Roles of Novelty, Violation of Expectation, and Stimulus Change in Auditory Distraction

Students! Have you ever wondered why a loud thud could easily sidetrack us from listening to the professor? Or how the subtle but sudden beep of our phones could quickly distract us from studying?

Well, aside from the fact that these activities could get mind-numbing when done for a prolonged period of time, numerous studies have demonstrated that unexpected novel sounds could involuntarily take our attention off of the task at hand (e.g., Jankowiak & Berti, 2007; Parmentier, Elsley, & Ljungberg, 2010; Bell, Dentale, Buchner & Mayr, 2010).

However, Parmentier, Elsley, Andrés, & Barceló (2011) begged to differ and said that novel sounds do not capture attention because of their novelty per se. To this, they proposed three hypotheses:

  1. Low base-rate probability. Novel sounds capture attention because they are rare, thereby triggering the detection of change.
  2. The expectation hypothesis. Novel sounds capture attention because they violate the cognitive system’s expectation about upcoming events.
  3. The local perceptual change hypothesis. Novel sounds capture attention because they differ perceptually from the preceding stimulus.

In order to test the hypotheses, the researchers made use of a cross-modal oddball task in which participants categorized the parity of visually presented digits. An auditory stimulus was presented before each digit, but the participants were instructed to ignore it. The standard sound (S; a sine-wave tone) was used in 75% of the trials, while the novel sound (N; burst of white noise) was used in the remaining 25%. The novel trials were organized in such a way that 8 out of 9 novels would form pairs of consecutive trials among otherwise randomly dispersed standard trials. This manipulation resulted to six types of trials: S following another S; first N in a pair; second N in a pair; isolated N; S following isolated N; and, S following a pair of N.

Fourteen females and six males, with mean age of 24.2 (SD=6.4) participated in this experiment. Their hit rates and mean response times for correct responses were analyzed using one-way ANOVA for repeated measures with the sound condition as the independent factor. Overall, hit rates were high and did not vary across conditions. Their response times, however, significantly differed across conditions, where “first N in a pair,” “isolated N,” and “S following isolated N” recorded the longest response times; intermediate in “S following a pair of N”; and, shortest in the “S following another S” and “second N in a pair” conditions.

Interpreting these results, the low base-rate probability was rejected because performance following a predictable novel (second N in a pair) was comparable to that in the S condition, while the unexpected “S following isolated N” yielded as much distraction as “first N in a pair” and “isolated N.” Meanwhile, taking the “first N in a pair,” “isolated N,” and “S following isolated N” as points of comparison, the relatively shorter response times yielded in the “S following a pair of N” condition is in line with the expectation hypothesis but clashing with the perceptual change hypothesis. But if we were to take the conditions in which the sound was predictable (S, and second N in a pair), the relatively longer response time in “S following a pair of N” is in line with the perceptual change hypothesis but is incongruous with the expectation hypothesis.

Thus, the researchers have come to accept the hypotheses that, in circumstances promoting distraction, novel sounds do not capture attention just because they are rare. Rather, it is because they violate the cognitive system’s expectation and clash with the perceptual trace from the previous auditory stimulus.

This research adds to previous knowledge on behavior novelty distraction by demonstrating the ways in which a novel stimulus may affect attention. This finding has the potential for practical application, as it provides valuable insights which may be used in fostering an environment conducive for studying. More specifically, this would help both parents and teachers in designing a space where external auditory distractions may be minimized.

References:

Bell, R., Dentale, S., Buchner, A., & Mayr, S. (2010). ERP correlates of the irrelevant sound effect. Psychophysiology, 47(6), 1182-1191. doi:10.1111/j.1469-8986.2010.01029.x

Jankowiak, S., & Berti, S. (2007). Behavioral and event-related potential distraction effects with regularly occurring auditory deviants. Psychophysiology, 44(1), 79-85. doi:10.1111/j.1469-8986.2006.00479.x

Parmentier, F. R., Elsley, J. V., Andrés, P., & Barceló, F. (2011). Why are auditory novels distracting? Contrasting the roles of novelty, violation of expectation and stimulus change. Cognition, 119(3), 374-380. doi:10.1016/j.cognition.2011.02.001

Parmentier, F. R., Elsley, J. V., & Ljungberg, J. K. (2010). Behavioral distraction by auditory novelty is not only about novelty: The role of the distracter’s informational value. Cognition, 115(3), 504-511.

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