ELSC Nervous Club: Nori Jacoby

April 28, 2014

Title of talk: "Finger-tapping, rhythm and working memory: the cognitive correlates of sensorimotor synchronization."

Speaker: Nori Jacoby

Monday, April 28 2014 at 16:00, at ELSC: Silverman Bldg., 3rd Wing, 6th Floor, Edmond J. Safra Campus


Sensorimotor synchronization, the temporal coordination of a rhythmic movement with an external rhythm, is studied experimentally by tapping experiments (Repp 2005) in which subjects are required to finger tap in synchrony with an auditory stimuli. Using data collected from tapping experiments together with a general cognitive battery, we show that the limited capacity of short-term information processing in the brain (working memory), often associated with the manipulation of discrete items such as digits and letters, also constrains the accuracy of sensorimotor synchronization.

Subjects (N=56) performed a battery of cognitive and sensory tasks, and two-step tapping experiments. We found high positive inter-subject correlations between successful performance in the tapping experiment (decreased tapping variance) and working memory related tasks, the highest correlation (r > 0.6) to an N-back auditory task, in which subjects are required to report whether the current tone matches a tone N-steps earlier (N is changed adaptively).

We interpret this surprising finding by suggesting a computational model, in which analog sensory information is coded through a limited capacity channel. The proposed model generalizes models proposed in the sensorimotor synchronization literature (e.g Mates 1994, Schulze et al. 2005) and consistent with models proposed for other sensory tasks (Sims et al. 2012, Raviv et al. 2013).

The model separates the effect of coding current noisy sensory information (input channel) from the effect of recent history (memory channel), showing that the former constitutes the main bottleneck for subjects with low working memory.