Purdue University Graduate School
Suma Chinta dissertation (FINAL).pdf (8.06 MB)

Neural mechanisms for the localization of external and self-generated motion

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posted on 2024-05-08, 02:34 authored by Suma ChintaSuma Chinta

Localizing movements in the external space is crucial for animals to navigate safely, find food, avoid predators, and interact with their surroundings. Efficient localization during body movements requires the brain to distinguish between externally generated movements and self-generated ones. This involves integrating external stimulation with a continuous estimate of one's body position, to isolate external motion by suppressing sensations arising from self-motion.

To explore the neural mechanisms underlying object localization during active touch, we focused on the mouse superior colliculus (SC), which harbors multiple egocentric maps of sensorimotor space. Our studies revealed that SC neurons exhibit a rapidly adapting tactile response during externally generated touch. The response is significantly attenuated during self-generated touch, thus enhancing the ability to distinguish between external and self-induced tactile stimuli. Additionally, the direction of external motion is precisely encoded in the firing rates of these tactile-responsive neurons, indicating a specialized localization mechanism within the SC.

In scenarios devoid of external stimuli, SC neural activity accurately reflects the kinematics of self-motion, such as whisker position and locomotion speed, capturing past, present, and future body positions. Half of the neurons that encode self-motion also respond to external tactile stimuli. This dual functionality suggests that these neurons not only track self-motion but also engage in the processing of external tactile information. The magnitude of the external tactile response in these neurons is modulated by the state of self-motion upon touch. These results suggest that SC neurons integrate internal estimates of body movements with external tactile inputs to compute the egocentric distance of objects.


Degree Type

  • Doctor of Philosophy


  • Biological Sciences

Campus location

  • West Lafayette

Advisor/Supervisor/Committee Chair

Dr. Scott R. Pluta

Additional Committee Member 2

Dr. Alex Chubykin

Additional Committee Member 3

Dr. Krishna Jayant

Additional Committee Member 4

Dr. Maria Dadarlat Makin

Additional Committee Member 5

Dr. Yuk Fai Leung

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