Reading and typing

As an extension to an earlier study on typing, an experiment was carried out on skilled touch typists in which they were asked to type texts that differed in word structure and word length. It was predicted from certain assumptions about the reading process that there should be significant effects of structure, length and their interaction. These predictions were confirmed.     

College Major Choice and Personal Adjustment

This investigation focused on the differences in reported personal adjustment problems between freshmen students who made a congruent college major choice and students who made an incongruent choice. Personal adjustment was defined operationally with the Mooney Problem Checklist. Congruent and incongruent college major choice groups were defined operationally using the Vocational Preference Inventory. In the analysis of variance of the adjustment scores, the interaction term involving congruence of major choice and sex and the test for the main effect of sex were not significant. The test for the main effect of congruence was found to be significant. Subjects who had made a congruent college major choice reported fewer personal adjustment problems when compared to subjects in the incongruent group.     

A technique for the construction of discrete dichotic stimulation material

Procedures are described for the generation, synchronization. and accurate spacing of discrete dichotic stimulation material. A suggested standard definition of interpair interval is proposed.     

Integrated circuit random foreperiod device and digital interval timer1

A digital integrated circuit computer that produces random (as opposed to pseudorandom) foreperiods is described. Also contained in the device is a precision digital interval timer.     

Reaction time as a function of the intensity and probability of occurrence of vibrotactile signals

Three Ss made judgments of the presence or absence of a burst of 60-cps vibration onthe index fingertip.The probability of S’s reporting the presence of a signal was found to be influenced by signal probability and signal intensity. Mean reaction time for reporting the presence of a signal decreased as a function of signal intensity and signal probability whereas mean reaction time for reporting the absence of a signal increased as a function of signal intensity and signal probability. On trials where no signal was presented mean R T for reporting a signal decreased with increases in the signal probability whereas mean RT for reporting the absence of a signal increased with increases in signal probability. The results were interpreted as support for the hypothesis that S’s decision time was longer the closer on the sensory continuum a particular observation was to his criterion.     

Monitoring simultaneous auditory messages

If a S is asked to monitor two simultaneous auditory speech messages and to report only on the occurrence of target words appearing at random in either message, then it is shown that he witt fail to detect all of them but will detect significantly more than half. The targets used in these experiments were immediate repeats of text words. The results reject theories that part of the sensory input is blocked or that all is recognized. Detection performance was a function of rate of speech and of intertarget interval; there was a small, not significant, effect of instruction to recognize message content.     

On the rate of stimulus occlusion during intermittent retinal stimulation

The CFF was determined with three sectored disks, each of which corresponded to one of the three rings in a Helmholtz disk. The fusion frequency is identical for all three rings of a Helmholtz disk but with the three sectored disks it was found that the rate of stimulus occlusion is a major factor in determining the CFF. It was tentatively concluded that the effect was not a consequence of different stimulus wave-forms. The phenomenon appears to have been reported late in the last century.     

Visual capture of haptically judged depth

Using a graduated scale. S was required to match with his left hand the depth of three objects of equal physical depth (or thickness) held with the right hand. While making these haptic depth judgments the objects were viewed. Due to its optical properties. one object was of greater apparent visual depth than the other two, which served as controls. The critical object was judged to be of greater haptic depth than the control objects, thus demonstrating visual capture of haptic depth. This outcome is similar to that noted previously for haptically judged direction, size, and orientation with transformed visual input.     

Detection and scaling of statistical differences between visual textures

Stochastically textured patterns were used to investigate the sensitivity of Ss to differences in the statistical distributions of locally defined properties of element density and shape. The results of the study indicate that when the textures were most structured, in terms of their variance, Ss were most accurate at detecting dissimilarities between pairs of patterns. Ss also rated the similarity of the statistical distributions of elements of patterns differing in local properties. Multidimensional scaling analysis of the ratings showed two dimensions, representing monotonic orderings of the stimuli.