A LISP program to determine similarity relations in letter displays

Similarity relations between letters are important in displays used in tacbistoscopic recognition experiments. A LISP program is described that calculates similarity relations on the basis of an empirical letter-similarity matrix or on the basis of feature sharing in a feature-set definition supplied by the user. With either derivation method, there are three options for the type of average to be calculated for target display: (1) the average for the whole target, (2) the average for each letter in the target paired to all other letters in the target, and (3) the average of each letter in the target paired with its immediate neighbors.     

Second-order isomorphism of internal representations of familiar faces

Following a suggestion by Shepard and Chipman (1970), photographs and names of 15 well-known faces were used as stimuli in judgments of similarity. Ss ranked all pairs of stimuli in terms of facial similarity either from memory when presented with pairs of names, or from photographs. There was a highly significant positive correlation between these two types of judgment. A simple classificatory analysis of the 15 faces in terms of the physical features provided evidence that judgments based on the internal representation of the faces utilized pictorial information. These results extend the generality of Shepard and Chipman’s findings and confirm the usefulness of an approach to the problem of mental images based on the concept of second-order isomorphism.     

Additivity of components of prismatic adaptation

Ss pointed with each hand at a light or at the unseen toe and looked in the direction of the unseen toe before, during, and after training one arm to point to a visual target which was progressively displaced to one side by a prism. Results show that a proprioceptive change in the trained arm is a universal component of the adaptation. When a change in the eye-head system occurs, it and the proprioceptive change in the arm sum to the total adaptation and it is accompanied by a predictable degree of intermanual transfer of the adaptation, as a felt-position theory of adaptation would predict. However, when there is no change in the eye-head system, the proprioceptive shift is not always sufficient to account for the total adaptive shift.     

Tactile-kinaesthetic perception of straightness in blind and sighted humans

A comparison is made between the tactile-kinaesthetic perception of straightness in twenty blind and twenty sighted subjects. Both types of subject are found to perceive a “plus curved” edge as straight, but this curve is significantly less for the blind than for the sighted, i.e. the blind subjects' judgments correspond more closely to the objective straight. Furthermore, the blind, both as individuals and as a group, are significantly finer in their judgments and more consistent. These results are thought to be explained in terms of the more highly developed organisation of the blind's tactile-kinaesthetic perception.     

A Complete Axiom System for Polygonal Mereotopology of the Real Plane

This paper presents a calculus for mereotopological reasoning in which two-dimensional spatial regions are treated as primitive entities. A first order predicate language with a distinguished unary predicate c(x), function-symbols , · and – and constants 0 and 1 is defined. An interpretation for is provided in which polygonal open subsets of the real plane serve as elements of the domain. Under this interpretation the predicate c(x) is read as region x is connected and the function-symbols and constants are given their meaning in terms of a Boolean algebra of polygons. We give an alternative interpretation based on the real closed plane which turns out to be isomorphic to A set of axioms and a rule of inference are introduced. We prove the soundness and completeness of the calculus with respect to the given interpretation.     

The Meaning and the Ends of Teaching Religion

This paper explores the relationship between assessment and ethical value. It starts by reflecting on the traditional assessment convention that distinguishes strongly between process (the ways in which a student constructs a piece of work) and conclusion. The paper then examines three case studies from Holocaust studies, feminist theology, and Providence. The argument of the paper is that these three case studies illustrate that imparting certain values is part of the teaching process, and therefore it should not be excluded from assessment.     

Methamphetamine effects on cognitive processing during extended wakefulness

We examined the effects of both 5- and 10-mg/7O kg body weight of d-methamphetamine HCl on high event rate vigilance and tracking performance in a 13.5-hr sustained-performance session during one night of sleep loss. At 0116 hours participants were administered either a 5 mg/70 kg oral dose of d-methamphetamine (n=10), 10 mg/70 kg d-methamphetamine (n=10), or a placebo (n=10) using standard double-blind procedures. Performance on all measures degraded markedly during the night in the placebo group. Both the 5- and 10-mg methamphetamines treatment reversed an initial decline in d', and reversed increases in nonresponses (lapses) and tracking error within approximately 3 hr of administration. No evidence that amphetamine treatment increased impulsive responding (fast guesses) was observed. The magnitude of the performance effects of the methamphetamine treatments was similar at 3 hr postadministration. However, the effects of the 5-mg dose were shorter-lived, disappearing by the last testing session (6.5 hr postadministration), whereas effects of the 10-mg dose tended to remain throughout testing. Both amphetamine treatments decreased subjective sleepiness during the night and tended to increase subjective sleep latencies during a post-testing sleep period.     

Effects of high-pass and low-pass spatial filtering on face identification

If face images are degraded by block averaging, there is a nonlinear decline in recognition accuracy as block size increases, suggesting that identification requires a critical minimum range of object spatial frequencies. The identification of faces was measured with equivalent Fourier low-pass filtering and block averaging preserving the same information and with high-pass transformations. In Experiment 1, accuracy declined and response time increased in a significant nonlinear manner in all cases as the spatial-frequency range was reduced. However, it did so at a faster rate for the quantized and high-passed images. A second experiment controlled for the differences in the contrast of the high-pass faces and found a reduced but significant and nonlinear decline in performance as the spatial-frequency range was reduced. These data suggest that face identification is preferentially supported by a band of spatial frequencies of approximately 8-16 cycles per face; contrast or line-based explanations were found to be inadequate. The data are discussed in terms of current models of face identification.