Natural sounds like speech and music are structured at many timescales, but it remains unclear how these diverse timescales are cortically represented. Do processing timescales increase along the putative cortical hierarchy? What timescales are used to code speech and music? Is there hemispheric or anatomical specialization for processing particular timescales? Answering these questions has been challenging because there is no general method for estimating integration periods: the time window within which stimulus features alter the neural response.

The first results of the 2019 AAPG (Appel À Projet Générique) have just been announced, six researchers from the DEC have obtained an ANR funding:

At the Institut Jean Nicod (IJN)

We will hear two presentations, first from Yuka Sasaki (10h) and then from Takeo Watanabe (11h), both from Brown University.

Visual perceptual performance fluctuates rhythmically over time,
reflecting the influence of endogenous brain oscillations in the theta
(~4–7 Hz) and alpha frequency band (~8–12 Hz). In two behavioural
studies, we show that these oscillations are not unique to vision but
also present in audition. Using signal detection theory (SDT), we
demonstrate that auditory sensitivity and criterion (changes in
decision boundary) oscillate at different frequencies: ~6 Hz for
sensitivity and ~8 Hz for criterion, implying distinct underlying

The pentagonal faces of a soccer ball or the smooth surface of an egg reflect light patterns that are readily perceived as three-dimensional shapes. Yet, each object projects different 3D signals. The regular pattern of projected pentagons from the ball form on the retina a compelling texture gradient. The unmarked surface of the egg, however, only a shading gradient. Traditionally, the presence or absence of image signals reflected by various objects in a scene has been modelled in terms of signal reliability.

We are activating the deafened auditory pathway with a penetrating auditory nerve electrode array. Our original motivation was to improve restoration of hearing for deaf people. Indeed, our short-term animal experiments show that this ‘intraneural’ stimulation is superior to results with a conventional cochlear implant by every measure that we have tested in anesthetized cats. We also made an unexpected observation that has both clinical and basic science relevance.

Performance on many perceptual tasks improves with practice, indicating that our sensory systems are not rigid but rather can be changed through experience. My coworkers and I have been investigating the factors that induce and those that prevent perceptual learning on auditory skills, including how those factors change with age and are affected by sensory and cognitive disorders. Conclusions drawn from learning on fine-grained auditory discrimination tasks have held for visual and speech learning, suggesting that common principles are at play across multiple domains.

Performance on many perceptual tasks improves with practice, indicating that our sensory systems are not rigid but rather can be changed through experience. My coworkers and I have been investigating the factors that induce and those that prevent perceptual learning on auditory skills, including how those factors change with age and are affected by sensory and cognitive disorders. Conclusions drawn from learning on fine-grained auditory discrimination tasks have held for visual and speech learning, suggesting that common principles are at play across multiple domains.

A general theory of development holds that a heightened period of neural plasticity underlies both a greater capacity for learning and a greater vulnerability to sensory deprivation, such as hearing loss. To explore the neural mechanisms associated with developmental skill learning, we recorded telemetrically from auditory cortex neurons as freely moving adult and adolescent gerbils attended to, and trained on, an auditory task.