PubMed · 6682540
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
J H Moyer, R Ranberg. 1983. Hypertension program needs feedback.. https://pubmed.ncbi.nlm.nih.gov/6682540/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
In order to investigate the contribution of the vestibular system to spatial orientation, we studied memory-guided saccades in three conditions: visual-memory guided saccades (ViC), saccades to the remembered spatiotopic position of a visual target, after whole-body rotation (SVeC) and saccades to the remembered retinotopic position of a visual target, after whole-body rotation (RVeC). Visual feedback presented after each trial allowed eye position correction. The error was larger in SVeC, but the performance improved throughout the experiment (learning) in that condition only. As learning occurred over the first four trials, we omitted these trials from the average computation, and the significant difference between the conditions disappeared. It is concluded that vestibular information does contribute to update the internal spatial representation of visual information when a visual feedback is provided.
We report a new method of generating nitric oxide (NO) that possesses several advantages for experimental use. This method consists of a photolysis chamber where NO is released by illuminating photolabile NO donors with light from a xenon lamp, in conjunction with feedback control. Control of the photolysis light was achieved by selectively gating light projected through a shutter before the light was launched into a light guide that conveyed the light to the photolysis chamber. By gating the light in proportion to a sensor that reported nearly instantaneous concentration from the photolysis chamber, a criterion NO concentration could be achieved, which could be easily adjusted to higher or lower criterion levels. To denote the similarity of this process with the electrophysiological process of voltage clamp, we term this process a concentration "clamp." This development enhances the use of the fiber-optic-based system for NO delivery and should enable the execution of experiments where the in situ concentration of NO is particularly critical, such as in biological preparations.
The present study investigated the generalizability of the hypothesis of transient coupling during the preparation of bimanual movements (Spijkers and Heuer 1995) to the specification of isometric forces. In the first experiment we used the timed response paradigm (TRP) to examine the time course of the specification process. Subjects had to generate bimanual isometric force pulses while preparation time was controlled by the TRP. Target forces were weak (20% of maximal voluntary force, MVF) or strong (40% MVF) and assigned randomly to each hand. The first experiment revealed the predicted pattern of correlations between the peak forces but, because the subjects tended to delay responding when time for preparation was very brief, the time course of the specification process did not fully match expectations. In the second experiment we improved force-trajectory feedback and presented two initial cues that were expected to induce better preparation of the default force (30% MVF). Both changes were successful and the results further corroborate the transient-coupling hypothesis.