Character Strengths Interventions: Building on What We Know for Improved Outcomes

For this review strengths intervention studies were located using online searches and collegial networks and included if they explicitly sought to teach or use a strengths classification to enhance well-being, and used pre- and post-intervention measures and a comparison group. Eight studies met the criteria and have been summarised by this review. To date, the effect sizes achieved by character strengths interventions have been small to moderate. An understanding of how these interventions work may facilitate development of more effective interventions, while expanding the field of character strengths interventions to include a broader range of activities and approaches may also offer benefits. Research examining individual factors, such as strengths use, psychological need satisfaction, goal-setting and goal-striving provides promising leads to explain how strengths interventions work. However, the effect on intervention efficacy of relational or contextual factors, such as intervention environment or facilitator attitude to strengths, has not yet been explored. Implications for interventions in school settings are considered.     

Could millisecond timing errors in commonly used equipment be a cause of replication failure in some neuroscience studies?

Neuroscience is a rapidly expanding field in which complex studies and equipment setups are the norm. Often these push boundaries in terms of what technology can offer, and increasingly they make use of a wide range of stimulus materials and interconnected equipment (e.g., magnetic resonance imaging, electroencephalography, magnetoencephalography, eyetrackers, biofeedback, etc.). The software that bonds the various constituent parts together itself allows for ever more elaborate investigations to be carried out with apparent ease. However, research over the last decade has suggested a growing, yet underacknowledged, problem with obtaining millisecond-accurate timing in some computer-based studies. Crucially, timing inaccuracies can affect not just response time measurements, but also stimulus presentation and the synchronization between equipment. This is not a new problem, but rather one that researchers may have assumed had been solved with the advent of faster computers, state-of-the-art equipment, and more advanced software. In this article, we highlight the potential sources of error, their causes, and their likely impact on replication. Unfortunately, in many applications, inaccurate timing is not easily resolved by utilizing ever-faster computers, newer equipment, or post-hoc statistical manipulation. To ensure consistency across the field, we advocate that researchers self-validate the timing accuracy of their own equipment whilst running the actual paradigm in situ.     

The effects of stimulus set size and word frequency on verbal serial recall

Two experiments are reported which examine immediate serial recall for high-and low-frequency words. The words in each list were either repeatedly drawn from the same small pool of candidates (in the closed set conditions) or each word only ever occurred once during the experiment (in the open set conditions). The results consistently show an effect of word frequency but the effect of set size was only apparent for low-frequency words. It is argued that both frequency and set size effects reflect processes concerning the “clean-up” of degraded short-term memory traces.     

The visual detection of threat: A cautionary tale

The fear response hypothesis and the associated claim that humans have an evolutionary propensity to detect threats automatically in their immediate visual environment are critically appraised. This review focuses on reports of visual search experiments in which participants were tested with speeded oddball tasks in which the search displays contained photographic images of naturally occurring entities. In such tasks, participants have to judge whether all the images are from one category or whether the display contains a distinctive image. The evidence, which has been used to support the fear response hypothesis, is assessed against a series of concerns that relate to stimulus factors and stimulus selection. It is shown that when careful consideration is given to such methodological details, it becomes very difficult to defend the fear response hypothesis. It is concluded that, at present, the fear response hypothesis has no convincing empirical support, and it is urged that, in the future, researchers who wish to study visual threat detection take stimulus selection much more seriously.     

Searching for threat

In a series of experiments, a visual search task was used to test the idea that biologically relevant threatening stimuli might be recognized very quickly or capture visuo-spatial attention. In Experiment 1, there was evidence for both faster detection and faster search rates for threatening animals than for plants. However, examination of the basis of this effect in Experiment 2 showed that it was not due to threat per se, as detection and search rate advantages were found for pleasant rather than threatening animals compared to plants. In Experiment 3, participants searched for the plants and pleasant and threatening animals used in Experiments 1 and 2, among a fixed heterogeneous selection of non-target items. There was no search rate or detection advantage for threatening animals compared to pleasant animals or plants. The same targets and non-targets as those used in Experiment 3 were also used in Experiment 4. In Experiment 4, participants searched for targets that were presented either close to or distant from an initial fixation point. There was no evidence for a "threat" detection advantage either close to or distant from the cross. Finally, an experiment was conducted in which target categories (fruit, flowers, and animals) were not pre-specified prior to each trial block. There were no differences in reaction times to detect pleasant animals, threatening animals, or fruit. We conclude that the visual search paradigm does not readily reveal any biases that might exist for threatening stimuli in the general population.     

Stimulus processing constraints in audition

In 3 experiments, the authors tested performance in simple tone matching and classification tasks. Each tone was defined on location and frequency dimensions. In the first 2 experiments, participants completed a same-different matching task on the basis of one of these dimensions while attempting to ignore irrelevant variation in the other dimension. In Experiment 3, in which the tones were classified either by frequency or location, the authors explored intertrial repetition effects. The patterns of performance across these different tasks were remarkably similar and were taken to reveal basic characteristics of stimulus encoding processes. The data suggest a processing sequence in audition that reveals an early stage in which location and frequency are treated as being integral and a latter stage in which location and frequency are separable.     

Cross-modal integration of simple auditory and visual events

Responses are typically faster and more accurate when both auditory and visual modalities are stimulated than when only one is. This bimodal advantage is generally attributed to a speeding of responding on bimodal trials, relative to unimodal trials. It remains possible that this effect might be due to a performance decrement on unimodal ones. To investigate this, two levels of auditory and visual signal intensities were combined in a double-factorial paradigm. Responses to the onset of the imperative signal were measured under go/no-go conditions. Mean reaction times to the four types of bimodal stimuli exhibited a superadditive interaction. This is evidence for the parallel self-terminating processing of the two signal components. Violations of the race model inequality also occurred, and measures of processing capacity showed that efficiency was greater on the bimodal than on the unimodal trials. These data are discussed in terms of a possible underlying neural substrate.     

Book reviews

Baddeley, A. (1986). Working memory. Oxford: Oxford University Press. Pp. 289. ISBN 0-19-852116-2. £30.00

Knapp, T. J. & Robertson, L. C. (Eds.). (1986). Approaches to cognition: Contrasts and controversies. Hillsdale, N.J.: Lawrence Erlbaum Associates Inc. ISBN 0-89859-623-8. £21.00.

Shlecter, T. M. & Toglia, M. P. (Eds.). (1985) New directions in cognitive science. Norwood, N.J.: Ablex Publications. ISBN 0-89391-230-1. £38.00.     

Matched and mismatched interventions with young adult smokers: testing a stage theory.

This experiment tested the transtheoretical model (J.O. Prochaska & C.C. DiClemente, 1983) of smoking cessation by matching or mismatching interventions to smokers in a particular stage. The interventions were tested against a no-intervention condition with 92 college-aged daily smokers in the precontemplation stage of change. The stage-matched intervention asked smokers to think more about quitting smoking; the stage-mismatched intervention provided action-oriented activities typically used for those ready to quit smoking. The results failed to support the value of matching interventions to a smoker's stage of change. Instead, more smokers who received the action intervention tried to quit smoking. Matching interventions to an individual's current stage may be less important than the transtheoretical model suggests.     

Interplay of the production and picture superiority effects: A signal detection analysis

Three experiments explored the interaction between the production effect (greater memory for produced compared to non-produced study items) and the picture superiority effect (greater memory for pictures compared to words). Pictures and words were presented in a blocked (E1) or mixed (E2, E3) design, each accompanied by an instruction to silently name (non-produced condition) or quietly mouth (produced condition) the corresponding referent. Memory was then tested for all study items as well as an equal number of foil items using a speeded (E1, E2) or self-paced (E3) yes-no recognition task. Experiments 1, 2, and 3 all revealed a small but reliable production×stimulus interaction. Production was also found to result in a liberal shift in response bias that could result in the overestimation of the production effect when measured using hits instead of sensitivity. Together our findings suggest that the application of multiple distinctive processes at study produces an especially discriminative memory trace at test, more so than the summation of each process individually.