Any sensory stimulus consists of a superposition of myriad different features. A simple visual object can for instance be characterized by its shape and colour, while an auditory tune is a combination of pitch and rhythm. The brain is able to flexibly focus on and extract the single feature that is behaviourally relevant, and for example segregate objects first by color, and then by shape. How do neural circuits achieve such flexible categorization?
Within the classical picture, sensory perception relies on progressive processing of information through a hierarchy of cortical areas. Primary sensory areas are believed to faithfully encode all sensory features, while subsequent areas extract increasingly abstract information. Within this picture, flexible categorization relies on high-level, prefrontal areas, while sensory areas play a marginal role. Recent publications have however shown that the activity in primary sensory areas is strongly modulated by behaviour1,2 and top-down inputs, and encodes information in a highly task-dependent fashion3. Those observations raise the question of the role of primary sensory areas in flexible categorization, and the importance of frontal regions in attentional switch.
This line of research will examine task-relevant flexible discrimination of auditory stimuli by behaving ferrets. We will develop a task in which identical stimuli need to be discriminated according to two different features depending on the current condition indicated by a contextual cue. The goal of the project will be to determine the neural mechanisms that underlie such flexible discrimination. To this end, we will perform recordings in the auditory cortex and frontal cortex with advanced population analyses (regression, dimensionality reduction, multivariate decoding).
Please contact Yves Boubenec (firstname.lastname@example.org) for additional information, including ongoing manuscript of the laboratory related to this project. The internship can be taylor-cut to your particular interests and backgrounds, from pure data analysis of existing datasets to animal behavior and training on new tasks. This internship can be indiscriminately conducted in English or in French.
1 GH Otazu, LH Tai, Y Yang, AM Zador (2009), Nat Neuro 12, 646 – 654.
2 CM Niell, MP Stryker (2010), Neuron 65: 472-479.
3 Fritz J, Shamma S, Elhilali M, Klein D (2003) Nat Neurosci 6:1216-1223.