Visual search for a target changing in synchrony with an auditory signal

Research output: Contribution to journalArticlepeer-review

Authors

  • Waka Fujisaki
  • Ansgar Koene
  • Derek Arnold
  • Alan Johnston
  • Shin'ya Nishida

Colleges, School and Institutes

Abstract

We examined whether the detection of audio-visual temporal synchrony is determined by a pre-attentive parallel process, or by an attentive serial process using a visual search paradigm. We found that detection of a visual target that changed in synchrony with an auditory stimulus was gradually impaired as the number of unsynchronized visual distractors increased (experiment 1), whereas synchrony discrimination of an attended target in a pre-cued location was unaffected by the presence of distractors (experiment 2). The effect of distractors cannot be ascribed to reduced target visibility nor can the increase in false alarm rates be predicted by a noisy parallel processing model. Reaction times for target detection increased linearly with number of distractors, with the slope being about twice as steep for target-absent trials as for target-present trials (experiment 3). Similar results were obtained regardless of whether the audio-visual stimulus consisted of visual flashes synchronized with amplitude-modulated pips, or of visual rotations synchronized with frequency-modulated up-down sweeps. All of the results indicate that audio-visual perceptual synchrony is judged by a serial process and are consistent with the suggestion that audio-visual temporal synchrony is detected by a 'mid-level' feature matching process.

Details

Original languageEnglish
Pages (from-to)865-74
Number of pages10
JournalRoyal Society of London. Proceedings B. Biological Sciences
Volume273
Issue number1588
Publication statusPublished - 7 Apr 2006

Keywords

  • Acoustic Stimulation, Auditory Perception, Hearing, Humans, Models, Biological, Photic Stimulation, Reaction Time, Visual Perception