The Fishbein and Ajzen Theory of Reasoned Action Applied to Contraceptive Behavior: Model Variants and Meaningfulness1

Suggested modifications of the theory of reasoned action, which conceptualize the functional operation of the attitudinal and normative components in intention formation as separate, separate but contingent, and inseparable, are discussed. The model structures are examined with regard to the underlying psychological assumptions (psychological meaningfulness) and with regard to the required scale levels for the model variables, so that the results of model tests are invariant under the admissible scale transformations (formal meaningfulness). Using a procedure that combines “optimal scaling” with hierarchical regression analysis, the model variants are tested for women's (n= 89) and men's (n= 89) intentions to use contraceptive methods (pill, intrauterine device, condom, and natural methods) that require the model variables to be measured on interval scales. The results strongly favored the theory of reasoned action above the other model variants. Only for the subjective norm model was a better model fit found for a belief-only model compared to the original product-sum model. Gender differences were found with regard to the salient belief sets and the explanatory power of the normative model component.     

Adaptive control of event integration

Identifying 2 target stimuli in a rapid stream of visual symbols is much easier if the 2nd target appears immediately after the 1st target (i.e., at Lag 1) than if distractor stimuli intervene. As this phenomenon comes with a strong tendency to confuse the order of the targets, it seems to be due to the integration of both targets into the same attentional episode or object file. The authors investigated the degree to which people can control the temporal extension of their (episodic) integration windows by manipulating the expectations participants had with regard to the time available for target processing. As predicted, expecting more time to process increased the number of order confusions at Lag 1. This was true for between-subjects and within-subjects (trial-to-trial) manipulations, suggesting that integration windows can be adapted actively and rather quickly.     

How do personality disorders modify suicide risk?

There is a lack of psychological autopsy studies assessing the influence of axis II disorders on other risk factors for suicide. Therefore, we investigated if the estimated suicide risk for axis I disorders and socio-demographic factors was modified by personality disorders. Psychiatric disorders were evaluated by a semi-structured interview including the Structured Clinical Interview for DSM-IV Axis I (SCID-I) and Personality Disorders (SCID-II) by psychological autopsy method in 163 completed suicides and by personal interview in 396 population-based control persons. Personality disorders modify suicide risk, differently for affective disorders, substance use disorders, smoking, life events during the last three months, and socio-demographic factors such as being single. Estimated suicide risk for socio-demographic factors and life events is not substantially altered following adjustment for affective disorders or substance use disorders. These findings suggest that treatment of personality disorders is essential for suicide prevention.     

Lifespan development of stimulus-response conflict cost: similarities and differences between maturation and senescence

Age gradient of the mechanism of stimulus-response conflict cost was investigated in a population-based representative sample of 291 individuals, covering the age range from 6 to 89 years. Stimulus-response conflict cost, indicated by the amount of additional processing time required when there is a conflict between stimulus and response options, follows a U-shaped function across the lifespan. Lifespan age gradient of conflict cost parallels closely those of processing fluctuation and fluid intelligence. Individuals at both ends of the lifespan displayed a greater amount of processing fluctuation and at the same time a larger amount of conflict cost and a lower level of fluid intelligence. After controlling for chronological age and baseline processing speed, conflict cost continues to correlate significantly with fluid intelligence in adulthood and old age and with processing fluctuation in old age. The relation between processing fluctuation and conflict cost in old age lends further support for the neuromodulation of neuronal noise theory of cognitive aging as well as for theories of dopaminergic modulation of conflict monitoring.     

Consciousness and control in task switching

Participants were required to switch among randomly ordered tasks, and instructional cues were used to indicate which task to execute. In Experiments 1 and 2, the participants indicated their readiness for the task switch before they received the target stimulus; thus, each trial was associated with two primary dependent measures: (1) readiness time and (2) target reaction time. Slow readiness responses and instructions emphasizing high readiness were paradoxically accompanied by slow target reaction time. Moreover, the effect of task switching on readiness time was an order of magnitude smaller then the (objectively estimated) duration required for task preparation (Experiment 3). The results strongly suggest that participants have little conscious awareness of their preparedness and challenge commonly accepted assumptions concerning the role of consciousness in cognitive control.     

Interaction of task readiness and automatic retrieval in task switching: Negative priming and competitor priming

When subjects switch between tasks, performance is slower after a task switch than after a task repetition, even when preparation time is long. We report two experiments that support the idea that a large part of these residual task shift costs can be due to stimulus-cued retrieval of previous task episodes. We demonstrate that there are two different factors at work: (1) facilitation of response to the current distractor stimulus, appropriate to the previously relevant, competing task (competitor priming), and (2) impaired processing of previously suppressed responses (negative priming). Negative priming was contingent on the size of the stimulus set, suggesting that distractor suppression comes into effect only if the distractors are highly activated. Importantly, both types of interference interacted with task readiness: Whereas in the nondominant task (picture naming), switch and nonswitch trials were equally affected, the dominant task (word reading) showed priming effects on switch trials only. Thus, the retrieval of previous processing episodes has a selective impact on situations in which task competition is high.