Visuo-motor control: when the brain loses track of the eyes.

In single-units studies, neuronal signals are recorded to assess their significance and, hopefully, their role in controlling behavior. A new study of neuronal signals associated with eye position helps to explain not only how the system normally works, but also how it sometimes fails.

Video game for monkeys.

Recent progress in neurophysiological recording has developed in two directions. One relies on multimicroelectrodes to study correlations in neuron firing. The other relies on sophisticated tasks to distinguish successive stages of neuronal processing.

Transfer of learned perception of sensorimotor simultaneity.

Synchronizing a motor response to a predictable sensory stimulus, like a periodic flash or click, relies on feedback (somesthetic, auditory, visual, or other) from the motor response. Practically, this results in a small (<50 ms) asynchrony in which the motor response leads the sensory event. Here we show that the perceived simultaneity in a coincidence-anticipation task (line crossing) is affected by changing the perceived simultaneity in a different task (pacing).

Frames of reference for saccadic command tested by saccade collision in the supplementary eye field.

In what frame of reference does the supplementary eye field (SEF) encode saccadic eye movements? In this study, the "saccade collision" test was used to determine whether a saccade electrically evoked in the monkey's SEF is programmed to reach an oculocentric goal or a nonoculocentric (e.g., head or body-centered) goal.