Measuring lexical diversity in children who stutter: application of vocd

There is growing but equivocal evidence that the language abilities of young children who stutter (CWS) may be depressed when compared to those of their fluent peers. In particular, the lexical skills of CWS have variously been reported to be weaker or stronger than comparison children in a number of recent studies. One source for such disagreement may be the measures used to compute lexical characteristics of these children's spoken conversations. In this study, we examined the concurrent validity of two measures of lexical diversity in spontaneous language samples, Type-Token Ratio (TTR) and the newly developed utility vocd (Malvern & Richards, 1997), using a standard test of expressive vocabulary as the comparison measure. Findings indicated that vocd values ("D") correlated well with standardized measures of expressive vocabulary, while TTR values did not. In addition, both the standardized measure and vocd revealed significantly poorer expressive lexical skills of CWS, whereas TTR analyses did not evidence this difference. Results are discussed in relation to the relative strength of vocd over TTR as a method for describing lexical characteristics of the spontaneous language samples of this population. EDUCATIONAL OBJECTIVES: The reader will learn about and be able to (1) identify several common measures of conversational vocabulary and the strengths and weaknesses of each, and (2) compare the performance of the young CWS in this study to their normally fluent peers in terms of vocabulary performance on both formal and conversational measures of vocabulary.     

Depressive Symptoms and Tobacco Use: Does Religious Orientation Play a Protective Role?

Many studies have established an association between depression and smoking. The main objective of this study was to determine whether religious orientation moderates the relationship between depressive symptoms and tobacco use. This study utilized a cross-sectional data collection strategy to examine the relationship among depressive symptoms, religious orientation, and tobacco use among undergraduate students (N = 349) at a midsize southeastern university. Participants completed a demographic questionnaire, the Center for Epidemiologic Studies Depression Scale, the Extrinsic/Intrinsic Religious Orientation Scale-Revised and the Drinking and Drug Habits Questionnaire. Analyses using hierarchical linear regression indicate a significant interaction effect (depressive symptoms × extrinsic religious orientation) on tobacco use. Additional moderation analyses reveal a significant interaction effect between depressive symptoms and the extrinsic-personal religious orientation on tobacco use. Results suggest that having an extrinsic religious orientation, and specifically, the extrinsic-personal subtype, can protect against the effects of depressive symptoms. In this regard, individuals who turn to religion for solace or comfort may be less likely to engage in tobacco use when experiencing depressive symptoms. Limitations, future directions, and implications are discussed.     

Tuning the engine of cognition: a focus on NMDA/D1 receptor interactions in prefrontal cortex

The prefrontal cortex of the primate frontal lobes provides the capacity for judgment which can constantly adapt behavior in order to optimize its outcome. Adjudicating between long-term memory programs and prepotent responses, this capacity reviews all incoming information and provides an interpretation dependent on the events that have just occurred, the events that are predicted to happen, and the alternative response strategies that are available in the given situation. It has been theorized that this function requires two essential integrated components, a central executive which guides selective attention based on mechanisms of associative memory, as well as the second component, working memory buffers, in which information is held online, abstracted, and translated on a mental sketchpad of work in progress. In this review, we critically outline the evidence that the integration of these processes and, in particular, the induction and maintenance of persistent activity in prefrontal cortex and related networks, is dependent upon the interaction of dopamine D1 and glutamate NMDA receptor signaling at critical nodes within local circuits and distributed networks. We argue that this interaction is not only essential for representational memory, but also core to mechanisms of neuroadaptation and learning. Understanding its functional significance promises to reveal major new insights into prefrontal dysfunction in schizophrenia and, hence, to target a new generation of drugs designed to ameliorate the debilitating working memory deficits in this disorder.     

The effects of reinforcer pairing and fading on preschoolers' snack selections

The effects of reinforcement pairing and fading on preschoolers' snack selections were evaluated in a multiple baseline design. Baseline preferences for snack options were assessed via repeated paired-item preference assessments. Edible, social, and activity-based reinforcers were then exclusively paired with a less preferred snack option. Once the snack paired with reinforcement was selected most frequently, the three types of reinforcement were systematically faded. Frequent selections of the previously less preferred snack option were produced with paired reinforcement, but were disrupted for all children as the paired reinforcement was reduced to low levels. These data showed that paired reinforcement was initially effective in increasing preference for the originally less preferred snack options, but more permanent changes in the value of the snack options were not achieved. Conditions for producing persistent changes in children's snack choices are discussed.     

Use of a high‐probability instructional sequence to increase compliance to feeding demands in the absence of escape extinction

We evaluated the effects of a high‐probability (high‐p) instructional sequence on the feeding‐related compliance (food acceptance) of a young boy diagnosed with a feeding disorder. The high‐p sequence consisted of three presentations of an empty spoon; the low‐probability (low‐p) instruction was the presentation of a spoon with food. Results showed that acceptance of food increased in the presence and not the absence of the high‐p sequence. Data are discussed in terms of the role of high‐p instructional sequences in the treatment of feeding problems. Copyright © 2007 John Wiley & Sons, Ltd.     

A FURTHER ANALYSIS OF THE VALUE OF CHOICE: CONTROLLING FOR ILLUSORY DISCRIMINATIVE STIMULI AND EVALUATING THE EFFECTS OF LESS PREFERRED ITEMS

We sought to address limitations of prior research that has isolated choice as an independent variable. Children's preferences for the opportunity to choose were evaluated in a concurrent‐chains arrangement in which identical consequences were available in choice and no‐choice conditions. Results demonstrated that preference for choice, in and of itself, was (a) evident in children, (b) not controlled by illusory discriminative stimuli such as the amount from which to choose, and (c) generally unaffected by less preferred and potentially unimportant consequences.     

AN EVALUATION OF THE RELATIVE EFFICACY OF AND CHILDREN'S PREFERENCES FOR TEACHING STRATEGIES THAT DIFFER IN AMOUNT OF TEACHER DIRECTEDNESS

The manner in which teachers mediate children's learning varies across early childhood classrooms. In this study, we used a multielement design to evaluate the efficacy of three commonly implemented strategies that varied in teacher directedness for teaching color‐ and object‐name relations. Strategy 1 consisted of brief exposure to the target relations followed by an exclusively child‐led play period in which correct responses were praised. Strategy 2 was similar except that teachers prompted the children to vocalize relations and corrected errors via model prompts. Strategy 3 incorporated the same procedures as Strategy 2 except that a brief period of teacher‐initiated trials was arranged; these trials involved the use of prompt delay between questions and prompts, and correct responses resulted in tokens and back‐up activity reinforcers. Children's preferences for the different teaching strategies were also directly assessed. Strategy 3 was most effective in promoting the acquisition and generalization of the color‐ and object‐name relations and was also most preferred by the majority of children, Strategy 1 was the least effective, and Strategy 2 was typically the least preferred. Implications for the design of early educational environments based on evidence‐based values are discussed.     

Use of treatment analysis following ambiguous functional analysis results

The present study used a treatment analysis following ambiguous functional analysis results to evaluate potential treatments to reduce the SIB of a 32‐year‐old male with profound mental retardation. In addition, effective treatments were determined for increasing compliance with increasingly more complex self‐care tasks. The results indicated that a positive reinforcement procedure with extinction was useful toward reducing SIB and increasing compliance during three increasingly more complex tasks. The usefulness of treatment analysis procedures following ambiguous functional analysis results are discussed. Copyright © 2009 John Wiley & Sons, Ltd.