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Physics teachers can help students understand physics concepts better by assigning them to keep a journal where they can write about the impact of physics in their lives. The practice is received generally favorably among students and achieves its intended outcome.

To view different objects of interest, primates use fast, accurate eye movements called saccades. If saccades become inaccurate, the brain adjusts their amplitudes so they again land on target, a process known as saccade adaptation. The different types of saccades elicited in different behavioral circumstances appear to utilize different parts of the oculomotor circuitry. To gain insight into where adaptation occurs in different saccade pathways, we adapted saccades of one type and examined how that adaptation affected or transferred to saccades of a different type. If adaptation of one type of saccade causes a substantial change in the amplitude of another, that adaptation may occur at a site used in the generation of both types of saccade. Alternatively, if adaptation of one type of saccade transfers only partially, or not at all, to another, adaptation occurs at least in part at a location that is not common to the generation of both types of saccade. We produced significant amplitude reductions in memory-guided, delayed, targeting and express saccades by moving the target backward during the saccade. After memory-guided saccades were adapted, the amplitude of express, targeting and delayed saccades exhibited only a partial reduction. In contrast, when express, targeting, or delayed saccades were adapted, amplitude transfer to memory-guided saccades was more substantial. These results, combined with previously published data, suggest that there are at least two sites of adaptation within the saccadic system. One is used communally in the generation of express, targeting, delayed and memory-guided saccades, whereas the other is specific for the generation of memory-guided saccades. [ABSTRACT FROM AUTHOR]

Saccadic eye movements are shifts in the direction of gaze that rapidly and accurately aim the fovea at targets of interest. Saccades are so brief that visual feedback cannot guide them to their targets. Therefore, the saccadic motor command must be accurately specified in advance of the movement and continually modified to compensate for growth, injury, and aging, which otherwise would produce dysmetric saccades. When a persistent dysmetria occurs in subjects with muscle weakness or neural damage or is induced in normal primates by the surreptitious jumping of a target forward or backward as a saccade is made to acquire the target, saccadic amplitude changes to reduce the dysmetria. Adaptation of saccadic amplitude or direction occurs gradually and is retained in the dark, thus representing true motor plasticity. Saccadic adaptation is more rapid in humans than in monkeys, usually is incomplete in both species, and is slower and less robust for amplitude increases than decreases. Adaptation appears to be motor rather than sensory. In humans, adaptation of saccades that would seem to require more sensory-motor processing does not transfer to saccades that seem to require less, suggesting the existence of distributed adaptation loci. In monkeys, however, transfer from more simple to more complex saccades is robust, suggesting a common adaptation site. Neurophysiological data from both species indicate that the oculomotor cerebellum is crucial for saccadic adaptation. This review shows that the precise, voluntary behaviors known as saccadic eye movements provide an alternative to simple reflexes for the study of the neuronal basis of motor learning. [Copyright &y& Elsevier]