Acquisition and generalization of action effects

Three experiments studied the acquisition of action-contingent events (action effects). In a first, acquisition phase participants performed free-choice reactions with each keypress leading to the presentation of either a particular category word (e.g., animal or furniture) or an exemplar word (e.g., dog or chair). In the test phase, choice responses were made to category or exemplar words by using a word-key mapping that was either compatible or incompatible with the key-word mapping during acquisition. Compatible mapping produced better performance than incompatible mapping if the words in the practice and the test phase were the same (e.g., animal M animal), if they had a subordinate-superordinate relationship (e.g., dog M animal), belonged to the same category (e.g., dog M cat), or referred to visually related concepts (e.g., orange M circle). The findings support the assumption that action effects are acquired and integrated with the accompanying action automatically, so that perceiving the effect leads to the priming of the associated response. And, most importantly, they demonstrate that effect acquisition generalizes to other, feature-overlapping events.     

Preparing for perception and action (II): Automatic and effortful processes in response cueing

In this paper we tested the automatic-effortful processing assumption of the Grouping Model. According to the Grouping Model, left-right cues are pull cues and inner-outer cues are push cues, evoking exogenous and endogenous control, respectively. In a series of four experiments we manipulated the characteristics of the cues: Onset vs. no-onset cues, spatial vs. symbolic cues, valid vs. invalid cues. The results consistently showed a dissociation between left-right and inner-outer cues. Together, the present findings provide converging evidence for the notion that left-right cues induce a fast, automatic selection of the cued responses, whereas inner-outer cues need slower, effortful processes to establish a selective preparatory set.     

Group interventions for patients with cancer and HIV disease: part IV. Clinical and policy recommendations

Group interventions have assumed a growing role in primary prevention and supportive care for cancer and HIV disease. Earlier sections of this Special Report examined empirical findings for these interventions and provided recommendations for future research. The current section offers brief recommendations for service providers, policymakers, and stakeholders. Group services now occupy an increasingly prominent place in primary prevention programs and medical settings. In previous sections of this Special Report (Sherman, Leszcz et al., 2004; Sherman, Mosier et al., 2004a, 2004b) we examined the efficacy of different group interventions at different phases of cancer or HIV disease, considered characteristics of the intervention and the participants that might influence outcomes, and discussed mechanisms of action. Methodological challenges and priorities for future research were highlighted. In this, the final section, we offer brief recommendations for service providers, policymakers, and other stakeholders. We consider some of the barriers that constrain use of empirically-based group interventions and note how these programs might be implemented more widely and effectively.     

A feature-integration account of sequential effects in the Simon task

Recent studies have shown that the effects of irrelevant spatial stimulus-response (S-R) correspondence (i.e., the Simon effect) occur only after trials in which the stimulus and response locations corresponded. This has been attributed to the gating of irrelevant information or the suppression of an automatic S-R route after experiencing a noncorresponding trial—a challenge to the widespread assumption of direct, intentionally unmediated links between spatial stimulus and response codes. However, trial sequences in a Simon task are likely to produce effects of stimulus- and response-feature integration that may mimic the sequential dependencies of Simon effects. Four experiments confirmed that Simon effects are eliminated if the preceding trial involved a noncorresponding S-R pair. However, this was true even when the preceding response did not depend on the preceding stimulus or if the preceding trial required no response at all. These findings rule out gating/suppression accounts that attribute sequential dependencies to response selection difficulties. Moreover, they are consistent with a feature-integration approach and demonstrate that accounting for the sequential dependencies of Simon effects does not require the assumption of information gating or response suppression.     

Coloring an action: Intending to produce color events eliminates the Stroop effect

The implications of an ideomotor approach to action control were investigated. In Experiment 1, participants made manual responses to letter stimuli and they were presented with response-contingent color patches, i.e., colored action effects. This rendered stimuli of the same color as an action's effect effective primes of that action, suggesting that bilateral associations were created between actions and the effects they produced. Experiment 2 combined this set-up with a manual Stroop task, i.e., participants responded to congruent, neutral, or incongruent color-word compounds. Standard Stroop effects were observed in a control group without action effects and in a group with target-incompatible action effects, but the reaction time Stroop effect was eliminated if actions produced target-compatible color effects (e.g., blue word --> left key --> blue patch). Experiment 3 did not replicate this interaction between target-effect compatibility and color-word congruency with color words as action effects, which rules out semantically based accounts. Theoretical implications for both action-effect acquisition and the Stroop effect are discussed. It is suggested that learning action effects, the features of which overlap with the target, allows and motivates people to recode their actions in ways that make them more stimulus-compatible. This provides a processing shortcut for translating the relevant stimulus into the correct response and, thus, shields processing from the impact of competing word distractors.     

Semantic generalization of stimulus-task bindings

People find it difficult to switch between two tasks, even if they have time to prepare—the so-called residual task shift cost. We studied a switch of tasks from picture naming to word reading, using picture-word Stroop stimuli. Consistent with previous findings, we demonstrate that a large part of the observed task shift cost was due to priming from prior stimulus-response episodes, in which the current task stimulus was encountered in a competing task. We further show that this task-priming effect generalizes to semantically related stimuli, which opens the possibility that most or all of these residual shift costs reflect some sort of generalized proactive interference from previous stimulus-task episodes.     

Second to fourth digit ratio and numerical competence in children

The ratio between the 2nd and 4th fingers (2D:4D)-a potential proxy for prenatal testosterone (T) exposure-shows a sex difference, with males usually having lower mean values; the latter potentially indicates higher prenatal T exposure. We studied relations between 2D:4D and competencies in the domains of counting, number knowledge, and visual-number representation in 73 children aged 6-11 years. Significant negative correlations between numerical performance in all of these areas and right and left hand 2D:4D ratios were found for boys but not girls. To the extent that 2D:4D ratios reflects prenatal exposure to T, the implications are (i) high prenatal T may be associated with better performance on some basic numerical measures for boys, and (ii) prenatal exposure to T may affect boys and girls differently with respect to some numerical competencies.     

How the brain blinks: towards a neurocognitive model of the attentional blink

When people monitor a visual stream of rapidly presented stimuli for two targets (T1 and T2), they often miss T2 if it falls into a time window of about half a second after T1 onset-the attentional blink (AB). We provide an overview of recent neuroscientific studies devoted to analyze the neural processes underlying the AB and their temporal dynamics. The available evidence points to an attentional network involving temporal, right-parietal and frontal cortex, and suggests that the components of this neural network interact by means of synchronization and stimulus-induced desynchronization in the beta frequency range. We set up a neurocognitive scenario describing how the AB might emerge and why it depends on the presence of masks and the other event(s) the targets are embedded in. The scenario supports the idea that the AB arises from "biased competition", with the top-down bias being generated by parietal-frontal interactions and the competition taking place between stimulus codes in temporal cortex.