A Fresh Look at the Unconscious Thought Effect: Using Mind-Wandering Measures to Investigate Thought Processes in Decision Problems With High Information Load.

Unconscious Thought Theory (Dijksterhuis, 2004) states that thinking about a complex problem unconsciously can result in better solutions than conscious deliberation. We take a fresh look at the cognitive processes underlying "unconscious" thought by analyzing data of 822 participants who worked on a complex apartment-evaluation task in three experiments. This task's information-presentation and evaluation parts were separated by different kinds of filler-interval activities, which corresponded to standard conscious-thought and unconscious-thought manipulations. Employing experience-sampling methods, we obtained thought reports during and after filler-interval engagement. Evidence concerning the existence of the Unconscious Thought Effect was mixed, with such an effect being present in the first two experiments only. In these experiments, we further found less problem deliberation to be associated with better performance on the apartment task. Interestingly, this benefit disappeared when we probed participants' thoughts during the filler interval. We suggested that explicit thought awareness diminishes the Unconscious Thought Effect.

Testing Hypotheses About Binding in Context Memory With a Hierarchical Multinomial Modeling Approach.

In experiments on multidimensional source memory, a stochastic dependency of source memory for different facets of an episode has been repeatedly demonstrated. This may suggest an integrated representation leading to mutual cuing in context retrieval. However, experiments involving a manipulated reinstatement of one source feature have often failed to affect retrieval of the other feature, suggesting unbound features or rather item-feature binding. The stochastic dependency found in former studies might be a spurious correlation due to aggregation across participants varying in memory strength. We test this artifact explanation by applying a hierarchical multinomial model. Observing stochastic dependency when accounting for interindividual differences would rule out the artifact explanation. A second goal is to elucidate the nature of feature binding: Contrasting encoding conditions with integrated feature judgments versus separate feature judgments are expected to induce different levels of stochastic dependency despite comparable overall source memory if integrated representations include feature-feature binding. The experiment replicated the finding of stochastic dependency and, thus, ruled out an artifact interpretation. However, we did not find different levels of stochastic dependency between conditions. Therefore, the current findings do not reveal decisive evidence to distinguish between the feature-feature binding and the item-context binding account.

Aging, source memory, and the experience of "remembering".

In a previous study, we found source memory for perceptual features to differentiate between younger but not older adults' reports of recollective ("remember"; R) and "know" (K) experiences. In two experiments with younger (17-30 years) and older (64-81 years) participants, we examined whether memory for meaningful speaker sources would accompany older adults' recollective experience. Indeed, memory for male and female speakers (but not partial memory for gender; Experiment 1) as well as bound memory for speakers and their facial expressions (Experiment 2) distinguished between both younger and older adults' RK reports. Thus, memory for some sources forms a common basis for younger and older adults' retrieval experience. Nonetheless, older adults still showed lower objective source memory and lower subjective source-attribution confidence than younger adults when reporting recollective experiences, suggesting that source memory is less relevant to their retrieval experience than for younger adults.

Commission errors of active intentions: the roles of aging, cognitive load, and practice.

Performing an intended action when it needs to be withheld, for example, when temporarily prescribed medication is incompatible with the other medication, is referred to as commission errors of prospective memory (PM). While recent research indicates that older adults are especially prone to commission errors for finished intentions, there is a lack of research on the effects of aging on commission errors for still active intentions. The present research investigates conditions which might contribute to older adults' propensity to perform planned intentions under inappropriate conditions. Specifically, disproportionally higher rates of commission errors for still active intentions were observed in older than in younger adults with both salient (Experiment 1) and non-salient (Experiment 2) target cues. Practicing the PM task in Experiment 2, however, helped execution of the intended action in terms of higher PM performance at faster ongoing-task response times but did not increase the rate of commission errors. The results have important implications for the understanding of older adults' PM commission errors and the processes involved in these errors.

Non-monotonic relationships between emotional arousal and memory for color and location.

Recent research points to the decreased diagnostic value of subjective retrieval experience for memory accuracy for emotional stimuli. While for neutral stimuli rich recollective experiences are associated with better context memory than merely familiar memories this association appears questionable for emotional stimuli. The present research tested the implicit assumption that the effect of emotional arousal on memory is monotonic, that is, steadily increasing (or decreasing) with increasing arousal. In two experiments emotional arousal was manipulated in three steps using emotional pictures and subjective retrieval experience as well as context memory were assessed. The results show an inverted U-shape relationship between arousal and recognition memory but for context memory and retrieval experience the relationship was more complex. For frame colour, context memory decreased linearly while for spatial location it followed the inverted U-shape function. The complex, non-monotonic relationships between arousal and memory are discussed as possible explanations for earlier divergent findings.

Controlling the stream of thought: working memory capacity predicts adjustment of mind-wandering to situational demands.

Although engaging in task-unrelated thoughts can be enjoyable and functional under certain circumstances, allowing one's mind to wander off-task will come at a cost to performance in many situations. Given that task-unrelated thoughts need to be blocked out when the current task requires full attention, it has been argued that cognitive control is necessary to prevent mind-wandering from becoming maladaptive. Extending this idea, we exposed participants to tasks of different demands and assessed mind-wandering via thought probes. Employing a latent-change model, we found mind-wandering to be adjusted to current task demands. As hypothesized, the degree of adjustment was predicted by working memory capacity, indicating that participants with higher working memory capacity were more flexible in their coordination of on- and off-task thoughts. Notably, the better the adjustment, the smaller performance decrements due to increased task demands were. On the basis of these findings, we argue that cognitive control does not simply allow blocking out task-unrelated thoughts but, rather, allows one to flexibly adjust mind-wandering to situational demands.

Conscious recollection and binding among context features.

Recent research suggests that the subjective feeling of conscious recollection is uniquely characterized by joint memory for several context features while merely familiar memories lack this property (Meiser, Sattler, & Weisser, 2008). In the present research we took the novel approach of extending the dual task paradigm to the simultaneous study of subjective retrieval experience (using the remember/know procedure) and joint memory for two orthogonal context features. While dual task load during encoding lead to reductions in the frequency of the subjective experience of conscious recollection and reductions in overall context memory, joint context memory was not affected. Furthermore, the relation of higher overall context memory for consciously recollected items than for familiar items was preserved even under dual task load. These results have import implications for theories of long-term feature binding and the processes involved in producing the experience of conscious recollection.

Bound context features are integrated at encoding.

In the present research, we tested the predictions of different accounts of context binding in "remember" judgements. Context binding, defined as the stochastically dependent retrieval of two different context features, has previously been suggested to be due to mechanisms operating at retrieval either by cueing among context features (Meiser & Bröder, 2002) or by cueing between item and context features (Starns & Hicks, 2008). These accounts, however, do not make specific assumptions regarding the underlying memory representation supporting context binding. By contrast, here we propose that a binding process at encoding integrates item and context information into a coherent memory representation. Varying the presentation of the context features during encoding either with both context features presented simultaneously or with features spread over two encoding episodes, data from two experiments corroborate the notion that binding is produced at encoding. This result suggests that a binding process integrating the context features at encoding is necessary for stochastically dependent retrieval of context features.

The role of attention for context-context binding of intrinsic and extrinsic features.

There is converging evidence that the feeling of conscious recollection is usually accompanied by the bound retrieval of context features of the encoding episode (e.g., Meiser, Sattler, & Weißer, 2008). Recently, however, important limiting conditions have been identified for the binding between context features in memory. For example, focusing on the semantics of the stimuli during encoding eliminates binding between perceptual context features (Meiser & Sattler, 2007). In the present research, we investigated the interplay of the focus of attention during encoding and stimulus characteristics in context-context binding. In particular, it has been suggested that context features differ in the degree to which they can be regarded as intrinsic or extrinsic to the items and that intrinsic features might be given more attentional processing during encoding than extrinsic features (e.g., Ecker, Zimmer, & Groh-Bordin, 2007a). In two experiments, we manipulated the "intrinsicality" of context features to investigate whether context-context binding might be limited to features that are in the focus of processing. Multinomial modeling analyses revealed that while context-context binding was eliminated for incidentally processed extrinsic context features (Experiment 1), it was preserved for intentionally processed extrinsic context features (Experiment 2).

The role of source memory in older adults' recollective experience.

Younger adults' "remember" judgments are accompanied by better memory for the source of an item than "know" judgments. Furthermore, remember judgments are not merely associated with better memory for individual source features but also with bound memory for multiple source features. However, older adults, independent of their subjective memory experience, are generally less likely to "bind" source features to an item and to each other in memory (i.e., the associative deficit). In two experiments, we tested whether memory for perceptual source features, independently or bound, is also the basis for older adults' remember responses or if their associative deficit leads them to base their responses on other types of information. The results suggest that retrieval of perceptual source features, individually or bound, forms the basis for younger but not for older adults' remember judgments even when the overall level of memory for perceptual sources is closely equated (Experiment 1) and when attention is explicitly directed to the source information at encoding (Experiment 2).

A diffusion model analysis of task interference effects in prospective memory.

Holding an intention often interferes with other ongoing activities, indicating that resource-demanding processes are involved in maintaining the intention and noticing the appropriate event to fulfill it. Little is known, however, about the nature of the processes underlying this task interference effect. The goal of the present research was to decompose the processes contributing to the task interference effect by applying the diffusion model (Ratcliff, Psychological Review 85:59-108, 1978) to an event-based prospective memory task. In the first experiment, we validated the interpretation of the response criterion parameter (a) of the diffusion model as reflecting strategies to cope with the anticipated demands of a prospective memory task in the context of the ongoing task. The second experiment served to investigate which underlying processes contribute to the task interference often found with prospective memory tasks. Diffusion model analyses revealed that the task interference effect was due to (1) less efficient processing in the more demanding than in the less demanding prospective memory task and (2) a more conservative response criterion. We suggest that the anticipated demands and the additional processing demands of the prospective memory task jointly contribute to the task interference effect.

Assessing the validity of multinomial models using extraneous variables: an application to prospective memory.

The class of multinomial processing tree (MPT) models has been used extensively in cognitive psychology to model latent cognitive processes. Critical for the usefulness of a MPT model is its psychological validity. Generally, the validity of a MPT model is demonstrated by showing that its parameters are selectively and predictably affected by theoretically meaningful experimental manipulations. Another approach is to test the convergent validity of the model parameters and other extraneous measures intended to measure the same cognitive processes. Here, we advance the concept of construct validity (Cronbach & Meehl, 1955 ) as a criterion for model validity in MPT modelling and show how this approach can be fruitfully utilized using the example of a MPT model of event-based prospective memory. For that purpose, we investigated the convergent validity of the model parameters and established extraneous measures of prospective memory processes over a range of experimental settings, and we found a lack of convergent validity between the two indices. On a conceptual level, these results illustrate the importance of testing convergent validity. Additionally, they have implications for prospective memory research, because they demonstrate that the MPT model of event-based prospective memory is not able to differentiate between different processes contributing to prospective memory performance.

The multinomial model of prospective memory: validity of ongoing-task parameters.

The objective of this research was to provide additional experimental validation of the multinomial processing tree (MPT) model of event-based prospective memory (Smith & Bayen, 2004). In particular, the parameters that measure trial-type detection in the ongoing task were examined. In three experiments with different response instructions, event-based prospective memory tasks were embedded in ongoing color-matching tasks. The results support the validity of the MPT model, that is, manipulations of ongoing-task difficulty affected the ongoing-task parameters of the MPT model, while leaving the estimates for the prospective and the retrospective components of prospective memory unaffected.