Late maturation of backward masking in auditory cortex.
Late maturation of backward masking in auditory cortex.
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DOI：
10.1152/jn.00114.2018
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发表时间：
2018-10
影响因子：
2.5
通讯作者：
Michelle M. Mattingly;Brittany M Donell;M. J. Rosen
中科院分区：
文献类型：
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作者：
Michelle M. Mattingly;Brittany M Donell;M. J. Rosen
言语感知依赖于对随时间迅速变化的简短连续声音的准确分辨。在听觉后掩蔽过程中检测信号的能力降低，表明对这些声音的感知缺陷与儿童的语言处理困难密切相关。正常发育过程中的向后掩蔽比许多其他听觉感知有更长的成熟轨迹，这意味着中枢听觉神经机制与延长的发育时间过程有关。尽管这种感觉很重要，但在任何发育阶段，它的神经相关性都没有得到很好的描述。因此，我们测量了听觉皮层的掩蔽信号在青少年和成年蒙古沙鼠和量化的检测能力，个别神经元和神经种群的方式与心理声学测量。感知上，听觉后向掩蔽表现为更高的阈值检测的短信号，其次是掩蔽比相同的信号在沉默。皮质掩蔽是由对信号的抑制反应和在掩蔽物存在下可用于信号检测的减小的动态范围的组合驱动的。这两个编码元件有助于更大的掩蔽阈值变化与成年人相比，在青少年，但信号诱发的放电抑制更明显的青少年。神经阈值偏移是一个更好的匹配人类心理物理阈值偏移时，量化与较长的时间窗口，包括延迟掩蔽的反应，这表明时间选择性听力可能有助于年龄相关的差异后掩蔽。新&值得注意的是，在儿童中，后向掩蔽信号的听觉检测在青春期还不成熟，检测缺陷与语音处理问题有关。我们的听觉皮层记录揭示了青春期动物不成熟的向后掩蔽，反映了儿童的长期发展。这是由信号诱发抑制和动态范围减小两者驱动的。分析的扩展窗口表明，在时间上集中的听力的差异可能会导致后向掩蔽信号的成熟阈值较晚。
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.