Instrumental responding following reinforcer devaluation

In two experiments, hungry rats were given instrumental lever-press training for an appetitive reinforcer and, in addition, were exposed to another type of food which was not contingent on lever pressing. In the first experiment, exposure to each type of food was on separate days, whereas in the second experiment rats were exposed to each type of food in strict alternation within each session. Subsequently, a food aversion was conditioned to the reinforcer for the experimental group and to the non-contingent food for the control group. In both experiments, animals with an aversion to the reinforcer responded less in an extinction test than animals with an aversion to the non-contingent food. Subsequent reacquisition tests confirmed that the aversion to the non-contingent food in the control group was of comparable strength with that to the reinforcer in the experimental group. The results were discussed in terms of whether the reinforcer is encoded in the associative structure set up by exposure to an instrumental contingency.     

The Struggle to Prevent and Evaluate: Application of Population Attributable Risk and Preventive Fraction to Suicide Prevention Researach

Population attributable risk (PAR) estimates have been used in suicide research to evaluate the impact of psychosocial and socioeconomic risk factors, including affective disorders, traumatic life events, and unemployment. A parallel concept of preventive fraction (PF), allowing for estimation of the impact of protective factors and effectiveness of preventive interventions, is practically unknown in suicidology. The study authors discuss the application of both concepts to suicide research and prevention, and review literature on the subject. Despite several methodological and conceptual limitations, both PAR and PF are valuable instruments to inform development and evaluation of suicide prevention programs.     

Influence of Connectives on Language Comprehension: Eye tracking Evidence for Incremental Interpretation

An eye-tracking experiment investigated whether incremental interpretation applies to interclausal relationships. According to Millis and Just's (1994) delayed-integration hypothesis, interclausal relationships are not computed until the end of the second clause, because the processor needs to have two full propositions before integration can occur. We investigated the processing of causal and diagnostic sentences (Sweetser, 1990; Tversky & Kahneman, 1982) that contained the connective because . Previous research (Traxler, Sanford, Aked, & Moxey, 1997) has demonstrated that readers have greater difficulty processing diagnostic sentences than causal sentences. Our results indicated that difficulty processing diagnostic sentences occurred well before the end of the second clause. Thus comprehenders appear to compute interclausal relationships incrementally.     

Cardiovascular reactivity to psychological stress in aerobically trained versus untrained mild hypertensives and normotensives

Cardiovascular reactivity to video game and mental arithmetic stressors was compared among three groups of men: aerobically trained mild hypertensives, untrained mild hypertensives, and a comparison group of untrained normotensives. Relative to the untrained hypertensives, the trained hypertensives reacted to the video game with marginally smaller systolic blood pressure and diastolic blood pressure, but there were no significant differences between these groups in reactivity during the mental arithmetic task. Comparisons between each hypertensive group and the normotensive group showed that blood pressure (BP) reactivity of normotensives during the video game was generally similar to that of trained hypertensives but smaller than that of untrained hypertensives. These results indicate that aerobic training, which has been found to reduce resting BP in mild hypertensives, may also exert a favorable impact in reducing cardiovascular reactivity of hypertensives during some stressful situations.     

The Construct Validity of Assertion: Contributions of Four Assessment Procedures and Norman's Personality Factors

ABSTRACT The construct validity of assertion was analyzed in three independent correlational studies The convergence of self-reported, laboratory roleplayed, self-observed, and peer-rated measures was examined, as well as their relationship to Norman's peer-rated five personality factors of extraversion, agreeableness, conscientiousness, emotional stability, and culture Twenty-three and 29 undergraduate students participated in Studies 1 and 2, respectively In general, results showed poor convergence among assertiveness measures even when increasing the representativeness and reliability of the role-played laboratory and self-observed measures, as in Study 2 In Study 3, the role-playing test was abandoned and 45 subjects served as peers for one another The results of Study 3 supported the prediction that assertiveness measures showed at least moderate convergence, in addition there were significant relationships between assertiveness and extraversion and between peer-rated assertiveness and agreeableness, conscientiousness, and culture The relative contribution of each assessment procedure to the construct validity of assertion is discussed     

Phonological priming in the lexical decision task: A failure to replicate

Some models of the lexicon predict that recognition of words should produce activation spreading to phonologically related words. Consistent with this prediction, Hillinger (1980) demonstrated priming in a visual lexical decision task for word targets preceded by graphemically similar or graphemically dissimilar primes that rhymed with the target. In Experiment 1, we investigated whether this phonological priming effect occurred automatically or because of subject strategies. Although semantically associated primes produced significant facilitation in Experiment 1, no evidence of phonological priming was obtained. Experiments 2 to 5 were conducted in an attempt to obtain the phonological priming effect. Experiment 5 was a replication of one of Hillinger’s experiments. In none of these experiments was phonological priming observed. These results indicate either that the lexicon is not organized such that spreading activation occurs on the basis of phonological similarity, or that visual lexical decisions are made without phonological mediation.     

A developmental study of the auditory Stroop effect

A pediatric auditory version of the Stroop procedure was developed and administered to 48 normal children from 3 to 6 years of age. Our purpose was to define the developmental course characterizing interaction between auditory and semantic speech dimensions in young children. The procedure was a reaction time (RT) task that required children to respond as quickly and as accurately as possible to words spoken by a male or a female voice. Children were instructed to ignore what was said and to push the "Mommy" button if Mommy was talking or the "Daddy" button if Daddy was talking. Performance was obtained for words with neutral, congruent, and conflicting semantic content. Preschool children manifested processing dependencies that were similar to those observed in adults on the visual Stroop procedure. Conflict between semantic and auditory dimensions significantly increased RT and congruence between the two dimensions significantly decreased RT relative to the neutral condition. The pattern of results indicated that the meaning of words was processed automatically in the normal children. The magnitude of the Stroop effect reflected developmental change with increasing age.     

Studies of psychosocial influences on coronary artery atherogenesis in cynomolgus monkeys

The cynomolgus macaque provides a suitable primate model for studying how psychosocial factors contribute to coronary artery atherogenesis. Important interactions with diet, sex, and behaviorally elicited cardiovascular reactivity are described.     

Self-esteem of adolescent girls as related to weight

The Rosenberg Self-esteem Scale was administered to 550 14- and 16-yr.-old (+/- 6 mo.) girls. Self-esteem scores were categorized by weight and weight by height. Scores on the Quetelet Index for obesity were correlated with self-esteem scores. Mean self-esteem of the low- and middle-weight by height group was significantly higher than the mean of the high-weight by height group. In analyzing weight alone, the self-esteem of the middle-weight group was significantly higher than the self-esteem of the high-weight group. The correlation of the obesity index and self-esteem indicated that as weight increased self-esteem decreased.