Working memory capacity predicts the beneficial effect of selective memory retrieval

Selective retrieval of some studied items can both impair and improve recall of the other items. This study examined the role of working memory capacity (WMC) for the two effects of memory retrieval. Participants studied an item list consisting of predefined target and nontarget items. After study of the list, half of the participants performed an imagination task supposed to induce a change in mental context, whereas the other half performed a counting task which does not induce such context change. Following presentation of a second list, memory for the original list's target items was tested, either with or without preceding retrieval of the list's nontarget items. Consistent with previous work, preceding nontarget retrieval impaired target recall in the absence of the context change, but improved target recall in its presence. In particular, there was a positive relationship between WMC and the beneficial, but not the detrimental effect of memory retrieval. On the basis of the view that the beneficial effect of memory retrieval reflects context-reactivation processes, the results indicate that individuals with higher WMC are better able to capitalise on retrieval-induced context reactivation than individuals with lower WMC.     

Part-list cuing with and without item-specific probes: The role of encoding

Part-list cuing—the detrimental effect of the presentation of a subset of studied items on recall of the remaining noncue items—was examined in three different study conditions and in the presence and absence of the noncues’ initial letters serving as item-specific probes. With a single study trial, part-list cuing was observed both with and without item-specific probes. By contrast, when participants received two study-test cycles or interrelated list items to a common story, part-list cues were found to be detrimental only in the absence of item-specific probes, but not in their presence. These results indicate that the role of item-specific probes in part-list cuing depends on encoding. The findings are consistent with a recent two-mechanism account of part-list cuing (Bäuml &; Aslan, 2006), according to which two different mechanisms mediate the effect in different encoding situations.     

Part-list cuing can be transient and lasting: the role of encoding

The presentation of a subset of learned items as retrieval cues can have detrimental effects on recall of the remaining items. For 2 types of encoding conditions, the authors examined in 3 experiments whether such part-list cuing is a transient or a lasting phenomenon. Across the experiments, the detrimental effect of part-list cues was consistently found to be transient with a high degree of interim associations and lasting with a low degree. These results indicate that the persistence of part-list cuing depends on encoding, thus challenging both strategy disruption and retrieval inhibition as general accounts of part-list cuing. A 2-mechanism account is provided according to which the 2 mechanisms mediate the effect in different encoding conditions.     

Part-list cuing as instructed retrieval inhibition

The reexposure of a subset of learned material as a retrieval cue can impair recall of the remaining material. Like part-list relearning--the reexposure of learned material for additional learning--this part-list cuing is often assumed to be the result of output order biases at test, caused by the increased strength of the reexposed material. We directly compared the effects of cuing and relearning when controlling for output order biases. In addition, we compared the two forms of reexposure with the effect of part-list retrieval. Both part-list cuing and part-list retrieval reduced recall performance for the remaining material. By contrast, part-list relearning had no such detrimental effect. These results indicate that the effect of reexposure depends on whether material is reexposed as a cue or for relearning, suggesting that part-list cuing reflects an instructional effect. Evidence is provided that part-list cuing leads to instructed covert retrieval of cue items and causes retrieval inhibition of noncue items, similar to how overt retrieval inhibits nonretrieved items.     

Obstructive sleep apnea and depression

Is there an association between obstructive sleep apnea (OSA) and depression? OSA is a common breathing-related sleep disorder. There have been reports that depressive symptoms can be associated with this sleep disorder. A number of investigations have addressed this issue. Although some have found no correlation, most studies have concluded that there is an association between OSA and depressive symptoms. Other investigations have shown that depressive symptoms improve with treatment of OSA, and that untreated OSA may contribute to treatment resistance in some cases of mood disorders. Within the framework of current psychiatric diagnostic criteria, the depressive symptoms associated with OSA can be viewed as a combination of a mood disorder secondary to a primary medical condition and an adjustment disorder with depressed mood. The question of whether OSA causes depressive symptoms can perhaps be best answered by viewing OSA and depression as having certain symptoms that are common to both disorders.     

No inhibitory deficit in older adults' episodic memory

Selectively retrieving a subset of previously studied material can cause forgetting of the unpracticed material. Such retrieval-induced forgetting is attributed to an inhibitory mechanism recruited to resolve interference among competing items. According to the inhibition-deficit hypothesis, older people experience a specific decline in inhibitory function and thus should show reduced retrieval-induced forgetting. However, the results of the two experiments reported here show the same amount of retrieval-induced forgetting in younger and older adults. These results indicate that retrieval inhibition is intact in older adults' episodic recall. The findings suggest that the common view of a general inhibitory deficit in older adults needs to be updated and that older adults show intact inhibition in some cognitive tasks and deficient inhibition in others.     

Practice Makes Perfect: Meditation and the Exchange of Spiritual Capital

Despite its ubiquity, the term ‘spiritual capital’ continues to lack a sufficient level of empirical scrutiny to merit categorical independence from its religious variant. To remedy this gap, this article presents an ethnographic study of a meditation group called the Dhyana Centre, situated at the heart of London, and offers a bottom-up account of the ways in which spiritual capital is recognized, exchanged, and adopted in the absence of institutional mechanisms of legitimacy. Building on Bradford Verter’s conceptualisation of spiritual capital as originally derived from Bourdieu’s theory of practice, this study argues that the distinct configuration between knowledgeable and practical mastery in the dynamics of spiritual capital exchange marks a modus operandi which is not fully accounted for by conventional notions of religious capital. This study of spiritual capital thus allows for the translation of a notoriously slippery phenomenon into a much more tangible object of study without having to resort to essentialist readings of spirituality.     

Directed forgetting in young children: Evidence for a production deficiency

When people are cued to forget a previously studied list of items and to learn a new list instead, such cuing typically leads to forgetting of the first list and to memory enhancement of the second. In two experiments, we examined such listwise directed forgetting in children (and adults), using a forget cue that placed either high emphasis or low emphasis on the need to forget. In the low-emphasis condition, (adult-like) List 1 forgetting was present in fourth graders, but not in first graders (and kindergartners); in contrast, in the high-emphasis condition, (adult-like) List 1 forgetting was present from first grade on. Only fourth graders showed (adult-like) List 2 enhancement, regardless of task instruction. The finding that first graders showed List 1 forgetting only in the high-emphasis condition points to a production deficiency in first graders’ directed forgetting, suggesting that the children are capable of intentional forgetting but fail to do so spontaneously. The finding that first graders showed List 1 forgetting without List 2 enhancement suggests that the two directed-forgetting effects are mediated by different processes with different developmental trajectories.     

The role of item similarity in part-list cueing impairment

The presentation of a subset of studied items as retrieval cues can have detrimental effects on recall of the remaining (target) items. In three experiments we examined whether such part-list cueing impairment depends on the similarity between cue and target items. Item similarity was manipulated by making use of pre-experimental semantic similarities between cue and target items (Experiments 1 and 2), or was episodically induced through a similarity-encoding task, in which participants were asked to interrelate cue and target items in a meaningful way (Experiment 3). In all three experiments reliable part-list cueing impairment arose when the similarity between cues and targets was low, but no impairment was found when the similarity between cues and targets was high. Inhibitory as well as non-inhibitory explanations of the findings are discussed.