The development of attention to simple and complex visual stimuli in infants: Behavioral and psychophysiological measures

The study of visual attention in infants has used presentation of single simple stimuli, multi-dimensional stimuli, and complex dynamic video presentations. There are both continuities and discontinuities in the findings on attention and attentiveness to stimulus complexity. A continuity is a pattern of looking that is found in the early part of infancy that remains throughout adulthood. A discontinuity is an emerging sensitivity to the content of the information in the stimulus presentations and alterations in patterns of attention based upon stimulus comprehensibility. The current paper reviews some of these findings with particular application to complex video presentations.     

The surprisingly low motivational power of future rewards: Comparing conventional money-based measures of discounting with motivation-based measures

Temporal discount rates are often poor predictors of behaviors that we expect will be motivated by the future. The current research suggests this may be because conventional discounting measures are poor measures of the motivational value of future rewards. In six studies, I develop motivation-based measures of the present value (PV) of future rewards and compare the PVs obtained with those obtained using conventional money-based discounting measures. Conventional money-based PVs consistently overestimate motivation-based PVs and are discriminable from them. I explore explanations for this mismatch, including timing of effort exertion (Study 2) and loss aversion (Study 3), both features of the motivation-based measures. In Study 5, I use self-reports of valuation strategies and a time pressure manipulation to demonstrate that participants use different valuation strategies in the conventional money-based and the motivation-based measures that, in part, determine the difference in PVs obtained and the relatively low correspondence between them.     

Identities and Their Uses: Response to ��Rate, Probability And Matching�� by Rachlin And Locey

Some of the differences between Rachlin & Locey (2010) and Thorne (2010) are due to what assumptions are taken as givens versus questionable. Most of the other apparent differences are largely linguistic and can be resolved by agreeing on terminology. The identity combining both rate and probability of reinforcement is general, has already revealed order not previously noted, even in its currently simple form, and provides a way of incorporating additional variables known to influence and characterize behavior.     

The effects of a local negative feedback function between choice and relative reinforcer rate

Four pigeons were trained on two-key concurrent variable-interval schedules with no changeover delay. In Phase 1, relative reinforcers on the two alternatives were varied over five conditions from .1 to .9. In Phases 2 and 3, we instituted a molar feedback function between relative choice in an interreinforcer interval and the probability of reinforcers on the two keys ending the next interreinforcer interval. The feedback function was linear, and was negatively sloped so that more extreme choice in an interreinforcer interval made it more likely that a reinforcer would be available on the other key at the end of the next interval. The slope of the feedback function was -1 in Phase 2 and -3 in Phase 3. We varied relative reinforcers in each of these phases by changing the intercept of the feedback function. Little effect of the feedback functions was discernible at the local (interreinforcer interval) level, but choice measured at an extended level across sessions was strongly and significantly decreased by increasing the negative slope of the feedback function.     

A review of research and theory on the relation between oral reading rate and reading comprehension

We review the conceptual and empirical literature on the relation between oral reading rate and reading comprehension. Three lines of conceptual analysis converge on this relation: (a) application of basic behavior analytic principles suggests that fluent decoding should produce better reading comprehension through direct and indirect relations, (b) behavior analytic understanding of the importance of the rate of behavior as developed by Skinner, Lindsley and Haughton implies that higher reading rate contributes to improved comprehension, and (c) cognitive theory of automaticity explicitly states that high rate reading sets the stage for effective comprehension. A wealth of correlational evidence indicates that reading rate and reading comprehension covary. These results have been replicated across elementary grades and across a variety of measures of reading comprehension. However, experimental analyses have not convincingly demonstrated a functional relation between the two. Experimental work has yielded results that are mixed at best. Examination of experimental design issues shows that although this is not a simple relation to investigate, behavior analysts can make major contributions to understanding the possible functional relation between reading rate and reading comprehension.     

How to teach a pigeon to maximize overall reinforcement rate

In two experiments deviations from matching earned higher overall reinforcement rates than did matching. In Experiment 1 response proportions were calculated over a 360-response moving average, updated with each response. Response proportions that differed from the nominal reinforcement proportions, by a criterion that was gradually increased, were eligible for reinforcement. Response proportions that did not differ from matching were not eligible for reinforcement. When the deviation requirement was relatively small, the contingency proved to be effective. However, there was a limit as to how far response proportions could be pushed from matching. Consequently, when the deviation requirement was large, overall reinforcement rate decreased and pecking was eventually extinguished. In Experiment 2 a discriminative stimulus was added to the procedure. The houselight was correlated with the relationship between response proportions and the nominal (programmed) reinforcement proportions. When the difference between response and reinforcement proportions met the deviation requirement, the light was white and responses were eligible for reinforcement. When the difference between response and reinforcement proportions failed to exceed the deviation requirement, the light was blue and responses were not eligible for reinforcement. With the addition of the light, it proved to be possible to shape deviations from matching without any apparent limit. Thus, in Experiment 2 overall reinforcement rate predicted choice proportions and relative reinforcement rate did not. In contrast, in previous experiments on the relationship between matching and overall reinforcement maximization, relative reinforcement rate was usually the better predictor of responding. The results show that whether overall or relative reinforcement rate better predicts choice proportions may in part be determined by stimulus conditions.     

Reinforcer frequency and restricted stimulus control.

Stimulus control was evaluated in 3 individuals with moderate to severe mental retardation by delayed identity matching-to-sample procedures that presented either one or two discrete forms as sample stimuli on each trial. On pretests, accuracy scores on one-sample trials were uniformly high. On two-sample trials, the correct stimulus (i.e., the one that subsequently appeared in the comparison array) varied unpredictably, and accuracy scores were substantially lower, suggesting that both sample stimuli did not exert stimulus control on every trial. Subjects were then given training sessions with the one-sample task and with a new set of four stimuli. For two of the stimuli, correct matching responses were followed by reinforcers on a variable-ratio schedule that led to a high reinforcer rate. For the other two stimuli, correct responses were followed by reinforcers on a variable-ratio schedule that led to a substantially lower reinforcer rate. Results on two-sample tests that followed showed that (a) on trials in which comparison arrays consisted of one high reinforcer-rate and one low reinforcer-rate stimulus, subjects most often selected the high-rate stimulus; and (b) on trials in which the comparison arrays were either two high reinforcer-rate stimuli or two low reinforcer-rate stimuli and the samples were one high reinforcer- and one low reinforcer-rate stimulus, accuracy was higher on trials with the high-rate comparisons. These results indicate that the frequency of stimulus control by high reinforcer-rate samples was greater than that by low reinforcer-rate samples. Following more training with the one-sample task and reversed reinforcement schedules for all stimuli, the differences in stimulus control frequencies on two-sample tests also reversed. These results demonstrate experimental control by reinforcement contingencies of which of two sample stimuli controlled selections in the two-sample task. The procedures and results may prove to be relevant for understanding restricted stimulus control and stimulus overselectivity.     

Baseline response rates affect resistance to change

The effect of response rates on resistance to change, measured as resistance to extinction, was examined in two experiments. In Experiment 1, responding in transition from a variable‐ratio schedule and its yoked‐interval counterpart to extinction was compared with pigeons. Following training on a multiple variable‐ratio yoked‐interval schedule of reinforcement, in which response rates were higher in the former component, reinforcement was removed from both components during a single extended extinction session. Resistance to extinction in the yoked‐interval component was always either greater or equal to that in the variable‐ratio component. In Experiment 2, resistance to extinction was compared for two groups of rats that exhibited either high or low response rates when maintained on identical variable‐interval schedules. Resistance to extinction was greater for the lower‐response‐rate group. These results suggest that baseline response rate can contribute to resistance to change. Such effects, however, can only be revealed when baseline response rate and reinforcement rate are disentangled (Experiments 1 and 2) from the more usual circumstance where the two covary. Furthermore, they are more cleanly revealed when the programmed contingencies controlling high and low response rates are identical, as in Experiment 2.