon re-learning of contextual fear is accompanied in HR animals by a selective increase in c-Fos expression and GRs-ir in the DG area of the hippocampus.     

South African International Migration and its Impact on Older Family Members

In this article, we explore the impact of South African families’ emigration on parents/grandparents who must renegotiate their lives in their loved ones’ physical absence. We adopted a transnational perspective in a bigger qualitative project to consider both sides of the migratory spectrum. Here we focus on elderly family members who remain behind—a group largely neglected in prior research. Our findings illustrate the complex emotions and relational changes experienced by elderly people whose families emigrate. New technologies bridge distances, allowing new ways to connect and take care of each other, and of re-imagining transnational relationships and what constitutes family life, but these bridges cannot negate the loss experienced by those remaining. People have to make sense of the emigration and forge new relational bonds with remaining family members. Our findings stress grandparents’ meaningful role in a family system and highlight some gendered and racial differences in families’ experiences.     

Remembering Early Childhood: How Much, How, and Why (or Why Not)

In this article, we consider recent research on three questions about people's memories for their early childhood: whether childhood amnesia is a real phenomenon, whether implicit memories survive when explicit memories do not, and why early episodic memories are sketchy. The research leads us to form three conclusions. First, we argue that childhood amnesia is a real phenomenon, as long as the term is defined clearly. Specifically, people are able to recall parts of their lives from the period between ages 2 and 5 years, but they recall less from that period than from other periods. Second, we conclude that implicit memories from early childhood may be evident even when explicit memories are not, a finding that suggests early experience may affect behavior in ways that people do not consciously recognize. Third, we argue that although young children are well known to be wonderfully efficient learners of semantic information, they have difficulty in either encoding or retrieving the interlinked aspects of events that lend them their autobiographical character. Although more evidence is needed, the relative lack of episodic memories of early childhood may be linked to maturation of prefrontal cortex.     

Frontal Lobe Function and Pain in the Elderly

We review the literature on pain and aging and conclude that evidence supports a hypothesis that right frontal cortex contributes to the mediation of the chronic pain experience in elderly persons with chronic pain syndromes. Evidence for the right frontal pain hypothesis comes from clinical, neurocognitive, and neuroimaging studies, which implicate right inferior and orbitofrontal cortex in (1) the persistent pain experience, (2) negative emotional states, (3) retrieval of negative emotional and autobiographical memories, (4) regulation of autonomic arousal, and (5) regulation of attentional and pain functions of the anterior cingulate region. Right frontal dysfunction is also implicated in the effects of cognitive aging. If right frontal neurocognitive systems are affected in cognitively impaired elderly, and if (by hypothesis) the right frontal cortex also plays a major role in the experience of chronic pain, then cognitively impaired elderly with right frontal dysfunction should be protected to some extent from persistent pain syndromes. Available evidence supports this proposition.     

The right parahippocampal gyrus contributes to the formation and maintenance of bound information in working memory

Working memory is devoted to the temporary storage and on-line manipulation of information. Recently, an integrative system termed the episodic buffer has been proposed to integrate and hold information being entered or retrieved from episodic memory. Although the brain system supporting such an integrative buffer is still in debate, the medial temporal lobe appears to be a promising candidate for the maintenance of bound information. In the current work, binding was assessed by comparing two conditions in which participants had to retain three letters and three spatial locations presented either bound or separate. At the behavioral level, lower performance was found for bound information than for separate information. When contrasting the two conditions, activation in the right parahippocampal gyrus was greater for the encoding and maintenance of bound information. No activation was observed in the medial temporal lobe during the retrieval of bound information. Together, our results suggest that the parahippocampal gyrus may underlie the integrative and maintenance functions of the episodic buffer.