Focused and divided attention in a simulated cocktail-party situation: ERP evidence from younger and older adults.
Speech perception under complex listening conditions usually decreases in aging. This is especially true for listening conditions requiring divided attention among 2 and more relevant speakers. Using a speech perception task and event-related potential measures, we studied the ability of younger and older adults to attend to speech information from a single-target speaker (focused attention) or from 2 different (alternative) target speakers (divided attention). The focused and divided attention conditions were presented either in silence or in the presence of 3 concurrent speakers. In the presence of concurrent speakers, older participants showed worse performance with divided versus focused attention. In contrast, there was no effect of attention condition for the younger adults. Relative to the young, event-related potential analysis in older subjects indicated a decline in preparatory activity for the critical speech information (a delayed and smaller contingent negative variation), and delayed attentional control (indicated by a longer P2 latency). Standardized low-resolution brain electromagnetic tomography revealed that the age-related decline in preparatory activity was associated with reduced activation of medial and superior frontal gyrus and anterior cingulate gyrus. The results suggest that age-related differences in these prefrontal brain areas reflect declines in preparatory attention and gating of subsequent task-related speech information, especially under conditions of divided attention. These findings may reflect mechanisms relating to impaired speech perception by older people in "cocktail-party" listening situations.
Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany. Electronic address: getzmann@ifado.de.
Stephan
S
Getzmann
Department of Psychology, Tulane University, New Orleans, LA, USA.
Edward J
EJ
Golob
Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany.
Edmund
E
Wascher
D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology / Q000523:psychology*; D001288:Attention / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology / Q000502:physiology / Q000503:physiopathology; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011930:Reaction Time; D012931:Social Environment; D013060:Speech / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology; D055815:Young Adult
Aging; Auditory spatial attention; Cocktail-party situation; Contingent negative variation; Event-related potentials; Speech perception