The role of the cs and avoidance period duration in discriminated avoidance conditioning

In an experiment investigating the effect of CS duration on discriminated bar-press conditioning, subjects were assigned to one warning period duration (1.5, 5.0 or 15.0 sec.) on the first day of avoidance training, and to one of the three durations on the second day of training. On each day avoidance behaviour was greatly influenced by the duration of the CS (warning) period, but the duration on day I had no effect on the second day's avoidance performance. Groups receiving no CS during training, although provided an avoidance contingency, showed little conditioning, but produced highly significant amounts of intertrial responding. In a second experiment, subjects receiving CS on day I were shifted to no CS on day II. Avoidance performance on day II was not significantly different from the day II performance of subjects in Experiment I having two training sessions with the CS present or absent on both days.     

A three-electrode system for EKG recording and aversive shock

The use of three electrodes to produce digitizable EKG’s and to deliver shocks to the tail of the monkey is described. Cardiac signals are taken from a head electrode and a “ground” tail electrode. Shock is administered through a “hot” tail electrode and the “ground” tail electrode.     

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.     

The Development of an SVIB Interest Scale for School Counselors

A professional school counselor key was developed on the Strong Vocational Interest Blank using Campbell's revised procedures. Of the 403 counselors initially contacted, 340 responded. Of this number, 203 were identified as professional counselors and were included in the professional school counselor scale. Each of these individuals was fully certified, possessed three or more years' experience as a counselor, was a member of a professional guidance association, and was thoroughly satisfied with his job as a counselor. Differences between professional counselors and non-professional counselors seemed to indicate a greater people-orientation in the professional counselor group. This was further supported by relationships of the professional counselor key with other scales on the SVIB.     

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.     

Stereopsis with opposite contrast contours

The effects of incidental stimuli, defined as visual stimuli not under verbal control, upon a selection task were observed as a function of feedback contingency. Ss judged letter pairs to be valid or invalid completions of preceding letter parts. During the presentation of the letter parts, the response pair or an alternative pair of letters was intermittently presented at a threshold value individually determined for each S. One group of Ss received a light feedback of performance contingent upon responding to the incidental stimuli; whereas a second group received a random noncontingent feedback. The results indicated: (a) both groups responded to the incidental stimuli; (b) feedback contingency had no effect on frequency of responding to the incidental stimuli; (c) frequency of responding to the incidental stimuli remained constant over 32 trials.     

Two types of short-term visual storage

Seven-letter words were flashed repetitively at various durations above and below the recognition threshold for single flashes. One form of a short-term storage effect was studied by measuring the interstimulus interval between flashes at which S reported that the stimulus became phenomenally discontinuous in time. Storage times reached a maximum of about 300 msec in this task. A second form of storage effect was measured by decreasing the interstimulus interval until S could correctly recognize a repeated stimulus whose duration was below the single-flash recognition threshold; this effect extended to 900 msec in some cases. Each of these effects was reliably obtained for both rare and frequent words. Both forms of storage were increased by providing a dark rather than a lighted adapting field between presentations of the test stimulus. Implications for Information processing of brief displays are discussed.     

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.