Process Overlap Theory: A Unified Account of the General Factor of Intelligence

The most replicated result in the field of intelligence is the positive manifold, which refers to an all-positive pattern of correlations among diverse cognitive tests. The positive manifold is typically described by a general factor, or g. In turn, g is often identified as general intelligence, yet this explanation is contradicted by a number of results. Here we offer a new account of g: process overlap theory. According to the theory, cognitive tests tap domain-general executive processes, identified primarily in research on working memory, as well as more domain-specific processes. Executive processes are tapped in an overlapping manner across cognitive tests such that they are required more often than domain-specific ones. The theory provides an account of a number of findings on human intelligence. As well, it is formalized as a multidimensional item response model and as a structural model, and the neural mechanisms underlying the proposed overlapping processes are discussed.     

More than meets the eye: The neural development of emotion face processing during infancy

This study explored the impact of infant temperament and maternal stress on the development of the infant medial prefrontal cortex (mPFC) among sixteen 6-8-month-old infants. Functional Near Infrared Spectroscopy (fNIRS) was used to measure activation of the infant mPFC in response to angry, happy, and sad faces. Infant temperament and dimensions of maternal stress were measured with the Infant Behavior Questionnaire and the Parenting Stress Index Respectively. Infants with high negative emotionality demonstrated increased mPFC activation in association with all emotion face conditions. Negative emotionality moderated the effect of total maternal stress on mPFC activation to angry and sad faces. Mother-infant dysfunctional interaction was related to increased mPFC activation associated with happy faces, supporting the “novelty hypothesis”, in which the mPFC responds more strongly to unique experiences. Therefore, this study provides additional evidence that infant temperament and the quality of the mother-infant relationship influence the development of the mPFC and how infants process emotions.     

Cognitive performance,monetary incentive,and aggression

Individuals with impaired cognitive abilities associated with frontal lobe function have recently been shown to manifest increased aggression. This study investigated the effect of contingent money to inhibit aggression in these individuals. One hundred and forty males, aged 18–40, were ranked according to their performance on the Spatial Conditional Associative-Learning task. Forty-eight males (24 with scores in each of the upper and lower performance quartiles) participated in the full study. Half of the subjects competed in a Taylor aggression task where they received a monetary incentive for choosing lower shocks; the remainder competed without any monetary contingency. Aggression was defined as shock intensity delivered to a sham opponent. Shock intensity significantly increased as a main effect of lower cognitive performance, absence of monetary incentive, and provocation. In addition, provocation interacted significantly with test performance. Finally, individuals in the upper cognitive performance quartile showed significantly greater reductions of unprovoked aggression in response to monetary incentive. The results are discussed in terms of impairments in the ability to associate inhibitory influences in the formulation of behavioral strategies under aggressive conditions. © 1996 Wiley-Liss, Inc.     

The role of the prefrontal cortex in the go/no-go task in humans: a positron emission tomography study

To study the localization of response inhibition in the human brain, especially the role of the prefrontal cortex and laterality of its activation, we used positron emission tomography (PET) to measure regional cerebral blood flow in 11 right-handed participants while they performed a go/no-go and a simple control reaction-time task. In the control task, the participants responded to a target stimulus following a cue stimulus. In the go/no-go task they were instructed to inhibit the required response if the target stimulus did not appear. These tasks were performed using each hand. The right prefrontal cortex was found to be significantly activated when the go/no-go task was compared with the control task, regardless of the responding hand. The results indicated that response inhibition per se may be controlled by the right prefrontal cortex regardless of response hand for right-handed participants.     

The Neuropsychological Bases of Category Learning

There is a long history of research into how people learn new categories of objects or events. Recent advances have led to new insights about the neuropsychological basis of this critically important cognitive process. In particular, there is now good evidence that the frontal cortex and basal ganglia contribute to category learning, that medial temporal lobe structures make a more minor contribution, and that categorization rules are not represented in visual cortex. There is also strong evidence that normal category learning is mediated by at least two separate systems. A recent neuropsychological theory of category learning that is consistent with these data is described.     

Mirror neurons and the simulation theory of mind-reading

A new class of visuomotor neuron has been recently discovered in the monkey's premotor cortex: mirror neurons. These neurons respond both when a particular action is performed by the recorded monkey and when the same action, performed by another individual, is observed. Mirror neurons appear to form a cortical system matching observation and execution of goal-related motor actions. Experimental evidence suggests that a similar matching system also exists in humans. What might be the functional role of this matching system? One possible function is to enable an organism to detect certain mental states of observed conspecifics. This function might be part of, or a precursor to, a more general mind-reading ability. Two different accounts of mind-reading have been suggested. According to ‘theory theory', mental states are represented as inferred posits of a naive theory. According to ‘simulation theory', other people's mental states are represented by adopting their perspective: by tracking or matching their states with resonant states of one's own. The activity of mirror neurons, and the fact that observers undergo motor facilitation in the same muscular groups as those utilized by target agents, are findings that accord well with simulation theory but would not be predicted by theory theory.     

颞叶皮层在灵长类不变性知觉和原型表征中的重要作用

如果要走出人工智能在感知觉领域的困境．就必须认识到人类特有的受生物现实约束的认知特点。综合分析各种证据表明,知觉和客体识别的本质不是分析千差万别的局部特征,而是提取环境中的大范围不变量（早期为拓扑特性检测）,形成并存贮一定原型表征;颞叶皮层在灵长类这种不变性知觉和原型表征中具有重要作用。     

Bilaterally recorded multiple-unit activity of the cingulate cortex during head turning conditioning with unilateral medial forebrain bundle stimulation

Cats were conditioned to turn their heads using a tone conditioned stimulus (CS) and medial forebrain bundle stimulation (MFB) unconditioned stimulus (US). The CS+ was delivered to one ear at a time, in random order, followed by the US. A tone of a different frequency was used as a CS-. The cats learned to respond differentially to the CSs showing head movements of greater acceleration to the CS+ than CS- over sessions. Bilateral recordings of cingulate cortex multiple-unit activity showed increased response amplitudes over sessions and larger responses in the hemisphere ipsilateral to the US. Since ipsilateral multiple-unit responses did not differ for the CSs, the asymmetry was probably due to the sensitizing effect of the unilateral US. Although increases in cingulate cortex neural activity coincided with increases in conditioned head movements, larger activation of the cingulate cortex ipsilateral to the US suggests that the neural changes were independent of these movements.     

Effect of a sex stereotype on cortical activity during a self-paced exercise: A motor-related cortical potential approach

Recent research has shown that inducing a negative stereotype toward women does not always decrease the subsequent motor performance of women, but can increase it, especially during endurance tasks. The mechanisms involved are nonetheless still poorly understood. The main aim of the present study was to investigate the effect of a negative stereotype toward women on men’s and women’s performance during an endurance task, and to analyze the neuropsychological mechanisms involved through motor-related cortical potentials and motivation toward men/women. Thirty-four participants were assigned to a negative stereotype toward women condition and a nullified-stereotype condition and performed 80 self-paced intermittent isometric elbow contractions at a moderate perceived intensity. Results showed that women performed better when assigned to the negative stereotype toward women condition, they were more motivated to outperform men, and their MRCP amplitudes were higher in this same condition over the prefrontal cortex (i.e., FP1 and FP2). Concerning men, they also performed better when the negative stereotype toward women was induced. However, no effect emerged on motivation toward women and MRCP amplitudes. This study showed that inducing a negative stereotype during an endurance task led to a performance increase in women, which is contrary to the stereotype threat theory, strengthening the idea of a task-dependency effect when inducing a negative stereotype. This performance improvement observed in women may be caused by increased motivation to outperform men and a planning of the upcoming movement. Concerning men, more research is needed to clarify the mechanisms involved in such performance improvement.     

腹内侧前额叶在内隐认知重评中的因果作用

情绪调节对维持个体心理健康、适应社会生活十分重要, 然而以往研究主要关注外显情绪调节, 目前我们对内隐情绪调节的认知神经机制的了解还非常有限。为揭示内隐情绪调节的核心脑区, 本研究使用句子整理任务启动内隐认知重评, 并采用经颅直流电刺激(transcranial direct current stimulation, tDCS)激活内侧前额叶特别是腹内侧前额叶(ventromedial prefrontal cortex, vmPFC), 考察该脑区在内隐情绪调节中的因果作用。结果表明, vmPFC被激活的被试组(实验组, n = 40)在内隐认知重评启动条件下比tDCS伪刺激组(对照组, n = 40), 在观看负性图片时报告了更少的负性情绪, 同时负性图片诱发的晚正成分(late positive potential, LPP)波幅更低(LPP是情绪体验强度的客观指标)。同时, 实验组比对照组在观看负性图片时表现出更低的枕区P1波幅(P1为早期视觉注意程度的客观指标)。以上结果说明, 激活以vmPFC为代表的内侧前额叶不但能增强内隐情绪调节的效果, 还能减少被试对负性刺激的早期注意分配。本研究是采用tDCS技术考察启动引起的内隐情绪调节的首次尝试, 研究结果不但表明了以vmPFC为代表的内侧前额叶在内隐认知重评中的关键作用, 还为临床应用研究指出了增强内隐情绪调节能力的神经调控潜在靶点。