Exploring objects with the sense of touch

The core problem in haptic recognition is determining the set of rules and processing steps underlying our ability to identify objects from the variable streams of somatic sensory information. When our hand explores an object —much like a flexible retina— the brain obtains partial and discontinuous chunks of sensory information. Variations in hand position and finger configuration, along with possible changes in object orientation, preclude a given sensory stream from ever repeating itself. Although, strictly speaking, we never touch the same object twice, the brain routinely identifies objects.

This line of research centers on object recognition as a way to study how the brain makes sense of the constantly varying streams of sensory information; how learning shapes neuronal circuits; and how stored information is retrieved. All of our cognitive functions rely directly on the brain’s ability to store information and to recall that information by recognition.

Time perception, rhythm entrainment, and rhythm maintenance

Our sensory perceptions and motor actions unfold through time and space. Thus, adaptive behavioral responses benefit from our ability to extract temporal regularities within a constantly changing environment.

In one of our behavioral tasks, subjects have to synchronize to a visual rhythm and then maintain that rhythm internally for a variable period of time. We use this task to identify the neuronal signals that underlie our ability to keep rhythms of different tempos in the absence of movements.

How good are our senses at detecting temporal regularities?

In this project we aimed to characterize the temporal sensibility of our sense of vision, hearing, and touch. For this, we developed an irregularity detection task in which human subjects had to decide whether a train of sensory pulses was regular or irregular.