title: The Franssen effect illusion in budgerigars (Melopsittacus undulatus) and zebra finches (Taeniopygia guttata).
abstract: The properties of the Franssen effect (FE) were measured in budgerigars and zebra finches. To elicit the FE, listeners are presented with a signal which has been split into a transient component, carrying an abrupt onset and ramped offset and separated in space from the sustained component which has a slowly rising onset and longer duration. When these two signals are played under certain conditions, the perception is that of a long-duration steady state tone being played at the location of the transient. The birds were trained using operant conditioning methods on a categorization task to peck a left key when presented with a stimulus from a left speaker and to peck a right key when presented with a stimulus from a right speaker. Once training was completed, FE stimuli were presented during a small proportion of trials. The FE was measured at speaker separations of 60 degrees and 180 degrees in both echoic and echoic-reduced conditions. Both species of birds exhibited the FE, although to varying degrees, across conditions. These results show that nonmammals also experience the FE illusion in confusing listening situations in a manner similar to mammals, suggestive of similar auditory processing mechanisms.
authors.affiliation: Department of Psychology, University at Buffalo, State University of New York, Buffalo, New York 14260, USA. mdent@buffalo.edu
authors.forename: Micheal L
authors.initials: ML
authors.lastname: Dent
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: McClaine
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Welch
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D003216:Conditioning, Operant; D003463:Cues; D005260:Female; D046369:Finches / Q000502:physiology*; D007088:Illusions; D008297:Male; D046408:Melopsittacus / Q000502:physiology*; D010470:Perceptual Masking; D010897:Pitch Discrimination; D013017:Sound Localization; D013028:Space Perception; D013045:Species Specificity; D013997:Time Factors