Search

Thousands of miles of submarine telephone cables form an important and growing part of the world pattern of communications. Repeaters every few miles along these cables maintain signal strengths, and many of the components in these repeaters are gold plated to ensure freedom from deterioration or failure in service. [ABSTRACT FROM AUTHOR]

'Set' is known to improve the accuracy of report of the stimulus attributes for which Ss are set to respond. The set may produce this effect by acting on either preperceptual or postperceptual processes, or both. To elucidate the manner by which set produces its effect, this paper explores the consequences of two assumptions concerning set (1) On any given trial, a S is either 'set' or 'not set': (2) if 'set' by the stimulus information. S's perception of the stimulus actually improves, whereas, if 'not set' by the stimulus reformation, the S's report correctness is improved by an independent interaction of stimulus and set information on a response process. Evidence is provided for both these assumptions. In addition. It is argued that only set given before stimulation can affect a perceptual process. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift für Lebensmittel-Untersuchung und -Forschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Zeitschrift für Lebensmittel-Untersuchung und -Forschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A detailed analysis was made of the data of a previous paper by Bliss et al (1966). That paper describes a series of experiments, in which 2 to 12 simultaneous air-jet stimuli were presented on the 24 phalanges of both hands. In addition, new data from an early blind S, whose performance was significantly better, is compared to the data of the original four Ss. Memory properties of all five Ss estimated by whole- and partial-reporting techniques gave evidence for a tactile short-term memory that (1) has a duration of a few seconds, (2) varies considerably in size (but not in temporal characteristics) for different Ss, and (3) has a capacity limited by spatial resolution. Tactile masking did not account for the limited spatial resolution, but a stimulus-spreading (or lateral-excitation) model did. [ABSTRACT FROM AUTHOR]

Data from an experiment in which Ss reported letters from two consecutive stimuli are analyzed by a nonmetric multiple regression analysis that permits the evaluation of nonlinear-e.g., quantal-hypotheses. The data are shown to contradict the hypothesis that total stimulus duration is the critical factor in response accuracy and the hypothesis of a quantal time period. Instead, they support the theory of visual persistence and continuous processing (Sperling, 1963): namely, visibility of a stimulus persists for a few lOths of a second after a stimulus has been turned off; the effect of a second stimulus exposure coming quickly after the first is to terminate visibility of the first stimulus and to substitute for it visibility of the second; information is retrieved at a rapid rate from whichever stimulus is visible. [ABSTRACT FROM AUTHOR]

An earlier paper examined a visual-search task that required a S to locate a two-digit symbol from an array of digits. The results were not subjected to a detailed theoretical analysis. The present paper suggests an information-theory analysis of the data and shows that all of the data can be reduced to a consistent format. It is also argued that such an analysis may prove fruitful in the investigation of search strategies. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift für Lebensmittel-Untersuchung und -Forschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Vos and Wabraven recently derived a new set of foveal primaries. These primaries, in conjunction with the revised zone fluctuation theory of color vision, account for more psychophysical color vision data than any other model to date. The new primaries depend heavily on Abney's law, and their success has been challenged by Guth's observations of additivity failure at absolute threshold. The present paper develops a probability summation model which accounts for threshold additivity failure within the framework of Vos's and Walraven's assumptions. [ABSTRACT FROM AUTHOR]

Copyright of Geologische Rundschau is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Geologische Rundschau is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Geologische Rundschau is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Geologische Rundschau is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Zeitschrift für Lebensmittel-Untersuchung und -Forschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Misreading of some published papers has led Dr. N. D. Chatterjee to erroneous conclusions about the local geology in the Ghatsila area in Singhbhum, eastern India, and his doubts regarding the metamorphic history deduced by the author here are therefore unjustified. The stratigraphy and structural geometry in this terrain are not at all debatable, and the evidences for a progressive metamorphism broadly contemporaneous with folding and preceding thrusting are incontrovertible. To take any particular metamorphic terrain, whether Simplon or Singhbhum, as the prototype of regional metamorphism is as yet premature. [ABSTRACT FROM AUTHOR]

In this paper the differential sensitivity of the visual system is investigated by means of two simultaneously presented stimuli in a yes-no procedure. The sensitivity measure σ appears to be proportional to stimulus intensity (i.e., Weber's law). The curve displaying Weber's law is little affected by variation of the background intensity or of the adaptation level. An increment threshold experiment using only one stimulus yields a proportionality of σ with the square root of the background intensity. An additional experiment shows that the sensitivity measure σ for two flashes decreases first, from dark up to a particular background intensity, and increases when the background tends to mask the flashes. So, in general, two background levels exist with the same differential sensitivity. The results cannot easily be explained by the simple quantum fluctuation concept. A model based partially on electrophysiological data from the literature is proposed which encounters a particular adaptation mechanism, a transducer with a limited dynamical range, and a range setting mechanism. [ABSTRACT FROM AUTHOR]

The brightness constancy problem is placed in perspective with a brief restatement of the main theoretical issue. Flock's use of our theoretical formulation with the Hess and Pretori empirical data to demonstrate that the k values fluctuate merely restates the fact that our own theoretical approximations to these and other data using a fixed value of k were not perfect fits, a fact we thought clear from graphs included in our original work. The reality of the observation that perceived brightness may increase, stay constant, or decrease with an increase in illumination is affirmed by replotting Hess and Pretori's 17 series of experiments. The basis on which interactive effects for complex fields were calculated appears to have been missed by our critic and is here retold, and his mistaken criticism of Brown and Mueller's citation of Heinemann's data is corrected. Attention is called to an elemental analysis derived from our integrated theory as a constructive alternative approach. [ABSTRACT FROM AUTHOR]

In this paper, consideration is given to the physiological foundations of visual masking with successive stimuli. Three experiments are performed with dot patterns. The results indicate that none of the classic characteristics of lateral inhibitory interaction are obtained with this type of stimulus material. A rather informal demonstration is then described that suggests further that lateral inhibitory interaction may also not be a satisfactory explanation of metacontrast and other kinds of masking that use continuous figures. [ABSTRACT FROM AUTHOR]

This paper concerns the cognitive simplicity of 35 black and white patterns. The patterns are rank-ordered according to four experimental measures of simplicity. The correlation between these different rank orders is high, and it is therefore possible to construct a single 'simplicity' order for the patterns. It is then shown that the simplicity of different patterns is almost perfectly accounted for by the relative numbers of subsymmetries in the different patterns. [ABSTRACT FROM AUTHOR]

In this paper we consider two problems concerning human psychophysical discriminability of variable interval nerve action potential patterns. The first question asks which of two possible alternatives-additional sample size or elongation of duration-is responsible for the improvement in performance as the number of pulses in a stimulus train increases. Our data strongly indicated that the answer to this question is increased sample size. The second question concerns what effect, if any, parallel rather than serial presentation of the two alternatives in a forced choice psychophysical test will have on the function relating interpulse interval and discriminability. The answer to this question appears to be that other than a slight elevation of the absolute levels no changes in the general form of the response is produced. [ABSTRACT FROM AUTHOR]

Six experiments were conducted to test the hypothesis that overestimation of vertical distance is a pervasive phenomenon. The experiments involved judgments of: (a) vertical distance looking upward; (b) vertical distance looking downward; (c) the slope of a real hill; (d) the recalled slopes of streets; (e) the magnitudes of angles drawn on paper; (f) the distances to afterimages projected into the sky. The results showed that a very strong illusion of overestimation of both vertical distance and slope occurred in all situations except for the judgments of drawn angles by males. Furthermore, in five of the six experiments females showed a greater amount of the illusion than males. The discussion pointed out the difficulty of explaining the moon illusion by the assumptions of a flattened sky surface and Emmert's law in light of the data. [ABSTRACT FROM AUTHOR]

In this paper we concern ourselves with the problem of whether or not conditioning stimuli of other modalities or stimuli applied to a distant locus of the body interact with a sensitive test of somesthetic temporal acuity we have called the gap test. The results of the experiment indicate that visual stimuli do not exert an observable influence on this temporal judgment, but that auditory stimuli and contralateral stimulation in the same modality do show a significant but relatively small effect. This is compared and contrasted with the very large and persistent effect reported when the conditioning stimulus is applied to the same electrodes as the gap test. By comparing our results with experiments of similar design carried out on lower animals by other investigators, some insights into the neural localization of the reported effects is obtained. [ABSTRACT FROM AUTHOR]

Two techniques for studying judgment are discussed. In the first of these one assumes invariance of perception over different judgment processes and conceives of the properties of one judgment process as known. Then, perceptions may be estimated under this process and utilized in the study of other judgment processes of interest. A second technique disposes of the reliance up on a basic, 'known' process and instead suggests that perception be treated as free parameters to be estimated from data. The paper then proceeds to show how this second technique may be used under certain conditions on perception themselves. A concept of sensation is introduced which is thought of as generating percepts in formally the same manner as percepts are thought of as generating judgments. The idea is tried out on the perception of movement time. A simple perception process appears to give a good fit to data. [ABSTRACT FROM AUTHOR]

When an observer is confronted with a stimulus pattern that in some aspect does not change over time, perception of that aspect of the pattern does change. This paper documents several different types of change, all of which progress linearly with the square root of the observing time. Examples are drawn from studies of figurai after-effects, motion after-effects, vigilance, motion neutralization, visibility of the stabilized retinal image, effects of contours on visibility and fluctuations in the perceptual organization of ambiguous figures. [ABSTRACT FROM AUTHOR]