The Limbic System and the Soul: Evolution and the Neuroanatomy of Religious Experience

The evolutionary neurological foundations of religious experience are detailed. Human beings have been burying and preparing their dead for the Hereafter for more than 100,000 years. These behaviors and beliefs are related to activation of the amygdala, hippocampus, and temporal lobe, which are responsible for religious, spiritual, and mystical trancelike states, dreaming, astral projection, near-death and out-of-body experiences, and the hallucination of ghosts, demons, angels, and gods. Abraham, Moses, Muhammad, and Jesus Christ, and others who have communed with angels or gods display limbic system hyperactivity, whereas patients report religious hallucinations or out-of-body experiences when limbic structures are stimulated or excessively activated. It is postulated that limbic and temporal lobe structures account for the sexual and violent aspects of religious behavior and also serve as a "transmitter to God," and that the evolution of these structures made spiritual experience possible.     

Neural Bases of Human Working Memory

Working memory is the memory system that allows us to briefly keep information active, often so we can operate on it. Studies with rhesus monkeys first established that this system is partly mediated by neural mechanisms in the prefrontal cortex. Recently, there has been a substantial effort to study the neural bases of working memory in humans, using neuroimaging techniques such as positron emission tomography and functional magnetic resonance imaging. Some of the initial neuroimaging studies with humans focused on the neural mechanisms that mediate our ability to keep spatial information active. These results indicated that human spatial working memory is partly mediated by regions in parietal and prefrontal cortex. Subsequent research has shown that a different neural system is involved when people store object (rather than spatial) information, a difference similar to that found in monkeys.     

Does medial prefrontal cortex activity during self‐knowledge reference reflect the uniqueness of self‐knowledge?1

Abstract: For this study, functional magnetic resonance imaging was used to examine whether medial prefrontal cortex (MPFC) activity during self‐knowledge reference reflects the uniqueness of self‐knowledge. Experiment 1 investigated neural activity during self‐knowledge reference (“Does the word describe you?”) and self‐monitoring (“Does the word make you feel pleasant?”). The results showed that self‐knowledge reference and self‐monitoring activate common neural substrates within the MPFC. Experiment 2 compared neural activity produced by self‐knowledge reference, other‐knowledge (acquaintance‐knowledge) reference (“Does this word describe the person?”), and evaluation (“Is this word socially desirable?”). Results showed no increase in MPFC activity during self‐knowledge reference relative to other‐knowledge reference. Furthermore, self‐knowledge reference and other‐knowledge reference share common neural substrates within the MPFC. The results described indicate that it is unlikely that MPFC activity during self‐knowledge reference reflects the uniqueness of self‐knowledge. The feature, as reflected in MPFC activity, is discussed.     

Enhanced divergent thinking and creativity in musicians: a behavioral and near-infrared spectroscopy study

Empirical studies of creativity have focused on the importance of divergent thinking, which supports generating novel solutions to loosely defined problems. The present study examined creativity and frontal cortical activity in an externally-validated group of creative individuals (trained musicians) and demographically matched control participants, using behavioral tasks and near-infrared spectroscopy (NIRS). Experiment 1 examined convergent and divergent thinking with respect to intelligence and personality. Experiment 2 investigated frontal oxygenated and deoxygenated hemoglobin concentration changes during divergent thinking with NIRS. Results of Experiment 1 indicated enhanced creativity in musicians who also showed increased verbal ability and schizotypal personality but their enhanced divergent thinking remained robust after co-varying out these two factors. In Experiment 2, NIRS showed greater bilateral frontal activity in musicians during divergent thinking compared with nonmusicians. Overall, these results suggest that creative individuals are characterized by enhanced divergent thinking, which is supported by increased frontal cortical activity.     

Object-location memory: A lesion-behavior mapping study in stroke patients

Object-location memory is an important form of spatial memory, comprising different subcomponents that each process specific types of information within memory, i.e. remembering objects, remembering positions and binding these features in memory. In the current study we investigated the neural correlates of binding categorical (relative) or coordinate (exact) position information with objects in memory. Therefore, an object-location memory battery was used, including different task conditions assessing object-location memory, i.e. memory for position information per se, and binding object information with coordinate and categorical position information. Sixty-one stroke patients with focal brain lesions were examined and compared with 77 healthy matched controls. The lesion subtraction method was used to define the area of overlap. Results indicate an important role of the left posterior parietal cortex in the binding of both categorical and coordinate positions with object information. Additionally, the hippocampus seems important for categorical object-location memory. This suggests that categorical and coordinate object-location memory depend on similar cognitive and neural systems.     

Hierarchically organized behavior and its neural foundations: a reinforcement learning perspective

Research on human and animal behavior has long emphasized its hierarchical structure—the divisibility of ongoing behavior into discrete tasks, which are comprised of subtask sequences, which in turn are built of simple actions. The hierarchical structure of behavior has also been of enduring interest within neuroscience, where it has been widely considered to reflect prefrontal cortical functions. In this paper, we reexamine behavioral hierarchy and its neural substrates from the point of view of recent developments in computational reinforcement learning. Specifically, we consider a set of approaches known collectively as hierarchical reinforcement learning, which extend the reinforcement learning paradigm by allowing the learning agent to aggregate actions into reusable subroutines or skills. A close look at the components of hierarchical reinforcement learning suggests how they might map onto neural structures, in particular regions within the dorsolateral and orbital prefrontal cortex. It also suggests specific ways in which hierarchical reinforcement learning might provide a complement to existing psychological models of hierarchically structured behavior. A particularly important question that hierarchical reinforcement learning brings to the fore is that of how learning identifies new action routines that are likely to provide useful building blocks in solving a wide range of future problems. Here and at many other points, hierarchical reinforcement learning offers an appealing framework for investigating the computational and neural underpinnings of hierarchically structured behavior.     

传递性推理的ERP研究

以抽象的内容作为实验材料,测定15名大学生在完成三种不同类型的传递性推理任务和基线任务(记忆判断任务)时的事件相关电位(ERP),探讨传递性推理过程的脑内时程动态变化。研究发现,三种推理任务所诱发的波形基本一致,而推理任务与基线任务之间的ERP波形存在明显的差异。这说明对于传递性推理,被试可能是根据视觉的空间表征对信息进行加工的,结果进一步支持了心理模型理论。     

The biology of visual perspective and depression: A reply to Sutin

A recent meta-analysis by Munafò, Durrant, Lewis, and Flint (2009) [Munafò, M. R., Durrant, C., Lewis, G., & Flint, J. (2009). Gene × environment interactions at the serotonin transporter locus. Biological Psychiatry, 65, 211–219] questioned the meaning of studies searching for endophenotypes associated with the serotonin-transporter-linked promoter region (5-HTTLPR) polymorphism, including our study on visual perspective during autobiographical memory retrieval. However, the association of 3rd person perspective with vulnerability for depression does not rely only on genetics. External consistency is provided by the influence of the 5-HTTLPR polymorphism on brain regions involved in emotion regulation and autobiographical memory retrieval (e.g. the medial prefrontal cortex). Internal consistency is provided by the increased prevalence of 3rd person perspective in both currently and previously depressed patients, as well as in depression-prone individuals. Further studies should examine therapeutic opportunities.     

Infusion of protein synthesis inhibitors in the entorhinal cortex blocks consolidation but not reconsolidation of object recognition memory

Memory consolidation and reconsolidation require the induction of protein synthesis in some areas of the brain. Here, we show that infusion of the protein synthesis inhibitors anisomycin, emetine and cycloheximide in the entorhinal cortex immediately but not 180 min or 360 min after training in an object recognition learning task hinders long-term memory retention without affecting short-term memory or behavioral performance. Inhibition of protein synthesis in the entorhinal cortex after memory reactivation involving either a combination of familiar and novel objects or two familiar objects does not affect retention. Our data suggest that protein synthesis in the entorhinal cortex is necessary early after training for consolidation of object recognition memory. However, inhibition of protein synthesis in this cortical region after memory retrieval does not seem to affect the stability of the recognition trace.