Research reportERP correlates of auditory goal-directed behavior of younger and older adults in a dynamic speech perception task

- We study speech perception of young and old adults in a dynamic multi-talker scenario.
- We analyzed behavioral performance and event-related brain potentials.
- Sudden shifts in speaker location decrease performance especially in the old group.
- This disadvantage comes along with delayed attentional re-orienting.
- Age-related declines in speech perception are partly based on cognitive slowing.

The ability to understand speech under adverse listening conditions deteriorates with age. In addition to genuine hearing deficits, age-related declines in attentional and inhibitory control are assumed to contribute to these difficulties. Here, the impact of task-irrelevant distractors on speech perception was studied in 28 younger and 24 older participants in a simulated “cocktail party” scenario. In a two-alternative forced-choice word discrimination task, the participants responded to a rapid succession of short speech stimuli (“on” and “off”) that was presented at a frequent standard location or at a rare deviant location in silence or with a concurrent distractor speaker. Behavioral responses and event-related potentials (mismatch negativity MMN, P3a, and reorienting negativity RON) were analyzed to study the interplay of distraction, orientation, and refocusing in the presence of changes in target location. While shifts in target location decreased performance of both age groups, this effect was more pronounced in the older group. Especially in the distractor condition, the electrophysiological measures indicated a delayed attention capture and a delayed re-focussing of attention toward the task-relevant stimulus feature in the older group, relative to the young group. In sum, the results suggest that a delay in the attention switching mechanism contribute to the age-related difficulties in speech perception in dynamic listening situations with multiple speakers.