The neural correlates of orienting to walking direction in 6‐month‐old infants: An ERP study

The ability to detect social signals represents a first step to enter our social world. Behavioral evidence has demonstrated that 6‐month‐old infants are able to orient their attention toward the position indicated by walking direction, showing faster orienting responses toward stimuli cued by the direction of motion than toward uncued stimuli. The present study investigated the neural mechanisms underpinning this attentional priming effect by using a spatial cueing paradigm and recording EEG (Geodesic System 128 channels) from 6‐month‐old infants. Infants were presented with a central point‐light walker followed by a single peripheral target. The target appeared randomly at a position either congruent or incongruent with the walking direction of the cue. We examined infants' target‐locked event‐related potential (ERP) responses and we used cortical source analysis to explore which brain regions gave rise to the ERP responses. The P1 component and saccade latencies toward the peripheral target were modulated by the congruency between the walking direction of the cue and the position of the target. Infants' saccade latencies were faster in response to targets appearing at congruent spatial locations. The P1 component was larger in response to congruent than to incongruent targets and a similar congruency effect was found with cortical source analysis in the parahippocampal gyrus and the anterior fusiform gyrus. Overall, these findings suggest that a type of biological motion like the one of a vertebrate walking on the legs can trigger covert orienting of attention in 6‐month‐old infants, enabling enhancement of neural activity related to visual processing of potentially relevant information as well as a facilitation of oculomotor responses to stimuli appearing at the attended location.     

顿悟式组块破解的时间进程：ERP研究

本研究旨在探讨顿悟式组块破解的信息加工机制及神经动态变化。被试完成汉字拆解任务,也即从一个源汉字中移动部件从而得到有效汉字。研究操纵部件之间在空间交错背景下的类别关系：同类（移动部件和剩余部件都是汉字）和异类（移动部件是笔画,剩余部件是汉字）。与此同时记录事件相关电位变化。结果显示,同类条件比异类条件引发了更大的N2波动和减小的LPC波动。早期的N2效应可能提示了组块破解过程中的识别困难,而晚期的LPC效应可能提示了组块破解过程中的知觉转换困难。     

Behavioral assessment of auditory processing deficits in schizophrenia: Literature review and suggestions for future research

During the last decades, a considerable number of studies about auditory processing deficits in schizophrenia have been published, some of them using the term of Auditory Processing Disorder (APD). Due to heterogeneous methodology and inconsistent results concrete conclusions may not be straightforward. We focused on studies that used at least one behavioral test for the assessment of auditory processing in schizophrenia, in order to identify new evidence on auditory processing deficits in schizophrenia, and to consider fields for future research. 28 studies met inclusion criteria and are presented in this review. The articles were divided into three groups, those that implemented a test battery approach, those that used only Dichotic Listening (DL), those that used DL along with imaging or electrophysiology techniques. Most of the studies that implemented a test battery showed significant performance differences between patients and controls. This indicates APD presence. Due to the limited number of studies implementing a test battery, this is not conclusive. The majority of all studies that used a DL task showed that patients' performance or laterality was significantly lower than that of controls. Age, duration of illness, total and specific positive symptoms seem to affect significantly DL performance and auditory laterality. The results support the existence of various schizophrenia subgroups that differ in their auditory processing performance, and also have structural and functional specificities. Further research in the field is needed, especially studies that implement a test battery, and studies that examine possible correlations between clinical variables and auditory processing deficits.     

Choosing the shortest way to Mum: auditory guided rotation in 6- to 9-month-old infants

The purpose of this study was to investigate the use of auditory information for rotation of the shortest way in twelve 6- to 9-month-old sighted infants. Behavior was manipulated by means of an auditory stimulus presented in four different directional angles (90°, 112.5°, 135°, and 157.5°) to the right and to the left behind the infants, and in one non-directional angle (180°). Infants lay in a prone position and had magnetic trackers fastened to the head and body which measured their rotation direction and angular velocity. The results showed that infants not only consistently chose the shortest over the longest way, but also rotated with a higher peak angular velocity as the angle to be covered between themselves and the goal increased. The results did not show significant preferences for one particular rotation direction. The study can contribute to the understanding of the auditory system as a functional listening system where auditory information is used as a perceptual source for prospectively guiding behavior in the environment.     

Early top-down influences on bistable perception revealed by event-related potentials

A longstanding debate exists in the literature concerning bottom-up vs. top-down influences on bistable perception. Recently, a technique has been developed to measure early changes in brain activity (via ERPs) related to perceptual reversals (Kornmeier & Bach, 2004). An ERP component, the reversal negativity (RN) has been identified, and is characterized as an increase in negative potential over the posterior scalp from 150 to 350 ms for perceptual reversals compared to perceptual stability. This finding, although interesting, has not helped resolve issues related to the bottom-up vs. top-down debate because top-down influences have not been directly manipulated. The current study focused on resolving some of these issues by measuring the RN while observers maintained one of three 'intentional approaches', (1) try to reverse perception as often as possible, (2) try to stabilize perception for as long as possible, and (3) maintain a passive approach. Enhancements in RN amplitude were found for the intention-to-reverse condition compared to the passive condition. This finding suggests an early influence (150 ms) of top-down control on perceptual reversals of bistable figures. Results are discussed in terms of competing attention shifting vs. fatigue-based theories of bistable perception.     

Vestibular influence on auditory metrical interpretation

When we move to music we feel the beat, and this feeling can shape the sound we hear. Previous studies have shown that when people listen to a metrically ambiguous rhythm pattern, moving the body on a certain beat--adults, by actively bouncing themselves in synchrony with the experimenter, and babies, by being bounced passively in the experimenter's arms--can bias their auditory metrical representation so that they interpret the pattern in a corresponding metrical form [Phillips-Silver, J., & Trainor, L. J. (2005). Feeling the beat: Movement influences infant rhythm perception. Science, 308, 1430; Phillips-Silver, J., & Trainor, L. J. (2007). Hearing what the body feels: Auditory encoding of rhythmic movement. Cognition, 105, 533-546]. The present studies show that in adults, as well as in infants, metrical encoding of rhythm can be biased by passive motion. Furthermore, because movement of the head alone affected auditory encoding whereas movement of the legs alone did not, we propose that vestibular input may play a key role in the effect of movement on auditory rhythm processing. We discuss possible cortical and subcortical sites for the integration of auditory and vestibular inputs that may underlie the interaction between movement and auditory metrical rhythm perception.     

Three kinds of rhymes: An ERP study

In a simple prime-target visual rhyming paradigm, pairs of words, nonwords, and single letters elicited similar event-related potential (ERP) rhyming effects in young adults. Within each condition, primes elicited contingent negative variation (CNV) while nonrhyming targets elicited more negative waveforms than rhyming targets within the 320-500ms (N400/N450) time window. The target rhyming effect, apparently primarily an index of phonological processing, was similar across conditions but tended to be smaller in mean amplitude for letters. One of the first reports of such a letter rhyming effect in the ERP literature, these findings could be important developmentally because letter rhyme tasks simultaneously index the two best predictors of ease of learning to read: letter name knowledge and phonological awareness.     

Immediate source-monitoring, self-focused attention and the positive symptoms of schizophrenia

Previous research suggests that tendencies to misattribute one's own thoughts to an external source, as assessed by an immediate source-monitoring test, are associated with auditory verbal hallucinations (AVHs). However, recent research suggests that such tendencies are associated instead with symptoms of thought interference. The main aim of the present study was to examine whether such tendencies are differentially associated with different types of thought interference, with AVHs, or with both. It has also been suggested that external misattributions are especially likely to occur with emotionally salient material and if the individual's focus is on the self. These suggestions were also tested. The positive psychotic symptoms of 57 individuals with a diagnosis of schizophrenia were assessed and they then completed the Self-Focus Sentence Completion blank. Immediately after completing each sentence they were asked to indicate to what extent the sentence was their own. The number of sentences that were not rated as completely their own served as their externalisation score. Externalisation scores correlated significantly with the severity of three symptoms: voices commenting, delusions of being controlled, and thought insertion. In a logistic regression analysis, all three of these symptoms were significantly and independently related to externalisation. Externalisation was not associated with either a negative or a neutral self-focus. Thus tendencies to misattribute one's own thoughts to an external source are associated with AVHs and some, but not all, symptoms of thought interference. The importance for externalisation of self-focused attention and of the emotional salience of the elicited thoughts was not supported.     

Auditory processing deficits in children with reading and language impairments: can they (and should they) be treated?

Sixty-five children with specific reading disability (SRD), 25 children with specific language impairment (SLI), and 37 age-matched controls were tested for their frequency discrimination, rapid auditory processing, vowel discrimination, and consonant–vowel discrimination. Subgroups of children with SRD or SLI produced abnormal frequency discrimination (42%), rapid auditory processing (12%), vowel discrimination (23%), or consonant–vowel discrimination (18%) thresholds for their age. Twenty-eight of these children trained on a programme that targeted their specific auditory processing deficit for 6 weeks. Twenty-five of these 28 trainees produced normal thresholds for their targeted processing skill after training. These gains were not explained by gains in auditory attention, in the ability to do psychophysical tasks in general, or by test–retest effects. The 25 successful trainees also produced significantly higher scores on spoken language and spelling tests after training. However, an untrained control group showed test–retest effects on the same tests. These results suggest that auditory processing deficits can be treated successfully in children with SRD and SLI but that this does not help them acquire new reading, spelling, or spoken language skills.