Santiago Jaramillo

Assistant Professor, Department of Biology
Member, ION

Office:
215 LISB
541-346-5207

 

Research Interests: Neuronal circuits that mediate behavioral flexibility and attention; auditory coding; neural computation

Overview: We study the neural circuits that mediate auditory cognition. Our goal is to understand how we assign meaning to sounds, how we attend to sounds or ignore them, how we remember them, and how disorders of the brain can affect these processes.
Of particular interest is how our responses to sounds can change depending on context, a phenomenon called behavioral flexibility. Behaving appropriately after changes in context requires that organisms rapidly modify their expectations, associations between cues and rewards, or attentional state. Our lab investigates these cognitive processes by addressing three questions:

  • What happens to the speed and accuracy of behavioral responses after a change in context?
  • Where in the brain is information selected and re-routed to allow for different interpretations of the same stimulus?
  • How do neural circuits implement this flexibility?

In our experiments, we use tools for monitoring and manipulating neuronal activity of specific cell types in behaving rodents, together with theoretical and computational approaches, to uncover the mechanisms that underlie flexible behaviors.

RECENT PUBLICATIONS

Related Articles

Author Correction: Response outcomes gate the impact of expectations on perceptual decisions.

Nat Commun. 2020 Jul 07;11(1):3470

Authors: Hermoso-Mendizabal A, Hyafil A, Rueda-Orozco PE, Jaramillo S, Robbe D, de la Rocha J

Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.

PMID: 32636370 [PubMed - in process]

Related Articles

Choice-Selective Neurons in the Auditory Cortex and in Its Striatal Target Encode Reward Expectation.

J Neurosci. 2019 05 08;39(19):3687-3697

Authors: Guo L, Weems JT, Walker WI, Levichev A, Jaramillo S

Abstract
Learned behavioral responses to sounds depend largely on the expected outcomes associated with each potential choice. Where and how the nervous system integrates expectations about reward with auditory sensory information to drive appropriate decisions is not fully understood. Using a two-alternative choice task in which the expected reward associated with each sound varied over time, we investigated potential sites along the corticostriatal pathway for the integration of sound signals, behavioral choice, and reward information in male mice. We found that auditory cortical neurons encode not only sound identity, but also the animal's choice and the expected size of reward. This influence of reward expectation on sound- and choice-related activity was further enhanced in the major striatal target of the auditory cortex: the posterior tail of the dorsal striatum. These results indicate that choice-specific information is integrated with reward signals throughout the corticostriatal pathway, potentially contributing to adaptation in sound-driven behavior.SIGNIFICANCE STATEMENT Learning and maintenance of sensory-motor associations require that neural circuits keep track of sensory stimuli, choices, and outcomes. It is not clear at what stages along the auditory sensorimotor pathway these signals are integrated to influence future behavior in response to sounds. Our results show that the activity of auditory cortical neurons and of their striatal targets encodes the animals' choices and expectation of reward, in addition to stimulus identity. These results challenge previous views of the influence of motor signals on auditory circuits and identifies potential loci for integration of task-related information necessary for updating auditory decisions in changing environments.

PMID: 30837264 [PubMed - indexed for MEDLINE]