Elephants in the living room

The elephant experience involves too much stimulation or input for a person to integrate. School personnel may help each other and their students to cope more effectively with these experiences by understanding the symptoms, the common sources, and the process of using them constructively. The symptoms are preoccupation, avoidance, overreaction, and flight into activity. Common sources are grades, test scores, and athletic success. The process of using them constructively involves facilitative people, use of personal resources, review of progress toward assimilation, and personal integration of experiential meaning. The elephant experience is seen as a source of learning that may be either devastating or enriching, and the challenge to the facilitator is to help each individual make it constructive.     

Continuously varying binocular disparity: An exploratory study

It was hypothesized that viewing an object under conditions of continually varying binocular disparity would result in the perception of a “real” object that would continually change its shape, yet retain its three-dimensionality. It was further hypothesized that observed changes would be systematically sequential and repetitive, reflecting systematic and repetitive changes in the stimulus conditions. Two Ss were used. They were shown 12 objects (one at a time) by means of the Groman Continuous Binocular Disparator. An analysis was made from taped verbal reports. The hypotheses were strongly supported. Other phenomena were noted and described. The observations were categorized on the basis of three types of breakdown of veridicality. Differences between the frequency of breakdown of veridicality in the three categories were found and discussed in terms of a functional theory of veridical perception.     

Direct quantitative judgments of sums and a two-stage model for psychophysical judgments

Judged magnitudes of differences between stimuli have previously been shown to support a two-stage interpretation of magnitude estimation, in which input transformations and output transformations are each describable as power functions. In an effort to provide support for the model independent of the difference estimation procedure. the present investigation employed two additional judgment tasks. We obtained magnitude judgments and category judgments of the combined magnitudes (sums) of paired weights from two groups of Ss. Values of the inferred input exponent k calculated from the two sets of data were very similar and were also remarkably similar to the exponent previously calculated from magnitude estimations of differences between weights. The output exponent calculated from magnitude judgments of sums described a concave upward function; however. the similar function describing category judgments was essentially linear. These results show that the inferred input exponent is not the result of the difference estimation task, and in addition provides support for the contention that the interval scale may be a less biased sensory measure than the magnitude scale. The introduction of an additive constant to the model improved its fit to the data but the rule by which it was introduced made very little difference.     

The effects of area and perimeter on detection rates

The detection of luminance increments in a homogeneously lighted field was studied as a function of the area and perimeter of the luminance increment. Sixteen targets representing all possible combinations of four values of area and four values of perimeter were foveally presented. Exposure durations were short (25 to 40 msec). Results of both an analysis of variance and linear discriminant analysis indicated that detection probability increases as area increases, but neither variations in perimeter nor perimeter-area combinations produced effects that were significant oyer the experiment as a whole. The linear discriminant analysis revealed individual differences in the effects of perimeter and area on detection probability. Results were contradictory to Kristofferson’s (1957) “element contribution theory” and gave only slight support to Hecht’s (Lamar, Hecht, Shlaer, & Hendley, 1947) “border-quantum theory.”     

Vibrotactile vigilance: The effects of costs and values on signals

Vibrotactile vigilance behavior was examined for the effects on signal detection performance of placing costs on misses and false detections and a positive value on the correct detection of a signal. Analyses over time showing that the frequencies of correct detection and false detection of signals decreased, while response times increased, indicated that increased costs for misses and false alarms lead to poorer correct detection performance, while the value placed on the correct detection of a signal had little effect. The d’ statistic of signal detection theory was invariant with both signal costs and time, while β varied with both factors.These results imply that the performance decrement during a vigil was due to an increased strictness in the criterion (β) the S set for deciding whether or not a signal was present. The cost factors were effective in manipulating performance during the watch by causing changes in the S’s decision criteria. Findings from this study clearly support those predicted by the “Decision Theory” of Swets, Tanner, and Birdsall (1961); this is suggested as perhaps being the best available basis for a theory of vigilance at this time.     

Orientation of letters and errors in their recognition

Subjects named alphabetic characters that had been rotated, reflected, or inverted. Inversions induce more errors than mirror reflections and reflections induce more than rotations. In a significant number of mistakes a transformed character was assumed to be normally oriented, but in most a transformed character was confused with the mirror image of the original. The data suggest the existence of an “orientation set” in which the identiflcation of ambiguous characters depends largely on their anticipated orientation. The individuality of the data for the different orientations suggests that different transformations are compensated for in part by different mechanisms.     

Two operations In character recognition: A partial replication

Subjects carried out a choice reaction time experiment in which they were required to press one lever ifa tachistoscopically flashed numeral was a member of a previously memorized list of numerals and a second lever if it was not a member of the list. The number of numerals in the list was varied from one to four. On half of the trials the numeral was partially masked by a pattern of visual noise. For one group a single fixed pattern of noise was used; for a second group four patterns presented in random order were used. Reaction time from the onset of the numeral to the lever press was found to be a linear function of list size, confirming Sternberg’s hypothesis that the list is scanned serially to determine a match. Partial masking was found to add a constant increment to reaction time for both groups, independent of set size. The increment was equal for both groups. The constancy of the reaction time increase contradicts Sternberg’s results in which the increment was found to be, in part, a function of list size. The results of the present study indicate that one cannot dismiss the possibility that Ss identify the character to the point of labeling prior to an attempt to determine list membership.