Apple II assembly language routines for digital data acquisition and contingency control

Modifications and corrections to Rayfield’s (1982) assembly language routines for data acquisition and experimental control using the Apple II computer are described. The modified routines, together with an optoisolated hardware interface, provide a reliable, accurate, and easy to use microcomputer system for experimental control and data acquisition.     

Concepts underlying the development of modules

The need for common pedagogical and design features in courseware is discussed. A particularly useful feature would allow use of courseware in either of two “modes”: as an “electronic chalkboard” for the instructor who wishes to take advantage of the computer in a traditional lecture setting, or as an “electronic study guide” in which students interact individually with the programs. Development of programs using these two modes can be facilitated using Author-Assist, a set of routines and a program skeleton being developed by CONDUIT (1983). Author-Assist provides procedures for use of several types of automatic menu generation, automatic text formatting in “text ports,” mixed text and graphics, protected input routines, lowercase characters in text, automatic scaling of graphic displays using “graphports,” on-screen calculator functions, and a variety of other features.     

Death and dying in medicine: What questions are still worth asking?

Theoretical Medicine and Bioethics -     

Pictorial rehearsal

Subjects were presented with a sequence of picture-word items. The pictures were line drawings of common objects, and the words were the names of the objects. Half of the items were followed quickly by the next item, and the other half by a 15-sec “rehearsal interval.” The subjects were told to use these intervals to rehearse the item just presented, either by saying the word over and over to themselves or by maintaining the picture before the mind’s eye. There followed a test in which each item from the study list was cued with a fragment of either the picture or the name. Consistent with previous findings, identification was more probable for fragments of items that had been followed by a rehearsal interval. In addition, this advantage was found to be greater when the type of cue matched the mode of rehearsal that the subject had been instructed to adopt; there was in fact little, if any, advantage of rehearsal when cue and mode of rehearsal mismatched. This pattern of results suggests functionally distinct pictorial and verbal modes of rehearsal that serve not only to maintain information in conscious mind but also to build up memory proper.     

Development of differences in response latencies to right and left visual fields

Robust lateralization developed in right-handed adults who were asked to judge letter pairs as "same" or "different" during 4608 trials. By the end of the first two blocks (768 trials) "same" responses were favored when presented in the RVF (transmitted directly to the left hemisphere) and "different" responses were favored when presented in the LVF (transmitted direction to the right hemisphere). This gradually reversed over sessions with "same" responses becoming faster for letters presented in the LVF, and "different" responses becoming faster for stimuli presented in the RVF. The laterality acquired under these conditions was cumulative and reproducible, appeared in all 16 subjects, and was preserved between sessions a week apart. The data suggest that laterality is a flexible and reversible characteristic of the human brain even when stimulus and task remain constant.     

Agreement between observers when the categories are not specified in advance

To test the agreement between two observers who categorize a number of objects when the categories have not been specified in advance, Brennan & Light (1974) developed a statistic A′ and suggested a normal approximation for its distribution. In this paper it is shown that this approximation is inadequate particularly when one, or both, of the observers place a fairly equal number of objects in all of their categories. A chi-squared approximation to the distribution of A′ is developed and is shown to work well in a variety of situations. The relative powers of A′ and the ordinary X² test for association are dependent on the type of ‘agreement between the observers’ that is assumed. However a simulation for a fairly general type of agreement indicates that the X² test is more powerful. As the X² test is also much easier to apply, it would seem preferable in most situations.     

Short-term memory for colors and color names in the absence of vocalization

In a previous experiment, Allen found no release from proactive inhibition using the Brown-Peterson procedure in a group who were shifted from recalling colors to recalling the names of colors. The lack of release suggests that colors and color names are encoded in similar ways. It was argued that the similarity of encoding might have been caused by the procedure of requiring the subjects to say out loud the names of the colors at the time of stimulus presentation and recall. In the present experiment, a procedure was devised that eliminated the need for verbalization of the colors. The same pattern of results was obtained, namely, release from proactive inhibition in the group shifted from recalling color names to colors but not in the group shifted in the opposite direction. It was concluded that if subjects encode colors as a verbal label, then this encoding strategy is not caused by the procedure of requiring the subjects to verbalize the colors.