How Perceptions Are Influenced by Expectations: Songbird Study Draws Parallels With Human Speech
taylorvich writes:
https://medicalxpress.com/news/2025-03-perceptions-songbird-parallels-human-speech.html
Expectations can influence perception in seemingly contradictory ways, either by directing attention to expected stimuli and enhancing perceptual acuity or by stabilizing perception and diminishing acuity within expected stimulus categories. The neural mechanisms supporting these dual roles of expectation are not well understood. Here, we trained European starlings to classify ambiguous song syllables in both expected and unexpected acoustic contexts. We show that birds employ probabilistic, Bayesian integration to classify syllables, leveraging their expectations to stabilize their perceptual behavior. However, auditory sensory neural populations do not reflect this integration. Instead, expectation enhances the acuity of auditory sensory neurons in high-probability regions of the stimulus space. This modulation diverges from patterns typically observed in motor areas, where Bayesian integration of sensory inputs and expectations predominates. Our results suggest that peripheral sensory systems use expectation to improve sensory representations and maintain high-fidelity representations of the world, allowing downstream circuits to flexibly integrate this information with expectations to drive behavior.
Past neuroscience and psychology studies have shown that people's expectations of the world can influence their perceptions, either by directing their attention to expected stimuli or by reducing their sensitivity (i.e., perceptual acuity) to variations within the categories of stimuli we expect to be exposed to.
While the effects of expectations on perceptions are now well-documented, their neural underpinnings remain poorly understood.
Researchers at University of California San Diego (UC San Diego) carried out a study involving songbirds aimed at better understanding how expectation-fueled biases in perception shape brain activity and behavior.
Their findings, published in Nature Neuroscience, suggest that the perceptions of songbirds, like those of humans, are influenced by expectations, with peripheral sensory systems utilizing expectations to enhance sensory perception and retain high-fidelity representations of the world.
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