Hanenberg Christina, Schlüter Michael-Christian, Getzmann Stephan, Lewald Jörg
Faculty of Psychology, Ruhr University Bochum, Bochum, Germany.
Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany.
Front Neurosci. 2021 Jul 1;15:645702. doi: 10.3389/fnins.2021.645702. eCollection 2021.
Audiovisual cross-modal training has been proposed as a tool to improve human spatial hearing. Here, we investigated training-induced modulations of event-related potential (ERP) components that have been associated with processes of auditory selective spatial attention when a speaker of interest has to be localized in a multiple speaker ("cocktail-party") scenario. Forty-five healthy participants were tested, including younger (19-29 years; = 21) and older (66-76 years; = 24) age groups. Three conditions of short-term training (duration 15 min) were compared, requiring localization of non-speech targets under "cocktail-party" conditions with either (1) synchronous presentation of co-localized auditory-target and visual stimuli (audiovisual-congruency training) or (2) immediate visual feedback on correct or incorrect localization responses (visual-feedback training), or (3) presentation of spatially incongruent auditory-target and visual stimuli presented at random positions with synchronous onset (control condition). Prior to and after training, participants were tested in an auditory spatial attention task (15 min), requiring localization of a predefined spoken word out of three distractor words, which were presented with synchronous stimulus onset from different positions. Peaks of ERP components were analyzed with a specific focus on the N2, which is known to be a correlate of auditory selective spatial attention. N2 amplitudes were significantly larger after audiovisual-congruency training compared with the remaining training conditions for younger, but not older, participants. Also, at the time of the N2, distributed source analysis revealed an enhancement of neural activity induced by audiovisual-congruency training in dorsolateral prefrontal cortex (Brodmann area 9) for the younger group. These findings suggest that cross-modal processes induced by audiovisual-congruency training under "cocktail-party" conditions at a short time scale resulted in an enhancement of correlates of auditory selective spatial attention.
视听跨模态训练已被提议作为一种改善人类空间听觉的工具。在此，我们研究了训练引起的事件相关电位（ERP）成分的调制，这些成分与在多个说话者（“鸡尾酒会”）场景中定位感兴趣的说话者时的听觉选择性空间注意过程相关。测试了45名健康参与者，包括年轻（19 - 29岁；n = 21）和年长（66 - 76岁；n = 24）年龄组。比较了三种短期训练条件（持续时间15分钟），要求在“鸡尾酒会”条件下对非语音目标进行定位，其中（1）共同定位的听觉目标和视觉刺激同步呈现（视听一致性训练），或（2）对正确或错误的定位反应立即给予视觉反馈（视觉反馈训练），或（3）在随机位置同步呈现空间不一致的听觉目标和视觉刺激（对照条件）。在训练前后，参与者在听觉空间注意任务（15分钟）中接受测试，要求从三个干扰词中定位一个预定义的口语单词，这些干扰词从不同位置同步呈现刺激起始。特别关注已知与听觉选择性空间注意相关联的N2，对ERP成分的峰值进行了分析。与其余训练条件相比，视听一致性训练后，年轻参与者而非年长参与者的N2振幅显著更大。此外，在N2出现时，分布式源分析显示，年轻组在背外侧前额叶皮层（布罗德曼区域9）中，视听一致性训练诱导的神经活动增强。这些发现表明，在“鸡尾酒会”条件下短时间尺度的视听一致性训练所引发 的跨模态过程导致了听觉选择性空间注意相关指标的增强。
