For decades, memory research has centered on the role of neurons, which do not function in isolation. However, astrocytes play important roles in regulating neuronal recruitment and function at the local and network levels, forming the basis for information processing as well as memory formation and storage. In this review, we discuss the role of astrocytes in memory functions and their cellular underpinnings at multiple time points. We summarize important breakthroughs and controversies in the field as well as potential avenues to further illuminate the role of astrocytes in memory processes.
Astrocytes ; Neuronal Plasticity/physiology* ; Memory/physiology* ; Neurons/physiology* ; Cognition/physiology*

Cognitive control refers to the brain functions that regulate variously specific mental activities in terms of task goal, forming the basis of goal-guided behaviors. In the last decade, our team devoted to investigating the neural mechanisms of basic functions of cognitive control, i.e., monitoring, controlling, and switching. We published a series of papers on the temporal course of monitoring initiating cognitive control and its mechanisms, the influential scope of controlling and new controlling mechanisms, brain networks related to controlling efficiency, brain hubs and neural dynamic encoding of switching. This paper reviews the related studies and further extracts their theoretical significance. In the future, more attention should be paid on causal studies, studies on functional implementation of cognitive control, and transfer-application studies, by which we expect to deeply elucidate neural mechanisms of cognitive control.
Brain ; physiology ; Brain Mapping ; Cognition ; Humans

Because of a limited capacity of information processing in the brain, the efficient processing of visual information requires selecting only a very small fraction of visual inputs at any given moment in time. Attention is the main mechanism that controls this selection process, namely selective attention. Selective attention is the mechanism by which the subset of incoming information is preferentially processed from the complex external environment. Research on selective attention has two key issues. One is what targets (inputs) are selected by attention. There are three different types of selective attention according to its selected target: space-based, feature-based, and object-based attention. Another issue is how selective attention is generated. There are two different types of selective attention according to its generating source: top-down and bottom-up attention. In this review, these two issues are introduced to systematically discuss the neural mechanism of visual selective attention.
Attention ; Brain ; physiology ; Cognition ; Humans ; Visual Perception

Neural oscillatory phenomenon generally exists in the nervous system through a dynamic form. It plays a very important role in the brain, especially in the higher cognitive activities, such as information processing, transfer and integration, consolidating memory and so on. Furthermore, the specific activity pattern of neural oscillations is often associated with cognitive functions and their alterations. Accordingly, how to quantitatively analyze the pattern of neural oscillations becomes one of the fundamental issues in the computational neuroscience. In this review, we addressed a variety of analytic algorithms, which are commonly employed in our recent studies to investigate the issues of neurobiology and cognitive science. In addition, we tried to classify these analytic algorithms by distinguishing their different metrics, synchronization and coupling modes. Finally, multidimensional analytic algorithms for potential application have also been discussed.
Brain ; physiology ; Cognition ; Humans ; Memory ; Nerve Net ; physiology

OBJECTIVES: The aim of this study is to examine the cognitive function change related to aging, the incidence of cognitive impairment, and the association between apolipoprotein E polymorphism and cognitive impairment through a follow-up of the elderly with normal cognitive ability at baseline. METHODS: Two hundred and fifteen subjects aged 65 and over were surveyed in February, 1998 (baseline survey), and their cognitive function was assessed again in 2003 (1st follow-up) and the once again in 2006 (2nd follow-up). Ninety one subjects completed all surveys up through the 2nd follow-up and their cognitive function scores using MMSE-K (Korean Version of the Mini-Mental State Examination) and the distribution of apolipoprotein E allele were analyzed. RESULTS: The cognitive function scores decreased with aging and the difference between baseline and the 2nd follow-up scores of the study increased with the age group. The incidence rate of cognitive impairment through an 8-year follow-up was 38.5% and higher in older age groups. Age was the only significant factor for incidence of cognitive impairment, but there was no significant association between apolipoprotein E genotype and incidence of cognitive impairment. CONCLUSIONS: The cognition of the elderly decreased with aging and the association of apolipoprotein E genotype with incidence of cognitive impairment was not significant in this study. To confirm the association between apolipoprotein E polymorphism and incidence of cognitive impairment further studies will be needed.
Aged ; Apolipoproteins E/*genetics ; Cognition/physiology ; Cognition Disorders/etiology/*genetics ; Female ; Humans ; Korea ; Male ; Polymorphism, Genetic

OBJECTIVETo discuss the present status and progress of clinical research on the cognitive effects caused by different types of brain tumors and common treatments.

DATA SOURCESThe data used in this review were mainly from PubMed articles published in English from 1990 to Febuary 2012. Research terms were "cognitive deficits" or "cognitive dysfunction".

STUDY SELECTIONArticals including any information about brain tumor related cognitive deficits were selected.

RESULTSIt is widely accepted that brain tumors and related treatments can impair cognitive function across many domains, and can impact on patients' quality of life. Tumor localization, lateralization, surgery, drugs, radiotherapy and chemotherapy are all thought to be important factors in this process. However, some conflicting findings regarding brain tumor-related cognitive deficits have been reported. It can be difficult to determine the mechanism of these treatments, such as chemotherapy, antibiotics, antiepileptics, and steroids. Future research is needed to clarify these potential treatment effects.

CONCLUSIONSCognitive function is important for patients with brain tumor. Much more focus has been paid on this field. It should be regarded as an important prognostic index for the patients with brain tumor, and neuropsychological tests should be used in regular examinations.

Cognition ; physiology ; Disease Management ; Humans ; Kearns-Sayre Syndrome ; diagnosis ; physiopathology

As a high-level cognitive function of actively regulating human behaviors, cognitive control plays essential roles in conflict processing, working memory, decision making and so on. However, it is still under debate whether a universal cognitive control mechanism underlies the processing of various conflicts. Many existing theories tend to hold that cognitive control is domain-general; however, this view has been challenged by recent empirical studies. The logics of studying generality/specificity mainly include transferability, parallel comparison, correlation and resources competition, etc. Current empirical findings support that cognitive control is domain-general, domain-specific or both, respectively. To tackle this controversy, future studies about cognitive control can be performed from the perspectives of life-span development, the dynamic brain network, combination of multiple logics, causal relationship from brain injury, computational modeling, cognitive flexibility and functional connectivity.
Brain ; physiology ; Brain Mapping ; Cognition ; Computer Simulation ; Humans ; Logic

Words denoting abstract concepts constitute nearly half of human lexicon and serve as building blocks of the human culture. Since the advent of non-invasive neuroimaging techniques, great progress has been made in revealing the neurobiological foundation of concrete object and action concepts, yet it remains unclear how abstract concepts are stored and processed in the brain. Here we review recent development in this field, focusing on both theoretical perspectives and neuroimaging findings. We found that abstract concepts can be represented via linguistic and experiential information; the neural correlates of abstract concepts are partly in line with such a theoretical framework. Future studies are warranted to uncover the cognitive and neural mechanisms of language and experience in abstract word representation, which will help to deepen our understanding of general computational principles of the human conceptual system and to promote the development of the brain-like artificial intelligence.
Brain ; physiology ; Cognition ; Concept Formation ; Humans ; Language ; Semantics

The core of visual processing is the identification and recognition of the objects relevant to cognitive behaviors. In natural environment, visual input is often comprised of highly complex 3-dimensional signals involving multiple visual objects. One critical determinant of object recognition is visual contour. Despite substantial insights on visual contour processing gained from previous findings, these studies have focused on limited aspects or particular stages of contour processing. So far, a systematic perspective of contour processing that comprehensively incorporates previous evidence is still missing. We therefore propose an integrated framework of the cognitive and neural mechanisms of contour processing, which involves three mutually interacting cognitive stages: contour detection, border ownership assignment and contour integration. For each stage, we provide an elaborated discussion of the neural properties, processing mechanism, and its functional interaction with the other stages by summarizing the relevant electrophysiological and human cognitive neuroscience evidence. Finally, we present the major challenges for further unraveling the mechanisms of visual contour processing.
Cognition ; Form Perception ; Humans ; Visual Cortex ; physiology ; Visual Perception