Neural responses are commonly studied in terms of "tuning curves," characterizing changes in neuronal response as a function of a continuous stimulus parameter. In the motor system, neural responses to movement direction often follow a bell-shaped tuning curve for which the exact shape determines the properties of neuronal movement coding. Estimating the shape of that tuning curve robustly is h...

Complex actions often can be decomposed into sequences of individual movements. Primate medial motor areas (SMA and pre-SMA) have been shown to be key players in the concert of such sequential actions. In this issue of Neuron, Lu and Ashe show for the first time that neurons in primate M1-the ultimate output stage of cortex-have anticipatory activity related to specific movement sequences. Thes...

Memory networks are formed in the cerebral cortex by associative processes, following Hebbian principles of synaptic modulation. Sensory and motor memory networks are made of elementary representations in cell assemblies of primary sensory and motor cortex (phyletic memory). Higher-order individual memories, e.g. episodic, semantic, conceptual - are represented in hierarchically organized neuro...

Many recent studies describe learning-related changes in sensory and motor areas, but few have directly probed for improvement in neuronal coding after learning. We used information theory to analyze single-cell activity from the primary motor cortex of monkeys, before and after learning a local rotational visuomotor task. We show that after learning, neurons in the primary motor cortex conveye...

The activity of the motor cortex during locomotion is profoundly modulated in the rhythm of strides. The source of modulation is not known. In this study we examined the activity of one of the major sources of afferent input to the motor cortex, the ventrolateral thalamus (VL). Experiments were conducted in chronically implanted cats with an extracellular single-neuron recording technique. VL n...

Previous studies have shown that synchronized beta frequency (14-30 Hz) oscillations in the primary motor cortex are involved in maintaining steady contractions of contralateral arm and hand muscles. However, little is known about the role of postcentral cortical areas in motor maintenance and their patterns of interaction with motor cortex. We investigated the functional relations of beta-sync...