Activity measures in anorexia nervosa.

Twenty-four-hour measurements of wrist and ankle kinetic energy expenditures were obtained on 20 hospitalized female anorectics during the first two weeks of their hospitalization. Kinetic energy was examined against measures of weight, depression, and Minnesota Multiphasic Personality Inventory scores in a regression analysis. Effect of cyproheptadine hydrochloride, amitriptyline hydrochloride, and placebo on activity was assessed. The results supported previous studies showing a positive relationship between weight gain and motor activity and challenge the commonly held notion that activity decreases in anorectics as their clinical condition improves. Motor activity was initially significantly suppressed by cyproheptadine and subsequently increased.

Accelerometric assessment of tardive dyskinesia.

Accelerometric measures associated with resting the hand, posturing the arm, and moving the arm were taken in 10 patients with tardive dyskinesia and eight schizophrenic patients matched for diagnosis, age, sex, likelihood of medication to induce extrapyramidal symptoms, and chlorpromazine-equivalent dose. A multivariate analysis of variance and follow-up univariate analyses revealed that the tardive dyskinesia patients showed 1) greater amplitude of dyskinetic movements, 2) lower peak frequency of dyskinetic movements, and 3) more spikes-points beyond four standard deviations from the mean. Multiple discriminant analyses revealed that all patients were correctly classified as to presence or absence of tardive dyskinesia.

Activity as a function of body weight.

Thirty-one undergraduate men and women who weighed more (overweight) or who weighed less (underweight) than the normal weight limits for their height wore actometers on all four limbs 24 h each day for 14 consecutive days. All groups were found to be equally active. This result fails to replicate previously reported results that overweight men and women are hypoactive. This discrepancy is explained in terms of differences in percent overweight between the present and previous samples. The possibility of a catastrophic decline in activity as a function of percent overweight is discussed.

How accurately does wrist actigraphy identify the states of sleep and wakefulness?

STUDY OBJECTIVES: Because sleep and wakefulness differ from each other by the amount of body movement, it has been claimed that the two states can be accurately distinguished by wrist actigraphy. Our objective was to test this claim in lengthy polysomnographic (psg) and actigraphic (acf) samples that included night and day components. DESIGN: Fourteen healthy young (21-35 years) and old (70-72 years) men and women lived in a laboratory without temporal cues for 7 days. Each subject continuously wore sleep-recording electrodes as well as 2 wrist-movement recorders. Act measurements were converted to predictions of sleep and wakefulness by simple-threshold and multiple-regression methods. Psg served as the gold standard for calculation of predictive values (PV, the probability that an act prediction is correct by psg criteria). SETTING: N/A. PARTICIPANTS: N/A. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: The 7-day act recordings showed clear circadian cycles of high and low activity that respectively corresponded to subjective days, when subjects were wakeful, and subjective nights when they slept. Lower act levels corresponded to deeper states of psg sleep. Logistic regression on a 20-minute moving average of act gave the highest overall PV's. Nevertheless, the mean PV for sleep (PVS) was only 62.2% in complete, day + night samples. PVS was 86.6% in night samples. Act successfully predicted wakefulness during subjective nights (PVW = 89.6) and accurately measured circadian period length and the extent of sleep-wake consolidation, but it overestimated sleep rate and sleep efficiency. Act systematically decreased before sleep onset and increased before awakening, but reliable transitions among joint psg/act states (the Markov-1 property) were not demonstrated. CONCLUSIONS: Low PV's and overestimation of sleep currently disqualify actigraphy as an accurate sleep-wake indicator. Actigraphy may, however, by useful for measuring circadian period and sleep-wake consolidation and has face validity as a measure of rest/activity.

Issues of validity in the Diagnostic Interview Schedule.

The Diagnostic Interview Schedule, the chief instrument in contemporary studies in psychiatric epidemiology, enhances the reliability of psychiatric diagnosis and enables lay interviewers to closely reproduce psychiatric interviews. However, despite frequent references in the literature to the validity of the Diagnostic Interview Schedule, most studies fundamentally represent variations of reliability paradigms to the neglect of criterion-related validity. Mistaken assertions of validity persist in the psychometric language used to describe the Diagnostic Interview Schedule. This article examines the basis for claims and counterclaims of validity in accordance with standard psychometric definition, and identifies sources of erroneous reasoning in attempts to infer validity from reliability. The article presents a general framework organizing the process of diagnostic validation and discusses strategies for research seeking to validate psychiatric diagnoses achieved through the Diagnostic Interview Schedule.

A bidirectional associative memory explanation of posttraumatic stress disorder.

Network theory is a relatively recent explanatory development to improve our understanding of emotions and emotional disorders. Connectionist neural networks are introduced as mathematically well-defined network theories that have been suggested as PTSD models, partly because of their ability to form and retrieve memories. Explanatory requirements that a comprehensive PTSD theory must have are reviewed. A connectionist neural network system called the bidirectional associative memory (BAM) is extended to encode emotion and cognition and is then shown to satisfy all PTSD explanatory requirements and consequently constitutes a comprehensive PTSD theory. Empirical work pertaining to a fundamental assumption that learning alters brain structure in ways that can be detected by neuroimaging is reviewed. Novel predictions are made, and relevance to neuroscience is discussed.

Modal attention asymmetry in patients with schizophrenia and bipolar disorder.

This cross-sectional study examined modal attention asymmetries in patients with schizophrenia (n = 47) and bipolar disorder (n = 42), as contrasted to a matched-sample comparison group of normal participants (n = 89). A test of continuous auditory and visual attention was the primary measure. The data were analyzed from 2 experimental conditions: simple modal responses (auditory and visual) and modal switching responses (ipsimodal and cross-modal switching). In the simple modal condition, patients with schizophrenia demonstrated a visual over auditory asymmetry; patients with bipolar disorder showed no differences. In modal switching conditions, however, patients with bipolar disorder displayed a significant auditory over visual asymmetry. No main effect was detected between medications and attention functioning. Results are discussed in light of differentiating these 2 populations on the basis of modal specificity of attention functioning.

Psychomotor retardation found in college students seeking counseling.

Psychomotor retardation (PMR) has been documented for inpatient populations. Futterman and Tryon (1994) [Journal of Behavior Therapy and Experimental Psychiatry, 25, 41-48] provided the first report of PMR in a female outpatient sample. Because 8 of their 11 depressed Ss were receiving medication, the possibility remains that Futterman and Tryon's findings were due to medication side effects. The present study documents PMR in a nonmedicated male and female college population. Two-week, 24-h per day, content-valid behavioral measurements were obtained using step-counters from 73 college students seeking counseling. The 20 males and 53 females completed the Inventory to Diagnose Depression, the State-Trait Anxiety Inventory, the Marlowe-Crowne Social Desirability Inventory, and a structured interview. Regression analysis revealed that depression was negatively related to daytime activity. Significant age and gender effects were statistically controlled.

Estimating and testing autocorrelation with small samples: a comparison of the C-statistic to a modified estimator.

Huitema and McKean (Psychological Bulletin, 110, 291-304, 1991) recently showed, in a Monte-Carlo study, that five conventional estimators of first-order autocorrelation perform poorly for small (< 50) sample sizes. They suggested a modified estimator and a test for autocorrelation. We examine an estimator not considered by Huitema and McKean: the C-statistic (Young, Annals of Mathematical Statistics, 12, 293-300, 1941). A Monte-Carlo study of the small sample properties of the C-statistic shows that it performs as well or better than the modified estimator suggested by Huitema and McKean (1991). The C-statistic is also shown to be closely related to the d-statistic of the widely used Durbin-Watson test.

Evaluating statistical difference, equivalence, and indeterminacy using inferential confidence intervals: an integrated alternative method of conducting null hypothesis statistical tests.

Null hypothesis statistical testing (NHST) has been debated extensively but always successfully defended. The technical merits of NHST are not disputed in this article. The widespread misuse of NHST has created a human factors problem that this article intends to ameliorate. This article describes an integrated, alternative inferential confidence interval approach to testing for statistical difference, equivalence, and indeterminacy that is algebraically equivalent to standard NHST procedures and therefore exacts the same evidential standard. The combined numeric and graphic tests of statistical difference, equivalence, and indeterminacy are designed to avoid common interpretive problems associated with NHST procedures. Multiple comparisons, power, sample size, test reliability, effect size, and cause-effect ratio are discussed. A section on the proper interpretation of confidence intervals is followed by a decision rule summary and caveats.

A neural network explanation of posttraumatic stress disorder.

An introduction to connectionistic neural networks and their importance for behavior therapists was provided by Tryon (1995a). This article shows that the bidirectional associative memory connectionistic neural networks model meets all four of Jones and Barlow's (1990) requirements and all five of Brewin, Dalgleish, and Joseph's (1996) requirements for a theoretical explanation of posttraumatic stress disorder (PTSD). The bidirectional associative memory model provides a theoretical basis for explaining the clinical symptom constellation of PTSD, with special emphasis on why trauma is re-experienced through memory; accounts for individual variation in symptom severity, including why some people do not develop PTSD; explains why persons with PTSD are comorbid with depression, generalized anxiety, and substance abuse; explains how abnormal behavior derives from normal memory formation processes; and makes novel predictions.

Study of the similar structure hypothesis with mentally retarded adults and nonretarded children of comparable mental age.

The similar structure hypothesis was tested by comparing the performance of mentally retarded adults and their nonretarded mental age peers on a series of Piagetian tasks. We controlled for variables that influence the testing of mentally retarded subjects and performance on Piagetian tasks. Statistical analysis revealed that five tests favored the developmental position whereas two tests favored the difference position. Qualitative analysis provided reason to question the validity of two of the seven tests. Nevertheless, the evidence still favored the developmental position 4:1. Corollaries challenged the use of vocabulary tests for matching and raised a caveat concerning the acquisition by mentally retarded adults of key concrete operations skills.

Validating a double-press method for computer administration of personality inventory items.

This study describes a double-press method for experimentally controlling item length and reading speed when measuring response latency to computer-administered personality items. Previous research has required several statistical transformations to control for item length and reading speed. Five approaches validated the new, double-press method. First, valid profiles showing reasonable read time and psychological response time resulted in few outliers. Second, read and psychological response times were internally consistent. Third, valid separation of read time from total response time was demonstrated by a positive relationship between read time and item length. Fourth, negatively stated items took longer to understand than positively stated items. Fifth, in accordance with schema research, items that were highly similar or dissimilar to the self-schema were answered more quickly than other items, resulting in an inverted-U effect.

Reinforcement history as possible basis for the relationship between self-percepts of efficacy and responses to treatment.

The empirical correlation of self-efficacy statements and treatment outcome reported by Bandura (1977) is acknowledged. The question at issue is whether this correlation is due to an integrative construct called self or social contingencies. Bandura (1982) demonstrated that the correlation exists in the absence of contemporary social contingencies for such a correlation (cf. Tryon, 1981). The present rejoinder argues that the correlation between self-efficacy statements and subsequent behavior could be due to social contingencies existing prior to the experiment. Supportive data from a series of vicarious verbal conditioning experiments are presented.

A methodological critique of Bandura's self-efficacy theory of behavior change.

This brief theoretical note identifies a major methodological problem in Bandura's argument in favor of self-efficacy theory and provides two methods of controlling for it. His data could likely be accounted for by social contingencies operating within his highly structured behavioral approach situation.

Synthesizing animal and human behavior research via neural network learning theory.

Animal and human research have been "divorced" since approximately 1968. Several recent articles have tried to persuade behavior therapists of the merits of animal research. Three reasons are given concerning why disinterest in animal research is so widespread: (1) functional explanations are given for animals, and cognitive explanations are given for humans; (2) serial symbol manipulating models are used to explain human behavior; and (3) human learning was assumed, thereby removing it as something to be explained. Brain-inspired connectionist neural networks, collectively referred to as neural network learning theory (NNLT), are briefly described, and a spectrum of their accomplishments from simple conditioning through speech is outlined. Five benefits that behavior therapists can derive from NNLT are described. They include (a) enhanced professional identity derived from a comprehensive learning theory, (b) improved interdisciplinary collaboration both clinically and scientifically, (c) renewed perceived relevance of animal research, (d) access to plausible proximal causal mechanisms capable of explaining operant conditioning, and (e) an inherently developmental perspective.

Classical conditioning of meaning--I. A replication and higher-order extension.

The meaning that individuals associate with verbal stimuli may be modified by using classical conditioning procedures. Clinically, such procedures may be used to modify a client's maladaptive associations. The current research investigated the existence and generalizability of this phenomenon by attempting to replicate Staats and Staats' (1957) language conditioning effect and then extent it to a second-order classical conditioning situation (CS1----UCS then CS2----CS1). Such higher-order conditioning would suggest that several different but related maladaptive associations can be modified simultaneously. Significant conditioning was obtained to the CS1, particularly for aware subjects, but no conditioning occurred to the CS2.

Classical conditioning of meaning--II. A replication and triplet associative extension.

The meaning associated with verbal stimuli is modifiable by classical conditioning, suggesting that such "language conditioning" may be used clinically to modify a client's maladaptive associative history. The current research investigated the existence and generalizability of this phenomenon by attempting to replicate Staats and Staats' (1957) language conditioning effect and then extend it to a triplet conditioning paradigm (CS2----CS1----UCS). Previous research by the current authors replicated language conditioning, yet failed to extend it to a higher-order situation. Significant conditioning was obtained to the CS1, particularly for aware subjects, but no conditioning occurred to the CS2. Implications for verbal conditioning theory and clinical practice are discussed.

Higher-order semantic counterconditioning of Filipino women's evaluations of heterosexual behaviors.

The purpose of this study was to determine if semantic counterconditioning could modify semantic differential ratings regarding premarital sexual behaviors, in Filipino women whose culture exerts great control over such matters. A total of 303 unmarried, predominantly middle class, English speaking, Roman Catholic Filipino women aged 15-21 years volunteered to be subjects. Significant changes in the semantic differential ratings were obtained in four of the five CS (conditioned stimuli) phrases for subjects receiving semantic counterconditioning. Lesser changes in the semantic differential ratings for the same phrases were obtained from subjects in the Pseudo Conditioning and Repetition Control groups.