Biology subjects

Lewald, J.

Publications and source records attributed to Lewald, J..

4 recordsLinked to original sources

bioRxiv2026

Effects of menstrual cycle on electrophysiological correlates of selective auditory spatial attention

The fluctuations in steroid hormones associated with the female menstrual cycle have been suggested to modulate attentional brain processes. This study focused on cycle-dependent changes in the electrophysiological correlates of sound localization in a cocktail-party task, which has been shown to reflect the neural correlates of auditory selective attention. Event-related-potentials were recorded in three (1 - luteal, 2 - menses, 3 - follicular) phases (determined based on self-reports) in women not taking hormonal contraceptives, at three corresponding points in time in women taking oral hormonal contraceptives, and in men. An effect of phase in women was obtained exclusively for the N2 component, which may reflect processes of auditory selective spatial attention. N2 amplitudes were strongest in phase 1 (luteal phase or initial phase of pill intake) and lowest in phase 2 (menses or pause of pill intake). Compared with the male group, the N2 amplitudes were lower in women in phase 2, but not in phase 1 and 3. Cortical source localization at the time of the N2 revealed a related modulation of electrical activity in right superior frontal sulcus depending on phase. Also, electrical activity in left inferior frontal gyrus was increased in women in phase 2 compared with men. These findings suggest that the neural correlates of auditory selective spatial attention varied in women depending on their hormonal phase. The observed pattern is compatible with the view that higher concentrations of female steroid hormones enhance brain processes of selective spatial attention.

neuroscience↗

bioRxiv2020

Short-term audiovisual spatial training enhances electrophysiological correlates of auditory selective spatial attention

Audiovisual cross-modal training has been proposed as a tool to improve human spatial hearing. Here, we investigated training-induced modulations of auditory-evoked 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 subjects were tested, including younger (19-29 yrs; n = 21) and older (66-76 yrs; n = 24) age groups. Three conditions of short-term training (duration 15 minutes) 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, subjects were tested in an auditory spatial attention task (15 minutes), 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, subjects. Also, at the time of the N2, electrical imaging revealed an enhancement of electrical 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.

neuroscience↗

bioRxiv2020

Training with audio and video games improves audiospatial performance in a "cocktail-party" task: A controlled intervention study in young adults

Computer game playing has been suggested to be an effective training to enhance perceptual and cognitive abilities. Focusing on potential improvements in auditory selective spatial attention induced by computer gaming, we compared a passive waiting-control group with two gaming groups, playing either a first-person audio-only action game requiring spatial attention and sound localization or a platform side-scroller video game without audiospatial components, which has been shown to improve cognitive performance in previous studies. Prior to and immediately after game training for 1 month for at least 30 min per day (total training time [≥]15 h), healthy young adults were tested in an audiospatial task simulating a "cocktail-party" situation with multiple speakers at different positions. The proportion of correct target localizations was significantly increased after audio and video gaming compared with the control group. However, there were no significant differences between gaming groups, with similarly strong effects of action audio game and non-action video game trainings on auditory selective spatial attention. Thus, it seems as if successful training of "cocktail-party" listening can be induced not only by modality-specific near-transfer learning within the audiospatial domain, but also by far transfer of trained cognitive skills across sensory modalities, which may enhance domain-general processes supporting selective attention.

neuroscience↗

bioRxiv2019

Unraveling the relation between EEG-correlates of attentional orienting and sound localization performance: a diffusion model approach

Understanding the contribution of cognitive processes and their underlying neurophysiological signals to behavioral phenomena has been a key objective in recent neuroscience research. Using a diffusion-model framework, we investigated to what extent well-established correlates of spatial attention in the electro-encephalogram contribute to behavioral performance in an auditory free-field sound-localization task. Younger and older participants were instructed to indicate the horizontal position of a pre-defined target among three simultaneously presented distractors. The central question of interest was whether posterior alpha lateralization and amplitudes of the anterior contralateral N2 subcomponent (N2ac) predict sound localization performance (accuracy, mean reaction time) and/or diffusion model parameters (drift rate, boundary separation, non-decision time). Two age groups were compared to explore whether in older adults, who struggle with multi-speaker environments, the brain-behavior relationship would differ from younger adults. Regression analyses revealed that N2ac amplitudes predicted drift rate and accuracy, whereas alpha lateralization was not related to behavioral or diffusion modeling parameters. This was true irrespective of age. The results indicate that a more efficient attentional filtering and selection of information within an auditory scene, reflected by increased N2ac amplitudes, was associated with a higher speed of information uptake (drift rate) and better localization performance (accuracy), while the underlying response criteria (threshold separation), mean reaction times, and non-decisional processes remained unaffected. The lack of a behavioral correlate of post-stimulus alpha power lateralization constrast the well-established notion that pre-stimulus alpha power reflects a functionally relevant attentional mechanism. This highlights the importance of distinguishing anticipatory from post-stimulus alpha power modulations.

neuroscience↗