Reception of Morse code through motional, vibrotactile, and auditory stimulation

The potential for communication through the kinesthetic aspect of the tactual sense was examined in a series of experiments employing Morse code signals. Experienced and inexperienced Morse code operators were trained to identify Morse code signals that were delivered as sequences of motional stimulation through up-down displacements (roughly 10 mm) of the fingertip. Performance on this task was compared with that obtained for both vibrotactile and acoustic presentation of Morse code using a 200-Hz tone delivered either to the fingertip through a minishaker or diotically to the two ears under headphones. For all three modalities, the ability to receive Morse code was examined as a function of presentation rate for tasks including identification of single letters, random three-letter sequences, common words, and sentences. Equivalent word-rate measures (i.e., product of percent correct scores and stimulus presentation rate) were nearly twice as high for auditory presentation as for vibrotactile stimulation, which in turn was about 1.3 times that for motional stimulation. The experienced subjects outperformed the inexperienced subjects by amounts that increased with task complexity. For example, the former were able to receive sentences at 18 words/min with motional stimulation, whereas the latter, following 75 h of training, were unable to perform this task. The present results and those of other research with tactual communication systems are compared, particularly regarding estimates of information-transfer rates.     

Perceptual Ambiguity, Gender, and Target Intoxication: Assessing the Effects of Factors That Moderate Perceptions of Sexual Harassment

Subjects read a passage which described an interaction between a man and a woman at an office party. The woman was either sober or intoxicated, and eventually the man engaged in 1 of 3 behaviors which involved varying degrees of sexual innuendo and/or aggression: (a) verbal comment, (b) verbal request, and (c) nonverbal physical display. The results indicated that perceptions did not vary as a function of target person's intoxication in the nonverbal-display condition. On the other hand, in the verbal-comment and verbal-request conditions, subjects in the intoxicated-target-person condition perceived the initiator more favorably than subjects in the sober-target-person condition. In addition, they indicated that perceptions did not vary as a function of target-person intoxication level in the nonverbal-display condition. On the other hand, in the verbal-comment and verbal-request conditions, male subjects were more favorable toward the initiator than toward female subjects.     

Context extinction following conditioning with delayed reward enhances subsequent instrumental responding

In Experiment 1, delayed reward generated low response rates relative to immediate reward delivered with the same frequency. Lister rats exposed to delayed reward subsequently responded at a higher rate in extinction if they received nonreinforced exposure to the conditioning context after instrumental training and prior to test, compared with animals that received home cage exposure. In Experiment 2, a signaled delay of reinforcement resulted in higher rates than an unsignaled delay. Nonreinforced exposure to the conditioning context elevated response rate for subjects in the unsignaled condition relative to a home cage group, but had no effect on response rates for subjects that had received the signaled delay. In Experiment 3, following an unsignaled reinforcement delay, groups receiving either no event or signaled food in the context responded faster in extinction than groups receiving no context exposure or unsignaled food.     

Terrestrial passage theory of the moon illusion

Theories of the celestial, or moon, illusion have neglected geometric characteristics of movement along and above the surface of the earth. The illusion occurs because the characteristics of terrestrial passage are attributed to celestial passage. In terrestrial passage, the visual angle subtended by an object changes discriminably as an essentially invariant function of elevation above the horizon. In celestial passage, by contrast, change in visual angle is indiscriminable at all elevations. If a terrestrial object gains altitude, its angular subtense fails to follow the expansion projected for an orbital course: Angular diminution or constancy is equivalent to distancing. On the basis of terrestrial projections, a similar failure of celestial objects in successive elevations is also equivalent to distancing. The illusion occurs because of retinal image constancy, not--as traditionally stated--despite it.     

Nonlinear submodels of orthogonal linear models

A model containing linear and nonlinear parameters (e. g., a spatial multidimensional scaling model) is viewed as a linear model with free and constrained parameters. Since the rank deficiency of the design matrix for the linear model determines the number of side conditions needed to identify its parameters, the design matrix acts as a guide in identifying the parameters of the nonlinear model. Moreover, if the design matrix and the uniqueness conditions constitute anorthogonal linear model, then the associated error sum of squares may be expressed in a form which separates the free and constrained parameters. This immediately provides least squares estimates of the free parameters, while simplifying the least squares problem for those which are constrained. When the least squares estimates for a nonlinear model are obtained in this way,i.e. by conceptualizing it as a submodel, the final error sum of squares for the nonlinear model will be arestricted minimum whenever the side conditions of the model become real restrictions upon its submodel. In this case the design matrix for the embracing orthogonal model serves as a guide in introducing parameters into the nonlinear model as well as in identifying these parameters. The method of overwriting a nonlinear model with an orthogonal linear model is illustrated with two different spatial analyses of a three-way preference table.     

Modeling strategy shifts in a problem-solving task

A computer simulation model was fitted to human laboratory data for the Missionaries and Cannibals task to explain (1) the effects upon problem performance of giving a hint, and (2) the effects of solving the problem a second time after one successful solution had been achieved. Most of the variance in the relative frequencies of different moves can be explained by positing that the effect of the hint, or of previous experience in solving the problem, is to cause subjects to switch more promptly from a strategy of balancing the numbers of missionaries and cannibals on both sides of the river, to a means-ends strategy.     

Recognition memory: One-component strength functions In the “short-term to long-term transition region”

Experimental manipulationofthe upper bound on the retention interval (30 sec, with average duration of 11 sec, vs. 2 min, with average duration of 18 sec) failed to produce evidence for independent adjustment of initial long-term and short-term storage strengths. Very accurate strength functions of retention time were obtained; these were fitted equally well by a two-component equation and a one-componentequation derived from a theory postulating sequential employment of an active attentional buffer and a one-trace passive storage system. The latter theory appears to be capable of accounting for both post-attentional and two-phase experimental strength data, using fewer free parameters than strength theories which postulate the simultaneous existence of short-term and long-term traces. Other arguments for two traces are also discussed In relation to the postulate of a single post-attentional trace.     

On the independence of positive and negative affect within hour-to-hour experience

This research investigates the hypothesis that the rates of positive and negative affect in a person's life are independent. Whereas prior research on this issue has relied upon people's recollections, a source of information subject to distortion, this research employs reports obtained from immediate experience. Members of an adolescent and an adult sample carried electronic pagers for 1 week and filled out reports on their immediate affective states upon receipt of signals sent to them at random times. The frequencies of positive and negative affective states for each person were then computed from this pool of time samples. The findings reveal strong internal consistency in each person's rates of positive and negative affect. However, congruent with the independence hypothesis, these frequency rates of positive and negative affect were not correlated with each other. The findings dispel the possibility that the results of prior research were affected by distortions of recollection, and they suggest that the occurrence of positive and negative affect in a person's life are independent, not only from week to week, but also from day to day and hour to hour.This research was carried out with support from the Psychiatric Research Fund of Michael Reese Hospital and Medical Center. The author wishes to express his appreciation to Norman Bradburn, Mark Freeman, Nancy Bradney, Randy Larsen, and Ed Diener for comments on an earlier draft of this paper. The author is indebted to Mihaly Csikszentmihalyi and Ronald Graef for use of the data from the adult sample.     

Low-cost microcomputer networking: How to get high throughput on a low budget

A very low-cost, high-throughput laboratory data acquisition and experiment control system may be configured by using a star network architecture with a low-cost microcomputer as network controller and one or more microprocessor-based single-board controllers as satellites. A network of this type, using Apple II microcomputer ($1,500 with 48K RAM and one minidiskette drive) as main node and up to seven KIM-1 microcontrollers ($159 each) as satellites is described, and its development is discussed in detail.