Sequence discrimination

Recognising a song or crossing a busy road safely requires our nervous system to transduce patterns of sound frequencies and the direction and speeds of cars in time.  In fact, learning patterns in our environment is an innate ability.  So how does the brain make decisions based on sequences of sensory stimuli over time?  To find out how, I have developed a behavioural task for mice where they discriminate patterns of vibrations delivered to their whiskers to receive rewards.  I am currently exploring the neural mechanisms of sequence discrimination in somatosensory cortex using multi-electrode array electrophysiology and two-photon imaging.

Neural coding in trigeminal primary afferents

Each individual rodent whisker follicle is innervated by approximately 200 primary afferents.  The necessary information required to encode every tactile event from social interaction to object localisation is therefore constrained by these few neurons.  One way these neurons could do this is to have a diverse feature representation and operate on very reliable and precise timescales (Bale and Petersen, 2009; Bale et al 2013).  In fact, the temporal precision of primary afferents following events of behaviourally relevant whisker speeds is in the microsecond range, making them some of the most precise observed in nature (Bale et al., 2015).