I am extremely humbled by the honor of introducing Roger Shepard, recipient of the 2006 David E. Rumelhart Prize for Contributions to the Theoretical Foundations of Human Cognition. Like so many of my generation of cognitive scientists, along with those of the generations that preceded and followed, I have been greatly inspired and profoundly moved by the power, depth, and sheer beauty of Profe...

1.1 The number.dat data file from Shepard, Kilpatric, and Cunningham (1975). 11 3.1 A proximity matrix, morse digits.dat, for the 10 Morse code symbols representing the first ten digits 9.1 Order-constrained least-squares approximations to the digit proximity data of Shepard et al. (1975); the upper-triangular portion is anti-Robinson and the lower-triangular portion is strongly-anti-9.2 The 45...

Children and adults identified or discriminated the version (normal or backwards) of letters presented in 10 different orientations between o and 180 degrees. Reaction time to discriminate version increased linearly with orientation for both children and adults, but reaction time to identify was not strongly influenced by orientation for either children or adults. This suggests that both childr...

Starting from the early 1970s, Shepard and colleagues (Shepard & Cooper, 1982; Shepard & Judd, 1976; Shepard & Metzler, 1971) conducted a series of experiments showing that mental transformations of 2-D shapes and 3-D objects appeared to follow the same laws as physical transformations of real objects. This finding of mental rotation was a cornerstone in the foundations of the emerging field of...

The present study investigates the decay of pitch memory over time. In a delayed pitch comparison paradigm, participants had to memorize the pitch of a Shepard tone, with silent, overt, or without any rehearsal. During overt rehearsal, recordings of the rehearsing were effectuated. Performance was best for silent rehearsal and worst for overt rehearsal. The differences, although partially signi...

Volume morphing is a technique used for generating smooth 3D image transformations and deformations. In this paper, several algorithms are developed for morphing transformations that create new forms and simulate shape deformation and growth in biomedical applications. 3D biological point landmarks and their movements are deened to guide the morphing transformation using a scattered data interp...

This article presents a series of experiments on concept formation. These experiments compared four different categorisation rules. The rules presume that the stimuli to be classified can be modelled psychologically as points in a dimensional space (Shepard 1987, Gärdenfors 1990a, 1990b). Two of the rules are based on the assumption that there are prototypical representatives of a concept, a th...

Multiplication of Mycobacteria leprae in the foot­ pads of mice has been reported by Shepard . 1 o The increase has been up to 1 ,000 fold. Other workers like Chatterji4 and BergeP have also reported successful transmission of M. leprae in ra ts and mice by using differen t s trains of animals and different food and technique. Mukherj i 6, 7 has not been able to confirm their works . This work ...