Relative preference for distinct reinforcers maintaining destructive behavior

The literature offers few recommendations for sequencing exposure to treatment conditions with individuals with multiply maintained destructive behavior. Identifying relative preference for the functional reinforcers maintaining destructive behavior may be one means of guiding that decision. The present study presents a preliminary attempt at developing a robust relative preference and reinforcer assessment for individuals with multiply maintained destructive behavior. Guided and free-choice trials were implemented in which participants chose between two multiple-schedule arrangements, each of which programmed signaled periods of isolated reinforcer availability and unavailability. Consistent participant choice and responding during free-choice trials was then used to thin the corresponding schedule of reinforcement. The results demonstrated a strong preference for one of the two functional reinforcers for all four participants, yet preferences differed across participants and were not well predicted by responding in prior analyses.     

Influence of multiple-day temporal distribution of repetitions on memory: A comparison of uniform,expanding, and contracting schedules

Very few studies have examined the influence of schedules of repetitions across multiple days (e.g., Tsai, 1927 Tsai, L.-S. 1927. The relation of retention to the distribution of relearning. Journal of Experimental Psychology, 10: 30–39. [Crossref] , [Google Scholar]). Three temporal schedules of four presentations of pseudoword/word pairs over a 7-day learning period were compared: a uniform (presentations on Days 1, 3, 5, and 7), an expanding (1, 2, 3, 7), and a contracting (1, 5, 6, 7) schedule. Schedule was a within-subjects variable. Experiment 1 was performed on the Internet and showed that cued recall on Day 9 led to higher scores for the stimuli of the expanding schedule. Experiment 2 was performed in the laboratory and showed that the expanding and the uniform schedules led to the highest scores on Day 9. A recognition task performed during the learning phase revealed that stimuli recognized at the time of their repetition were more likely to be retrieved later than the others. Our results are discussed within the framework of the study-phase retrieval and encoding variability theories.     

The Schematic Representation of Effector Function Underlying Perceptual-Motor Skill

Conceptual and methodological problems related to Schmidt’s (1975) motor schema theory are discussed. In particular, the motor schema is interpreted as representing the dynamics of the system being controlled, which may or may not be associated with a referent movement pattern. Furthermore, it is suggested that prior familiarity with a control system’s dynamics is a critical but uncontrolled factor in tests of the theory, and largely accounts for their equivocal findings. These ideas are examined by two experiments in which subjects had to bimanually control the movement of a computer-displayed cursor along a track on a CRT screen. Different track orientations required different patterns of movement not entailing a single generalized motor program. Experiment 1 shows that variable track performance with a given control system, results in better transfer to novel tracks than does fixed practice. Experiment 2 demonstrates that altering the control system disrupts performance whether or not the required movements remain the same. These results indicate the need for a fundamental modification of schema theory, such that a schematic representation of effector-environment relations (effector function) is available independently of particular movement patterns used in its acquisition.     

Auditory Model Enhances Relative-Timing Learning

In recent experiments (Q. Lai, C. H. Shea, & M. Little, 2000; C. H. Shea, G. Wulf, J. Park, & B. Gaunt, 2001), auditory models were found to be effective in enhancing relative-timing performance and learning in constant practice conditions. In the present experiment, the authors examined (a) whether an auditory model also enhances relative-timing learning in blocked and random practice conditions and (b) whether experience with the auditory model enhances participants' ability to produce the response by using different effector sequences. Participants (N = 48) were randomly assigned to 1 of 4 acquisition conditions in which an auditory model was or was not present and the practice schedule was blocked or random. In the acquisition phase, all participants alternately pressed 2 keys on a keyboard in an attempt to match 5 goal intervals. In the auditory model conditions, a sequence of tones was played before each acquisition trial. The tones represented the correct timing sequence for that trial. One retention and 3 effector-transfer tests without feedback were administered about 24 hr after the completion of acquisition. The results indicated that the auditory model enhanced relative-timing performance and learning independently of practice schedule. In addition, the auditory model enhanced relative timing on the effector-transfer tests, but absolute-timing performance and learning were not affected by the auditory model. Thus, relative timing was found to be effector independent but absolute timing was not.     

A comparison of dense-to-lean and fixed lean schedules of alternative reinforcement and extinction

Behavior-reduction interventions typically employ dense schedules of alternative reinforcement in conjunction with operant extinction for problem behavior. After problem behavior is reduced in the initial treatment stages, schedule thinning is routinely conducted to make the intervention more practical in natural environments. In the current investigation, two methods for thinning alternative reinforcement schedules were compared for 3 clients who exhibited severe problem behavior. In the dense-to-lean (DTL) condition, reinforcement was delivered on relatively dense schedules (using noncontingent reinforcement for 1 participant and functional communication training for 2 participants), followed by systematic schedule thinning to progressively leaner schedules. During the fixed lean (FL) condition, reinforcement was delivered on lean schedules (equivalent to the terminal schedule of the DTL condition). The FL condition produced a quicker attainment of individual treatment goals for 2 of the 3 participants. The results are discussed in terms of the potential utility of using relatively lean schedules at treatment outset.