Modulating Cortical Instrument Representations During Auditory Stream Segregation and Integration With Polyphonic Music

Numerous neuroimaging studies demonstrated that the auditory cortex tracks ongoing speech and that, in multi-speaker environments, tracking of the attended speaker is enhanced compared to the other irrelevant speakers. In contrast to speech, multi-instrument music can be appreciated by attending not only on its individual entities (i.e., segregation) but also on multiple instruments simultaneously (i.e., integration). We investigated the neural correlates of these two modes of music listening using electroencephalography (EEG) and sound envelope tracking. To this end, we presented uniquely composed music pieces played by two instruments, a bassoon and a cello, in combination with a previously validated music auditory scene analysis behavioral paradigm (Disbergen et al., 2018). Similar to results obtained through selective listening tasks for speech, relevant instruments could be reconstructed better than irrelevant ones during the segregation task. A delay-specific analysis showed higher reconstruction for the relevant instrument during a middle-latency window for both the bassoon and cello and during a late window for the bassoon. During the integration task, we did not observe significant attentional modulation when reconstructing the overall music envelope. Subsequent analyses indicated that this null result might be due to the heterogeneous strategies listeners employ during the integration task. Overall, our results suggest that subsequent to a common processing stage, top-down modulations consistently enhance the relevant instrument’s representation during an instrument segregation task, whereas such an enhancement is not observed during an instrument integration task. These findings extend previous results from speech tracking to the tracking of multi-instrument music and, furthermore, inform current theories on polyphonic music perception.

Rhetorical versus Substantive Reconciliation After Cultural Genocide in Canada

The Canadian Truth and Reconciliation Commission (‘TRC’) report calls for the Canadian government and (settler) Canadians to acknowledge the painful past of the Indian Residential Schools (‘IRS’) (1890s–1990s) and to chart a new nation-to-nation(s) relationship with Canada’s Indigenous peoples. However, the reconciliation discourse replicates unequal power dynamics between Indigenous and non-Indigenous communities endemic in Canadian politics and society. The selective listening of the IRS story is grounded in a constructed identity that paints Canada and (non-Indigenous) Canadians as an inclusive and tolerant society. This self-conception has led various levels of government to emphasize the idea of reconciliation as a process by which settler colonialism is conceptualized as a closed historical event that is now firmly in the past. There is little acknowledgement that the logic and structures of settler colonialism, which as the TRC notes amounts to cultural genocide, are still foundational to contemporary Canadian politics, law, economy, and society.

Correlates of auditory decision making in prefrontal, auditory, and basal lateral amygdala cortical areas

Auditory selective listening and decision making underlies important processes, including attending to a single speaker in a crowded room, often referred to as the cocktail party problem. To examine the neural mechanisms underlying these behaviors, we developed a novel auditory selective listening paradigm for monkeys. In this task, monkeys had to detect a difficult to discriminate target embedded in noise when presented in a pre-cued location (either left or right) and ignore it if it was in the opposite location. While the animals carried out the task we recorded neural activity in primary auditory cortex (AC), dorsal lateral prefrontal cortex (dlPFC) and the basal lateral amygdala (BLA), given that these areas have been implicated in auditory decision making, selective listing, and/or reward-guided decision making. There were two main findings in the neural data. First, primary AC encoded the side of the cue and target, and the monkey’s choice, before either dlPFC or the amygdala. The BLA encoded cue and target variables negligibly, but was engaged at the time of the monkey’s choice. Second, decoding analyses suggested that errors followed primarily from a failure to encode the target stimulus in both AC and PFC, but earlier in AC. Thus, AC neural activity is poised to represent the sensory volley and decision making during selective listening before dlPFC, and they both precede activity in BLA.

DEVELOPMENT DESIGN OF SELECTIVE LISTENING LEARNING MATERIAL BASED ON CORRELATED CORE WITH THE APPLICATION OF LISTENING IN ACTION METHODS

The design of the development of learning methods involves the pattern of organizing elements or components in the curriculum. the development of learning materials listening to correlated core-based learning with the application of listening in action methods seen from two dimensions, namely horizontal and vertical dimensions. The horizontal dimension is related to the compilation of the scope of learning content. This spatial arrangement is often integrated with the learning and teaching process. The vertical dimension concerns the compilation of material sequences based on the order of difficulty. Arranged materials start from the easy ones, then go to the more difficult ones, or start with the basic ones followed by the continuation. This development describes in detail about the components that must be present in each listening learning material that can be used for the learning process. The design of the development of the listening learning material consists of several components, including the objectives of the curriculum, teaching materials or the material or content of the curriculum, teaching strategies or teaching methods, teaching media and teaching evaluation and improving teaching. These components are related to each other in the development of learning materials listening to correlated core-based learning by applying listening in action methods.

Late maturation of backward masking in auditory cortex

Speech perception relies on the accurate resolution of brief, successive sounds that change rapidly over time. Deficits in the perception of such sounds, indicated by a reduced ability to detect signals during auditory backward masking, strongly relate to language processing difficulties in children. Backward masking during normal development has a longer maturational trajectory than many other auditory percepts, implicating the involvement of central auditory neural mechanisms with protracted developmental time courses. Despite the importance of this percept, its neural correlates are not well described at any developmental stage. We therefore measured auditory cortical responses to masked signals in juvenile and adult Mongolian gerbils and quantified the detection ability of individual neurons and neural populations in a manner comparable with psychoacoustic measurements. Perceptually, auditory backward masking manifests as higher thresholds for detection of a short signal followed by a masker than for the same signal in silence. Cortical masking was driven by a combination of suppressed responses to the signal and a reduced dynamic range available for signal detection in the presence of the masker. Both coding elements contributed to greater masked threshold shifts in juveniles compared with adults, but signal-evoked firing suppression was more pronounced in juveniles. Neural threshold shifts were a better match to human psychophysical threshold shifts when quantified with a longer temporal window that included the response to the delayed masker, suggesting that temporally selective listening may contribute to age-related differences in backward masking. NEW & NOTEWORTHY In children, auditory detection of backward masked signals is immature well into adolescence, and detection deficits correlate with problems in speech processing. Our auditory cortical recordings reveal immature backward masking in adolescent animals that mirrors the prolonged development seen in children. This is driven by both signal-evoked suppression and dynamic range reduction. An extended window of analysis suggests that differences in temporally focused listening may contribute to late maturing thresholds for backward masked signals.