Force and rate relations in responding during variable-interval reinforcement

Four rats responded on one-minute variable-interval schedules with several variations in peak-force of response required for food reinforcement. Measures of peak force and rate were taken for the responses, which were the downward exertions of force against a static force-transducing operandum. The analysis distinguished responses, a generic class of measured behavior, from criterion responses, an operationally specified subclass required for reinforcement. Absolute rate of response showed no systematic change, but the rate of responses meeting a newly required criterion of peak-force invariably increased through changes in the absolute rate of response, the relative-frequency distributions of peak force, or some combination of both. The relative frequency of responses meeting an elevated force criterion during variable-interval reinforcement exceeded that maintained with the same criterion with continuous reinforcement. The requirement of more effortful responding for reinforcement does not necessarily reduce response rate. Conformity of the behavior to the requirement for reinforcement is the salient effect.     

Sex and coding strategy effects on reaction time to hemispheric probes

Two experiments were conducted to investigate the influence of coding instructions on cerebral laterality differences. Experiment I required 20 subjects (10 female) to use either rehearsal or imagery coding strategies in a recognition task with word probes to the right and left hemispheres. No hemispheric differences were found, but sex of subject was found to be related to coding strategy. Ten subjects (5 female) in Experiment II performed a similar task, except picture probes were used. Subjects using rehearsal coding responded faster to left-hemisphere probes, but faster to right-hemisphere probes when imagery coding was employed. The differing laterality effects in these experiments were attributed to naming responses implicitly required in Experiment II.     

Semantic priming and retrieval from lexical memory: Evidence for facilitatory and inhibitory processes

Immediately prior to each visually presented target letter string to which the subject made a speeded word-nonword classification response, a visually presented prime to which no overt response was required was shown for 360, 600, or 2,000 msec. For word (W) target trials, the priming event was either a semantically neutral warning signal (Condition NX), a word semantically related to the target word (Condition R), or a word semantically unrelated to the target word (Condition U); for nonword (N) target trials, the priming event was either the neutral warning signal (Condition NX) or a word prime (Condition WP). For the W target trials, reaction times (RTs) were slower in Condition U than in Condition NX and equally so for all three prime durations; RTs were faster in Condition R than in Condition NX and to a greater degree for the 600- and 2,000-msec prime durations than for the 360-msec prime duration. For the N targets, RTs were faster in Condition WP than in Condition NX and equally so for all prime durations. These results were interpreted within the framework of a two-factor theory of attention proposed by Posner and Snyder (1975a).     

Effects of peer reporting on cooperative play and aggression of kindergarten children

Kindergarten children were given opportunities to report to their class during “sharing time” the cooperative or friendly behaviors of their peers which had occurred during the day. Children whose cooperative behavior was reported by a peer received a happy face badge as a reward. Later, only peer praise served as a reward for those whose friendliness was mentioned by a peer. Cooperative behavior increased and aggressive acts decreased when peers reported prosocial behavior to the class. A reversal phase, in which unfriendly acts were reported, produced a decrease in cooperation and an increase in aggression. Peer reporting was a natural and inexpensive means of increasing prosocial responses of these children. Anecdotal teacher reports suggested a generalized behavioral improvement.     

Authoritarian personalities, 1950-1973

This study concerns a comparison of American college graduates of the post Kent State era with those of the post Hitler era as to authoritarian type personality. A short 17-item scale for authoritarian personality traits was devised and found to correlate with the F Scale. This was administered to 314 college graduates in 1950. It was again administered to 400 graduates of the same college in 1973. The results show that the 1973 group is less authoritarian than the 1950 group.     

The“response” in behavior theory

The term“response” is a basic one in behavior theory, particularly reflex theory, but its definition is not clear. The origin of the term in the common vocabulary has affected its later extensions in the analysis of behavior. Some contemporary theorists accept the existence of two“types” of response, coordinating one with the Pavlovian conditioning procedure, the other with the operant conditioning procedure of the so-called“contingent” variety. Reservations are expressed here about such distinctions between response classes and conditioning paradigms, emphasizing the difficulties that arise from certain conventions and inadequacies in current definitions and conceptions of“response.” The critical nature of the problem for behavior theory is illustrated once again by the recent laboratory finding that a familiar and accepted conditional reflex, that of the“conditioned cardiac CR,” can be fractionated into“parts” and is therefore perhaps no longer to be treated as a single unitary“response.”     

Selective adaptation effects on end-point stimuli in a speech series

Recent experiments in speech perception using the selective adaptation paradigm have found that the phonetic boundary of a test series shifts following adaptation. However, no changes within the phonetic category have been found. In the present experiment, a series of voiced CV syllables which varied along the feature of place was used in a selective adaptation paradigm. The end-point stimuli trom the test series were used as adaptors. Subjects used a 6-point rating scale to respond to the stimuli instead of the usual two-category identification. The average rating for end-point stimuli from the same category as the adaptor, as well as the boundary stimuli, shifted as a function of adaptation. In all cases, the average rating response shifted toward that of the unadapted category. The average rating for stimuli in the opposite category from that of the adaptor remained relatively unchanged. These results indicate that the entire category of the adapting stimulus changes as a function of selective adaptation and that the effect is not confined to stimuli near the phonetic boundary.     

Reversible effects of ambient housing stimulation upon stimulation-seeking in rats

Two types of housing condition, low and high ambient stimulation, were alternated. The effects of this treatment upon rats' subsequent stimulation-seeking behaviour were assessed in a multiple-choice head-input apparatus. The aim of the experiment was to determine whether adult animals would adapt and re-adapt to varying periods of upward and downward shifts in the levels of housing stimulation. A given housing-stimulation had a lawfully cumulative effect which could be completely reversed when housing conditions altered. The most sensitive measures were latency and response rate in the first 5 min of the test. One measure, relative preference for illuminated stimuli over a dark stimulus, gave an indication of the time-lag involved in adaptation to a new housing condition.     

Classical aversive conditioning of heart rate in curarized rats at different blood gas levels

In an effort to examine whether normal blood gas tensions were essential for conditioning, paralyzed rats received a classical aversive heart rate (HR) conditioning session while respirated at different peak expired CO₃ values. After the session, arterial blood was drawn for analysis. That peak expired CO₂ was effective in manipulating Pco₂ was indicated by a significant correlation (r = 0.594, df = 17, P < 0.05). In addition, only rats with blood gas values similar to those of anesthetized controls displayed a discriminated HR CR. These animals also had lower baseline HRs and greater HR variability. Further, 7 of the 9 rats with normal blood gas values were respirated at peak expired CO₂ values from 5.0–5.1 per cent, and no animal ventilated within this range displayed abnormal values. These findings suggest that previous difficulties in obtaining classical and operant conditioning in paralyzed animals may, in part, be attributable to inadequate ventilation.