The N1 hypothesis and irrelevant sound: Evidence from token set size effects

Tom Campbell, István Winkler, Teija Kujala, Risto Näätänen

Research output: Contribution to journalArticle

29 Citations (Scopus)


This study investigated how increases in the number of different types of sound (token set size) within a heard but ignored sequence influence brain activity and performance in a serial recall task (the irrelevant sound effect). We tested the hypothesis that brain processes affected by the refractory state of the neuronal populations involved in generating the auditory N1 play a role in the memory disruption produced by irrelevant sound. Auditory event-related potentials (ERPs) were recorded when volunteers performed a serial recall task that required remembering lists of visually presented numbers that were followed by a distractor-filled retention interval. The results showed that both increments in set size from 1 to 2 and from 2 to 5 elicited an increase of the N1 amplitude. Furthermore, increases in set size from 2 to 5, but not from 1 to 2, caused a significant decrease of the serial recall performance. This result suggested that, if N1 were to play a role in the disruption produced by irrelevant sound, the processes underlying the N1 wave may only serve as a necessary rather than a sufficient condition for disruption.

Original languageEnglish
Pages (from-to)39-47
Number of pages9
JournalCognitive Brain Research
Issue number1
Publication statusPublished - Dec 2003



  • Auditory N1
  • Immediate memory
  • Irrelevant sound effect
  • Serial recall
  • Token set size

ASJC Scopus subject areas

  • Experimental and Cognitive Psychology
  • Cognitive Neuroscience
  • Behavioral Neuroscience

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