Noncortical coding of biological motion in newborn chicks' brain

Area of Science:

• Neuroscience
• Comparative Psychology
• Developmental Biology

Background:

• Biological motion is crucial for survival and is perceived spontaneously by newborns.
• Previous neural studies focused on cortical areas, overlooking subcortical contributions.
• Innate preference for biological motion exists in newly hatched chicks and human infants.

Purpose of the Study:

• To investigate the neural basis of biological motion perception in visually naive domestic chicks.
• To identify brain regions activated by biological motion stimuli at hatching.
• To explore the role of subpallial/subcortical regions in early visual processing.

Main Methods:

• Presentation of biological and rigid motion point-light displays to newly hatched chicks.
• Measurement of brain activation using Immediate Early Gene (c-Fos) expression.
• Analysis of c-Fos expression in subpallial/subcortical and cortical areas.

Main Results:

• Selective activation of the preoptic area of the hypothalamus was observed.
• The nucleus taeniae of the amygdala also showed significant activation.
• No significant activation was found in cortical areas for biological motion stimuli.

Conclusions:

• Subpallial/subcortical regions, specifically the hypothalamus and amygdala, are critical for processing biological motion at hatching.
• These findings challenge the traditional view of a purely cortical network for biological motion perception.
• This research provides a foundation for further investigation into the evolution and development of biological motion processing.