Stream segregation revisited: Dynamic listening and influences of emotional context on stream perception and attention

A classical experiment of auditory stream segregation is revisited, reconceptualising perceptual ambiguity in terms of affordances and musical engagement. Specifically, three experiments are reported that investigate how listeners’ perception of auditory sequences change dynamically depending on emotional context. The experiments show that listeners adapt their attention to higher or lower pitched streams (Experiments 1 and 2) and the degree of auditory stream integration or segregation (Experiment 3) in accordance with the presented emotional context. Participants with and without formal musical training show this influence, although to differing degrees (Experiment 2). Contributing evidence to the literature on interactions between emotion and cognition, these experiments demonstrate how emotion is an intrinsic part of music perception and not merely a product of the listening experience.     

Trial-to-trial dynamics of selective long-term-memory retrieval with continuously changing retrieval targets

How do we control the successive retrieval of behaviorally relevant information from long-term memory (LTM) without being distracted by other potential retrieval targets associated to the same retrieval cues? Here, we approach this question by investigating the nature of trial-by-trial dynamics of selective LTM retrieval, i.e., in how far retrieval in one trial has detrimental or facilitatory effects on selective retrieval in the following trial. Participants first learned associations between retrieval cues and targets, with one cue always being linked to three targets, forming small associative networks. In successive trials, participants had to access either the same or a different target belonging to either the same or a different cue. We found that retrieval times were faster for targets that had already been relevant in the previous trial, with this facilitatory effect being substantially weaker when the associative network changed in which the targets were embedded. Moreover, staying within the same network still had a facilitatory effect even if the target changed, which became evident in a relatively higher memory performance in comparison to a network change. Furthermore, event-related brain potentials (ERPs) showed topographically and temporally dissociable correlates of these effects, suggesting that they result from combined influences of distinct processes that aid memory retrieval when relevant and irrelevant targets change their status from trial to trial. Taken together, the present study provides insight into the different processing stages of memory retrieval when fast switches between retrieval targets are required.     

Keeping the end in mind: Preliminary brain and behavioral evidence for broad attention to endpoints in pre-linguistic infants

Infants must learn to carve events at their joints to best understand who is doing what to whom or whether an object or agent has reached its intended goal. Recent behavioral research demonstrates that infants do not see the world as a movie devoid of meaning, but rather as a series of sub-events that include agents moving in different manners along paths from sources to goals. This research uses behavioral and electrophysiological methods to investigate infants’ (10–14 months) attention to disruptions within relatively unfamiliar human action that does not rely on goal-objects to signal attainment (i.e., Olympic figure skating). Infants’ visual (Study 1, N = 48) and neurophysiological (Study 2, N = 21) responses to pauses at starting points, endpoints, and within-action locations were recorded. Both measures revealed differential responses to pauses at endpoints relative to pauses elsewhere in the action (i.e., starting point; within-action). Eye-tracking data indicated that infants’ visual attention was greater for events containing pauses at endpoints relative to events with pauses at starting points or within-actions. ERP activity reflecting perceptual processes in early-latency windows (<200 ms) and memory updating processes in long-latency windows (700−1000 ms) showed differential activation to disruptions at the end of a figure-skating action compared to other locations. Mid-latency windows (250−750 ms), in contrast, showed enhanced activation at frontal regions across conditions, suggesting electrophysiological resources may have been recruited to encode disruptions within unfamiliar dynamic human action. Combined, results hint at broad sensitivity to endpoints as a mechanism that supports infants’ proclivity for carving continuous and complex event streams into meaningful units. Findings have potential implications for language development as these units are mapped onto budding linguistic representations. We discuss empirical and methodological contributions for action perception and address potential merits and pitfalls of applying behavioral techniques in conjunction with brain-based measures to study infant development.     

Covert orienting of attention in 3-month-old infants: The case of biological motion

Humans attend to different positions in the space either by moving their eyes or by moving covertly their attention. The development of covert attention occurs during the first year of life. According to Colombo’s model of attention (2001), within the first years there is a significant change in infants’ visuo-spatial orienting mechanisms, from a predominantly overt form to a covert orienting starting from 4 to 5 months of life. The use of non-invasive brain imaging techniques can shed light on the origin of such mechanisms. In particular, EEG and ERP studies can directly investigate the neural correlates of covert attention in young infants. The present study investigated the neural correlates of covert attention employing a visuo-spatial cueing paradigm in 3-month-old infants. Infants were presented with a central point-light walker (PLD) 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 P1 component and the saccade latencies toward the peripheral target. Results showed that the P1 component was larger in response to congruent than to incongruent targets and saccade latencies were faster for congruent rather than incongruent trials. Moreover, the facilitation in processing sensory information (priming effects) presented at the cued spatial location occurs even before the onset of the oculomotor response, suggesting that covert attention is present before 4 months of age. Overall, this study highlights how ERPs method could help researchers at investigating the neural basis of attentional mechanisms in infants.     

A proposal for an auditory sensation cognitive architecture and its integration with the motor-system cognitive function

The auditory system is capable of producing a wide range of information through the acquisition and perception of the vibrations present in the environment, even when the receptor is not directly facing the stimulus’s source. Said information can be crucial for survival and useful for a variety of systems like the visual system and the motor system. Despite that, the quantity of studies involving the auditory system or its interactions with other systems is limited, even though anatomical evidence recognizes this relationships’ existence. In this work, we study its interaction with the motor system. A bio-inspired model that explores the relationship between the auditory and motor systems, grounded on neuroscientific research, is presented to address this proposal. To validate our proposal, a case study in which we endow a virtual entity with our proposed model. Then, we ask both a group of persons and the virtual creature to compute and face towards the direction were the sound was originated.     

The power of the written word: Comparing word meaning inferencing from auditory and written modalities throughout grade school

Previous research indicates that word learning from auditory contexts may be more effective than written context at least through fourth grade. However, no study has examined contextual differences in word learning in older school-aged children when reading abilities are more developed. Here we examined developmental differences in children’s ability to deduce the meanings of unknown words from the surrounding linguistic context in the auditory and written modalities and sought to identify the most important predictors of success in each modality. A total of 89 children aged 8–15 years were randomly assigned to either read or listen to a narrative that included eight novel words, with five exposures to each novel word. They then completed three posttests to assess word meaning inferencing. Children across all ages performed better in the written modality. Vocabulary was the only significant predictor of success on the word inferencing task. Results indicate support for written stimuli as the most effective modality for novel word meaning deduction. Our findings suggest that the presence of orthographic information facilitates novel word learning even for early, less proficient readers.     

Pupillometric decoding of high-level musical imagery

Humans report imagining sound where no physical sound is present: we replay conversations, practice speeches, and “hear” music all within the confines of our minds. Research has identified neural substrates underlying auditory imagery; yet deciphering its explicit contents has been elusive. Here we present a novel pupillometric method for decoding what individuals hear “inside their heads”. Independent of light, pupils dilate and constrict in response to noradrenergic activity. Hence, stimuli evoking unique and reliable patterns of attention and arousal even when imagined should concurrently produce identifiable patterns of pupil-size dynamics (PSDs). Participants listened to and then silently imagined music while eye-tracked. Using machine learning algorithms, we decoded the imagined songs within- and across-participants following classifier-training on PSDs collected during both imagination and perception. Echoing findings in vision, cross-domain decoding accuracy increased with imagery strength. These data suggest that light-independent PSDs are a neural signature sensitive enough to decode imagination.     

Neural Processing to Visual Stimuli in a Three-Choice Reaction-Time Task

Some authors have suggested that certain components of the event-related potentials (ERPs) reflect underlying stages in the discrimination process. Previous studies have shown that in an auditive three-choice reaction-time task the discrimination is accomplished as a two-stage process, with the more frequently occurring stimulus discriminated at an earlier point than the rarer stimulus and the subjects could be classified as fast and slow responders in function of their response to the most frequent of the three tones. We continuously recorded the electrocerebral activity (EEG) from the scalp and the electromyographic activity (EMG) from the responding muscles in a visual three-choice reaction-time task in 10 strictly right-handed subjects. EEG and EMG responses were subsequently analyzed off-line by aligning them by the onset of either the stimulus (stimulus-synchronized) or the response (response-synchronized). The results suggest that processes of visual stimuli evaluation and response execution are continuously integrated. The discrimination and response systems to visual stimuli is accomplished as a three-stage process, one to frequent tone, another for rare 1, and the last for rare 2. The subjects were classified as fast and slow responders in function of their response to the most frequent of the three tones.     

Rational Redundancy in Referring Expressions: Evidence from Event-related Potentials

In referential communication, Grice's Maxim of Quantity is thought to imply that utterances conveying unnecessary information should incur comprehension difficulties. There is, however, considerable evidence that speakers frequently encode redundant information in their referring expressions, raising the question as to whether such overspecifications hinder listeners’ processing. Evidence from previous work is inconclusive, and mostly comes from offline studies. In this article, we present two event-related potential (ERP) experiments, investigating the real-time comprehension of referring expressions that contain redundant adjectives in complex visual contexts. Our findings provide support for both Gricean and bounded-rational accounts. We argue that these seemingly incompatible results can be reconciled if common ground is taken into account. We propose a bounded-rational account of overspecification, according to which even redundant words can be beneficial to comprehension to the extent that they facilitate the reduction of listeners’ uncertainty regarding the target referent.     

返回抑制训练效应的认知神经机制——来自ERP研究的证据

返回抑制是指个体对呈现在先前(约250 ms前)线索化或注视过位置的刺激反应更慢的现象。尽管有研究表明IOR在长时训练下存在稳定的训练效应,但其相应的认知神经机制,即训练究竟是如何影响IOR的迄今为止尚不明确。本研究采用对信息加工过程高敏感的事件相关电位技术结合长时训练和线索-靶子范式来对该问题进行考察。结果发现:在行为上同前人研究结果相一致,返回抑制效应在长时训练下表现出稳定的下降趋势;更重要的是在脑电上同IOR行为效应量在训练后变小的结果相一致,标识早期知觉加工的成分如N1等在有效和无效线索条件间的差异也表现出在训练后的降低。结果表明早期的知觉加工阶段是训练影响IOR的一个重要阶段,为探明IOR训练效应的认知神经机制提供了来自电生理学的重要证据。