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.     

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.     

不同注意条件下动态面孔表情识别的ERP研究

利用ERP技术对16名被试在不同注意负荷下对动态表情识别的脑时程特点进行了考察,结果发现：N170成分不受注意负荷和表情效价影响;低注意负荷条件下动态表情加工早期负性表情诱发的EPN成分（early posterior negativity）显著大于中性、正性表情,后期高级分析阶段正、负性表情均诱发明显的LPP成分（late positive potentials）,且负性较正性表情诱发更大的LPP成分;而在高注意负荷条件下并未发现表情识别诱发明显的EPN或LPP成分。这些结果说明,动态表情识别明显受到注意资源调节,只有在注意资源不断增加时表情加工才会出现注意偏向效应,尤以负性表情的加工优势最为凸显且持久,正性表情相对微弱和短暂。     

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。     

Transformative Theory in Social and Organizational Research

In social and organizational research, theory is conventionally used to explain social phenomena. However, theory may be transformative in the sense that in using and testing the theory in a practical domain, researchers may attempt to help practitioners transform and improve their social practices and institutions. This idea is illustrated by a research-and-development project in Denmark, headed by the author, which used transformative theory to design professional conferences that are more conducive to participant learning and involvement than is the conventional, lecture-based format. A number of learning techniques were derived from the theory and were tested as hypotheses: When implemented in thirty live conference experiments, did they contribute to learning, as specified by the theory? Used in this manner, transformative theory may supplement the aspirations motivating change agents by some of the well-known qualities of scientific research, including theoretical grounding, a coherent ontology, testable hypotheses, systematic evaluation, external validity, and theory–action consistency.     

Written threat: Electrophysiological evidence for an attention bias to affective words in social anxiety disorder

Social anxiety disorder (SAD) is associated with heightened sensitivity to threat cues, typically represented by emotional facial expressions. To examine if this bias can be transferred to a general hypersensitivity or whether it is specific to disorder relevant cues, we investigated electrophysiological correlates of emotional word processing (alpha activity and event-related potentials) in 20 healthy participants and 20 participants with SAD. The experimental task was a silent reading of neutral, positive, physically threatening and socially threatening words (the latter were abusive swear words) while responding to a randomly presented dot. Subsequently, all participants were asked to recall as many words as possible during an unexpected recall test. Participants with SAD showed blunted sensory processing followed by a rapid processing of emotional words during early stages (early posterior negativity – EPN). At later stages, all participants showed enhanced processing of negative (physically and socially threatening) compared to neutral and positive words (N400). Moreover, at later processing stages alpha activity was increased specifically for negative words in participants with SAD but not in healthy controls. Recall of emotional words for all subjects was best for socially threatening words, followed by negative and positive words irrespective of social anxiety. The present findings indicate that SAD is associated with abnormalities in emotional word processing characterised by early hypervigilance to emotional cues followed by cognitive avoidance at later processing stages. Most importantly, the specificity of these attentional biases seems to change as a function of time with a general emotional bias at early and a more specific bias at later processing stages.     

Can we distinguish an “I” and “ME” during listening?—an event-related EEG study on the processing of first and second person personal and possessive pronouns

Theoretically, stimuli can be related to the self as subject (“I”) or object (“ME”) of experience. This event-related brain potential (ERP) study investigated whether listening to personal and possessive pronouns elicits different modes of self-processing regarding time-course and neural sources. Going beyond previous research, first (1PP) and second person (2PP) pronouns were included to determine the specificity of self-processing. Participants listened passively to German pronouns while the electroencephalogram was recorded. Modulation of ERPs revealed a processing advantage for the 2PP personal pronoun “du” (“you”) already in early time windows. Regarding possessive pronouns, N1 amplitudes indicated increased attention orientation to the 1PP pronoun “mein” (“my”), whereas during later time windows, processing of 1PP and 2PP possessive pronouns did not differ but differed from the third person pronoun “sein” (“his”). ERP source imaging suggests that primary sensory brain regions (auditory cortex), the insula and cortical midline structures are differentially involved into these two processing modes. The results support the idea of distinct self-processing modes (“I” and “ME”) and confirm their dynamic nature. Moreover, they demonstrate that on a neural level neither “I” or “ME” are invariantly tied to the first person, in line with the hypothesis that self-processing is relational and context-dependent.     

ERP correlates of language-specific processing of auditory pitch feedback during self-vocalization

The present study investigated whether the neural correlates for auditory feedback control of vocal pitch can be shaped by tone language experience. Event-related potentials (P2/N1) were recorded from adult native speakers of Mandarin and Cantonese who heard their voice auditory feedback shifted in pitch by −50, −100, −200, or −500 cents when they sustained the vowel sound /u/. Cantonese speakers produced larger P2 amplitudes to −200 or −500 cents stimuli than Mandarin speakers, but this language effect failed to reach significance in the case of −50 or −100 cents. Moreover, Mandarin speakers produced shorter N1 latencies over the left hemisphere than the right hemisphere, whereas Cantonese speakers did not. These findings demonstrate that neural processing of auditory pitch feedback in vocal motor control is subject to language-dependent neural plasticity, suggesting that cortical mechanisms of auditory-vocal integration can be shaped by tone language experience.