Coding strategies,perceptual grouping,and the “variability effect” in free recall

Three experiments examined the effects of constant vs. varied input of letter strings on recall, and then examined the effects of such training in the learning of new lists of letter strings. Letter strings were constructed from pairs of trigrams spatially grouped, and were presented either consistently or with different spatial groupings on successive presentations. In Experiments I and II, varied input produced substantially greater recall than constant input. When transferred to a new list of letter strings, containing either the same general structure or a new scrambled structure, recall of the second list was determined primarily by conditions of first-list input, and unaffected by second-list structure. Although the "variability effect" did not appear in the training phase of Experiment III, Varied input led subjects to regroup or integrate the letter sequences more frequently and produced similar transfer effects as in Experiments I and II.     

On-line brain stimulation: Measurement of threshold of reinforcement

This program and interface for a small computer (PDP8/e) performs the following operations: generates and delivers constant current stimulation to the brain of an animal, monitors electrical resistance at the stimulating electrode, and calculates the threshold of reinforcement based upon the frequency of characteristic pauses in the animal’s responding.     

Stability of daily preference across multiple individuals

Preference stability provides clues about the extent to which a clinician might be able to deliver a particular stimulus contingent on behavior as a reinforcer. Previous research has been somewhat mixed in terms of evidence for preference stability. Results of the current study are consistent with studies that have reported correlations between preference assessments, suggesting that preferences are relatively stable across time.     

The Role of Non-Numerical Stimulus Features in Approximate Number System Training in Preschoolers from Low-Income Homes

Recent findings have suggested that adults’ and children’s approximate number system (ANS) acuity may be malleable through training, but research on ANS acuity has largely been conducted with adults and children who are from middle- to high-income homes. We conducted 2 experiments to test the malleability of ANS acuity in preschool-aged children from low-income homes and to test how non-numerical stimulus features affected performance. In Experiment 1, mixed-effects models indicated that children significantly improved their ratio achieved across training. Children’s change in probability of responding correctly across sessions was qualified by an interaction with surface area features of the arrays such that children improved their probability of answering correctly across sessions on trials in which numerosity conflicted with the total surface area of object sets significantly more than on trials in which total surface area positively correlated with numerosity. In Experiment 2, we found that children who completed ANS acuity training performed better on an ANS acuity task compared with children in a control group, but they only did so on ANS acuity trials in which numerosity conflicted with the total surface area of object sets. These findings suggest that training affects ANS acuity in children from low-income homes by fostering an ability to focus on numerosity in the face of conflicting non-numerical stimulus features.     

The Munroe-Meyer Approach: Continuous Integration of Didactic Instruction,Research, and Clinical Practice

Increased demand for applied behavior analysis (ABA) services has increased the need for additional masters-level practitioners and doctoral-level academicians and clinical directors. Based on these needs, the University of Nebraska Medical Center’s (UNMC) Munroe-Meyer Institute has developed a PhD program. The academic structure at UNMC allowed us to create our PhD program in a relatively quick and efficient manner. Our PhD program has many unique features, including (a) close integration of didactic instruction with clinical and research training provided by leading experts in ABA in which students immediately apply concepts introduced in the classroom during coordinated clinical and research practica; (b) structured grant writing training in which students learn to write and submit an NIH-level grant; (c) financial support in the form of a stipend of $23,400 per year, free health benefits, and a full-tuition waiver for up to 12 credits per semester for UNMC courses (a benefits package worth approximately $50,000 per year for an out-of-state student); and (d) encouragement and financial support to present papers at local, regional, and national behavior analysis conferences.     

Spatial part-set cuing facilitation

Cole, Reysen, and Kelley [2013. Part-set cuing facilitation for spatial information. Journal of Experimental Psychology: Learning, Memory, &; Cognition, 39, 1615–1620] reported robust part-set cuing facilitation for spatial information using snap circuits (a colour-coded electronics kit designed for children to create rudimentary circuit boards). In contrast, Drinkwater, Dagnall, and Parker [2006. Effects of part-set cuing on experienced and novice chess players’ reconstruction of a typical chess midgame position. Perceptual and Motor Skills, 102(3), 645–653] and Watkins, Schwartz, and Lane [1984. Does part-set cuing test for memory organization? Evidence from reconstructions of chess positions. Canadian Journal of Psychology/Revue Canadienne de Psychologie, 38(3), 498–503] showed no influence of part-set cuing for spatial information when using chess boards. One key difference between the two procedures was that the snap circuit stimuli were explicitly connected to one another, whereas chess pieces were not. Two experiments examined the effects of connection type (connected vs. unconnected) and cue type (cued vs. uncued) on memory for spatial information. Using chess boards (Experiment 1) and snap circuits (Experiment 2), part-set cuing facilitation only occurred when the stimuli were explicitly connected; there was no influence of cuing with unconnected stimuli. These results are potentially consistent with the retrieval strategy disruption hypothesis, as well as the two- and three-mechanism accounts of part-set cuing.     

The Behavioral Dyscontrol Scale and Functional Status Among Elderly Medical and Surgical Rehabilitation Patients

This research was conducted in a sample of 150 older adults (mean age = 78.0) who were inpatients receiving rehabilitation services for a variety of medical and postsurgical conditions. The purpose of the study was to test the hypothesis that the Behavioral Dyscontrol Scale (BDS), a measure of the ability to use intentions to guide purposeful activity, would be strongly associated with concurrent functional status after controlling for age, sex, education, severity of pain, medical comorbidity, depression (Geriatric Depression Scale), and general mental status (Mini Mental State Exam [MMSE]). Functional status was assessed by rehabilitaion nurses' ratings of patients on 11 individual Activities of Daily Living (ADL) items and the Barthel Index. The hypothesis, tested by means of multiple regression analysis, was supported by the results. The BDS was the independent variable most strongly associated with all 11 ADL items and the Barthel Index. The MMSE contributed significantly to none of the models. Other covariates made minimal contributions to the variance shared with functional ability. Consistent with prior results in other samples, the ability to use intentions to guide purposeful behavior appears to be an important contributor to everyday functioning among older adults.     

Development of a Screening Instrument for Exposure to Violence in Children: The KID-SAVE

The present study provided psychometric data on the KID-SAVE, an empirically based measure of children's exposure to community violence. The KID-SAVE was administered to 470 inner-city children in the third through seventh grades and demonstrated excellent reliability. Factor analysis yielded three subscales: Traumatic Violence, Indirect Violence, and Physical/Verbal Abuse. Initial investigation of construct validity suggested that the KID-SAVE successfully discriminated between groups of children reporting high and low levels of traumatic symptoms. The KID-SAVE appears to be a promising assessment tool and allows for quantification of the severity of violence exposure.