Uninstructed human responding: Sensitivity of low-rate performance to schedule contingencies

College students' presses on a telegraph key occasionally turned on a light in the presence of which button presses produced points later exchangeable for money. Initially, responding was maintained by low-rate contingencies superimposed on either random-interval or random-ratio schedules. Later, the low-rate contingencies were relaxed. Low-rate key pressing had been established for some students by shaping and for others by demonstration and written instructions. After the low-rate contingencies were relaxed, higher response rates generally did not increase point earnings with random-interval scheduling, but did so with random-ratio scheduling. In both cases, shaped responding usually increased, and instructed responding usually continued at an unchanged low rate. The insensitivity of instructed responding typically occurred despite contact with the contingencies. The differential sensitivity to schedule contingencies of shaped responding relative to instructed responding is consistent with the different properties of contingency-governed and rule-governed behavior and is not rate-dependent.     

On the sensitivity of a composite to its weights

A method is presented for investigating two aspects of the sensitivity of a linear composite to the values of its weights.     

Successive independence of multiple-schedule component performances

In three experiments, pigeons' responses were reinforced on two keys in each component of a series of multiple-schedule conditions. In each series, concurrent variable-interval schedules were constant in one component and were varied over conditions in the other component. In the first experiment both components arranged the same, constant total number of reinforcers, in the second the two components arranged constant but different totals, and in the third experiment the total was varied in one component and remained constant in the other. Relative reinforcer rate during the varied component was manipulated over conditions in all three experiments. In all these experiments, response and time allocation in the constant component were invariant when reinforcer ratios varied in the other component, demonstrating independence of behavior allocation in a multiple-schedule component from the relative reinforcer rate for the same alternatives in another component. In the two experiments which maintained constant reinforcer totals in components, sensitivity to reinforcement in the multiple schedules was the same as that in the concurrent schedules arranged during the varied component, with multiple-schedule bias in the experiment in which the totals were unequal.     

Choice: Effects of changeover schedules on concurrent performance

The components of concurrent schedules were separated temporally by placing interval schedules on the changeover key. The rates of responding on both the main and changeover keys were examined as a function of the reinforcement rates. In the first experiment, the sensitivity of main-key performance to changing reinforcement rates was inversely related to the temporal separation of components, and changeover performance was monotonically related to the ratio of the reinforcement rates. In the second experiment, when the ratio of the reinforcement rates was scheduled to remain constant while the frequency of reinforcement was varied, changeover performance did not remain constant. A “sampling” interpretation of changeover responding was proposed and subsequently tested in a third experiment where extinction was always scheduled in one component and the frequency of reinforcement was varied in the second component. It was concluded that changeover performance can be interpreted using molar measures of reinforcement and that animals sample activities available to them at rates which are controlled by relative reinforcement rates.     

Protecting Sexual Minority Youth from Research Risks: Conflicting Perspectives

We describe the dilemmas we encountered in the informed consent process for an HIV prevention project targeting Black gay, bisexual, and non-gay identified young men. We highlight the complexities of applying informed parental consent procedures to sexual minority youth and identify some of the challenges that researchers who work with sexual minority youth face when they must balance the needs and rights of this population against the needs and rights accorded to parents by federal guidelines for protecting minor participants in research.     

An Evaluation of the Response Modulation Hypothesis in Relation to Attention–Deficit/Hyperactivity Disorder

Several hypotheses related to Newman's (e.g., Patterson & Newman, 1993) response modulation hypothesis were examined among adolescents with attention-deficit/hyperactivity disorder (ADHD; n=18) and normal controls (n=23). Consistent with predictions, youth with ADHD committed more passive avoidance errors (PAEs) than controls during the latter trials of a computerized go/no go task with mixed incentives, and this effect remained significant or marginally significant even after common variance associated with variables that covary with ADHD (i.e., IQ, oppositional-defiant/conduct disorder [ODD/CD] symptoms, anxious/depressed mood) was removed. While a moderate inverse association was observed between PAE frequency and the amount of time spent viewing response feedback following punishment, both categorical (diagnostic) and dimensional analyses of ADHD symptomatology indicated that ADHD and reflection on punishment feedback are uniquely associated with PAE commission. Findings from this study are discussed in relation to models of disinhibition applicable to youth with ADHD.

The association between heroin use and anxiety sensitivity among inner-city individuals in residential drug use treatment

The current study represents an initial investigation of the association between heroin use and anxiety sensitivity (AS). Within a sample of 172 inner-city treatment seeking drug users, AS was compared across past year (1) heroin users with no crack/cocaine use (n=12); (2) crack/cocaine users with no heroin use (n=66); (3) users of both heroin and crack/cocaine (n=45); and (4) individuals with no use of heroin or crack/cocaine (n=49). Consistent with expectations, primary heroin users evidenced higher levels of AS than all other groups, with these differences also evidenced for the physical and social subscales. Differences in AS total score and physical subscale score persisted after controlling for demographic variables, depressive symptoms, and primary use of drugs other than heroin and crack/cocaine including alcohol, nicotine, marijuana, and hallucinogens. Findings suggest a unique relationship between AS and heroin, and set the stage for future work explicating the direction of the observed association.     

Anxiety sensitivity taxonicity across gender among youth

The present investigation comparatively evaluated the latent class structure and parameters of anxiety sensitivity (AS) among female and male youth using the Childhood Anxiety Sensitivity Index. Participants were 4462 adolescents (2189 females) in grades 7-12 (M(age)=15.6 years). Consistent with prediction, taxometric analyses indicated the latent structure of AS was taxonic in both males and females, demonstrating the taxonic latent structure of AS is similarly observed across gender. Also consistent with prediction, the base rate of the AS taxon differed between genders -- higher for females (12%) compared to males (7%). These findings are discussed in terms of their implications for the study of AS and panic vulnerability among youth.     

Risk-factor research and prevention programs for anxiety disorders: a translational research framework

The aim of the present essay is to discuss the interconnection between risk-factor research and prevention program development for panic-spectrum psychopathology. We argue that prevention of panic-spectrum psychopathology specifically, and anxiety disorders more generally, is likely to be best advanced through active, systematic translation of basic, risk-factor research. After operationalizing key terminology, we present some exemplar risk-factor candidates for panic-spectrum psychopathology, summarize research related to their role as risk-factors for panic problems, and link this discussion to risk-factor nomenclature. We then present a translational framework for extrapolating extant knowledge on these and other potential risk-factors for panic-spectrum psychopathology with respect to the development of preventative interventions. The proposed translational framework is intended to describe a forward-feeding process by which risk-factor research could be used by clinical researchers to inform prevention programs; and reciprocally, how such prevention knowledge could be most effectively utilized to drive new, clinically focused risk-factor research.     

Fear of Physical Harm: Factor Structure and Psychometric Properties of the Injury/Illness Sensitivity Index

Three fundamental fears—anxiety sensitivity, fear of negative evaluation, and injury/illness sensitivity—are believed integral components of anxiety-related psychopathologies. S. Taylor (1993) performed a cumulative factor analysis on measures of these and found them factorially distinct. Subsequently, separate factor analyses have been performed on measures of anxiety sensitivity and fear of negative evaluation. No such analysis exists for the Injury/Illness Sensitivity Index (ISI; S. Taylor, 1993). The ISI, an 11-item self-report questionnaire intended to measure fear of illness and injury, has the potential to inform the understanding of mechanisms underlying anxiety-associated chronic health conditions. The primary purpose of this study was to assess the factor structure and psychometric properties of the ISI. A principal components analysis with oblique rotation, conducted on data from 122 participants, suggests the ISI comprises two distinct lower order factors—Fear of Illness and Fear of Injury—that load onto a higher order factor of Fear of Physical Harm.