Motivational effects of smoked marijuana: behavioral contingencies and low-probability activities.

Six adult male research volunteers, in two groups of 3 subjects each, lived in a residential laboratory for 15 days. All contact with the experimenters was through a networked computer system, and subjects' behavior was monitored continuously and recorded. During the first part of each day, they were allowed to socialize. Two cigarettes containing active marijuana (2.7% delta 9-THC) or placebo were smoked during the private work period and the period of access to social activities. Three-day contingency conditions requiring subjects to engage in a low-probability work activity (instrumental activity) in order to earn time that could be spent engaging in a high-probability work activity (contingent activity) were programmed during periods of placebo and active-marijuana smoking. During placebo administration, the contingency requirement reliably increased the amount of time that subjects spent engaged in the low-probability instrumental activity and decreased the time spent engaged in the high-probability activity. During active-marijuana administration, however, the increases in instrumental activity were consistently larger than observed under placebo conditions. The decreases in contingent activity were similar to those seen under placebo conditions. Smoking active marijuana was thus observed to produce increments in instrumental activity under motivational conditions involving contingencies for "work activities."     

Causal ambiguity and heterosexual affiliation

A male's decision to approach a physically attractive female stranger may be fraught with ambivalence. He is drawn by her beauty but he may fear rejection. The conflict lessens, however, if approach can occur under the guise of a motive other than desire to be with the attractive woman. This is because keeping one's true approach motive ambiguous may make direct personal rejection less likely. The effect of ambiguity on males' tendencies to approach females was explored in two experiments. In the first study, presented to subjects as a movie rating exercise, an excuse to sit with an attractive female confederate (a movie preference) was available to some subjects but not to others. As predicted, males only sat with the confederate when a reason for their affiliative behavior, other than her attractiveness, was available. In the second study, male-female dyads were run through the film rating paradigm with the female subjects in the role played by the confederate in Study I. The results of Study I were replicated for the dyads which included attractive females, as expected. The relationships between fear of failure and attributional ambiguity in social and achievement settings are examined. The tendency to discount a person's physical appearance as a cause of social behavior is discussed.     

Cognitive biases and depression

Compared symptomatically depressed, clinically remitted, and normal controls using cognitive measures designed to be traitlike and statelike in cross-sectional and longitudinal designs, respectively. Remitted depressives and normal subjects did not differ in their attributional biases, endorsement of dysfunctional attitudes, or interpretation of schema-relevant ambiguous events, but both groups differed from symptomatic depressives. Depressive episodes thus affect cognition, but cognitions measured by self-reports are more statelike than traitlike.     

Semantic priming: subliminal perception or context?

Briefly presented, masked priming stimuli that cannot be identified by themselves can affect the processing of subsequent targets. The effect, which is sometimes viewed as a demonstration of unconscious processing, has been linked to the subliminal perception literature. Experiments 1 and 2 indicated that the identification of primes in the context of semantically related targets is superior to the identification of primes presented alone, and that the identification of primes in the context of semantically unrelated targets is inferior to the identification of primes presented alone. Experiment 3 indicated parallel findings in a recognition task. Consequently, an explanation of semantic priming in terms of the interactive nature of stimuli that are near to one another in time seems preferable to one based upon concepts of unconscious processing and subliminal perception.     

Trait-anxiety and sense of coherence: a longitudinal study

A study of trait-anxiety and sense of coherence on a group of medical students over 18 mo. shows that, although both characteristics are rather stable over time, the measure of sense of coherence is more sensitive to stressors than A-trait and is better predicted by A-trait than the opposite.     

State vs trait anxiety: A case study in confirmatory factor analysis

The State-Trait Anxiety Inventory (STAI; Spielberger et al., 1970) originally divided anxiety into two factors: state anxiety, reflecting how an individual currently feels, and trait anxiety, reflecting how an individual generally feels. Recently, however, Spielberger revised his position to separate the presence and absence of anxiety symptoms within state and trait factors, yielding a hypothetical correlated 4-factor structure (Spielberger et al., 1980). Endler and Magnusson (1965) and Endler et al. (1976) have challenged the state vs trait distinction based upon their own factor analytical results. Since both sets of investigations used exploratory approaches, which do not postulate a particular factor structure, these studies do not provide an explicit test of the state vs trait distinction. A confirmatory factor analytic approach was used in the present study to evaluate Spielberger's 4-factor hypothesis. The subjects were large samples of male air force trainees and high school students for whom STAI data were available. The results of these confirmatory analyses indicated that the factors identified in exploratory analysis by Spielberger and his colleagues accounted for the data quite well.     

An interactive program for observation and analysis of human behavior in a long-term continuous laboratory

An Apple II microcomputer is used for processing observations of human behavior in a long-term live-in laboratory. On-line analysis produces multiple measures of response strength and response pattern for experiments on the reinforcement value of ordinary human activities. An interactive program with an informative screen display monitors observers’ data input and operation of the experimental procedures, preventing certain classes of errors. Redundant storage is included to avoid loss of data in the event of equipment failure. The data are handled by humans only one time, as opposed to three with the previous system, reducing both expense and errors. Immediate availability of fine-grained analysis allows more sophistication in within-subjects designs.