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Multidimensional perceptual development: consistency of responses to frequency and intensity in young chickens
Insights
Newborn chickens develop consistent responses to sound changes within days. Their perception of acoustic stimuli, like frequency and intensity, refines rapidly after birth.
Area of Science:
- Developmental neuroscience
- Auditory perception
- Animal behavior
Background:
- Young chicks exhibit stimulus-dependent suppression of vocalizations (peeps).
- The duration of peep suppression correlates with the magnitude of acoustic stimulus change.
- This suppression provides a measure of perceived differences between acoustic stimuli.
Purpose of the Study:
- To investigate the development of consistent responses to multidimensional acoustic stimuli in newborn chickens.
- To determine how perceptual dimensions are established and refined during early postnatal development.
Main Methods:
- Measured peep suppression durations in response to transitions between 5 acoustic stimuli varying in frequency, intensity, and repetition rate.
- Assessed responses at two different ages: newborns and 4-day-old chicks.
- Analyzed suppression data using multidimensional scaling.
Main Results:
- 4-day-old chicks showed interpretable structure in responses to stimuli varying in frequency and intensity.
- Newborn chicks exhibited inconsistent responses and lacked interpretable structure.
- Neither age group showed interpretable structure for stimuli varying in three dimensions (frequency, intensity, repetition rate).
Conclusions:
- Consistent perception of 2-dimensional acoustic stimuli emerges within the first few postnatal days in chickens.
- Perceptual dimensions, specifically frequency and intensity, become associated with physical stimulus properties as chicks mature.
- Auditory perception processing shows significant developmental refinement in early life.
Abstract:
The development of consistent responses to multidimensional acoustic stimuli was investigated in newborn chickens. Young chicks suppress their ongoing peeps when they hear a change in an acoustic stimulus, and the amount of that suppression is related to the amount of change. Durations of suppression can thus be interpreted as perceived differences between pairs of stimuli. The suppressions elicited by all possible transitions between pairs of 5 acoustic stimuli that differed in frequency, intensity, and repetition rate were measured at 2 ages. These data were analyzed with a multidimensional scaling program. Interpretable structure is evident in the results from 4-day-old chicks to a subset of the stimuli that vary in frequency and intensity. Newborn chicks, in contrast, showed inconsistent responses. Neither age group responded with interpretable structure to stimuli that differed in 3 dimensions. Thus, consistent responses to 2-dimensional acoustic stimuli emerge over the first few postnatal days. Perceptual dimensions become associated with the physical dimensions of frequency and intensity as animals mature.