Female túngara frogs do not experience the continuity illusion.

Abstract

In humans and some non-human vertebrates, a sound containing brief silent gaps can be rendered perceptually continuous by inserting noise into the gaps. This so-called ‘continuity illusion’ arises from a phenomenon known as ‘auditory induction’ and results in the perception of complete auditory objects despite fragmentary or incomplete acoustic information. Previous studies of auditory induction in gray treefrogs (Hyla versicolor and H. chrysoscelis) have demonstrated an absence of this phenomenon. These treefrog species produce pulsatile (non-continuous) vocalizations, whereas studies of auditory induction in other taxa, including humans, often present continuous sounds (e.g., frequency-modulated sweeps). This study investigated the continuity illusion in a frog (Physalaemus pustulosus) with an advertisement vocalization that is naturally continuous and thus similar to the tonal sweeps used in human psychophysical studies of auditory induction. In a series of playback experiments, female subjects were presented with sets of stimuli that included complete calls, calls with silent gaps, and calls with silent gaps filled with noise. The results failed to provide evidence of auditory induction. Current evidence, therefore, suggests that mammals and birds experience auditory induction, but frogs may not. This emerging pattern of taxonomic differences is considered in light of potential methodological, neurophysiological, and functional explanations.

Is the susceptibility to visual illusions related to the relative brain size? Insights from small-brained species

“…It would not be adaptive if we could not grasp the meaning of a sentence in a noisy environment, as this type of fragmentary/noisy information is common in everyday life. When presented with stimuli that included complete social calls, calls with silent gaps, and calls with gaps filled with noise, Hyla chrysoscelis, H. chrysoscelis, and Physalaemus pustulosus did not show any clear evidence of being susceptible to this illusory phenomenon (Baugh, Ryan, Bernal, Rand, & Bee, 2016;Seeba, Schwartz, & Bee, 2010).…”