Aperiodic neural activity during speech comprehension in aging: Insights into cognitive effort

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Cognitive Neuroscience

Background:

• Aperiodic activity in electroencephalography (EEG) signals is increasingly recognized for its neurophysiological relevance.
• Characteristics of aperiodic activity correlate with cognitive states and individual cognitive abilities.

Purpose of the Study:

• To investigate if aperiodic neural activity can quantify cognitive effort in older adults during speech comprehension.
• To examine the influence of background noise and hearing acuity on aperiodic activity related to listening effort.

Main Methods:

• Recorded EEG from older adults (N=48) with varying hearing acuity listening to sentences in quiet and noise.
• Analyzed aperiodic EEG activity, specifically slope and offset, in relation to acoustic challenge.
• Conducted an age-comparative analysis with young adults (N=35).

Main Results:

• Aperiodic activity's slope flattened and offset reduced with increased background noise, reflecting listening effort.
• Noise-induced changes in aperiodic activity were more pronounced in older adults with poorer hearing.
• Age-related reductions in aperiodic slope and offset were confirmed, with noise sensitivity present in both age groups.

Conclusions:

• Aperiodic EEG activity serves as a valuable biomarker for cognitive listening effort in older adults.
• This EEG measure is sensitive to acoustic challenges and individual differences in hearing acuity.
• Aperiodic activity analysis offers a promising avenue for understanding cognitive effort in demanding tasks.