Handedness and dementia

Some researchers have speculated that left-hand dominance is more prevalent among patients suffering from dementia of the Alzheimer's type which began prior to age 65 yr. and that, in those patients, the disease runs a more rapid course. In the present study, seven left-handed dementia patients were matched with seven right-handed dementia patients on the basis of age and years of education and were compared with regard to neuropsychological compromise. While the left-handed group was somewhat more impaired than the right-handed subjects, the difference between the two groups was not statistically significant.     

Mechanisms underlying satiation of feeding behavior of the mollusc Aplysia

Animals filled almost to satiation by nonnutritive bulk do not satiate when they ingest a small amount of seaweed. This suggests that satiation is not triggered by chemostimulation of an anteriorly located "hot spot." Inflation of a balloon placed in the gut of the animal results in satiation as reflected in a number of different parameters of feeding behavior. The suppressive effect of a relatively brief inflation is rapidly and fully reversible, although repeated inflation and deflation appeared to produce slowly reversible or irreversible effects. The parameters of the changes in feeding during gut inflation are comparable to those of normal animals that are slowly fed individual pieces of food. The inflation volume needed to satiate the animal is a function of the rate of inflation--more rapid inflations requiring larger volumes. Cutting of the esophageal nerves results in a significant increase in the volume needed to satiate the animals, but nevertheless they eventually cease feeding and generally do not show a burst gut. The evidence indicates that the satiation that eventually occurs in nerve-sectioned animals, at least in part, is due to depression of feeding following very prolonged sensory stimulation. The data suggest that for a rapidly consumed meal, satiation results primarily due to distension-related gut signals conveyed by the esophageal nerves, whereas for very slowly consumed meals, the former factor interacts with a process associated with sensory stimulation, such as receptor adaptation. The current results indicate that balloon distension can serve as a reasonable stimulus in experiments in simplified preparations in which the nervous system can be studied.     

Juvenile homicide: The need for an interdisciplinary approach

Most of the empirical literature on juvenile homicide has emerged from the clinical experience of mental health professionals who have diagnosed and/or treated youngsters who killed. After a critical review of this literature, data on 787 juvenile homicide offenders are presented and discussed. These data indicate that intrafamilial killings represent but a small fraction of all homicides perpetrated by juveniles and that there are clear differences between intrafamilial and extrafamilial juvenile homicides.     

A view of aggression in phobic states

This article attempts to apply a theory of aggression as motivation to overcome obstacles to the understanding of phobic states and their formation. The role of aggression in the genesis of phobic conditions is discussed, and the traditional analytic view of aggression as instinctual drive is contrasted with a motivational approach. The motivational view offers the advantage of a clearer understanding of the stimulus contexts, representational connections, and both real and imaginary object connections that are lacking in the more traditional understanding of aggression as a biological drive.     

Invariance in the MMPI's component structure

Bernstein and Garbin (1985b) suggested that the Minnesota Multiphasic Personality Inventory's major clinical scales (excluding Scales ? and 5) can be approximated by an oblique three-component structure: (a) Profile Elevation, (b) Test-taking Attitudes, and (c) Optimism-Pessimism, collectively termed the salient weight model. In this study, we found that both this model and the MMPI's principal component structure remain invariant across race, sex, and, as previously noted, context of testing (job applicants vs. inmates in correctional institutions). We further noted that several alternative definitions of Profile Elevation provide equally satisfactory representation of the relations among the scales. This factor invariance is necessary, but not sufficient, for the MMPI to be viewed as unbiased.     

Variables which differentiate placement of adolescents into juvenile justice or mental health systems

Studies of the variables that determine whether an adolescent is placed in the mental health or juvenile justice system for treatment have led to conflicting conclusions based on impressionistic data. The primary hypothesis of this study--that demographic variables would and personality/psychopathology variables would not differentiate into which system a youth will be placed--was supported. Adolescents were studied at intake into both the juvenile justice system and the mental health system. Data were collected on demographics (structured interviews), personality/psychopathology (MMPI), social adjustment (CAAP), and academic achievement (PIAT). A discriminant function analysis identified eight statistically significant variables which differentiated the two groups. In order of decreasing importance they are: ethnicity, gender, MMPI-depression, previous mental health history, CAAP-productivity, drug use, parental marital history, and parental religious preference.     

Relationship between specific disfluency variables and dichotic listening in stutterers

86 stutterers' disfluency patterns were examined in relation to their laterality preferences. Results suggest that young stutterers are a heterogeneous group and that specific disfluency variables were not related to ear preferences on a dichotic consonant-vowel listening task.     

Effect of directed attention on cerebral asymmetries in stuttering adults

9 stutterers and 9 nonstutterers were administered a dichotic digits test under conditions of free recall and directed attention. Analysis indicated right-ear preference for both groups and no differences between the free recall and directed listening conditions. Results are discussed in relation to previous studies in which dichotic digit-stimuli were presented to stutterers.     

Statistics,data analysis and Psychometrika: Major developments

Approximately 15% of all papers appearing inPsychometrika during the period 1960–1984 have been statistical or data analytic in nature. While these papers cover a very wide range of issues and are technically quite similar to those appearing in other major statistical journals, collectively they possess features which make them identifiablyPsychometrika.