Alexandra Lang

Individual Differences in Multisensory Illusory Perception

Faculty Mentor: Aleksandra Sherman, Cognitive Science Department

Major: Cognitive Science

Funding: Undergraduate Research Center Summer Research Fellowship


Prior research indicates that susceptibility to multisensory illusions varies among individuals. This present study examines the rate of illusory percepts for two multisensory illusions, the McGurk Effect and the Double-Flash Illusion (DFI). The McGurk Effect occurs when audio of one syllable paired with a visual of another syllable causes the perception of a third syllable. SIF occurs when the presentation of two auditory stimuli (beeps) causes one visual stimulus (flash) to be perceived as two. 26 undergraduates from Occidental College participated in a two-session study. For the McGurk Effect trials, participants were presented with a video of a person speaking and were asked to respond with the perceived syllable (Ba, Ga, Da, or Tha). Similarly, for the DFI trials, participants were presented with a series of flashes and beeps and were asked to respond with the perceived number of flashes (0, 1, or 2). Observed data included both behavioral data and neural data measured using an electroencephalogram (EEG). Background research into this topic suggests that there is a high rate of individual variability for perception of these illusions. Research suggests this could be due to several factors that may prime participants to observe the illusions, such as brain state or previous trials, as well as aspects of the illusory stimulus itself. Previous research also shows an inverse relationship between the two illusions, with implications about how the brain processes and forms multisensory percepts.


Watch my research presentation below.

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