Microsaccades exhibit systematic oscillations in direction after spatial cueing, and these oscillations correlate with facilitatory and inhibitory changes in behavioral performance in the same tasks. However, independent of cueing, facilitatory and inhibitory changes in visual sensitivity also arise pre-microsaccadically. Given such pre-microsaccadic modulation, an imperative question to ask be...

Two general mechanisms based on anatomical studies are possible for modulation of motor activity by the caudate nucleus and globus pallidus. These mechanisms are: (1) modulation of the output of cortical neurons that exert motor influences; and (2) modulation of subcortical neurons that exert motor influences. Differentiation between these two mechanisms was accomplished in the present study by...

We investigated whether specular highlights facilitate the perception of shape from shading in a search paradigm and how highlights interact with shading to facilitate this perception. Our results indicated that stimuli containing highlights led to shorter searching time with the dependence on the light source direction (top lights make searching faster), suggesting that highlights indeed facil...

During hyperventilation apnoea in vagotomized, anaesthetized rabbits, paralyzed and artificially ventilated, the effects of electrical afferent stimulation of the vagus nerve on the provocation and inhibition of inspiratory activity were investigated. The experiments were repeated using hyperinflation or short-lasting inflation in nonvagotomized animals. It was found that the possibility of obs...

Ca(2+)-dependent exocytosis of synaptic vesicles is mediated by the SNARE proteins synaptobrevin/VAMP, SNAP-25, and syntaxin. SNARE function is controlled by conserved regulatory proteins, including the complexins. In a study by Xue et al. in this issue of Neuron, contradictory data from Drosophila and mouse complexin mutants have been resolved, revealing a complex pattern of facilitatory and i...

The potentiation of H-reflexes during effort has been studied in 16 patients with mild hemiparesis. Impaired potentiation was present in all but one patient, and was still evident in some who had recovered fully from weakness. A tentative explanation has been proposed for these findings; it is suggested that there is loss of a background facilitatory pathway to motoneurones.