An analysis of independence and interactions of brain substrates that subserve multiple attributes, memory systems, and underlying processes

It is proposed that memory is organized into event-based, knowledge-based, and rule-based memory systems. Furthermore, each system is composed of the same set of multiple attributes and characterized by a set of process oriented operating characteristics that are mapped onto multiple neural regions and interconnected neural circuits. Based on this theoretical model of memory, it is possible to investigate the independence and interaction among brain regions between any two systems for any of the proposed attributes or processes. This applies also to the investigation of independence and interactions between any two attributes within a system and between processes associated with a system for any of the proposed attributes. In this article, research evidence is presented to suggest that there are both dissociations and interactions between the hippocampus and caudate nucleus in mediating spatial and response attributes within the event-based memory system, between the hippocampus and the parietal cortex in subserving the spatial attribute within the event-based and knowledge-based memory systems, and between the hippocampus and the prefrontal cortex in subserving the spatial attribute within the event-based and rule-based memory systems.     

Automatic and effortful information processing in unipolar major depression

The present study investigated attentional dysfunction in patients with recurrent unipolar major depression in a visual search paradigm. The attentional aspects of automatic and effortful information processing were examined. The general hypothesis was that patients with unipolar major depression would have more problems with tasks that require effortful information processing than with tasks that require only automatic information processing. A task requiring effortful processing attracts attention, is more demanding, and is instruction-driven. A task that is automatically processed does not invoke attention, is less demanding, and is stimulus-driven. The results showed that the patient group needed significantly longer reaction times on the tasks requiring more effortful information processing than the control group, but there were no significant differences between groups on tasks requiring automatic information processing. Thus it seems as if the depressed patients show an impaired profile as a function of the degree of effort a task requires.     

Sex differences in parietal lobe morphology: relationship to mental rotation performance

Structural magnetic resonance imaging (MRI) studies of the human brain have reported evidence for sexual dimorphism. In addition to sex differences in overall cerebral volume, differences in the proportion of gray matter (GM) to white matter (WM) volume have been observed, particularly in the parietal lobe. To our knowledge there have been no studies examining the relationship between the sex differences in parietal lobe structure and function. The parietal lobe is thought to be involved in spatial ability, and particularly involved in mental rotation. The purpose of this study is to examine whether sex differences in parietal lobe structure are present, and if present to relate these differences to performance on the mental rotations test (MRT). We found that women had proportionately greater gray matter volume in the parietal lobe compared to men, and this morphologic difference was disadvantageous for women in terms of performance on the MRT. In contrast, we found that men compared to women had proportionately greater parietal lobe surface area, and this morphologic difference was associated with a performance advantage for men on mental rotation. These findings support the possibility that the sexual dimorphism in the structure of the parietal lobe is a neurobiological substrate for the sex difference in performance on the mental rotations test.     

Controlled & automatic processing: behavior,theory, and biological mechanisms

This paper provides an overview of developments in a dual processing theory of automatic and controlled processing that began with the empirical and theoretical work described by Schneider and Shiffrin (1977) and Shiffrin and Schneider (1977) over a quarter century ago. A review of relevant empirical findings suggests that there is a set of core behavioral phenomena reflecting differences between controlled and automatic processing that must be addressed by a successful theory. These phenomena relate to: consistency in training, serial versus parallel processing, level of effort, robustness to stressors, degree of control, effects on long‐term memory, and priority encoding. We detail a computational model of controlled processing, CAP2, that accounts for these phenomena as emergent properties of an underlying hybrid computational architecture. The model employs a large network of distributed data modules that can categorize, buffer, associate, and prioritize information. Each module is a connectionist network with input and output layers, and each module communicates with a central Control System by outputting priority and activity report signals, and by receiving control signals. The Control System is composed of five processors including a Goal Processor, an Attention Controller, an Activity Monitor, an Episodic Store, and a Gating & Report Relay. The transition from controlled to automatic processing occurs in this model as the data modules become capable of transmitting their output without mediation by the Control System. We describe recent progress in mapping the components of this model onto specific neuroanatomical substrates, briefly discuss the potential for applying functional neuroimaging techniques to test the model's predictions, and its relation to other models.     

赖氨酰氧化酶在动脉粥样硬化中的作用

赖氨酰氧化酶(lysyl oxidase,LOX)是一种铜依赖性氨基氧化酶,在多个组织器官中均有表达,能参与催化细胞外基质(extracellular matrix,ECM)中胶原和弹性纤维的赖氨酸残基交联,以维持细胞外基质的结构和功能正常。新近研究发现LOX与动脉粥样硬化亦有紧密关系。本文就LOX在动脉粥样硬化发生、发展过程中的联系作一综述。     

尼莫地平改善高钙所致记忆障碍的脑内突触机制

海马内微量注射高钙造成小鼠记忆障碍后,观察了尼莫地平（腹腔注射）对记忆障碍的改善作用,并用透射电镜和图像分析仪对海马CA3区Gray I型突触界面结构参数进行了观测和定量分析,进一步探讨尼莫地平改善高钙所致记忆障碍的脑内突触机制。结果表明,尼莫地平确能改善高钙所致记忆障碍,并能显著逆转高钙所致的小鼠海马CA3区突触间隙宽度显著增大,PSD极显著变薄,平坦型突触显著增多,凹型和穿孔型突触显著减少等一系列突触界面结构的病理性变化。提示海马CA3区Gray I型突触界面结构参数的逆转可能是钙拮抗剂尼莫地平改善高钙所致记忆障碍的形态学基础     

A Combined-Constructionist Therapeutic Approach to Couples Experiencing Erectile Dysfunction: Part II

This paper is Part II of an exploration of the treatment and conceptualization of Erectile Dysfunction (ED). In the past two decades, there has been a shift in the treatment of Erectile Dysfunction to more medically based approaches. Part I of the paper presented the role of biomedical and organic factors involved in ED. However, although important for the couple therapist to understand, by focusing only on the bio-medical aspects of ED, the couple may face new issues in their considerably different relationship with sex now a part of their lives. The current paper, while respectful of the medical model approach, emphasizes the overall quality of the couple relationship, presenting information on the psychological and systemic therapies and issues that may be related to Erectile Dysfunction, encouraging a combined-constructionist approach.     

Atrophy of the parietal lobe in preclinical dementia

Cortical grey matter atrophy patterns have been reported in healthy ageing and Alzheimer disease (AD), but less consistently in the parietal regions of the brain. We investigated cortical grey matter volume patterns in parietal areas. The grey matter of the somatosensory cortex, superior and inferior parietal lobule was measured in 75 older adults (38 cognitively stable and 37 individuals with cognitive decline after 3 years). Dementia screening 6 years after scanning resulted in nine AD cases from the cognitively stable (n=3) and cognitive decline group (n=6), who were assigned to a third group, the preclinical AD group. When regional differences in cortical volume in the parietal lobe areas were compared between groups, significant differences were found between either the cognitive decline or stable group on the one hand and preclinical AD individuals on the other hand in the inferior parietal lobule. Group membership was best predicted by the grey matter volume of the inferior parietal lobule, compared to the other parietal lobe areas. The parietal lobe was characterised by a differential atrophy pattern based on cognitive status, which is in agreement with the 'last-developed-first-atrophied' principle. Future studies should investigate the surplus value of the inferior parietal lobe as a potential marker for the diagnosis of AD compared to other brain regions, such as the medial temporal lobe and the prefrontal lobe.     

Common spatial organization of number and emotional expression: a mental magnitude line

Converging behavioral and neural evidence suggests that numerical representations are mentally organized in left-to-right orientation. Here we show that this format of spatial organization extends to emotional expression. In Experiment 1, right-side responses became increasingly faster as number (represented by Arabic numerals) or happiness (depicted in facial stimuli) increased, for judgments completely unrelated to magnitude. Additional experiments suggest that magnitude (i.e., more/less relations), not valence (i.e., positive/negative), underlies left-to-right orientation of emotional expression (Experiment 2), and that this orientation accommodates to the context-relevant emotion (e.g., happier faces are more rightward when judged on happiness, but more leftward when judged on angriness; Experiment 3). These findings show that people automatically extract magnitude from a variety of stimuli, representing such information in common left-to-right format, perhaps reflecting a mental magnitude line. We suggest that number is but one dimension in a hyper-general representational system uniting disparate dimensions of magnitude and likely subserved by common neural mechanisms in posterior parietal cortex.     

Psychosomatic disorders: the canalization of mind into matter

Psychosomatic disorders represent a therapeutic conundrum. Despite compelling evidence to suggest the integrity of mind and body, humans are famously prone to experiencing them as separate. This paper explores the scientific challenges posed by psychosomatic disorders and how changing cultural notions contribute to their perplexing presentations. Excerpts of cases from patients with chronic pelvic pain, chronic fatigue, and a factitious disorder are presented as examples of the challenges that these patients pose in analysis. An explanatory model of mind/body interaction based on early maternal-infant interactions and the placebo response complex is proposed as the basis for how psychosomatic pathologies may develop. Finally, therapeutic approaches to the psychological treatment of patients with psychosomatic issues are considered.