工作记忆的保持与操控：腹侧和背侧额叶皮层的特异性功能磁共振成像活动

为了进行大样本的老化与记忆的功能磁共振成像(fMRI)研究, 研究者设计了言语工作记忆的方案, 并且对一组健康青年人进行了施测。字母的呈现方式主要为两种条件: (i) 保持, 要求被试记住呈现的字母并且能够在4秒的间隔后保持; (ii) 操控, 被试需要将呈现的字母按字母表的顺序进行转换, 并且记住新的顺序。不管是用全脑分析, 还是用预先定义的感兴趣区域的分析方法, 对fMRI数据的分析表明本方案诱发了可靠的额叶皮层的激活, 且操控条件则引发了更为广泛的激活。背外侧和腹内侧前额叶的激活也表现出了不同特点, 操控引发了更多的背外侧前额叶激活。一些皮下区域也得到了激活, 特别是以前发现与工作记忆任务相关的一些区域。这说明该工作记忆研究方案适合探索额叶功能的与年龄相关的改变。     

Dynamics of frontal alpha asymmetry in mother-infant dyads: Insights from the Still Face Paradigm

The parent-infant dynamic has a foundational role in emotion regulation development. Electroencephalography (EEG) hyperscanning from mother-infant dyads can provide an unprecedented window into inter-brain dynamics during the parent-infant exchange. This potential depends on the feasibility of hyperscanning with dyads in emotionally taxing contexts. We sought to demonstrate feasibility of hyperscanning from 10 mother-infant dyads during the Still Face Procedure (SFP). We measured frontal alpha asymmetry (FAA) to elucidate ongoing regulatory dynamics and considered maternal caregiving quality as a window into dyads’ history. Results showed dyads exhibited a rightward shift in FAA over the course of SFP, indicating growing negative emotionality and desire to withdraw. Results also showed growing variability in FAA for infants over the course of SFP, indicating less active emotional control as stress ensued. Variability was especially low for mothers during periods when asked to be emotionally unavailable, suggesting active control to match the task demands. Dyads with a more responsive mother exhibited higher (more left) FAA relative to dyads with a less responsive mother, which might reflect a more positive emotional experience overall. We raise important methodological and theoretical questions that hyperscanning during SFP can address, such as the developmental origins of trait-like self-regulatory dispositions.     

Modeling development of frontal electroencephalogram (EEG) asymmetry: Sex differences and links with temperament

Asymmetric patterns of frontal brain electrical activity reflect approach and avoidance tendencies, with stability of relative right activation associated with withdrawal emotions/motivation and left hemisphere activation linked with approach and positive affect. However, considerable shifts in approach/avoidance‐related lateralization have been reported for children not targeted because of extreme temperament. In this study, dynamic effects of frontal electroencephalogram (EEG) power within and across hemispheres were examined throughout early childhood. Specifically, EEG indicators at 5, 10, 24, 36, 48, and 72 months‐of‐age (n = 410) were analyzed via a hybrid of difference score and panel design models, with baseline measures and subsequent time‐to‐time differences modeled as potentially influencing all subsequent amounts of time‐to‐time change (i.e., predictively saturated). Infant sex was considered as a moderator of dynamic developmental effects, with temperament attributes measured at 5 months examined as predictors of EEG hemisphere development. Overall, change in left and right frontal EEG power predicted declining subsequent change in the same hemisphere, with effects on the opposing neurobehavioral system enhancing later growth. Infant sex moderated the pattern of within and across‐hemisphere effects, wherein for girls more prominent left hemisphere influences on the right hemisphere EEG changes were noted and right hemisphere effects were more salient for boys. Largely similar patterns of temperament prediction were observed for the left and the right EEG power changes, with limited sex differences in links between temperament and growth parameters. Results were interpreted in the context of comparable analyses using parietal power values, which provided evidence for unique frontal effects.     

Functional magnetic resonance imaging of human cognitive processes

Functional magnetic resonance imaging (fMRI) is now widely accepted as a tool for analyzing human brain function. Since the realization of fMRI in the early 1990s, numerous reports have been published. In this paper, we present three studies. The first examined syntactic processing of Japanese sentences and the results prove that Broca's area is involved in the use of grammar. The second study compared binocular with monocular stereopsis. There were significant activations in the right inferior parietal lobe. The third study concerned the encoding and retrieval processes underlying face recognition. It revealed activations mainly in the right prefrontal areas, which is contrary to the hemispheric encoding and retrieval asymmetry (HERA) theory. fMRI will continue to play an important role in the analysis of human brain function.     

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.     

Evolutionary neurology,responsive equilibrium,and the moral brain

The relation between morality and the brain is a topic usefully examined through the evolutionary neurology of John Hughlings-Jackson, who considered higher mental function to be progressively inclusive integration of sensori-motor processes. His view, based on careful observations of patients with neurological disorders, implies that moral reasoning involves integration and coordination of behaviour through a process of representation and re-representation encompassing broader and broader types of information sensitive to environmental contingencies. The relevant information is processed in diverse brain areas: superior temporal sulcus (STS), inferior parietal lobule (IPL), inferior frontal gyrus (IFG), dorsolateral prefrontal (DLPF) areas, as well as anterior temporal (AT) structures. Moral function can be regarded as maximally integrating emotion, social cognition, and other-regarding sensibilities using propositionally organised cognitive structures that map a shared world of human activity and relationships so that they take account of what in social and personal life counts as something.     

Decrease of prefrontal-posterior EEG coherence: loose control during social-emotional stimulation

In two experiments we aimed to investigate if individual differences in state-dependent decreases or increases of EEG coherence between prefrontal and posterior cortical regions may be indicative of a mechanism modulating the impact social-emotional information has on an individual. Two independent samples were exposed to an emotional stimulation paradigm in which the participants were invited to get involved and sympathize with the persons they were watching (study 1) or listening to (study 2), and who were expressing sadness or anxiety. The two studies yielded consistent results. Higher scores in trait absorption and in the propensity to ruminate were associated with decreased EEG beta coherence during the stimulation, whereas coherence increased in individuals low in absorption or rumination. Coherence changes did not predict to which degree the participants felt infected by the displayed emotions, but in individuals showing decreased prefrontal-posterior coupling during the stimulation, feelings of sadness and anxiety had a greater tendency to persist. The findings suggest that more loose prefrontal-posterior coupling may be related to loosening of control of the prefrontal cortex over incoming social-emotional information and, consequently, to deeper emotional involvement and absorption, whereas increased prefrontal-posterior coupling may be related to strong control, dampening of emotional experience, and not letting oneself become emotionally affected.     

Hemispheric asymmetries in meaning selection: Evidence from the disambiguation of homophonic vs. heterophonic homographs

Research investigating hemispheric asymmetries in meaning selection using homophonic homographs (e.g., bank), suggests that the left hemisphere (LH) quickly selects contextually relevant meanings, whereas the right hemisphere (RH) maintains a broader spectrum of meanings including those that are contextually irrelevant (e.g., Faust & Chiarello, 1998). The present study investigated cerebral asymmetries in maintaining the multiple meanings of two types of Hebrew homographs: homophonic homographs and heterophonic homographs (e.g., tear). Participants read homographs preceded by a biasing, or a non-biasing sentential context, and performed a lexical decision task on targets presented laterally, 1000 ms after the onset of the sentence-final ambiguous prime. Targets were related to either the dominant or the subordinate meaning of the preceding homograph, or unrelated to it. When targets were presented in the LVF/RH, dominant and subordinate meanings, of both types of homographs, were retained only when they were supported by context. In a non-biasing context, only dominant meanings of homophonic homographs were retained. Alternatively, when targets were presented in the RVF/LH, priming effects for homophonic homographs were only evident when meanings were supported by both context and frequency (i.e., when context favored the dominant meaning). In contrast, heterophonic homographs resulted in activation of dominant meanings, in all contexts, and activation of subordinate meanings, only in subordinate-biasing contexts. The results challenge the view that a broader spectrum of meanings is maintained in the right than in the left hemisphere and suggest that hemispheric differences in the time course of meaning selection (or decay) may be modulated by phonology.     

Left-view sequences of faces are superior to right-view ones for view generalization

Faces learned from multiple viewpoints are recognized better with left than right three-quarter views. This left-view superiority could be explained by perceptual experience, facial asymmetry, or hemispheric specialization. In the present study, we investigated whether left-view sequences are also more effective in recognizing same and novel views of a face. In a sequential matching task, a view sequence showing a face rotating around a left (?30°) or a right (+30°) angle, with an amplitude of 30°, was followed by a static test view with the same viewpoint as the sequence (?30° or +30°) or with a novel one (0°, +30°, or ?30°). We found a superiority of left-view sequences independently of the test viewpoint, but no superiority of left over right test views. These results do not seem compatible with the perceptual experience hypothesis, which predicts superiority only for left-side test views (?30°). Also, a facial asymmetry judgement task showed no correlation between the asymmetry of individual faces and the left-view sequence superiority. A superiority of left-view sequences for novel as well as same test views argues in favour of an explanation by hemispheric specialization, because of the possible role of the right hemisphere in extracting facial identity information.     

Postural Asymmetries in Response to Holding Evenly and Unevenly Distributed Loads During Self-Selected Stance

The authors examined postural asymmetries during quiet stance and while holding evenly or unevenly distributed loads. Right-hand dominant subjects preferentially loaded their right lower limb when holding no load or a load evenly distributed in both hands, but no differences in center of pressure (CoP) were observed between the left and right limbs. However, longer CoP displacement was observed under the preferentially loaded limb, which may reflect a functional asymmetry that allows quick movement of one limb in response to a potential perturbation. When a load was held only in the nondominant hand, sample entropy decreased in the left (loaded) limb but increased in the right (unloaded) limb, suggesting the unloaded foot compensated for a loss of control flexibility in the loaded foot.