Neural mechanisms for the localization of unexpected external motion

Area of Science:

• Neuroscience
• Sensory Processing
• Computational Neuroscience

Background:

• Animals must differentiate self-generated sensory input from external stimuli for effective navigation and object localization.
• The superior colliculus (SC) is known to contain egocentric maps crucial for sensorimotor integration.

Purpose of the Study:

• To investigate the neural mechanisms underlying the differentiation of self-generated versus externally generated tactile stimuli.
• To explore the role of the superior colliculus (SC) in active sensing and object localization.

Main Methods:

• Utilized a whisker-guided virtual reality system to precisely control tactile input.
• Recorded neural activity in the SC of mice during active sensing tasks.
• Manipulated sensory history to examine adaptation and prediction mechanisms.

Main Results:

• Discovered a rapidly adapting tactile response in the SC that emerges during externally generated whisker contact.
• Demonstrated that responses to self-generated touch are attenuated, indicating control by sensorimotor predictions.
• Observed a gradual decrease in response magnitude with repeated external motion, suggesting slow habituation based on external history.
• Found that the direction of external motion is encoded in the firing rates of transiently responsive SC neurons.

Conclusions:

• SC neurons exhibit whisker-specific adaptation and rely on sensorimotor predictions to process tactile information.
• These neural mechanisms enhance the localization of unexpected, externally generated changes in tactile space.
• The study provides insights into the neural basis of active sensing and distinguishing self-motion from environmental motion.