Although extensively studied since years through dissimilarity ratings experiments, the acoustical correlates of musical instruments timbre perception remain not fully understood and somewhat controversial. Whereas it’s now commonly accepted that spectral and temporal envelops correlate well with the two first dimensions of so-called perceptual timbre spaces, critical questions remain: is it relevant to look for global audio descriptors correlating with the higher order dimensions of timbre spaces? can human dissimilarity ratings be computed directly from acoustic representations?

Sensory augmentation seeks to non-invasively extend sensory functions using artificial sensors. In my talk, I present a new project that tests the spatial integration of a recently developed novel sensory augmentation device that indicates a perceivers head orientation relative to geomagnetic north. The new device ‘piggy-backs’ the output of a head-based electronic compass on lower-level sensory characteristics of distal auditory-directional cues using 3D sound.

Most of what we know about perception derives from experiments conducted on members of developed Western societies. Yet many additional insights can be gained by studying other cultures. Phenomena that are consistent across cultures likely reflect biological constraints on perception, whereas those that vary cross-culturally could represent effects of culture-specific experience. I will describe our experiments assessing aspects of music-related audition in remote populations in rural Bolivia.

Most of what we know about perception derives from experiments conducted on members of developed Western societies. Yet many additional insights can be gained by studying other cultures. Phenomena that are consistent across cultures likely reflect biological constraints on perception, whereas those that vary cross-culturally could represent effects of culture-specific experience. I will describe our experiments assessing aspects of music-related audition in remote populations in rural Bolivia.

Visual segmentation is a core function of biological vision, key to adaptive behavior in complex environments. Past studies with artificial stimuli have identified Gestalt principles of segmentation, e.g. grouping by proximity, similarity, and good continuation, and found that visual cortical neurons are sensitive to those cues. These strategies may reflect an optimization to the statistics of the natural environment. Yet, the processes
underlying human segmentation of natural images remain poorly understood.

This session will present the very beginning of Pierre Lelièvre's PhD project, supervised by Peter Neri from the LSP and funded by the SACRe program (Sciences, Art, Creation and Research - ENS Doctoral school).

Animals and humans learn to make nearly optimal decisions based on  received and expected rewards they get from the environment. Recent data  indicate that the prevalent learning signal for such reinforcement learning is the error between the expected (previously learned) and the received reward. In our team we recently developed a minimal biolgically based computational model for how these errors are computed in the brain.

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Abstract:

In most models of vision, low level visual tasks are explained by low 
level neural mechanisms. For example, in crowding, perception of a 
target is impeded by nearby elements because, as proposed, responses of 
neurons coding for nearby elements are pooled. Indeed, performance 
deteriorated when a vernier stimulus was flanked by two lines, one on 
each side. However, performance improved strongly when the lines were 
extended to squares. Classic models cannot explain this uncrowding