May I have your attention please: Binding of attended but response-irrelevant features

The feature codes of stimuli and responses can be integrated, and if a stimulus is repeated it can retrieve the previously integrated response. Furthermore, even irrelevant features can be integrated and, upon repetition, retrieve the response. Yet the role of attention in feature integration and retrieval is not clearly understood. Some theories assume a central role of attention (e.g., Logan, 1988; Treisman & Gelade, 1980), but other studies have shown no influence of attention on feature binding (e.g., Hommel, 2005). In the present experiments the effect of attention on the integration of two different response-irrelevant features of the same stimulus was examined. In two experiments, participants responded to the color (response feature) of word stimuli, while two irrelevant features of the words (word type and valence) were systematically varied. Participants’ attention was directed to either one or the other of the response-irrelevant features by asking participants to report that feature at the end of the trial. Feature–response binding effects in the color task were observed to be stronger for the attended response-irrelevant feature. These results indicate that feature binding is not only very flexible but also sensitive to the distribution of attention. It is also automatic, in the sense that as long as attention is available, feature binding occurs irrespective of the task-specific demands.     

Patterns, chunks, and hierarchies in serial reaction-time tasks

The impact of relational structures (i.e., the systematicity of relations between successive items) on incidental sequence learning was investigated in a serial reaction-time (SRT) task while keeping constant the statistical structure. In order to assess the influence of relational structures in stimulus and response sequences separately, the strength of relational patterns in sequences of digits as stimuli and of keystrokes as responses was orthogonally varied. In Exps. 1 and 2, the variation of relational patterns was mainly effective in the keystroke sequence. In Exp. 2, in addition to the variation of relational patterns, the presentation of stimuli was delayed at serial positions that were incongruent with the relational structure. The results show that these incongruent pauses reduced the learning of strongly structured sequences of keystrokes but improved the learning of weakly structured sequences. Experiment 3 suggests that even higher-order relations between elementary patterns are utilized to accelerate responses. The data are interpreted as evidence for the impact of relational patterns, in addition to statistical redundancies, on the formation of chunks. Reasons are discussed for the finding that relational chunking was more pronounced in the keystroke than in the digit sequences. Received: 25 June 1998 / Accepted: 3 December 1998     

Creating partially deleted objects for perception research

Line drawings are commonly used in perception research. A basic strategy used in such research is to remove portions of the line drawings in order to determine what features of an object are important for recognition. However, it is important to monitor the amount of contour and type of information that are deleted when one is making partially deleted or fragmented objects. With the Image Fragmenting Program, researchers can use random or manual contour deletion strategies to create fragmented objects while controlling for the amount of contour removed from the images.     

Comparison of behavioral and cognitive-behavioral one-session exposure treatments for small animal phobias

This study evaluated the efficacy of behavioral and cognitive-behavioral one-session exposure treatment procedures with and without programmed generalization for participants with small animal phobias. Forty participants were randomly assigned to the treatment and generalization conditions. Both treatments produced significant improvements from pre-test to post-test and these results were maintained for 1 year. The treatment effect sizes ranged from large to very large across behavioral, self-report, and subjectively rated measures. Participants in the behavioral treatment condition reported that the treatment was significantly more intrusive than participants in the cognitive-behavioral treatment group. The programmed generalization condition did not produce additional measured benefit. The results are discussed in terms of the overall effectiveness of one-session exposure treatment components for small animal phobias.     

College students, tattoos, and sexual activity

This research examined the association of having a tattoo and engaging in premarital sexual intercourse. Data gathered from a convenience sample of 450 college students indicated that tattooed respondents were substantively and significantly more likely to be sexually active than nontattooed college students. Tattooed men became sexually active at a significantly earlier age than nontattooed men but no such difference was found between tattooed and nontattooed college women.     

Involuntary retrieval in alphabet-arithmetic tasks: Task-mixing and task-switching costs

This study explores the effects of memory retrieval in task switching. To this end, item-specific stimulus-to-task mappings were manipulated in two alphabet-arithmetic experiments. Letter-stimuli were presented and the responses were verbal letter names. The task was either to name the next letter in the alphabet, (e.g., C D, task plus), or to name the preceding letter (e.g., C B, task minus). The mapping of individual stimuli to the two tasks (and thus to responses) was either consistent (CM) or varied (VM). In Experiment 1, performance was worse for VM items relative to CM items, indicating item-specific task-mapping effects. These task-mapping effects also contributed to mixing costs (i.e., worse performance in mixed-task blocks than in pure-task blocks) but not to switch costs (worse performance in task-switch trials than in repeat trials within mixed blocks). Experiment 2 manipulated pure and mixed tasks between-participants, and the data again showed differential effects of the task-mapping manipulation on mixing costs and switch costs. This suggests that, in these memory-dependent, alphabet-arithmetic tasks, interference due to involuntary task (and/or response) retrieval primarily increases general multi-task effects, such as maintaining activation of the current task.     

Effects of response selection on the task repetition benefit in task switching

A task switch typically leads to worse performance than a repetition does. This shift cost can be reduced with sufficient task preparation time, but a residual cost usually remains. We propose that a large part of this residual cost is caused by an activation bias produced by response selection processes in the preceding trial. In our experiments, we manipulated response selection requirements using a go/no-go methodology. The residual shift cost disappeared after no-go trials, suggesting that response selection is crucial to establish an activation bias for the current category-response rules and that this bias persists into the next trial. A comparison with a go-only group confirmed this analysis by revealing no differences in preparatory strategy due to the inclusion of no-go trials. In addition, no-go trials had no significant effects on subsequent trials in a single-task experiment, suggesting that no-go trials are not coded as a task different from go trials and that there is no inhibition of the prepared task in a no-go trial. We thus conclude that a persisting activation bias of response rules plays a major role in task switching.     

Linking inhibition to activation in the control of task sequences

Inhibition of abandoned tasks in task switching can be inferred when a worse performance is found withn− 2 task repetitions (ABA sequences) than with nonrepetitions (CBA sequences). Recent evidence has shown that this inhibition effect decreases with long intertrial intervals (i.e., response-cue intervals, RCIs). Two alternatives have been proposed to account for this decrease. One alternative attributes the observed decrease to the decay of inhibition itself. The other alternative proposes that decay of the activation of competing tasks reduces the interference and leads to less inhibition. To decide between these alternatives, we manipulated RCI trialwise. The results favor the decay-of-activation account as an explanation for the decreased inhibition effect. This links the amount of inhibition to the activation level of the competing tasks, whereas evidence for the decay of inhibition remains weak.