Psychophysics of key-peck duration in the pigeon

The duration of the pigeon's key peck was differentially reinforced in either a trials or a free-operant procedure. Mean emitted peck duration was a power function of the duration required for food delivery to occur. The exponents of the power function differed considerably from those observed in earlier research involving longer duration responses in pigeons and other species. The coefficients of variation also did not correspond with those of the earlier research on other responses, nor did consideration of the durations actually reinforced resolve the differences. Duration was neither a function of response rate nor of intermittency of reinforcement. Key-peck duration was changed in an orderly way by differential reinforcement. However, it appeared to be more strongly determined by its duration in the absence of differential reinforcement than were longer duration responses.     

Discriminative functions of schedule stimuli and memory: a combination of schedule and choice procedures

Pigeons responded under a combination brief-stimulus schedule and choice procedure. Normally, a fixed-interval schedule was in effect, where completion randomly produced either a brief stimulus or food. Intermittently, this schedule was interrupted by a choice arrangement. Two choice keys were lit, either a short or a long time since a prior event (food or stimulus). One choice response produced food if the time had been short, and the alternate response produced food if the time had been long. Across conditions, the duration of the fixed-interval schedule was varied, the stimuli that comprised the brief-stimulus operation were changed, and the stimuli were presented as paired and nonpaired with food. The focus of the study was the control of both schedule performance and choice responding across conditions. The results showed that choice accuracy was correlated with the degree of fixed-interval curvature, the response pattern of a pause followed by a gradually accelerated rate. As fixed-interval schedule duration was increased, both the degree of fixed-interval curvature and choice accuracy decreased. The particular brief stimulus used affected schedule and choice performance, with a more salient stimulus producing a greater degree of curvature and higher accuracy. Pairing and nonpairing operations produced striking differences in performance with the less salient brief stimulus, but not with the more salient stimulus. The results suggest that brief-stimulus schedule performance may be conceptualized in the context of memory research.     

《易经》的宇宙观与阴阳五行家思想之渊源

若从思想自身的发展来看,阴阳五行家与《易经》有着重要的渊源关系。《易经》的阴阳变化观念和带有浓厚的原始思维特性的宇宙观,是阴阳五行家思想的理论基石,阴阳五行家的宇宙发生图式和序列便滥觞于此。《易经》的以“因果联想”为重要特征的认知方式对阴阳五行家认识和把握世界的基本方式产生了重要的影响。《易经》的时空观念也与阴阳五行家以阴阳五行配四时、四方,以阴阳五行说明宇宙之大化、社会之变迁、人事之行止的思想紧密联系在一起。     

EFFECTS OF MORPHINE ON TEMPORAL DISCRIMINATION AND COLOR MATCHING: GENERAL DISRUPTION OF STIMULUS CONTROL OR SELECTIVE EFFECTS ON TIMING?

Discrepant effects of drugs on behavior maintained by temporal-discrimination procedures make conclusive statements about the neuropharmacological bases of timing difficult. The current experiment examined the possible contribution of a general, drug-induced disruption of stimulus control. Four pigeons responded on a three-component multiple schedule that included a fixed-interval 2-min, temporal discrimination, and color-matching component. Under control conditions, response rates and choice responses during the first two components showed evidence of control by time, and accuracy for color matching was high in the third component. Morphine administration flattened the distribution of fixed-interval responding and produced a general disruption of accuracy in the temporal-discrimination component, whereas accuracy in the color-matching component was relatively unaffected. Analysis of the psychophysical functions from the temporal-discrimination component indicated that morphine decreased accuracy of temporal discrimination by decreasing overall stimulus control, rather than by selectively affecting timing. These results suggest the importance of determining the neurophysiological bases of stimulus control as it relates to temporal discrimination.     

Critical appraisal of the discussion on delay discounting by Bailey et al. and Stein et al.: A scientific proposal for a reinforcer pathology theory 3.0

Delay discounting is one of the most studied phenomena in Psychology in the last decades. Recently, it has been proposed as a transdiagnostic variable accounting for several psychopathological problems. A review of current practices and clinical application (Bailey et al., 2021) and a response article (Stein et al., 2022) have been recently published. Despite both of them being stimulating, the articles raise issues needing further discussion. The first part of the present article critically appraises both publications by highlighting their strengths/limitations and offers an alternate perspective that clarifies some theoretical issues and allows new lines in research. In the second part, one of these new lines of research is presented by describing a research proposal based on the analysed critiques and current developments in both psychopathology and addiction research. This article contributes to the discussion on delay discounting suggesting alternative interpretations and future studies to improve theoretical models.     

Mental rotation and temporal contingencies.

A task that requires subjects to determine whether two forms of the same shape, but in different orientations, are mirror images or identical except for orientation is called a handedness recognition task. Subjects' reaction times (RT) on this task are consistently related to the angular disparity (termed alpha) between the two presented forms. This pattern of data has been interpreted to indicate that subjects solve the task by imagining that one of the forms rotates into the orientation of the other (termed mental rotation). The speed with which one imagines one of the forms rotating has been widely considered a fixed capability of the individual, and thus immune to the effect of contingencies. We present an experiment that assesses the effects of temporal contingencies in a handedness recognition task on the slope of the function RT = f(alpha). The data indicate that the slope of this function can come under the control of temporal contingencies.     

Serial conditioning as a function of stimulus, response, and temporal dependencies

Six experiments were used to examine the effects of explicit response, stimulus, and temporal dependencies on responding in an interfood interval. The first two experiments demonstrated that 10-segment 60-s interfood clocks controlled similar distributions of key pecking in pigeons regardless of whether response–reinforcement contiguity was required, allowed, or precluded. The third and fourth experiments found that in the absence of an explicit response–reinforcement dependency, systematic explicit stimuli in an interfood interval were sufficient to establish and maintain the characteristic distribution of key pecking and that an interval without an explicit clock failed to establish or maintain key pecking. The last two experiments demonstrated that the interfood interval need not be of fixed length, and that a simple correlation of stimuli with increments from either a minimum to a maximum imminency or probability of food presentation controlled behavior in a similar manner. Successively higher rates generally occurred to successively later stimuli in the upper half of the range.     

Pigeons' wait-time responses to transitions in interfood-interval duration: Another look at cyclic schedule performance

Recent developments reveal that animals can rapidly learn about intervals of time. We studied the nature of this fast-acting process in two experiments. In Experiment 1 pigeons were exposed to a modified fixed-time schedule, in which the time between food rewards (interfood interval) changed at an unpredictable point in each session, either decreasing from 15 to 5 s (step-down) or increasing from 15 to 45 s (step-up). The birds were able to track under both conditions by producing postreinforcement wait times proportional to the preceding interfood-interval duration. However, the time course of responding differed: Tracking was apparently more gradual in the step-up condition. Experiment 2 studied the effect of having both kinds of transitions within the same session by exposing pigeons to a repeating (cyclic) sequence of the interfood-interval values used in Experiment 1. Pigeons detected changes in the input sequence of interfood intervals, but only for a few sessions—discrimination worsened with further training. The dynamic effects we observed do not support a linear waiting process of time discrimination, but instead point to a timing mechanism based on the frequency and recency of prior interfood intervals and not the preceding interfood interval alone.