Age differences in prefrontal cortical activity in working memory

Working memory (WM) declines with advancing age. Brain imaging studies indicate that ventral prefrontal cortex (PFC) is active when information is retained in WM and that dorsal PFC is further activated for retention of large amounts of information. The authors examined the effect of aging on activation in specific PFC regions during WM performance. Six younger and 6 older adults performed a task in which, on each trial, they (a) encoded a 1- or 6-letter memory set, (b) maintained these letters over 5-s. and (c) determined whether or not a probe letter was part of the memory set. Comparisons of activation between the 1- and 6-letter conditions indicated age-equivalent ventral PFC activation. Younger adults showed greater dorsal PFC activation than older adults. Older adults showed greater rostral PFC activation than younger adults. Aging may affect dorsal PFC brain regions that are important for WM executive components.     

Rostro‐caudal and dorso‐ventral gradients in medial and lateral prefrontal cortex during cognitive control of affective and cognitive interference

Characterizing the anatomical substrates of major brain functions such as cognition and emotion is of utmost importance to the ongoing efforts of understanding the nature of psychiatric ailments and their potential treatment. The aim of our study was to investigate how the brain handles affective and cognitive interferences on cognitive processes. Functional magnetic resonance imaging investigation was performed on healthy individuals, comparing the brain oxygenation level dependent activation patterns during affective and cognitive counting Stroop tasks. The affective Stroop task activated rostral parts of medial prefrontal cortex (PFC) and rostral and ventral parts of lateral PFC, while cognitive Stroop activated caudal parts of medial PFC and caudal and dorsal parts of lateral PFC. Our findings suggest that the brain may handle affective and cognitive interference on cognitive processes differentially, with affective interference preferentially activating rostral and ventral PFC networks and cognitive interference activating caudal and dorsal PFC networks.     

Catecholamine modulation of prefrontal cortical cognitive function

The prefrontal cortex (PFC) utilizes working memory to guide behavior and to release the organism from dependence on environmental cues and is commonly disrupted in neuropsychiatric disorders, normal aging, or exposure to uncontrollable stress. This review posits that the PFC is very sensitive to changes in the neuromodulatory inputs it receives from norepinephrine (NE) and dopamine (DA) systems and that this sensitivity can lead to marked changes in the working-memory functions of the PFC. While NE and DA have important beneficial influences on processing in this area, very high levels of catecholamine release, for example, during exposure to uncontrollable stress, disrupt the cognitive functions of the PFC. This fresh understanding of the neurochemical influences on PFC function has led to new treatments for cognitive disorders such as Attention Deficit Hyperactivity Disorder (ADHD), and may help to elucidate the prevalence of PFC dysfunction in other mental disorders.     

Performance-related activity in medial rostral prefrontal cortex (area 10) during low-demand tasks

Neuroimaging studies have frequently observed relatively high activity in medial rostral prefrontal cortex (PFC) during rest or baseline conditions. Some accounts have attributed this high activity to the occurrence of unconstrained stimulus-independent and task-unrelated thought processes during baseline conditions. Here, the authors investigated the alternative possibility that medial rostral PFC supports attention toward the external environment during low-demand conditions. Participants performed a baseline simple reaction time (RT) task, along with 3 other tasks that differed in the requirement to attend to external stimuli versus stimulus-independent thought. Medial rostral PFC activation was observed in the baseline task and in a condition requiring strong engagement with external stimuli, relative to 2 conditions with a greater requirement for stimulus-independent thought. An important finding was that activity in this region was associated with faster RTs in the baseline task, ruling out an explanation in terms of task-unrelated thought processes during this condition. Thus, at least under certain circumstances, medial rostral PFC appears to support attention toward the external environment, facilitating performance in situations that do not require extensive processing of experimental stimuli.     

绘画是人们最适宜的心灵表达方式--绘画在心理治疗中的应用及其作用机理

绘画作为一种心理治疗方法有其独特作用,不仅可以处理人们的情绪和心理创伤问题,而且可以使心理障碍患者的自我形象、自尊或自我概念、社交技能等得到提升,促进语言的发展与认知功能的改善.机理是,绘画是人们最适宜的心灵表达方式,它作为一种人类心理意象的主要表现形式,发展象征性的语言,能触及人所不知的心灵感受,并能创造性地将它们整合到人格里,直至发生治疗性的变化.     

乐观偏差的认知神经机制

乐观偏差是指人们趋向于认为好事发生在自己身上, 坏事发生在他人身上的一种心理期望(Weinstein, 1980)。乐观偏差的研究范式主要有社会比较范式、过去未来想象范式以及信息转变任务范式。运用fMRI对乐观偏差研究发现, 乐观偏差的神经机制主要涉及前喙扣带皮质和杏仁核、前额叶、多巴胺等。未来要结合社会比较和信息转变范式对乐观偏差进行测量; 研究乐观偏差认知机制的神经机制, 特别是采用ERP技术研究乐观偏差的认知机制; 同时要进一步揭示不同亚型乐观偏差的神经机制; 最后还要开展乐观偏差影响心理健康的神经机制研究。     

Quitting-unmotivated and quitting-motivated cigarette smokers exhibit different patterns of cue-elicited brain activation when anticipating an opportunity to smoke

The authors examined the effects of smoking expectancy on cue-reactivity among those motivated and those unmotivated to quit smoking using functional MRI. Cue-elicited activation was observed in the rostral prefrontal cortex (PFC) in smokers who expected to smoke within seconds, but not in those who expected to have to wait hours before having the chance to smoke, regardless of quitting motivation. For quitting-unmotivated smokers expecting to smoke, rostral PFC activation was strongly positively correlated with the activation of several areas previously linked to cue-reactivity, including the medial orbitofrontal cortex (OFC) and rostral anterior cingulate cortex (ACC). In contrast, there was a nonsignificant negative relationship between activation of the rostral PFC and activation of the medial OFC/rostral ACC in quitting-motivated smokers expecting to smoke. Results extend previous work examining the effects of smoking expectancy and highlight the utility of examining interregional covariation during cue exposure. Findings also suggest that investigators may need to pay close attention to the motivational contexts associated with their experiments when studying cue-reactivity, as these contexts can modulate not only responses to drug cues, but perhaps also the functional implications of observed activity.     

Beyond IQ: a new perspective on the psychological assessment of intellectual abilities

The article presents a new approach to the psychological assessment of intellectual abilities, which is based on the new theory of human intelligence. The main shortcomings of conventional intelligence tests are briefly discussed. The nine methodological and procedural principles, which form this approach, are considered along with the examples of new intelligence tests. According to these principles, new intelligence tests should examine psychological mental context generated by an individual himself or herself. They should also have an “open character”, evaluate the basis of intelligence, and allow both retrospective and prospective assessment. New tests of intellectual abilities should not evaluate psychological functions (e.g., memory or attention) and mental speed, and they should not be very long and time-consuming. Cognitive styles and metacognitive abilities should also be assessed by new intelligence tests.     

Association of catechol-O-methyltransferase (COMT) polymorphism and academic achievement in a Chinese cohort

Catechol-O-methyltransferase (COMT) is a methylation enzyme that catalyzes the degradation pathway and inactivation of dopamine. It is accepted widely as being involved in the modulation of dopaminergic physiology and prefrontal cortex (PFC) function. The COMT Val158Met polymorphism is associated with variation in COMT activity. COMT 158Met allele may be advantageous for PFC-related cognitive abilities; however, it is also associated with increased anxiety, depression, and emotional vulnerability in response to stress or educational adversity. We hypothesized that the COMT polymorphism might be associated with academic performance. In this study, 779 Taiwanese tenth-grade volunteers were recruited. Scores from the Basic Competency Test (BCT), an annual national competitive entrance examination, were used to evaluate academic performance. The results indicated that students bearing homozygous for the Met allele tended to perform more poorly in all BCT subtests as compared to the other groups. In particular, the former performed significantly more poorly in the science and social science subtests. These findings provide evidence that affective factors might overwhelm cognitive abilities in high-stake tests like the BCT.     

Association of catechol-O-methyltransferase (COMT) polymorphism and academic achievement in a Chinese cohort

Catechol-O-methyltransferase (COMT) is a methylation enzyme that catalyzes the degradation pathway and inactivation of dopamine. It is accepted widely as being involved in the modulation of dopaminergic physiology and prefrontal cortex (PFC) function. The COMT Val158Met polymorphism is associated with variation in COMT activity. COMT 158Met allele may be advantageous for PFC-related cognitive abilities; however, it is also associated with increased anxiety, depression, and emotional vulnerability in response to stress or educational adversity. We hypothesized that the COMT polymorphism might be associated with academic performance. In this study, 779 Taiwanese tenth-grade volunteers were recruited. Scores from the Basic Competency Test (BCT), an annual national competitive entrance examination, were used to evaluate academic performance. The results indicated that students bearing homozygous for the Met allele tended to perform more poorly in all BCT subtests as compared to the other groups. In particular, the former performed significantly more poorly in the science and social science subtests. These findings provide evidence that affective factors might overwhelm cognitive abilities in high-stake tests like the BCT.     

Developing PFC representations using reinforcement learning

From both functional and biological considerations, it is widely believed that action production, planning, and goal-oriented behaviors supported by the frontal cortex are organized hierarchically [Fuster (1991); Koechlin, E., Ody, C., & Kouneiher, F. (2003). Neuroscience: The architecture of cognitive control in the human prefrontal cortex. Science, 424, 1181-1184; Miller, G. A., Galanter, E., & Pribram, K. H. (1960). Plans and the structure of behavior. New York: Holt]. However, the nature of the different levels of the hierarchy remains unclear, and little attention has been paid to the origins of such a hierarchy. We address these issues through biologically-inspired computational models that develop representations through reinforcement learning. We explore several different factors in these models that might plausibly give rise to a hierarchical organization of representations within the PFC, including an initial connectivity hierarchy within PFC, a hierarchical set of connections between PFC and subcortical structures controlling it, and differential synaptic plasticity schedules. Simulation results indicate that architectural constraints contribute to the segregation of different types of representations, and that this segregation facilitates learning. These findings are consistent with the idea that there is a functional hierarchy in PFC, as captured in our earlier computational models of PFC function and a growing body of empirical data.     

Autobiographical memory: exploring its functions in everyday life

This special issue of Memory spotlights research that uses a functional approach to investigate autobiographical memory (AM) in everyday life. This approach relies on studying cognition, in this case AM, taking into account the psychological, social, or cultural-historic context in which it occurs. Areas of interest include understanding to what ends AM is used by individuals and in social relationships, how it is related to other cognitive abilities and emotional states, and how memory represents our inner and outer world. One insight gained by taking this approach is that levels and types of accuracy need not always be regarded as memory "failures" but are sometimes integral to a self-memory system that serves a variety of meaningful ends of human activity. Previously hypothesised functions of AM fall into three broad domains: self, social, and directive. Each of the contributions addresses how AM serves one or more of these functions and thereby examines the usefulness and adequacy of this trio.     

Language,social ecology and experience

Experience is structured by thoughts which are composed of general concepts and conceptions of objects. Both of these elements of thought are rule‐governed and rest on norms which are shared by thinkers. Concepts and conceptions of objects as the elements of thoughts whose content is essentially communicable plausibly rest on abilities tied to the use of linguistic terms. This suggests that language plays an active part in structuring human experience and cognition as suggested by both Vygotsky and Luria. The role of language in thought implies that the human brain which is the information processing structure realizing thoughts is itself subject to shaping by the social milieu. Neural network theory suggests that this might proceed via the use of cue stimuli based on the responses of other human beings and, therefore, supports the view that cognitive neuroscience may be radically mistaken in thinking that it can provide an individualistic analysis of human mental life.     

A Sex Difference on a Novel Spatial Working Memory Task in Humans

Neurophysiological and behavioral evidence suggests that the prefrontal cortex (PFC) may be sexually differentiated in nonhuman primates. The present study examined whether there are sex differences in working memory in humans that might reflect sexual differentiation of human PFC. Male and female undergraduates were administered a novel multitrial spatial working memory task (SPWM) and a verbal working memory task. In three experiments, females committed significantly fewer working memory errors and took significantly less time to reach criterion than males on the SPWM task. The female advantage was not accounted for by differences in general intellectual ability, attention, perceptual speed, incidental memory, or speed of verbal access. In Study 3, a sex difference was also observed on a measure of verbal working memory. The findings suggest that some prefrontal functions may be sexually differentiated in humans.     

Midsagittal brain shape correlation with intelligence and cognitive performance

Brain shape might influence cognitive performance because of the relationships between functions, spatial organization, and differential volumetric development of cortical areas. Here we analyze the relationships between midsagittal brain shape variation and a set of basic psychological measures. Coordinates in 2D from 102 MRI-scanned young adult human brains were superimposed through a Procrustes approach, and the residual variation was regressed onto 21 cognitive tests performed by the same individuals. Most of the composite and specific variables (including general intelligence, working memory, attention, and executive functions) do not show meaningful correlations with midsagittal brain morphology. However, variables related to mental speed display subtle but consistent correlations with brain shape variation. Such correlations are small, suggesting that the influence of midsagittal brain geometry on individual cognitive performance is negligible. Nevertheless, this evidence can supply information on brain biology and evolution. Areas associated with the parietal cortex appear to be involved in relationships between brain geometry and mental speed. These areas have been associated with relevant endocranial differences between living and extinct humans, and are important as functional and structural components of brain organization. The limited correlation between brain geometry and mental speed among modern individuals might be more relevant when the large paleoneurological variation of the genus Homo is taken into account.     

Unconscious Representations 1: Belying the Traditional Model of Human Cognition

The traditional model of human cognition (TMHC) postulates an ontological and/or structural gap between conscious and unconscious mental representations. By and large, it sees higher-level mental processes as commonly conceptual or symbolic in nature and therefore conscious, whereas unconscious, lower-level representations are conceived as non-conceptual or sub-symbolic. However, experimental evidence belies this model, suggesting that higher-level mental processes can be, and often are, carried out in a wholly unconscious way and/or without conceptual representations, and that these can be processed unconsciously. This entails that the TMHC, as well as the theories on mental representation it motivates and that in turn support it, is wrong.     

Spatial and temporal limits in cognitive neuroimaging with fMRI

A large body of research in human perception and cognition has been concerned with the segregation of mental events into their presumed hierarchical processing stages, the temporal aspect of such processing being termed ‘mental chronometry’. Advances in single-event functional magnetic resonance imaging (fMRI) have allowed the extraction of relative timing information between the onset of activity in different neural substrates as well as the duration of cognitive processing during a task, offering new opportunities in the study of human perception and cognition. Single-event fMRI studies have also facilitated increased spatial resolution in fMRI, allowing studies of columnar organization in humans. Important processes such as object recognition, binocular vision and other processes are thought to be organized at the columnar level; thus, these advances in the spatial and temporal capabilities of fMRI allow a new generation of cognitive and basic neuroscience studies to be performed, investigating the temporal and spatial relationships between these cortical sub-units. Such experiments bear a closer resemblance to single-unit or evoked-potential studies than to classical static brain activation maps and might serve as a bridge between primate electrophysiology and human studies. These advances are initially demonstrated only in simple visual and motor system tasks and it is likely to be several years before the techniques we describe are robust enough for general use.     

Sources of openness/intellect: cognitive and neuropsychological correlates of the fifth factor of personality

We characterize Openness/Intellect as motivated cognitive flexibility, or cognitive exploration, and develop a neuropsychological model relating it to dopaminergic function and to the functions of the prefrontal cortex (PFC). Evidence is reviewed for sources of Openness/Intellect shared with Extraversion and sources unique to Openness/Intellect. The hypothesis that the cognitive functions of the dorsolateral PFC are among the latter was tested using standard measures of cognitive ability and a battery of tasks associated with dorsolateral PFC function (N=175). Dorsolateral PFC function, as well as both fluid and crystallized cognitive ability, was positively related to Openness/Intellect but no other personality trait. Additionally, facet level analysis supported the characterization of Openness/Intellect as a primarily cognitive trait.     

INTELLIGENCE,COGNITIVE STYLES,AND BRAIN LATERALIZATION

The concept of intelligence as a kind of mental power is criticized, since it is essentially static. Many authors wish to substitute the concept of processes or styles of thinking and learning, which might be developed by appropriate training. But there is no consensus as to which styles are of major importance in intellectual growth, and few of those suggested can be assessed objectively. They resemble the historical notion of types; and like types, they may be weak in internal consistency and generalizability. Some types which are defined by psychometric variables or factors are more promising. Currently the contrast between left brain and right brain functions is over-popularized. But it is associated both with verbal vs visuospatial abilities, and with analytic-sequential vs holistic processing. The right brain has been credited with a wide range of other functions for which there is little evidence, e.g., intuition, creativity, meditational trance states, etc. Findings from studies of brain-damaged or commissurotomized patients, and experiments with normal subjects, are outlined. The dichotomy is not the same as Das' simultaneous vs successive, Freud's primary vs secondary processes, Witkin's field independence, or Guilford's convergent vs divergent. Certain implications for education, for mental testing, and for cross-cultural research are discussed.