Department of Cognitive Sciences, University of California, Irvine, USA.
College of Health Solutions, Arizona State University, Tempe, USA.
J Assoc Res Otolaryngol. 2023 Feb;24(1):67-79. doi: 10.1007/s10162-022-00877-9. Epub 2022 Dec 5.
Auditory stream segregation and informational masking were investigated in brain-lesioned individuals, age-matched controls with no neurological disease, and young college-age students. A psychophysical paradigm known as rhythmic masking release (RMR) was used to examine the ability of participants to identify a change in the rhythmic sequence of 20-ms Gaussian noise bursts presented through headphones and filtered through generalized head-related transfer functions to produce the percept of an externalized auditory image (i.e., a 3D virtual reality sound). The target rhythm was temporally interleaved with a masker sequence comprising similar noise bursts in a manner that resulted in a uniform sequence with no information remaining about the target rhythm when the target and masker were presented from the same location (an impossible task). Spatially separating the target and masker sequences allowed participants to determine if there was a change in the target rhythm midway during its presentation. RMR thresholds were defined as the minimum spatial separation between target and masker sequences that resulted in 70.7% correct-performance level in a single-interval 2-alternative forced-choice adaptive tracking procedure. The main findings were (1) significantly higher RMR thresholds for individuals with brain lesions (especially those with damage to parietal areas) and (2) a left-right spatial asymmetry in performance for lesion (but not control) participants. These findings contribute to a better understanding of spatiotemporal relations in informational masking and the neural bases of auditory scene analysis.
听觉流分离和信息掩蔽在脑损伤个体、无神经疾病的年龄匹配对照组和年轻大学生中进行了研究。使用一种称为节奏掩蔽释放（RMR）的心理物理范式来检查参与者识别通过耳机呈现的 20ms 高斯噪声突发的节奏序列变化的能力，并通过广义头部相关传递函数进行滤波，以产生外部化听觉图像（即 3D 虚拟现实声音）的感知。目标节奏与掩蔽器序列在时间上交错，掩蔽器序列由类似的噪声突发组成，当目标和掩蔽器从相同位置呈现时，掩蔽器序列会导致均匀的序列，没有关于目标节奏的信息（这是一项不可能的任务）。空间分离目标和掩蔽器序列使参与者能够确定在目标节奏呈现过程中是否发生了变化。RMR 阈值定义为目标和掩蔽器序列之间导致 70.7%的正确性能水平的最小空间分离，采用单间隔 2 替代强制选择自适应跟踪程序。主要发现包括：（1）脑损伤个体（尤其是顶叶区域受损者）的 RMR 阈值显著较高；（2）损伤（但非对照组）参与者的表现存在左右空间不对称性。这些发现有助于更好地理解信息掩蔽中的时空关系和听觉场景分析的神经基础。
