College students actively felt complex objects for 3 sec, and, after delay intervals of 5, 15, 30, or 45 sec, they received either the same object or a different object for comparison. In a signal detection framework, it was observed that d' scores were significantly higher for the 5-and 15sec intervals than for the 30-and 45-sec intervals. Although a clearly negatively accelerated function was not obtained, this is one of the rare instances in which any decay function has been observed for haptic memory. Although it seems counterintuitive that the entire short-term-memory decay function occupies the narrow band extending from 15 to 30 sec, it is clear from previous studies that short-term haptic memory is unique. Results were discussed in terms of findings in both active-and passive-touch experiments.Invited speakers will include Graham Hitch, Asher Koriat, Michael Pressley, and Wolfgang Schneider. The workshop program will include oral presentations, guest speakers, and poster presentations.The registration fee is 80,000 Italian Liras for participants and 40,000 Italian Liras for students. Payment of the fee should be addressed to PSY.CO 41554/0 Cassa di Risparmio di Trieste, Sede Centrale, Via Cassa di Risparmio 10, 34100 Trieste.

In 8 experiments college students felt 32 geometric objects and were tested in a signal-detection framework to same or distractor items. Retention intervals and intervening experiences were also manipulated following initial touching. In all instances performance was high, and there was no evidence of a decline in haptic sensitivity over the retention intervals employed. These surprising results were interpreted as consistent with the 1985 contention of Klatzky, Lederman, and Metzger that the haptic modality constitutes an expert system.

College students were assigned to factorial combinations of picture context (homogeneous, heterogeneous) and picture color (color, black and white). Subjects were then given homogeneous slides in a picture-recognition test using two distractor types. One distractor type included stimuli not previously shown to the subjects; the other type involved previous stimuli in a different (mirror-image)orientation. Each group was shown 240 pictorial stimuli and was then tested with 48. Results revealed that picture recognition was not influenced by picture color. However, the results indicated a significant interaction between picture context and distractor type, with performance being significantly influenced only by the homogeneous context with new distractors. Results were discussed in terms of the importance of the initial viewing context.The processes and parameters of human recognition memory have been extensively studied (e.g., Kausler, 1974 ;Murdock , 1982). Picture recognition involves memory for concrete stimuli such as wilderness scenes, faces, and many other pictorial categories. In a recognition study involving 10,000 heterogeneous photographs, Standing (1973) found high recognition. By extrapolating his results, he conjectured that this memory was for all practical purposes limitless and that if he had employed one million items under the same conditions , his subjects could have recognized approximately 731,400. Other researchers have found a similar capacity. Shepard (1967) presented 600 picture stimuli , and subjects attained recognition rates as high as 98% in a two-choice testing procedure. Standing, Conezio, and Haber (1970) provided single presentations of up to 2,568 photographic stimuli and observed approximately 90% correct recognition.Not all researchers have encountered this remarkable picture memory capacity. Howe (1967) examined recognition memory for pictorial stimuli presented in homogeneous sets, such as dogs, ships, birds, and trains. The recognition rates for subjects in this study were approximately 72%, which were lower than the rates for heterogeneous stimuli. Goldstein and Chance (1970) utilized a range of complex stimuli and found an inverse relationship between stimulus complexity and recognition performance. The complex homogeneous sets used were pictures of faces, ink blots, and snow crystals. Faces, which were lesscomplex and more familiar, yielded the highest recognition, followed , in descending order, by ink blots and snow crystals, 78%, 54%, and 39%, reRequests for reprints should be addressed to : Henry A. Cross, Department of Psychology, Colorado State University, Fort Collins. Colorado 80523 .spectively. Even though the recognition rates were lower for such complex stimuli , it is apparent that subjects still make reliable recognitions of the stimuli. The lower rates may have been attributable, at least in part, to the homogeneous quality of the stimuli and not simply to their judged complexity.The purpose of this study was to examine recognition sensitivities for complex h...

Although recognition memory for pictorial stimuli has been explored using either homogeneous or heterogeneous picture sets, apparently no single study has combined these stimuli and subsequently tested recognition for both types of stimuli. Subjects in two experiments were administered one ofthree picture sets of 100 slides. Each set consisted of homogeneous and heterogeneous slides that differed only in the ratio of homogeneous to heterogeneous stimuli: 80:20, 50:50, or 20:80. A subject's recognition memory was then examined for both types of slides. Overall recognition was high for the heterogeneous stimuli but low for the homogeneous test slides. In a signal detection analysis, the picture set involving the largest proportion of heterogeneous stimuli, 20:80, yielded the lowest recognition sensitivity to the heterogeneous stimuli. This interaction of viewing-set composition and type of test stimuli was discussed in relation to picture recognition memory research employing either homogeneous or heterogeneous stimuli.Since the study by Shepard (1967), it has been fashionable to think of picture memory as a superior memory, and a number of investigators (Shepard, 1967;Standing, Conezio, & Haber, 1970;Standing, 1973) have, indeed, reported recognition rates that stand in contrast to those reported for nonmeaningful materials, such as digits and the traditional nonsense syllables. However, the pictorial stimuli employed in these studies have almost always been exceedingly diverse (heterogeneous) and drawn from collections of magazine photographs that varied greatly in context and subject matter.Goldstein and Chance (1974) argued that it is important that the nature of the pictorial stimuli be carefully described, and some investigators have utilized materials more homogeneous in nature. Howe (1967) examined recognition memory for homogeneous sets of pictures of, for example, dogs, ships, reptiles, birds, and trains and found an overall recognition rate of approximately 72 %, which is considerably below that reported for heterogeneous pictures. Goldstein and Chance (1970) also grouped stimuli into homogeneous sets of pictures of, for example, human faces, ink blots, and snow crystals. Faces exhibited the highest recognition (78%); ink blots and snow crystals, however, showed only 54% and 39% recognition rates, respectively.A recent study by Barnard, Breeding, and Cross (1984) supported the Goldstein and Chance (1974) admonition that the nature of the stimuli be considered. Barnard et al. found that the informational characteristics of exhibited objects, as revealed by cluster analysis, were important determiners of how such objects were later recognized. Overall object recognition was relatively high, but it was shown that objects low in "familiarity" did not receiveRequests for reprints should be addressed to Henry A. Cross, Department of Psychology, Colorado State University. Fort Collins, CO 80523. 109the disproportionate boost in recognition after a single exposure that is characteristic of unfamiliar words.The...