Embodied Micro-Transitions

Employing multimodal conversation analysis, this article examines a single episode of interaction taken from a studio session, during which two musicians check a chord progression. It illustrates how intra-activity micro-transitions are solely achieved through embodied actions. The detailed analysis reveals (a) how the suspension of “playing-along” is occasioned to exhibit participants’ orientation to auditory objects whose “turning-on” makes relevant disengagement from other interactional involvements; and (b) how the temporal complexities of multiactivity are contingently managed in exclusive order, explicating (c) members’ embodied practices for working around the organizational constraints of the auditory objects.

The role of temporal coherence and temporal stability in the build-up of auditory grouping

To form complex representations of sounds, i.e. auditory objects, the auditory system needs to make decisions about which information is part of one object and which is part of another. These decisions are usually taken over a short period of time at the beginning of the sound, known as build-up, by using the available grouping cues. Here we investigate the use of temporal coherence and temporal stability to influence subsequent grouping. We show that these two grouping cues behave independently from one another and except when put into conflict. In these situations, the cues available during the build-up period determine subsequent perception.

Distributed networks for auditory memory contribute differentially to recall precision

The representations held in working memory are inherently noisy, but attention directed to relevant objects can effectively enhance their fidelity. While recent working memory models suggest that memory representations are distributed across sensory and cognitive-control brain regions, it remains unknown how multiple brain networks generate this attentional gain in fidelity. Here, we investigated the contributions of the distinct brain networks in maintaining and enhancing memory representations using psychophysical modeling and fMRI. Human listeners performed an auditory syllable pitch-discrimination task, in which they received valid (vs. neutral) retro-active cues to selectively attend to one of the two syllable categories maintained in memory. Valid (vs. neutral) retro-cues facilitated task performance, eliciting faster recall and enhanced recall precision of syllables in memory. Valid retro-cues also led to increased neural activation in fronto-parietal and cingulo-opercular networks, but not in sensory-specific superior temporal cortex. Multivariate pattern analysis as a proxy for representational fidelity in memory revealed that attended syllable objects were maintained in distributed areas across superior temporal, frontal, parietal, and sensorimotor brain areas. However, neural fidelity in left superior temporal sulcus and its enhancement through attention-to-memory best predicted the ensuing individual gain in recall precision of auditory objects from memory. These results demonstrate that maintaining versus attentionally enhancing auditory memory representations are functionally separable mechanisms across distributed brain regions.Significance StatementWorking memory is distributed across sensory and cognitive-control brain regions. But how do these brain networks enhance working memory precision when attention is re-directed to memory? We here investigate the contributions of distinct brain networks in maintaining and enhancing auditory memory representations through attention-to-memory using fMRI. We demonstrate that re-directing attention to the relevant auditory memory objects mainly recruits higher-order cognitive-control networks. Among the multiple brain regions retaining memory representations, however, attentional enhancement of the neural fidelity in superior temporal sulcus best predicts the individual gain in recall precision of auditory objects from memory. This study provides evidence of the interplay among the discrete, functionally specialized brain regions in maintaining and attentionally enhancing working memory representations.

Treefrogs exploit temporal coherence to form perceptual objects of communication signals

For many animals, navigating their environment requires an ability to organize continuous streams of sensory input into discrete ‘perceptual objects’ that correspond to physical entities in visual and auditory scenes. The human visual and auditory systems follow several Gestalt laws of perceptual organization to bind constituent features into coherent perceptual objects. A largely unexplored question is whether nonhuman animals follow similar Gestalt laws in perceiving behaviourally relevant stimuli, such as communication signals. We used females of Cope's grey treefrog ( Hyla chrysoscelis ) to test the hypothesis that temporal coherence—a powerful Gestalt principle in human auditory scene analysis—promotes perceptual binding in forming auditory objects of species-typical vocalizations. According to the principle of temporal coherence, sound elements that start and stop at the same time or that modulate coherently over time are likely to become bound together into the same auditory object. We found that the natural temporal coherence between two spectral components of advertisement calls promotes their perceptual binding into auditory objects of advertisement calls. Our findings confirm the broad ecological validity of temporal coherence as a Gestalt law of auditory perceptual organization guiding the formation of biologically relevant perceptual objects in animal behaviour.