Alleys in visual space

Geometry of frameless visual space is dealt with. First, parallel and equidistant alleys, horopters in the horizontal plane of eyes' level are discussed within the framework of the Luneburg's model that the frameless visual space is a Riemannian space of constant curvature. That basic postulate and the specific mapping functions assumed by Luneburg between the euclidean map of visual space and the physical space are kept separate, and efforts are directed to make the model applicable to more natural conditions of our visual space. A possibility is pointed out to remove the constraint “frameless” in the sense that perceptual geometrical properties are primarily determined by the convergence of optic axes. So far, only alleys in the horizontal plane extending from us toward infinity have been studied, but more often we perceive parallel lines, horizontal or vertical, in front of us like shelves of a bookcase. Hence, equations are derived for horopter plane appearing fronto-parallel in the three-dimensional visual space and alleys running horizontally or vertically on the horopter plane. It is shown that parallel and equidistant alleys are not the same in the horopter plane as in the horizontal plane, if the visual space is not euclidean. A method to evaluate the discrepancy between the two alleys without using any mapping functions is stated with some numerical examples.     

Acquisition and forgetting in monkeys' memory of informational object-reward associations

The first experiment showed the monkeys could recall whether an object had been rewarded with peanuts or with sultanas, two equally preferred foods. The second investigated the effect of rewarded trials with an object on monkeys' ability to recall a nonrewarded trial with the same object. The third demonstrated that monkeys could use the memory of reward to predict nonreward and the memory of nonreward to predict reward, in a Win-Shift Lose-Stay paradigm. The fourth found differences between Win-Shift Lose-Stay and Win-Stay Lose-Shift in the rate at which associations between objects and reward events were forgotten. These results are discussed in relation to D. L. Medin's (In A. M. Schrier, Ed., Behavioral primatology, Hillsdale, N.J.: Erlbaum, 1977, Vol. I, pp. 33–69) distinction between informational and hedonic effects of reward in monkeys. It is argued that the association between an object and a reward event is represented in memory by many independent traces, different traces recording the object's association with different attributes of the reward event.     

Cognitive flexibility-rigidity, repetition effects, and memory

This experiment examined the role of cognitive flexibility-rigidity in memory. On the basis of several personality tests, subjects were classified as flexible, intermediate, or rigid, using a postexperimental blocking procedure. All subjects were given a perceptual grouping task, which masks the meaningful structure of the material. Subjects have the option of discovering the more meaningful structure consisting of word pairs, or alternatively, processing less meaningful chunks of letters. Results were that flexible subjects recalled substantially more items than intermediate and rigid subjects, in that order. In addition, subjects given different (varied) groupings of the letter chunks recalled substantially more than subjects given repeated presentations of the same grouping structure. Transfer tests indicated that subjects acquired different coding strategies under varied and constant input. Repetitious input led subjects to adopt inefficient strategies in processing the material to be remembered, whereas varied input led subjects to adopt efficient encoding strategies.     

Through the looking glass: Sex differences in memory for self-facial poses

This study investigated recognition memory of photographs of the subject's own face. Male and female subjects were photographed as they projected sociable faces, trustworthy faces, and intelligent faces. After deciding which face of 10 best represented each characteristic, and judging which photograph best represented their “real self,” a recognition memory test of poses was given. Half of each sex were tested under intentional learning conditions and the remainder were tested under incidental learning conditions. Females demonstrated superior recognition memory of their own facial projections and, in particular, recalled photographs of their “real self” and “most sociable” self most easily. No differences were found between the two learning conditions. Subjects' recognition performance was not related to their confidence of judgments. The results were discussed in terms of sex differences and the role of self in memory.     

Factors affecting judgments of fluency: I. interjections

Six speech samples containing varying amounts of schwa interjections were tape-recorded and presented to 36 male and 36 female listeners. For each sample, listeners were asked to make judgments of fluent, disfluent, and stuttered speech, and to answer the question “Would you recommend speech therapy?” Results indicated that speech samples containing 5% or more interjections evoked a judgment of disfluent speech by a majority of listeners. The sample containing 20% interjections, however, was found to evoke judgments of disfluent and stuttered speech about equally. Varying numbers of listeners recommended clinical services for disfluent speech. In general, the results indicated that (1) the presence of interjections in connected speech is not normal regardless of frequency, (2) fluent speech may not contain interjections in excess of 5%, and (3) with 20% interjections in speech, the distinction between disfluency and stuttering may be blurred.     

What is right with “deep” dyslexic patients?

Two aphasic adults with a specific acquired dyslexia were given tests requiring the processing of written words and sentences. Despite the general severity of the patients' deficits, some aspects of such processing appear to be relatively well preserved. The patients have particular difficulty reading aloud function words and abstract words; yet in word/nonword discrimination tests, both patients showed normal recognition of function words and one showed normal performance with abstract words. The patients do have a deficit in comprehension of visually presented words and sentences; yet their performance on comprehension tests was considerable and, moreover, showed meaningful relationships with their ability to read aloud.     

Memory scanning,introversion-extraversion,and levels of processing

Individual differences in information processing were studied in the form of the hypothesis that arousal, as indexed by a personality measure of introversion-extraversion, affects the speed with which certain kinds of processing are completed. The Sternberg paradigm was used, and the results suggested that introverts and extraverts scanned for physical features equally rapidly, but that introverts were slower than extraverts at scanning for the semantic features of category membership. There was limited support for the hypothesis that introverts, thought to be more aroused than extraverts, are less able to engage in shared or parallel processing. It was concluded that information processing in introverts and extraverts may differ qualitatively as well as quantitatively.     

Lateralization for reading musical chords: Disentangling symbolic, analytic, and phonological aspects of reading

It has been repeatedly shown that the left hemisphere (right visual field) is superior to the right hemisphere (LVF) in reading English, a bias possibly due to any or all of three confounded factors: (1) the symbolic nature of the coding system; (2) the analytic requirements of the decoding process; and (3) the phonological associations of the elements. Recent work on reading Japanese ideograms (Kanji) disentangles (1) from (2) and (3), but leaves the latter two confounded. We further disentangle (2) and (3) by examining visual field preference for reading musical chords, representatives of an analytic, nonphonological symbol system. The strong RVF advantage is interpreted as indicating that the left hemisphere is dominant for reading an analytic symbol system that is not phonologically based. We conclude that the left-hemisphere advantage traditionally found for reading phonological symbols is due to their analytic nature in addition to any effect due to their linguistic association.