Abstract

Keywords

۱٫ Introduction

۲٫ Methods

۳٫ Results

۴٫ Discussion

Declaration of Competing Interest

Acknowledgements

References

Abstract

The N1 event-related potential (ERP) enhancement to auditory transients preceded briefly by another transient has been interpreted as a reflection of latent inhibition, or alternatively, as a superimposing mismatch negativity (MMN) to rare transient event combinations. In a previous study when rare glides preceded frequent gaps by 150 ms in continuous tones, gap-related N1 was enhanced in younger adults while P2 was attenuated both in younger and older adults, which could be parsimoniously explained by MMN overlap which was delayed with aging. The present study replicated and extended these results with a condition in which the roles of the two event types were reversed. Transients separated by 150 ms elicited delayed MMN in older adults, supporting the MMN interpretation over the latent inhibition account. Furthermore, the divergence of N1 and MMN elicitation patterns demonstrated the independence of N1 and MMN.

Introduction

Adaptation requires that the organism detects and responds to changes of the environment. The human sensory systems feature several mechanisms of change detection. In the auditory domain acoustic changes are processed pre-attentively, which allows us to safely ignore and focus on task-relevant parts of our environment. Rare, sudden changes in the acoustic background – potentially carrying information relevant to our survival – are still processed, and draw our attention to these changes (Schröger, 1997). Auditory change detection processes have been related mainly to two auditory event-related potentials (ERPs): the N1 and the mismatch negativity (MMN)