Summation of food and shock based responding

In a multiphase experiment, dogs first received discriminative, discretetrial, barrier-jumping training with two tones (S^D, S^Δ) in a shuttle box reinforced by either shock avoidance (Group I) or by food (Group II). Then the dogs were trained on free-operant barrier-jumping reinforced by the qualitatively opposite reinforcer—food in Group I and shock avoidance in Group II. Finally, test presentations of the tone stimuli were superimposed on the free-operant behavior. The tone S^Ds markedly facilitated responding in all animals. This experiment demonstrates a summation of responding maintained by shock avoidance and food reinforcement and casts doubt on explanations of conditioned suppression outcomes that appeal solely to incompatible motivational states within the organism.     

Psychophysical scales of the odor oiliness of homologous alcohols

In determining the relative oiliness of an alcohol, a category, a ratio estimation, and three magnitude scales were constructed from the observations of 12 Os who judged the oiliness of a C₂-C₁₀ series of homologous alcohols. Oiliness was found to be monotonicly increasing on [C₂, C₈], after which it declines, octanol being the oiliest. Ratio scales were stable and resemble power functions with exponents of 0.624 to 0.784 on this interval. The oiliness attribute has a short subjective range of 2.5/1, which is consistent with the tendency toward short ranges of olfactory attributes, generally. Oiliness across the series shows only slight evidence of being prothetic.     

Adaptation to field displacement during head movement unrelated to the constancy of visual direction

Adaptation to vertical field displacements dependent on head turning about a vertical axis was demonstrated under two conditions, rapid training with 100 head movements and 1-h-long training with continuous head turning. The effect of rapid training was measured with the slant estimation method. Adaptation after the longer training was ascertained by comparing the uncertainty ranges for apparent target immobility before and after the adaptation period. Adaptation to field displacements in directions parallel to the plane of the head rotation obtained under corresponding conditions was also measured and found to be somewhat greater than adaptation to vertical field displacements. The result of work by Wallach and Frey that adaptation to field displacement in the direction with the head rotation is greater than to displacement against it was corroborated. While the previous result had, been obtained with rapid adaptation and with the slant estimation method, we confirmed it with 1-h training and by measuring the uncertainty ranges before and after the adaptation period.     

The effects of information exchange and communication in an asymmetrical negotiation situation

Seventy-eight dyads of male university students participated in a bargaining experiment. The bargaining situation was asymmetrical insofar as the two players had different payoff possibilities. Experimental instructions did not provide information about the opponent's payoff possibilities but players could ask each other for such information (except in the control condition). It was found that the players in the advantaged position (with better payoff possibilities) bluffed more frequently and communicated less with the opponent than their disadvantaged opponents. But there were no differences in the frequency of refusing to give requested information, nor in the frequency of requesting information. Verbal communication opportunities reduced the frequency of bluffing (false information) but did not by themselves lead to smaller payoff differences between the two players. Payoff differences were smallest when information exchange was obligatory and truthful and they were greatest when neither information exchange nor communication was possible.     

Aversive conditioning in the sociopath

Results of two experiments on differential conditioning of the skin conductance (SCR) in sociopaths and normal control subjects are described. In the first experiment it was found that an equal number of sociopaths and control subjects were aware of the conditioning contingency. However, only the normal subjects displayed reliable differential SCR conditioning. Sociopaths showed a dissociation between verbal learning and conditioning of a physiological change. The second experiment examined the differential conditioning of normal subjects and sociopaths in partial remission. The number of aware subjects in the two groups did not differ. Aware subjects in both groups showed differential SCR conditioning. Differential conditioning in sociopaths did not persist over trials as it did in control subjects. A deficiency in ACTH 4–10 as well as neurological dysfunctions were considered possible factors in the etiology of sociopathy. Further research on the relation of neuropeptides to the etiology and treatment of sociopathy is suggested.     

A kinesthesiometer for assessing digital passive movement sensitivity in man

An electromechanical system for the delivery of kinesthetic stimulation to human digits is described. The system provides highly precise control over angular velocity (in degrees per second), angular displacement (in degrees), and stimulus duration (in seconds) and uses an electromagnetic brake to terminate the stimuli. It also permits three measures of passive movement sensitivity to be made: correct detections, response time, and angular displacement.     

Timesharing on the PDP-11 under RT-11

A timesharing system for the Digital Equipment Corporation PDP-11 is described. In keeping with the general philosophy of the RT-11 operating system, the permanently resident portion of the system is kept to an absolute minimum size. The system supports from 2 to 16 users, and provides each with full editing and batch execution capabilities.