On the relationship between stimulus intensity and duration of visible persistence

Stimulus intensity and duration of visible persistence have been found to vary directly in some studies but inversely in others. Hawkins and Shulman (1979) have proposed that this inconsistency can be resolved by separating the studies that employed a decrement-threshold measure of persistence (Type I measure) from those that measured the total duration of persistence (Type II measure). They suggested that Type I measures yield an inverse relationship, whereas Type II measures yield a direct relationship between intensity and persistence. Hawkins and Shulman's model is incomplete in ways that are easily remedied. However, the model is totally contradicted by the experimental evidence. A new resolution of the inconsistent results is proposed in terms of retinal afterimages.     

Reading-disabled hyperactive children: A distinct subgroup of Attention Deficit Disorder with Hyperactivity?

Mixed hyperactive/reading-disabled children, selected from a large sample of hyperactive children, were compared to pure hyperactive children on demographic, behavioral, and neuropsychological measures. Children in the Mixed group were reading-disabled relative to age and IQ; those in the Pure group had achievement scores that were average relative to age and IQ. The Mixed group was significantly older than the Pure group; there were no differences in gender, race, or socioeconomic status. Behaviorally, the groups did not differ significantly on teacher ratings or on psychiatric ratings of aggression. The Mixed group had a significantly higher Performance IQ, whereas the Pure group had a significantly higher Verbal IQ and performed better on measures of cognitive impulsivity. Several other measures failed to distinguish the groups. The data give minimal support to the notion that pure hyperactive and mixed hyperative/reading-disabled children constitute distinct subgroups of Attention Deficit Disorder with Hyperactivity.This research was supported in part by Mental Health Clinical Research Grant MH-30906 and by U. S. Public Health Service Grant MH-18579.     

学前和初小儿童智能筛查——图片词汇测试法

美国L.M.Dunn 1965年修改发表的皮勃迪图片词汇测试(PeabodyPicture Vocabulary Test简称PPVT)目前仍是美国智力不足协会(AAMD)所介绍的常用智能测试方法之一。本文参考PPVT制订出适合我国城市学前期与小学初期儿童的图片词汇测试;在上海市区进行标准化;制订了智龄量表、智商和百分位数量表。本测试再测信度r=0.945,二测试者间信度r=0.913。奇偶信度r=0.945,测试标准误σ=4.5。本方法与“学前儿童能力筛查五十项”,“画人试验”,“WPPSI”总智商、语言智商、操作智商,语文成绩,算术成绩的效度相关分别为:r=0.478,r=0.466,r=0.590,r=0.531,r=0.427,r=0.652,r=0.609。本测试制订以来已经数千人次应用,证明是一种简便易行,省时经济,准确性较好,且能进行集体测试的学前及小学初期儿童一般智能(generalintelligence)的筛查方法(Screening test)。     

On the relation between metacontrast masking and suppression of visible persistence

Does the introduction of additional contours in a display sequence (an operation known to reduce the strength of suppression in metacontrast) also reduce suppression of visible persistence? In three experiments, duration of visible persistence was estimated by a method in which successful performance depends on the temporal integration of a pattern whose elements are displayed in two successive frames. In this procedure, the arrival of the trailing frame is known to exert a suppressive influence on the visible persistence of the leading frame. Embedding the elements of the leading frame within additional contours (a line grid) reduced the degree of suppression exerted by the trailing frame. This did not occur when the grid was part of the trailing display. We conclude that suppression of visible persistence and metacontrast masking belong to the same class of events.     

2-Deoxy-d-Galactose Effects on Passive Avoidance Memorization in the Rat

2-Deoxy-d-galactose (do-gal) hinders glycoprotein fucosylation. This compound was intracerebroventricularly administered to male adult Wistar rats in order to assess whether it could exert amnesic effects on a passive avoidance response (PAR) to be learned in the light–dark box apparatus. Three experiments were performed. In the first, do-gal was administered immediately after the acquisition trials at three dosages (2, 4, and 8 μmol). It was found that only the 4-μmol dosage was followed by PAR disruption. In the second, do-gal was administered at the adequate dosage (4 μmol) either 30 min before the acquisition trial or 30 min before retrieval testing. It was found that only the preretrieval administration was followed by PAR impairment. In the third, do-gal (4 μmol) was administered in postacquisition, at increasing postacquisition delays (0.25, 1.5, 4, and 6 h). It was found that there was PAR disruption only after do-gal administration at the shortest (0.25 h) delay. The results confirm that in the rat, glycoprotein fucosylation is involved in some of the phases of memory trace processing, and they are discussed in relation to other findings in the rat and the chick.     

Do substance abuse and mental health clients prefer automated assessments?

In both psychiatric and substance-abuse services, clinicians have been concerned with the introduction of automated assessments and with their clients’ reactions toward those assessments. The positive reactions of psychiatric clients have been well documented, but little has been known about substance-abusing clients’ impressions of automated assessments. The impact of automated assessment on clients seeking substance-abuse services was evaluated and compared with a previously analyzed sample of clients seeking mental health services. On the whole, both groups responded similarly and positively to automated assessments. Factor analyses revealed three underlying dimensions in client attitudes toward automated assessment,Completeness and satisfaction,Ease of use and enjoyment, andNegative attitudes. In addition, statistically, though not clinically, significant differences in attitudes were found between various demographic groups. Overall, the results support the use of automated assessments with individuals seeking either substance-abuse or mental-health services.     

A behavioral assessment scale for attention deficit disorder in brazilian children based on DSM-IIIR criteria

A teacher scale based on DSM-III-R diagnostic criteria for attention deficit hyperactivity disorder (ADHD) was developed for the behavioral assessment of children in Brazil. A total of 2, 082 children (782 males and 1,300 females) with a mean age of 11.2 years who were attending a public school in the greater Rio de Janeiro area were the subjects of this study. Two factors (Hyperactivity-Impulsivity and Inattention) were extracted from a principal-factor analysis conducted on the data, and the factor structure of the scale was found to be stable. Ratings of boys were higher than ratings of girls, and younger children had higher ratings than older children for both factors. Test-retest reliability for each item of the scale ranged from .56 to .70. The data are discussed in view of current controversies in the factor structure of teacher ratings of DSM-III-R ADHD symptoms.This research was supported by FINEP (42.88.0138.00) and FUNPENE. GNOB is the recipient of a CNPq Research Career Development Award (30.0197/82). RCAP was supported by a CNPq fellowship (82.2151/87). The authors are grateful to Rosely V. Magalhaes and Angela S. Guedes for assistance in data analysis with the SAS and SPSS packages. The authors wish to thank the school staff and teachers who participated in the study. This work was presented at the Fifteenth European Conference of the International Neuropsychological Society, Portugal, 1993.     

Applications of a computer algebra system in introductory statistics

Maple, a computer algebra system, is employed in introductory statistics courses to promote conceptual learning by students of statistical principles without direct use of mathematics. Maple’s symbolic computation, graphic display, and animation capabilities support an integrated set of procedures for active study of sampling distributions and concepts related to samples, populations, and statistical decision making, error, and power. Students select parameter values for one-line commands and examine the effects of alternatives on computer-generated graphical representations of distributions. The 20 procedures written to support active student exploration of basic statistical concepts are described, and examples of exercises to support their use are provided.     

Perfect MV-algebras are categorically equivalent to abelianl-groups

In this paper we prove that the category of abelianl-groups is equivalent to the category of perfect MV-algebras. Furthermore, we give a finite equational axiomatization of the variety generated by perfect MV-algebras.Presented byDaniele Mundici