Fixed-ratio punishment by timeout of concurrent variable-interval behavior

Pigeons' responding was maintained by two concurrently available variable-interval reinforcement schedules. A fixed-ratio punishment schedule of timeout periods from the concurrent reinforcement schedules was arranged for responding during one of the variable-interval schedules. The greater the probability of a timeout after a response on the punished variable-interval schedule (the smaller the fixed ratio that produced timeout), the greater the decline in the relative punished response rates. Relative reinforcement rates remained invariant when relative response rates declined. Both behavioral contrast and induction effects were observed on the unpunished variable-interval schedule as a function of timeout punishment of the other schedule.     

Further evidence of a sensory-tonic interaction in pigeons

The five pigeons in Group 1 were given successive intradimensional discrimination training in which responses to a line of 49 degrees were reinforced on a variable-interval schedule and responses to a line of 33 degrees were not reinforced. Subsequent generalization testing with other line orientations revealed a peak shift from the positive stimulus in the direction away from the negative stimulus in all subjects. The four pigeons in Group 2 received successive discrimination training with the 49 degrees value on the key during both stimuli. During the negative stimulus, however, the floor was tilted 16 degrees counterclockwise. When tested (with the floor flat) these subjects showed peak shifts similar to those observed with Group 1. A third group of three pigeons, given successive interdimensional discrimination training with the 49 degrees line as the positive stimulus and the absence of the line as the negative, showed no peak shift in a subsequent generalization test. It was concluded that tilting the floor on which the pigeon stood systematically distorted the bird's visual perception of the orientation of the line in a manner consistent with the results of other studies in this laboratory.     

Performance of two species of quail on basic reinforcement schedules

Two bobwhite quail (Colinus virginianus) and two Japanese quail (Coturnix coturnix japonica) were trained to peck a response key to obtain food. In general, performance on fixed ratio 20 and variable- and fixed-interval 60-sec schedules was comparable to the response patterns of other species under these schedules.     

Rules, praise, and ignoring: elements of elementary classroom control

An attempt was made to vary systematically the behavior of two elementary school teachers to determine the effects on classroom behavior of Rules, Ignoring Inappropriate Behaviors, and showing Approval for Appropriate Behavior. Behaviors of two children in one class and one child in the other class were recorded by observers, as were samples of the teachers' behavior. Following baseline recordings, Rules, Ignoring, and Approval conditions were introduced one at a time. In one class a reversal of conditions was carried out. The main conclusions were that: (a) Rules alone exerted little effect on classroom behavior, (b) Ignoring Inappropriate Behavior and showing Approval for Appropriate Behavior (in combination) were very effective in achieving better classroom behavior, and (c) showing Approval for Appropriate Behaviors is probably the key to effective classroom management.     

Spatial factors in masking with black or white targets

Two masking experiments were carried out. In the first, duration thresholds were measured for a 10 min black test disc paired with a larger concentric black mask, ranging in size from 15 min to 2 deg. The stimuli were tachistoscopically presented centrally, or at 2 deg or 6 deg in the left binocular field. As mask diameter increased, test threshold decreased in a negatively accelerated function, which approached an asymptote below the unmasked condition. All functions are similar with systematic upward shifts for more peripheral stimulation. In Experiment 2, threshold luminance was adjusted for a 1 deg, 5-msec test flash paired with a 250-mseC., 34-mL mask, ranging from 1 deg to 6.2 deg in diameter. Stimuli were presented in Maxwellian view at 7.2 deg in the right eye nasal field. Results were similar to Experiment 1, except that the asymptote is significantly above the control condition. Both experimental results support a border inhibition hypothesis.     

High-speed data processing and unobtrusive monitoring of eye movements

A system has been developed that monitors eye movements without imposing any unnatural constraints or mechanical attachments on the subject. The system also features high-speed on-line data processing.     

Time perception and the filled-duration illusion

A reproduction design is used to show that temporal intervals containing brief tones appear longer than empty intervals of the same duration, the effect being independent of duration. These and previous data are discussed within a theoretical framework which allows for the interrelation of data from different time perception tasks; and a reversible encoding model is stated which accounts for much of the data obtained with empty intervals. A “chunking” model, in which tones occurring in an interval serve to segment the interval during encoding, can account for the filled-duration illusion if certain conditions are met. Finally, mechanisms that are consistent with these conditions are stated.     

Detection of temporal gaps within and between perceptual tonal groups

Two experiments were conducted to explore the hypothesis that tones widely separated in frequency are processed in separate communication channels. Listeners attempted to detect brief temporal gaps between items in a simple tonal sequence of two high tones followed by two low tones. Temporal resolution within both the high and low groups was near perfect; between-group detection scores were significantly lower. Results are interpreted as evidence for a processing time delay when shifts of focal attention occur between perceptual structures organized within the frequency domain.