Showing papers in "Journal of Experimental Psychology in 1957"

The discrimination of speech sounds within and across phoneme boundaries.

Abstract: In listening to speech, one typically reduces the number and variety of the many sounds with which he is bombarded by casting them into one or another of the phoneme categories that his language allows. Thus, a listener will identify as b, for example, quite a large number of acoustically different sounds. Although these differences are likely to be many and various, some of them will occur along an acoustic continuum that contains cues for a different phoneme, such as d. This is important for the present study because it provides a basis for the question to be examined here: whether or not, with similar acoustic differences, a listener can better discriminate between sounds that lie on opposite sides of a phoneme boundary than he can between sounds that fall within the same phoneme category. There are grounds for expecting an affirmative answer to this question. The most obvious, perhaps, are to be found in the common experience that in learning a new language one often

The relation of eye movements during sleep to dream activity: an objective method for the study of dreaming.

Abstract: The study of dream activity and its relation to physiological variables during sleep necessitates a reliable method of determining with precision when dreaming occurs. This knowledge, in the final analysis, always depends upon the subjective report of the dreamer, but becomes relatively objective if such reports can be significantly related to some physiological phenomena which in turn can be measured by physical techniques. Such a relationship was reported by Aserinsky and Kleitman (1) who observed periods of rapid, conjugate eye movements during sleep and found a high incidence of dream recall in Ss awakened during these periods and a low incidence when awakened at other times. The occurrence of these characteristic eye movements and their relation to dreaming were confirmed in both normal Ss and schizophrenics (4), and they were shown to appear at regular intervals in relation to a cyclic change in the depth of sleep during the night as measured by the EEC (5). This paper represents the results of a rigorous testing of the relation between eye movements and dreaming. Three approaches were used: (a) Dream recall during rapid eye movement or quiescent periods was elicited without direct contact between E and S, thus eliminating the 1 Postdoctoral Public Health Service Research Fellow of the National Institute of Neurological Diseases and Blindness. 2 Aided by a grant from the Wallace C. and Clara A. Abbott Memorial Fund of the University of Chicago.

Serial effects in recall of unorganized and sequentially organized verbal material

Abstract: One of the best established generalizations in the study of verbal learning is found in the serial position effect for the learning of homogeneous, discrete verbal items by the method of serial anticipation. Some form of the classical serial position curve is found for a considerable variety of verbal material and conditions of testing; the essential restriction seems to be that the learning and/or recall be by the method of serial anticipation or some modification of it (5). Several studies (4, 8) show that there is quite a different form of the serial position effect when free recall is the method of testing employed. With the method of free recall, the middle items are less frequently recalled, the first items are moderately well recalled, and the last items are most frequently recalled. Thus, the serial position curve for serial anticipation and that for free recall are roughly mirror images of one another. This, of course, is a qualitative comparison, since the exact form of the curves will depend upon the material and method of testing. Recently, Bousfield, Cohen, and Silva (2) have noted that in free recall the order in which items are recalled depends upon their probability of being recalled. Items frequently recalled by everyone are apt to be recalled first by particular individuals. Since, in free recall, the

Physical determinants of the judged complexity of shapes.

Abstract: Many psychological tasks vary in difficulty with the complexity of the stimulus objects involved. Complex visual objects are not only harder to reproduce from memory than simple ones (4, 6), but also harder to learn by name (4, 7) and to match (11). Complexity is an ill-defined variable, however. No two of the experiments referenced above employ exactly the same operations of physical measurement , and an essential communality between them is not easy to specify in objective terms. In the study reported here, ratings of the complexity of nonrepresenta-tional shapes were obtained from a large number of Ss and related to measurable physical characteristics of the shapes. The results not only have interest in their own right, but also serve to indicate the physical variables most likely to be relevant to other tasks, like those initially mentioned , on which data are typically harder to get and less precise. The relationship of judged complexity to informational content, "degrees of freedom," compactness, and certain other variables will be considered. METHOD Materials.-—The stimuli were 72 "random" shapes, each constructed by the following general method. In a k X k matrix, n random points were plotted, i.e., all coordinates of the points were random numbers between 1 and k. The points were then connected randomly into a polygon of n sides. This connecting process involved two steps. First, peripheral points were connected into a convex polygon which enclosed all the points not included in its contour (as if a pin were stuck into each point and a rubber band snapped around the whole cluster). Second, the unconnected points were given a random order and each in turn was "taken into" a randomly chosen segment of the surrounding polygon (as if by hooking that segment of the rubber band over the interior pin). Since lines connecting the points were not permitted to cross, the number of alternative segments into which a given point might be taken could either increase or decrease as the process continued; hence the assignment of a random sequence to the unconnected points. Connections which placed certain points outside the polygon were permitted, though in consequence the ways in which such points could themselves be connected were restricted. Some of the polygons thus constructed were further developed into curved figures by replacing angles with inscribed arcs of random 221

Continuous perspective transformations and the perception of rigid motion

Abstract: An exploratory survey of the varieties of optical motion which could serve as stimuli for the perception of motions in the world (6, 7) suggested the hypothesis that one kind of geometrical motion in a plane yields an impression of a rigid motion in space but that any other kind of geometrical motion in a plane does not. The stimulus pattern was always a \"texture,\" that is, a grouping of dark shapes on a light background. If, on a motion picture screen, it underwent a continuous sequence of perspective transformations in any of six ways, it gave a perception of a rigid surface moving in one of six ways—the three transpositions and three rotations which, in combination, exhaust the possibilities of mechanical movement. If it underwent continuous transformations not of this geometrical kind (but only a few examples were presented) it aroused perceptions of nonrigid or elastic surface motions, of the kind exemplified in the movements of organisms. Of the six rigid phenomenal motions, three (rotation around the line of sight, transposition up or down, and transposition right or left) are

Simple reaction time as a function of time uncertainty.

Abstract: An earlier study (3) showed that simple reaction time (RT) varies 'with S's uncertainty about time of stimulus occurrence. This time uncertainty is a function of both the mean duration of the time (foreperiod) between a warning signal and the stimulus and the variability within the series of foreperiods. Foreperiod variability adds uncertainty directly and mean foreperiod is important since S's ability to predict time of stimulus occurrence is very much a function of the length of time he must predict. In the previous report the two sources of time uncertainty were considered separately because no single measure was available. The present experiment illustrates with new data, a method by which all of S's time uncertainty can be expressed as a single number and reaction time plotted as a single-valued function of time uncertainty. In addition, time uncertainty is expressed in terms of the information measure. In order to estimate the amount of time uncertainty due to S's imperfect time-keeping ability, it is necessary to run time-interval prediction tests with intervals equal to the mean foreperiods of the reaction time tests. The variance of the distribution of each S's times of response in the time prediction test is taken as a measure of his \"subjective\" time uncertainty

Transfer of experience with a class-schema to identification-learning of patterns and shapes.

Abstract: The idea that experience provides the organism with some \"apperceptive mass\" which facilitates later perception and learning is an old one, with many variants and elaborations. The concept of a \"schema\" as an entity mediating the effects of past experience has been prominent in recent British psychology, chiefly because of the thinking of Bartlett (5) and his associates, as reflected in the summary and review of Oldfield and Zangwill (12). Woodworth (13) and Hebb (7) have used the term \"schema\" in a sense which is somewhat more restricted and more definite than Bartlett's. After considering a number of experiments on memory for form, Woodworth concluded that a new configuration is usually remembered in terms of a \"schema, with correction.\" For example, a figure which may be described as \"a square with a nick on one side\" is easier to learn than