Similarity of cardiac CR forms in the rhesus monkey during several experimental procedures

Cardiac rates of rhesus monkeys were observed in a variety of different conditioning procedures, each of which involved a visual stimulus (CS) followed by an electric shock (US). With a 30-sec CS, cardiac rate accelerated rapidly after CS onset, reached a maximum in the middle of CS, and decelerated thereafter, with a terminal CS rate often at the level of, or below, pre-CS levels. A similar biphasic cardiac rate response in CS was also observed under subsequent exposure to intermittent pairings of CS and US, avoidance of US, response-produced termination of US, and when CS-US pairings were superimposed upon an avoidance baseline, even when CS duration was varied from 12 to 60 seconds. The unusual regularity of cardiac rate responses in several different procedures may result from one or more of these factors: (a) characteristics of the rhesus monkey, (b) initial exposure to Pavlovian conditioning, or (c) the uniformity of measurement of cardiac rate employed in this study.     

The bioelectrical activity of cerebellar structures in the freely-moving rat

Electrodes were implanted in the brains of 27 freelymoving rats and the bioelectrical activity of cerebellar cortical structures (lobus simplex, tuber verrais, lobus ansiformis, crus II) and the dentate nucleus was measured simultaneously with the activity of the cerebral cortex and dorsal hippocampus and respiratory rate and motor activity. Different behavioral states were produced by habituation procedures and by elaborating conditional avoidance reflexes to light-flash or click series. In addition, startle reflexes to acoustic stimuli were used to evaluate behavioral state. The following conclusions could be drawn: 1) in the awake rat the various cerebellar structures have clearly distinguishable bioelectrical activity patterns; 2) changes in these patterns depend on the actual behavioral state of the animal; 3) this dependence upon behavior is especially clear in crus II, one of the projection zones of the tactile and proprioceptive afferent nerves in the cerebellar cortex. The changes in the electrocerebellogram of the unrestrained rat may be used as an indicator of the behavioral state of the animal.     

A titration procedure for generating escape behavior

In a grid-shock escape paradigm using time-out as reinforcement, both fixed-ratio and variable-interval performances were established directly from a continuous reinforcement schedule with rats and guinea pigs. A procedure was developed that employed a stepwise decrease in reinforcement time for all responses except the terminal response. Acquisition and long-term maintenance data were obtained from Ss trained on this titrated negative-reinforcement procedure.     

Vibrotactile vigilance: The effects of costs and values on signals

Vibrotactile vigilance behavior was examined for the effects on signal detection performance of placing costs on misses and false detections and a positive value on the correct detection of a signal. Analyses over time showing that the frequencies of correct detection and false detection of signals decreased, while response times increased, indicated that increased costs for misses and false alarms lead to poorer correct detection performance, while the value placed on the correct detection of a signal had little effect. The d’ statistic of signal detection theory was invariant with both signal costs and time, while β varied with both factors.These results imply that the performance decrement during a vigil was due to an increased strictness in the criterion (β) the S set for deciding whether or not a signal was present. The cost factors were effective in manipulating performance during the watch by causing changes in the S’s decision criteria. Findings from this study clearly support those predicted by the “Decision Theory” of Swets, Tanner, and Birdsall (1961); this is suggested as perhaps being the best available basis for a theory of vigilance at this time.     

Temporal sequence effects in auditory oddity discrimination

The oddity method was used in assessing pitch, loudness, simultaneous tone, successive tone, and speech sound discrimination in 35 normal children and 15 children with learning problems. With this method three auditory stimuli are presented, two of which are identical, and the S is required to indicate the temporal position of the odd stimulus. For both groups, discrimination was most accurate when the odd stimulus was in the third position. These results could be explained by assuming that the oddity response was based upon successive Same-Different judgments of the first and second stimuli and the second and third stimuli, since a correct response to third-position oddity would require only a Same judgment of the first and second stimuli. Other findings were not as easily explained by this simple model, and alternative hypotheses are discussed.     

The relationship between cognitive,motor-kinesthetic,and oculomotor adaptation

The literature concerning adaptation to prism indicates that several adaptive mechanisms may be important. The particular mechanism or mechanisms involved depends (at least in part) upon the type of adaptive exposure. In the present study. three adaptive mechanisms (cognitive. oculomotor, and motor-kinesthetic) were investigated. Ss were asked to point in the dark at an illuminated target. The target was seen displaced from its veridical position due to a wedge prism placed before S’s right eye. The left eye was occluded. Ss then viewed their visual target pointing errors through the displacing prism without seeing any part of their bodies. One group of Ss was instructed to ignore these prism-induced errors and to continue pointing at the target’s visual position. A second group of Ss was instructed to compensate fully for their errors and to at tempt to eliminate them on all future trials. For the latter group errors were completely eliminated, while for Ss instructed to ignore their errors, relatively small improvement in visual target settings occurred. This improvement was called cognitive adaptation, since it depended on the S’s conscious control. In addition. for both conditions. evidence was found that allowing Ss to view their prism-induced pointing errors resulted in some form of motor-kinesthetic adaptation. This adaptation was hypothesized to represent a change in the judged position of the pointing hand relative to its felt position. It was concluded that this motor-kinesthetic adaptation was dependent, in part, upon cognitive information concerning the effects of the prism and that it serves to reduce conflict between cognitive and visual cues, i.e., between what S believes and what he sees.     

Individual half-judgment brightness functions

Nine Ss made half-judgments of each of nine brightness standards. Individual half-judgment brightness functions were constructed, one for each of the two threshold forms of the power law. The ω-Law (translation on the psychological axis) provided a better fit to the half-judgment data than did the ?-Law (translation on the intensity axis). A test of scale consistency for the fractionation method was confounded with the power law hypothesis, but the data are interpreted as providing fair support for the method independent of the form of the power law. The effect of Standard on exponent estimates was significant for both forms of the law, and the effect of Standard on threshold estimates was significant for the ?-Law but not for the ω-Law. Both forms of the law contain a so-called threshold parameter, but the interpretation of this parameter as a threshold was rejected for the ?-Law and accepted for the ω-Law.     

The word-frequency effect and incongruity perception: Methodological artifacts?

Two experimental results often reported in support of perceptual interpretations concerning the influence of set on perception are critically examined: (a) the relation between word frequency and recognition threshold, and (b) the so-called compromise reactions between set and stimulus. Alter elimination of certain methodological artifacts (e.g., introduction of a temporal forced-choice method instead of the ascending-limits method), both phenomena disappear; the influence of set on perception appears to be wholly a matter of response bias.     

Visual capture of haptically judged depth

Using a graduated scale. S was required to match with his left hand the depth of three objects of equal physical depth (or thickness) held with the right hand. While making these haptic depth judgments the objects were viewed. Due to its optical properties. one object was of greater apparent visual depth than the other two, which served as controls. The critical object was judged to be of greater haptic depth than the control objects, thus demonstrating visual capture of haptic depth. This outcome is similar to that noted previously for haptically judged direction, size, and orientation with transformed visual input.