Cognitive and emotional processes during dreaming: a neuroimaging view

Dream is a state of consciousness characterized by internally-generated sensory, cognitive and emotional experiences occurring during sleep. Dream reports tend to be particularly abundant, with complex, emotional, and perceptually vivid experiences after awakenings from rapid eye movement (REM) sleep. This is why our current knowledge of the cerebral correlates of dreaming, mainly derives from studies of REM sleep. Neuroimaging results show that REM sleep is characterized by a specific pattern of regional brain activity. We demonstrate that this heterogeneous distribution of brain activity during sleep explains many typical features in dreams. Reciprocally, specific dream characteristics suggest the activation of selective brain regions during sleep. Such an integration of neuroimaging data of human sleep, mental imagery, and the content of dreams is critical for current models of dreaming; it also provides neurobiological support for an implication of sleep and dreaming in some important functions such as emotional regulation.     

人类大脑结构和功能的性别差异：来自脑成像研究的证据

大脑的性别差异近年来受到了广泛关注。脑成像技术的出现为脑结构和脑功能性别差异的研究开辟了新的道路。借助结构磁共振成像和弥散张量成像等脑结构信息, 以及脑电图、正电子发射断层扫描技术和功能性磁共振成像等脑功能信息, 当前研究主要探讨了脑灰质、脑白质和大脑的基线活动在脑局部区域、脑子系统、全脑连接组三个层次上的性别差异及其在年龄上的发展变化。此外, 为了更好地理解脑性别差异, 当前文章还探讨了脑性别差异研究领域的一些认识误区。有关脑性别差异的研究虽然已经取得了丰富的成果, 但现有的研究结果存在很多分歧, 仍然有深入挖掘的空间。未来应该加强对具有性别特异性的心理疾病脑机制的研究, 关注基因和环境对脑性别差异的交互作用, 并利用脑功能活动动态变化的特性、以及结合多模态的脑成像技术进一步阐明脑性别差异。     

Functional Neuroimaging and the Law: Trends and Directions for Future Scholarship

Under the umbrella of the burgeoning neurotransdisciplines, scholars are using the principles and research methodologies of their primary and secondary fields to examine developments in neuroimaging, neuromodulation and psychopharmacology. The path for advanced scholarship at the intersection of law and neuroscience may clear if work across the disciplines is collected and reviewed and outstanding and debated issues are identified and clarified. In this article, I organize, examine and refine a narrow class of the burgeoning neurotransdiscipline scholarship; that is, scholarship at the interface of law and functional magnetic resonance imaging (fMRI).     

脑功能定位在社会认知研究中的作用及其启示

本文阐述了脑功能定位的具体技术及其与社会心理现象相结合的心理神经模型。这种结合的趋势有助于促进神经科学和社会心理学的发展,有助于解释社会心理现象中固有的一些具体问题。同时,由于社会心理现象的复杂性,因此并不一定都适合直接进行脑功能定位。     

神经成像读心中的认知本体论疑难

认知神经科学的研究者们在使用神经成像技术进行读心时,运用到了反向推理和大脑解码两种策略。但目前相关研究中所涉及的同一认知过程或心理功能的具体内涵并不统一,反映出认知神经科学部分术语存在定义混乱的现象。这一方面使得反向推理面临相关脑区缺乏选择性的难题,另一方面也限制了大脑解码的准确率。对此最有希望的一种解决办法是建立认知本体论,可它仍然在技术、方法以及哲学三个层面上存在疑难,这削弱了利用神经成像去读取他人思想这一做法的可靠性及合理性。

     

Effects of tasks on BOLD signal responses to sentence contrasts: Review and commentary

Functional neuroimaging studies of syntactic processing have been interpreted as identifying the neural locations of parsing and interpretive operations. However, current behavioral studies of sentence processing indicate that many operations occur simultaneously with parsing and interpretation. In this review, we point to issues that arise in discriminating the effects of these concurrent processes from those of the parser/interpreter in neural measures and to approaches that may help resolve them.     

Functional neuroimaging of autobiographical memory

Functional neuroimaging studies of autobiographical memory have grown dramatically in recent years. These studies are important because they can investigate the neural correlates of processes that are difficult to study using laboratory stimuli, including: (i) complex constructive processes, (ii) recollective qualities of emotion and vividness, and (iii) remote memory retrieval. Constructing autobiographical memories involves search, monitoring and self-referential processes that are associated with activity in separable prefrontal regions. The contributions of emotion and vividness have been linked to the amygdala and visual cortex respectively. Finally, there is evidence that recent and remote autobiographical memories might activate the hippocampus equally, which has implications for memory-consolidation theories. The rapid development of innovative methods for eliciting personal memories in the scanner provides the opportunity to delve into the functional neuroanatomy of our personal past.     

Functional neuroimaging of autistic disorders

Functional neuroimaging methods hold promise for elucidating the neurobiology of autistic disorders, yet they present difficult practical and scientific challenges when applied to these complex and heterogeneous syndromes. Single-state studies of brain metabolism and blood flow thus far have failed to yield consistent findings, but suggest considerable variability in regional patterns of cerebral synaptic activity. Patients with idiopathic autism are less likely to show abnormalities than are patients with comorbid illness or epilepsy. Activation studies have begun to suggest alterations in brain organization for language and cognition. Neurotransmitter studies using positron emission tomography (PET) suggest abnormalities of serotonergic and dopaminergic function. Studies using magnetic resonance spectroscopy (MRS) have begun to document metabolic deficits in the frontal cortex and cerebellum. A single study using magnetoencephalography suggests a high incidence of epileptiform activity in children with autistic regression. Research needs include well-controlled developmental studies, particularly of young subjects and relatively homogeneous subgroups, which balance scientific rigor with ethical constraints. Investigations of the serotonergic and dopaminergic systems, limbic-based memory and emotional systems, and the role of epileptiform activity in autism represent priorities for future research.     

A Brain-Based Account of the Development of Rule Use in Childhood

ABSTRACT— The ability to follow explicit rules improves dramatically during the course of childhood, but relatively little is known about the changes in brain structure and function that underlie this behavioral improvement. Drawing from neuroscientific studies in human adults and other animals, as well as from an emerging literature in developmental cognitive neuroscience, we propose a brain-based account of the development of rule use in childhood. This account focuses on four types of rules represented in different parts of the prefrontal cortex: simple rules for reversing stimulus–reward associations, pairs of conditional stimulus–response rules (both univalent and bivalent), and higher-order stimulus–response rules for selecting among task sets. It is hypothesized that the pattern of developmental changes in rule use reflects the different rates of development of specific regions within the prefrontal cortex.     

创造力的脑结构与脑功能基础

从脑结构和脑功能两方面对创造力的脑神经基础进行了评述。就创造力的脑结构而言,尸体脑解剖研究表明创造力可能与顶叶与角回有关;活体脑结构成像研究则显示,创造力主要与额叶、扣带回以及皮下白质或灰质浓度有关。就创造力的脑功能而言,任务取向研究表明创造力任务主要激活了额叶和顶叶及少数其他皮层区域;而个体差异取向研究则表明创造力被试激活了右侧额叶、大脑皮层以及小脑的某些区域。未来研究需在加强脑结构影像研究基础上,注重从被试抽样和筛选等方面细化任务模式和个体差异模式的创造力研究,以获得更一致的结果。     

Functional role theories of representation and content explanation: with a case study from spatial cognition

The aim of this paper is to show that the widespread opinion, according to which functional role theories of representation fail to account for content explanations of human and animal behaviour, cannot be confirmed with respect to each type of functional role theory. Functional resemblance theories (as referred to by O’Brien and Opie in Representation in mind, Elsevier, 2004) allow for content explanations of successfully performed cognitive abilities as much as for explanations of systematic errors resulting from misrepresentation. How functional roles do their explanatory work in actual scientific research examples is shown by a detailed exploration of model assumptions about homing performances based on path integration mechanisms in humans and animals.

Functional neuroimaging studies of syntactic processing

This paper reviews studies of the functional neuroanatomy of syntactic processing using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), focusing on interpretability of studies and the model of functional neuroanatomy that emerges from existing work. It is argued that existing studies suggest a specialization for one aspect of syntactic processing in the left inferior frontal cortex in proficient language users, with variability in this localization across the entire population.     

Functional neuroimaging correlates of functional amnesia

Especially in the field of memory encoding and retrieval, the results of functional neuroimaging have provided new insights in anatomico-functional interactions. In particular this holds true for the role of the prefrontal cortex in mnestic information processing, for the contribution and participation of the two hemispheres in various processes of information transmission, and for views on disturbed information processing after organically obvious and so-called psychogenic forms of memory impairments. This report particularly stresses the insights obtained by functional neuroimaging for probably environmentally triggered deficiencies in memory processing and discusses possible subtle neuroanatomical correlates of functional amnesias. It is especially emphasised that stress conditions and depressive states may modify the release of steroids (glucocorticoids) and transmitter agonists at the brain level with the consequence of selective memory disturbances which may manifest as a "mnestic block syndrome".     

Functional neuroimaging studies of human emotions

Neuroimaging studies with positron emission tomography and functional magnetic resonance imaging have begun to describe the functional neuroanatomy of human emotion. Taken separately, specific studies vary in task dimensions and in type(s) of emotion studied, and are limited by statistical power and sensitivity. By examining findings across studies in a meta-analysis, we sought to determine if common or segregated patterns of activations exist in different emotions and across various emotional tasks. We surveyed over 55 positron emission tomography and functional magnetic resonance imaging activation studies, which investigated emotion in healthy subjects. This paper will review observations in several regions of interest in limbic (eg, amygdala, anterior cingulate cortex) and paralimbic (eg, medial prefrontal cortex, insula) brain regions in emotional responding.     

Integrating functional neuroimaging and human operant research: brain activation correlated with presentation of discriminative stimuli

Results of numerous human imaging studies and nonhuman neurophysiological studies on "reward" highlight a role for frontal, striatal, and thalamic regions in operant learning. By integrating operant and functional neuroimaging methodologies, the present investigation examined brain activation to two types of discriminative stimuli correlated with different contingencies. Prior to neuroimaging, 10 adult human subjects completed operant discrimination training in which money was delivered following button pressing (press-money contingency) in the presence of one set of discriminative stimuli, and termination of trials followed not responding (no response-next trial contingency) in the presence of a second set of discriminative stimuli. After operant training, subjects were instructed to memorize a third set of control stimuli unassociated with contingencies. Several hours after training, functional magnetic resonance imaging was performed while subjects viewed discriminative and control stimuli that were presented individually for 1,500 ms per trial, with stimulus presentations occurring, on average, every 6 s. Activation was found in frontal and striatal brain regions to both sets of discriminative stimuli relative to control stimuli. In addition, exploratory analyses highlighted activation differences between discriminative stimuli. The results demonstrate the utility of coupling operant and imaging technologies for investigating the neural substrates of operant learning in humans.     

Putative sex differences in verbal abilities and language cortex: a critical review

This review brings together evidence from a diverse field of methods for investigating sex differences in language processing. Differences are found in certain language-related deficits, such as stuttering, dyslexia, autism and schizophrenia. Common to these is that language problems may follow from, rather than cause the deficit. Large studies have been conducted on sex differences in verbal abilities within the normal population, and a careful reading of the results suggests that differences in language proficiency do not exist. Early differences in language acquisition show a slight advantage for girls, but this gradually disappears. A difference in language lateralization of brain structure and function in adults has also been suggested, perhaps following size differences in the corpus callosum. Neither of these claims is substantiated by evidence. In addition, overall results from studies on regional grey matter distribution using voxel-based morphometry, indicate no consistent differences between males and females in language-related cortical regions. Language function in Wada tests, aphasia, and in normal ageing also fails to show sex differentiation.