The association between auditory memory span and speech rate in children from kindergarten to sixth grade.

This study reexamined the association between speech rate and memory span in children from kindergarten to sixth grade (N = 152) in order to potentially account for the inconsistencies within the published literature on this topic. Some of the inconsistencies in past research may reflect the different methods adopted in assessing speech rate. In particular, repeating word triples may itself involve memory demands, contaminating the correlation between speech rate and memory span in younger children. Analyses using composite speech rate and memory span measures showed that speech rate for word triples shared variance with memory span that was independent of speech rate for single words. Moreover, speech rate for word triples was largely redundant with age in explaining additional variation in memory span once the effects of speech rate for single words were controlled.     

The relationship of diabetes knowledge to regimen compliance and metabolic control during pregnancy

Abstract

The relationship of diabetes knowledge to regimen compliance and metabolic control was examined in a sample of pregnant women with preexisting insulin-dependent and noninsulin-dependent diabetes mellitus (N = 27) and women who developed gestational diabetes during pregnancy (N = 45). Subjects completed self-report measures of diabetes knowledge and compliance with their diabetic regimen and blood glucose levels were monitored. Knowledge was positively, although modestly, related to dietary compliance, compliance with insulin administration and insulin reaction management recommendations, as well as fasting blood glucose levels. Findings suggest that among pregnant women, efforts to increase knowledge of diabetes specific to pregnancy may result in some improvement in selected aspects of the diabetic regimen.     

Type A behaviour in pre-school children: Interrater reliability, stability over six months and subcomponents

Type A behaviour was measured in 250 boys and 245 girls (ages 3-7) using a Swedish version of Matthews' Youth Test for Health (MYTH). In addition, speech and voice characteristics (speed, loudness, response latency) were measured. Each child was independently rated by two play group leaders and measurements were repeated after a six month interval. Interrater reliability (first session) was 0.76 for both sexes and did not change with the age of the child. Boys obtained significantly (p less than 0.0001) higher scores than girls. Correlations over the six month period were 0.64 and 0.60 (p less than 0.001) for the two possible combinations of different raters and slightly higher (0.75 and 0.68, p less than 0.001) when the same rater was used. Two components of Type A behaviour were identified from a factor analysis of the data: impatience and competitiveness, and they accounted for 57% of the total variance. As for the total scale, boys obtained significantly higher scores than girls on both subscales. Scores on the competitiveness scale increased systematically with age. Speech and voice characteristics correlated significantly with Type A scores (total Type A behaviour: r = 0.50, using different raters, and 0.71, using the same raters, p less than 0.001) and, once again, boys obtained significantly (p less than 0.001) higher scores than girls. The results are in close agreement with the American findings from the original scale. It was concluded that the scale provides a reliable and valid instrument for measuring Type A or Type A-like behaviours in pre-school children.     

大连城区四单位职工糖代谢异常和合并其他代谢异常分析

采用体格检查和生化及超声检查方法对大连地区城市四个单位的6478名(21岁~60岁)职工进行血糖(空腹血糖)、血压、血脂、血尿酸、肝脏B超、体重指数、腰围测定检查,以了解大连地区糖代谢异常及代谢综合征发病率。显示大连地区城市四个单位职工糖尿病患病率为7.90%;空腹血糖减损患病率为11.26%;大连地区代谢综合征发病率14.33%,糖尿病中代谢综合征患病率为23.26%,空腹血糖减损率中代谢综合征患病率为15.92%,血糖正常中患病率仅为10.28%。糖代谢异常与血糖正常者相比,代谢综合征发生率有显著性差异,而糖尿病与糖耐量异常者相比,无显著性差异。     

The moderating role of emotional stability in the relationship between exposure to violence and anxiety and depression

This study investigated the associations among exposure to violence, emotional stability, and psychological symptoms. The moderating role of emotional stability in the relationship between exposure to violence and anxiety and depression was examined in a sample of 482 high school students in Hong Kong. Results showed that both witnessing violence and low levels of emotional stability were positively associated with symptoms of anxiety and depression. Low levels of emotional stability exacerbated the relation between witnessing violence and symptoms of anxiety and depression; the opposite pattern was found among adolescents with high levels of emotional stability. This study sheds light on the role of emotional stability in ameliorating the detrimental effects of witnessing violence on symptoms of anxiety and depression among adolescents. Findings of this study also have implications for the development of emotionally healthy personalities.     

Span and rate of apprehension in children and adults.

Children and adults quantified random patterns of dots, under unlimited exposure duration. For adults and children two distinct processes appear to operate. For adults the quantification of collections of from one to three dots is essentially errorless, and proceeds at the rate of 46 msec per item, while the quantification rate for from 4 to 10 dots is 307 msec per dot. For children the same operating ranges appear to hold, however children are much slower. The lower slope is 195 msec per dot, while the upper is 1049. Although the results for adults and children are similar except for the overall rates, the nature of the isomorphism between children and adults is unclear.     

Effects of variations in local reinforcement rate on local response rate in variable interval schedules

Rats trained to lever press for sucrose were exposed to variable-interval schedules in which (i) the probability of reinforcement in each unit of time was a constant, (ii) the probability was high in the first ten seconds after reinforcement and low thereafter, (iii) the probability was low for ten seconds and high thereafter, (iv) the probability increased with time since reinforcement, or (v) the probability was initially zero and then increased with time since reinforcement. All schedules generated similar overall reinforcement rates. A peak in local response rate occurred several seconds after reinforcement under those schedules where reinforcement rate at this time was moderate or high ([i], [ii], and [iv]). Later in the inter-reinforcement interval, local response rate was roughly constant under those schedules with a constant local reinforcement rate ([i], [ii], and [iii]), but increased steadily when local reinforcement rate increased with time since reinforcement ([iv] and [v]). Postreinforcement pauses occurred on all schedules, but were much longer when local reinforcement rate was very low in the ten seconds after reinforcement ([iii]). The interresponse time distribution was highly correlated with the distribution of reinforced interresponse times, and the distribution of postreinforcement pauses was highly correlated with the distribution of reinforced postreinforcement pauses on some schedules. However, there was no direct evidence that these correlations resulted from selective reinforcement of classes of interresponse times and pauses.     

The stability and clinical significance of distress: A rejoinder to pepper and coyne

Past research has established that some individuals with high Beck Depression Inventory (BDI) scores at one time point have scores that are lower at a second time point. Recently, we provided evidence indicating that the temporal instability of certain BDI scores may be due partly to the regression to the mean phenomenon. Pepper and Coyne (1996) question this statistical interpretation; they argue that distress among students is unstable for substantive reasons. In the current paper, we reaffirm our view that statistical and measurement factors may account, in part, for changes in BDI scores over time. Given this possibility, inferences about distress or depression as a latent construct in student samples are not warranted if these inferences are based on the administration of a single instrument such as the BDI; any conclusions about distress as a psychological construct must be qualified by acknowledging the possible roles of error and method variance. Clearly, empirical research is needed in order to obtain a better understanding of the nature of distress as a latent variable, especially in light of evidence which indicates that subthreshold levels of depression have a high degree of clinical significance.     

The effects of explicit timing and feedback on compositional response rate in elementary school children

The effects of several variables on compositional response rate were investigated in three classrooms. After establishing baseline composition rates in each of the three classrooms, an experimental phase was introduced that consisted of: explicit timing of the children's composition period with a stopwatch, immediate feedback on the number of words each child produced, public posting of the greatest number of words written by each child to date, and instructions to try to exceed their highest score. In the second-grade classroom, these conditions were introduced, removed, and re-introduced. In two fifth-grade classrooms, these conditions were introduced according to a multiple baseline, across classes. In all cases, introduction of the experimental conditions led to a doubling of rate of words written by students and an increase in subjective quality ratings of compositions made by independent judges.     

The stability of dimensions of behavior in ADHD and normal children over an 8-year followup

The present study reports on standardized behavioral ratings received by a large sample of hyperactive children meeting research diagnostic criteria (n=108) and a community control sample of normal children (n=61) who were followed prospectively over 8 years into adolescence. On some parentreport measures both groups declined in the severity of their behavior problems across time, while on other measures only the hyperactive group declined, but the hyperactives always remained more deviant than the controls at followup. The hyperactives and controls also differed on most teacher and selfreport ratings at followup. The greatest degree of agreement between raters at adolescence was between parent and youth ratings. These results are consistent with previous research demonstrating more deviant scores for hyperactive children than controls on various rating scales at adolescent followup. They also are consistent with research showing significant longitudinal continuity of both internalizing and externalizing behavioral pathology.This research was supported by NIMH gram 42181. We are grateful to Craig S. Edelbrock, Ph.D., for his assistance with the data entry program, and to Ann Edwards and Gerry Gillespie for their assistance in locating subjects.     

Concurrent-schedule performance: Effects of relative and overall reinforcer rate

Six pigeons were trained to respond on two keys, each of which provided reinforcers on an arithmetic variable-interval schedule. These concurrent schedules ran nonindependently with a 2-s changeover delay. Six sets of conditions were conducted. Within each set of conditions the ratio of reinforcers available on the two alternatives was varied, but the arranged overall reinforcer rate remained constant. Each set of conditions used a different overall reinforcer rate, ranging from 0.22 reinforcers per minute to 10 reinforcers per minute. The generalized matching law fit the data from each set of conditions, but sensitivity to reinforcer frequency (a) decreased as the overall reinforcer rate decreased for both time allocation and response allocation based analyses of the data. Overall response rates did not vary with changes in relative reinforcer rate, but decreased with decreases in overall reinforcer rate. Changeover rates varied as a function of both relative and overall reinforcer rates. However, as explanations based on changeover rate seem unable to deal with the changes in generalized matching sensitivity, discrimination accounts of choice may offer a more promising interpretation.     

The relationship between feeding rate and patch choice.

Rats in a laboratory foraging simulation searched for sequential opportunities to feed in two patches that differed in the rate at which food pellets were delivered (controlled by fixed-interval schedules) and in the size of the pellets. The profitability of feeding in each patch was calculated in terms of time (grams per minute) and in terms of effort (grams per bar press). These values were the result of the imposed fixed interval, the size of the pellets, and the rate at which the rats pressed the bar in each condition. The rats ate more food and larger meals, but not more frequent meals, at the patch offering the higher rate of food consumption, calculated as grams per minute. The relative intake at any patch was a function of the relative rate of intake during meals at that patch compared to the other patch. Rats respond to explicit manipulations of feeding time in the same manner as they respond to manipulations of feeding effort.     

Relationship between response rate and reinforcement frequency in variable-interval schedules: III. The effect of d-amphetamine.

Four rats were exposed to variable-interval schedules specifying a range of different reinforcement frequencies. The effects of two doses of d-amphetamine (1.6 and 3.2 mumol/kg) upon performance maintained under each schedule were examined. In the case of each rat, the response rates observed under control conditions (no injection or injection of the vehicle alone) were increasing, negatively accelerated functions of reinforcement frequency, the data conforming closely to Herrnstein's (1970) equation. In each rat, d-amphetamine (3.2 mumol/kg) significantly reduced the value of the constant Rmax, which expresses the theoretical maximum response rate. In each rat, the value of KH, which expresses the reinforcement frequency needed to obtain the half-maximal response rate, was also reduced, although this only achieved statistical significance in the case of one rat. When the proportional change in response rate in the presence of the drug was plotted against the response rate under control conditions on double logarithmic co-ordinates, linear functions of negative slope were obtained; in each rat the slope was steeper and the value of the control response rate at which d-amphetamine exerted no effect was lower in the case of the higher dose (3.2 mumol/kg) than in the case of the lower dose (1.6 mumol/kg).     

On the rate of gain of information in children

Previous studies of the development of information processing in children have frequently been methodologically suspect and inconclusive in outcome. A study was designed to overcome some of the difficulties encountered in earlier studies. Six boys and six girls at each year of age from 5 to 11 inclusive were tested for one week on a serial, numerals-keys choice reaction time task with 2, 4, and 8 alternatives. Results were consistent with Hick's (1952) law. Both reaction time (RT) and the rate of gain of information improved with age, but the intercept constant, a more labile index, did not. These findings suggest that development is largely restricted to the process of response selection within a 4-stage decomposition of RT. Girls consistently exhibited both faster RTs and higher rates of gain of information than boys. These sex differences are interpreted in relation to recent notions of cerebral maturation in males and females.     

The maximization of overall reinforcement rate on concurrent chains

We model behavioral allocation on concurrent chains in which the initial links are independent variable-interval schedules. We also quantify the relationship between behavior during the initial links and the probability of entering a terminal link. The behavior that maximizes overall reinforcement rate is then considered and compared with published experimental data. Although all the trends in the data are predicted by rate maximization, there are considerable deviations from the predictions of rate maximization when reward magnitudes are unequal. We argue from our results that optimal allocation on concurrent chains, and prey choice as used in the theory of optimal diets, are distinct concepts. We show that the maximization of overall rate can lead to apparent violations of stochastic transitivity.     

Differences in the search rate of children and adults in short-term memory

When people recognize a test item as belonging or not belonging to a previously presented set, recognition latency increases with the number of items in the set. Although some evidence suggests otherwise, it is currently held that the rate of this increase is the same for children and adults. In contrast, the present experiments indicated a much slower search rate for second graders (mean age = 7.33 years) than for seventh (mean age = 12.50 years) and twelfth graders (mean age = 17.25 years). Moreover, search rate for second graders was invariant under instructions which did or did not emphasize speed and with presentation of the memory set in either the auditory or visual modality. Experiment II showed that the slow search rate for children was not due to differences in encoding between children and adults.     

The role of offer rates in controlling sharing by young children

The effects of different reinforcement contingencies on the rates of offers to share and their corresponding rates of acceptance by two small groups of preschool children were investigated in two experiments. In the first experiment, food and praise were given after a 5-min play period to any subject who had made one or more offers to share during the play period. This procedure increased the rate of share-offers by all subjects. However, as share-offers increased, the percentage of offers accepted decreased. In the second experiment, reinforcement was made contingent on a subject reducing offers to share to only one or two per 5-min period. This led to a higher percentage of the offers being accepted. The results suggest that by controlling the rate of a social behavior, the manner in which other persons in the environment respond to the behavior may also be influenced.     

The effects of reinforcement rate on the spontaneous social initiations of socially withdrawn preschoolers.

Social skills priming was used to increase the spontaneous social initiations of 2 socially withdrawn preschoolers, 1 of whom had been diagnosed with autism. During priming sessions, the teacher prompted and reinforced social behaviors (e.g., smiling, verbal initiations). We varied the rate of reinforcement during priming sessions and measured the effects of this manipulation on the rate of spontaneous social initiations during the subsequent classroom activity. Spontaneous initiations were more frequent after high rates of reinforcement than after low rates of reinforcement.     

The effects of metronomic pendular adjustment versus tap-tempo input on the stability and accuracy of tempo perception

This study explores tempo stability and accuracy while comparing two subject-response modes: the traditional metronomic pendular adjustment task versus tap-tempo input. Experiment 1 questioned if a single correct tempo measurement consistently emerges from repeated listenings, and if subject-response mode affects tempo stability and accuracy. Experiment 2 assessed incremental improvement between two repeated sessions, and questioned the incidence of self-pacing or congruent effects of potential delays on tempo responses. While single-session studies have shown that listeners find some tempos more enjoyable, can notice discrete differences in pace, and can remember rhythmic speed over prolonged periods of time, the current study employs a multiple-session format focusing on two diametrically opposed subject-response modes. The findings show that tempo responses by listeners without formal music training were consistent across listening sessions, and that responses from tap-tempo input were significantly more stable and accurate than responses from metronomic pendular adjustment tasks.