额叶EEG偏侧化:情绪调节能力的指标

采用EEG测查个体静息状态额叶活动偏侧化的研究发现,额叶活动左侧化程度可能预示情绪调节能力的高低——焦虑和抑郁伴随着额叶活动左侧化减弱;情绪调节能力高的个体额叶活动左侧化强;额叶活动左侧化程度能够预测患焦虑和抑郁的风险;情绪调节增强了左额叶活动;增强左额叶活动的生物反馈训练能够促进情绪调节。未来的研究可致力于证实情绪调节能力的提高会增强额叶活动左侧化,以完善对额叶EEG偏侧成为情绪调节能力指标的论证。     

P300 to emotionally relevant stimuli as an indicator of aggression levels

Severe acts of aggression have been associated with prefrontal dysfunction. Less severe aggression may be associated with more subtle abnormalities. P300 event‐related potentials were recorded from 32 healthy volunteers during a novel modified oddball task. The task required participants to respond only to rare, food words (targets), which occurred randomly among neutral words. Aggressive words appeared randomly with the same frequency as the target words. A median split divided subjects into high‐ and low‐aggression groups based on their scores on the Buss–Durkee Hostility Inventory. The groups did not differ in their responses to the target words. Participants with higher aggression scores had lowered responses to the aggressive words at the frontal relative to the other electrode sites. Cognitive processing of aggressive stimuli was less efficient at frontal sites in individuals who reported higher levels of aggression. This result extends work showing frontal P300 decrements in more severe aggressive groups, using simple oddball tasks. Aggr. Behav. 32:1–8, 2006. © 2006 Wiley‐Liss, Inc.     

Brain activation patterns in response to complex triggers in the Word Association Test: results from a new study in the United States

C.G. Jung's theory of psychological complexes lies at the root of analytical psychology theory and practice. Functional magnetic resonance imaging (fMRI) provides a powerful tool to validate the theory of complexes and eludicate the neuropsychologic mechanisms underlying the unconscious activation of significant memories. In this study, using fMRI, we identify two brain circuits which are activated in response to complex triggering words. Circuit one involves brain regions involved in episodic memory and somatic (body) responses and the experience of uncertainty. A second circuit involves episodic memory, emotion, visual and language association, and semiotic meaning. Specific brain regions include the right prefrontal cortex, SMA cortex, left temporal cortex, and the caudate and cingulate. These brain circuits may be thought of as the biological form in which complexes are experienced. Implications for analytic psychology practice and theory are discussed.     

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.     

Individual differences in skilled adult readers reveal dissociable patterns of neural activity associated with component processes of reading

We used fMRI to examine patterns of brain activity associated with component processes of visual word recognition and their relationships to individual differences in reading skill. We manipulated both the judgments adults made on written stimuli and the characteristics of the stimuli. Phonological processing led to activation in left inferior frontal and temporal regions whereas semantic processing was associated with bilateral middle frontal activation. Individual differences in reading subskills were reflected in differences in the degree to which cortical regions were engaged during reading. Variation in sight word reading efficiency was associated with degree of activation in visual cortex. Increased phonological decoding skill was associated with greater activation in left temporo-parietal cortex. Greater reading comprehension ability was associated with decreased activation in anterior cingulate and temporal regions. Notably, associations between reading ability and neural activation indicate that brain/behavior relationships among skilled readers differ from patterns associated with dyslexia and reading development.     

TMS to the “occipital face area” affects recognition but not categorization of faces

The human cortical system for face perception is comprised of a network of connected regions including the middle fusiform gyrus (“fusiform face area” or FFA), the inferior occipital cortex (“occipital face area” or OFA), and the superior temporal sulcus. The traditional hierarchical feedforward model of visual processing suggests information flows from early visual cortex to the OFA for initial face feature analysis to higher order regions including the FFA for identity recognition. However, patient data suggest an alternative model. Patients with acquired prosopagnosia, an inability to visually recognize faces, have been documented with lesions to the OFA but who nevertheless show face-selective activation in the FFA. Moreover, their ability to categorize faces remains intact. This suggests that the FFA is not solely responsible for face recognition and the network is not strictly hierarchical, but may be organized in a reverse hierarchical fashion. We used transcranial magnetic stimulation (TMS) to temporarily disrupt processing in the OFA in neurologically-intact individuals and found participants’ ability to categorize intact versus scrambled faces was unaffected, however face identity discrimination was significantly impaired. This suggests that face categorization but not recognition can occur without the “earlier” OFA being online and indicates that “lower level” face category processing may be assumed by other intact face network regions such as the FFA. These results are consistent with the patient data and support a non-hierarchical, global-to-local model with re-entrant connections between the OFA and other face processing areas.     

From left to right: Processing acronyms referring to names of political parties activates spatial associations

In line with previous studies, showing that abstract concepts like “power” or “god” implicitly activate spatial associations, in the present study we hypothesized that spatial associations are coactivated during the processing of acronyms referring to names of political parties as well. In four studies, it was found that the reading of these acronyms was accompanied by the implicit activation of spatial left–right associations. That is, participants responded faster to left-wing parties by means of a left-hand button press and vice versa for right-wing parties (Experiments 1 to 3), and participants responded faster when a political acronym was presented at the side of the screen corresponding to the political orientation of the acronym (Experiment 4). Interestingly, a correlation was observed between the effect size for left-wing parties and participants' political preferences, suggesting that the reaction time effects reflect the perceived distance of a party to one's own political orientation. Together these findings indicate that spatial representations activated in response to political acronyms do not simply reflect lexical–semantic associations or spatial metaphors, but representations of parties' political orientation relative to one's own sociopolitical position.     

Age-Related Changes in Executive Function: An Event-Related Potential (ERP) Investigation of Task-Switching

ABSTRACT

Older adults have difficulty when executive control must be brought on line to coordinate ongoing behavior. To assess age-related alterations in executive processing, task-switching performance and event-related potential (ERP) activity were compared in young and older adults on switch, post-switch, pre-switch, and no-switch trials, ordered in demand for executive processes from greatest to least. In stimulus-locked averages for young adults, only switch trials elicited fronto-central P3 components, indicative of task-set attentional reallocation, whereas in older adults, three of the four trial types evinced frontal potentials. In response-locked averages, the amplitude of a medial frontal negativity (MFN), a component reflecting conflict monitoring and detection, increased as a function of executive demands in the ERPs of the young but not those of the older adults. These data suggest altered executive processing in older adults resulting in persistent recruitment of prefrontal processes for conditions that do not require them in the young.     

Aberrant neural mediation of verbal fluency in autism spectrum disorders

Objective

Contrasts of verbal fluency and automatic speech provide an opportunity to evaluate the neural underpinnings of generativity and flexibility in autism spectrum disorders (ASD).

Method

We used functional magnetic resonance imaging (fMRI) to contrast brain activity in high functioning ASD (n = 17, mean verbal IQ = 117) and neurotypical (NT; n = 20, mean verbal IQ = 112) adolescent and young adult males (12–23 years). Participants responded to three word generation conditions: automatic speech (reciting months), category fluency, and letter fluency.

Results

Our paradigm closely mirrored behavioral fluency tasks by requiring overt, free recall word generation while controlling for differences in verbal output between the groups and systematically increasing the task demand. The ASD group showed reduced neural response compared to the NT participants during fluency tasks in multiple regions of left anterior and posterior cortices, and sub-cortical structures. Six of these regions fell in cortico-striatal circuits previously linked to repetitive behaviors (Langen, Durston, Kas, van Engeland, & Staal, 2011), and activity in two of them (putamen and thalamus) was negatively correlated with autism repetitive behavior symptoms in the ASD group. In addition, response in left inferior frontal gyrus was differentially modulated in the ASD, relative to the NT, group as a function of task demand.

Conclusions

These data indicate a specific, atypical brain response in ASD to demanding generativity tasks that may have relevance to repetitive behavior symptoms in ASD as well as to difficulties generating original verbal responses.     

Asymmetries for the visual expression and perception of speech

This study explored asymmetries for movement, expression and perception of visual speech. Sixteen dextral models were videoed as they articulated: 'bat,' 'cat,' 'fat,' and 'sat.' Measurements revealed that the right side of the mouth was opened wider and for a longer period than the left. The asymmetry was accentuated at the beginning and ends of the vocalization and was attenuated for words where the lips did not articulate the first consonant. To measure asymmetries in expressivity, 20 dextral observers watched silent videos and reported what was said. The model's mouth was covered so that the left, right or both sides were visible. Fewer errors were made when the right mouth was visible compared to the left--suggesting that the right side is more visually expressive of speech. Investigation of asymmetries in perception using mirror-reversed clips revealed that participants did not preferentially attend to one side of the speaker's face. A correlational analysis revealed an association between movement and expressivity whereby a more motile right mouth led to stronger visual expressivity of the right mouth. The asymmetries are most likely driven by left hemisphere specialization for language, which causes a rightward motoric bias.