Hand function,not proximity,biases visuotactile integration later in object processing: An ERP study

Behavioral studies document a functional hand proximity effect: objects near the palm, but not the back of the hand, affect visual processing. Although visuotactile bimodal neurons integrate visual and haptic inputs, their receptive fields in monkey cortex encompass the whole hand, not just the palm. Using ERPs, we investigated whether hand function influenced the topology of integrated space around the hand. In a visual detection paradigm, target and non-target stimuli appeared equidistantly in front or in back of the hand. Equivalent N1 amplitudes were found for both conditions. P3 target versus non-target amplitude differences were greater for palm conditions. Hand proximity biased processing of visual targets equidistant from the hand early in processing. However, hand function biases emerged later when targets were selected for potential action. Thus, early hand proximity effects on object processing depend on sensory-reliant neural responses, whereas later multisensory integration depend more on the hand’s functional expertise.     

Determinants of attentive blank stares. An EFRP study

Attentive blank stares mean a failure to notice changes in a visual scene, despite looking at the area of change (Caplovitz, Fendrich, & Hughes, 2008). In this research project we have shown that people differ in terms of attentive blank stare incidences. Novices tend to fail to notice changes in the target area more often than experts. This effect is greater in persons with low visual working memory capacity (VWMC) than with high VWMC. In addition, in a group of novices with low VWMC, attentive blank stares are more frequent compared to a group with high VWMC. Attentive blank stares did not disappear even after the high VWMC group were given expertise training. With the method of eye-fixation-related potentials (EFRP) we analyzed the amplitude of lambda response, which may reflect the state of the attentional system, during encoding information about a change, prior to a decision whether a change has occurred or not. We demonstrate that the cases of attentive blank stares are accompanied by significantly lower amplitude of the lambda response compared with cases involving change detection. In addition, we discovered greater lambda responses in a group with expertise who noticed the change than in novices. The EFRP record coming from occipital electrodes in the 80–180 ms window function was marked by left-sided asymmetry in the cases of change detection and by right-sided asymmetry in the cases of attentive blank stares.     

内-外倾人格对情绪调节的影响及神经机制

内—外倾人格(即外倾性)是与情绪活动密切相关的人格特质：该特质不但影响人类的适应能力与主观幸福感，还与焦虑、冲动等情绪—行为障碍的产生有密切关联。在以往研究中，外倾性与情绪健康的关系集中体现为内—外倾人格对情绪事件易感性的影响，如外倾人格得分的增高伴随着对奖赏刺激更强的积极情绪反应水平。然而，上述联系也有可能是由于外倾性不同的人群具有不同的情绪调节特点导致。因此，可通过系统操纵外倾性人格因素与情绪调节方式，从外倾性人格特质对情绪调节方式及调节效果影响的角度，深入探讨外倾性和人类情绪与健康的关系。拟综合使用行为调查与生理测量、EEG/ERP 与 fMRI 手段，开展如下三个层面的研究工作：1)情绪调节问卷的编制及内、外倾人群情绪调节策略的比较研究；2)外倾性对情绪调节的影响及其脑机制研究，探讨认知情绪调节的生理变化、时间进程及神经基础与内—外倾人格的关系；3)情绪稳定性不同的内、外倾人群其情绪调节的特点及其脑机制研究。通过上述系列研究，深化对情绪与人格关系的认识，从而为心理健康的维护，情绪障碍的治疗及相关疗法的开发应用奠定理论基础。     

Left-hemisphere activation is associated with enhanced vocal pitch error detection in musicians with absolute pitch

The ability to process auditory feedback for vocal pitch control is crucial during speaking and singing. Previous studies have suggested that musicians with absolute pitch (AP) develop specialized left-hemisphere mechanisms for pitch processing. The present study adopted an auditory feedback pitch perturbation paradigm combined with ERP recordings to test the hypothesis whether the neural mechanisms of the left-hemisphere enhance vocal pitch error detection and control in AP musicians compared with relative pitch (RP) musicians and non-musicians (NM). Results showed a stronger N1 response to pitch-shifted voice feedback in the right-hemisphere for both AP and RP musicians compared with the NM group. However, the left-hemisphere P2 component activation was greater in AP and RP musicians compared with NMs and also for the AP compared with RP musicians. The NM group was slower in generating compensatory vocal reactions to feedback pitch perturbation compared with musicians, and they failed to re-adjust their vocal pitch after the feedback perturbation was removed. These findings suggest that in the earlier stages of cortical neural processing, the right hemisphere is more active in musicians for detecting pitch changes in voice feedback. In the later stages, the left-hemisphere is more active during the processing of auditory feedback for vocal motor control and seems to involve specialized mechanisms that facilitate pitch processing in the AP compared with RP musicians. These findings indicate that the left hemisphere mechanisms of AP ability are associated with improved auditory feedback pitch processing during vocal pitch control in tasks such as speaking or singing.     

Regional and inter-regional theta oscillation during episodic novelty processing

Recent event-related potential (ERP) and functional magnetic resonance imaging (fMRI) studies suggest that novelty processing may be involved in processes that recognize the meaning of a novel sound, during which widespread cortical regions including the right prefrontal cortex are engaged. However, it remains unclear how those cortical regions are functionally integrated during novelty processing. Because theta oscillation has been assumed to have a crucial role in memory operations, we examined local and inter-regional neural synchrony of theta band activity during novelty processing. Fifteen right-handed healthy university students participated in this study. Subjects performed an auditory novelty oddball task that consisted of the random sequence of three types of stimuli such as a target (1000 Hz pure tone), novel (familiar environmental sounds such as dog bark, buzz, car crashing sound and so on), and standard sounds (950 Hz pure tone). Event-related spectra perturbation (ERSP) and the phase-locking value (PLV) were measured from human scalp EEG during task. Non-parametric statistical tests were applied to test for significant differences between stimulus novelty and stimulus targets in ERSP and PLV. The novelty P3 showed significant higher amplitude and shorter latency compared with target P3 in frontocentral regions. Overall, theta activity was significantly higher in the novel stimuli compared with the target stimuli. Specifically, the difference in theta power between novel and target stimuli was most significant in the right frontal region. This right frontal theta activity was accompanied by phase synchronization with the left temporal region. Our results imply that theta phase synchronization between right frontal and left temporal regions underlie the retrieval of memory traces for unexpected but familiar sounds from long term memory in addition to working memory retrieval or novelty encoding.     

Responsiveness and functional connectivity of the scene-sensitive retrosplenial complex in 7–11-year-old children

Brain imaging studies have identified two cortical areas, the parahippocampal place area (PPA) and the retrosplenial complex (RSC), that respond preferentially to the viewing of scenes. Contrary to the PPA, little is known about the functional maturation and cognitive control of the RSC. Here we used functional magnetic resonance imaging and tasks that required attention to scene (or face) images and suppression of face (or scene) images, respectively, to investigate task-dependent modulation of activity in the RSC and whole-brain functional connectivity (FC) of this area in 7–11-year-old children and young adults. We compared responsiveness of the RSC with that of the PPA. The RSC was selectively activated by scene images in both groups, albeit less than the PPA. Children modulated activity between the tasks similarly in the RSC and PPA, and to the same extent as adults in PPA, whereas adults modulated activity in the RSC less than in PPA. In children, the whole brain FC of the RSC was stronger in the Sf than Fs task between the left RSC and right fusiform gyrus. The between groups comparison suggested stronger FC in children than adults in the Sf task between the right RSC and the left inferior parietal lobule and intraparietal sulcus. Together the results suggest that the function of the RSC and the related networks undergo dynamic changes over the development from 7–11-year-old children to adulthood.     

Strategic retrieval processing and the impact of knowing when a memory was first created

Retrieval orientation refers to a process where participants strategically alter how a memory cue is processed in response to different task demands. In the present study we explored whether retrieval orientation is influenced by knowing when an old stimulus was first encoded. Participants completed separate remember/know test blocks for old items from a recent delay (40 min) and old items from a remote delay (48 h). Manipulations at encoding ensured that performance levels were matched between these two blocks, thus avoiding confounds with differences in retrieval effort. Importantly, a third test block comprised old items from both delays randomly intermixed. As the nature of the old items varies unpredictably in the mixed block, it should not be possibly to adopt a specific retrieval orientation and the mixed block therefore acts as a control condition. Participants saw the words “mixed,” “recent” or “remote” prior to each test block. Comparing ERPs from the recent and remote blocks permitted an investigation of whether participants alter their retrieval orientation in response to the specific length of the retention interval. Comparing ERPs from the pure (recent and remote) test blocks to ERPs from the mixed block permitted an investigation of whether delay information per se led to differences in retrieval strategy. Analysis of the ERP data found no differences between the recent and remote blocks. However, ERPs from these pure blocks were significantly less positive than ERPs from the mixed block from 200 ms towards the end of the epoch. The findings suggest that the delay information was useful in a general sense and encouraged retrieval strategies distinct from those engaged in the mixed block. We speculate that such strategies might relate to whether or not the retrieval search is specific and constrained and/or whether processes that serve to reinstate the original encoding context are engaged.     

The association of physical activity to occipito-temporal processing during face recognition

ObjectivesThis study examined the association between physical activity level and primitive cognitive processing during a face recognition task in young adults, a topic that has received little attention.DesignCross-sectional.MethodsThe face recognition task required participants to respond to famous faces but not respond to unfamiliar faces. Task performance and several occipito-temporal event-related brain potentials reflecting the various stages of face processing, from perceptual encoding (N170) to recognition (N250 and face-N400), were assessed during the face recognition task.ResultsAlthough analyses revealed no significant group differences in behavioral performance measures, neuroelectric data showed different time courses of face recognition processes between groups. Active individuals exhibited larger N250 amplitude, reflecting an early stage of facial recognition, for famous relative to unfamiliar faces, whereas inactive individuals did not exhibit such a difference.ConclusionsThese findings are suggestive of a possible association between physical activity and relatively early, primitive cognitive processes.     

人类面孔早期加工特异性神经机制

在面孔识别研究领域中,大量研究探讨人类对这一类刺激的加工是否具有与其他刺激不同的认知神经机制,即面孔的加工具有领域特异性还是过程特异性？由于各类研究使用的方法各不相同,导致对这一问题的回答尚缺乏一致性。本研究假设,如果面孔刺激具有特异性,无论在何种任务被试采用何种加工方式下,人类面孔N170反应在统计值上均显著高于其他类别的N170反应;相反,面孔与其他刺激在N170上则没有统计上的差异。研究将人类面孔、动物面孔、水果／蔬菜、房屋4类刺激呈现在不同任务设置下,测量人类面孔在不同任务中与各类刺激间的早期反应差异。当前研究结果发现,人类面孔在不同任务中始终保持着比其他刺激更为显著的ERPs（Event-Related Potentials,ERPs）反应优势,表现在额中部的早期正成分VPP和右侧颞枕部负成分N170对人类面孔反应幅度显著高于其他三类刺激的。人类面孔与其他刺激的ERP间差异反应模式在不同任务下相对稳定,并末发现动物面孔有类似效应。研究结果支持人类面孔加工的领域特异性说法。