Memory Without Consolidation: Temporal Distinctiveness Explains Retroactive Interference

Is consolidation needed to account for retroactive interference in free recall? Interfering mental activity during the retention interval of a memory task impairs performance, in particular if the interference occurs in temporal proximity to the encoding of the to‐be‐remembered (TBR) information. There are at least two rival theoretical accounts of this temporal gradient of retroactive interference. The cognitive neuroscience literature has suggested neural consolidation is a pivotal factor determining item recall. According to this account, interfering activity interrupts consolidation processes that would otherwise stabilize the memory representations of TBR items post‐encoding. Temporal distinctiveness theory, by contrast, proposes that the retrievability of items depends on their isolation in psychological time. According to this theory, information processed after the encoding of TBR material will reduce the temporal distinctiveness of the TBR information. To test between these accounts, implementations of consolidation were added to the SIMPLE model of memory and learning. We report data from two experiments utilizing a two‐list free recall paradigm. Modeling results imply that SIMPLE was able to model the data and did not benefit from the addition of consolidation. It is concluded that the temporal gradient of retroactive interference cannot be taken as evidence for memory consolidation.     

Sleep enhances explicit recollection in recognition memory

Recognition memory is considered to be supported by two different memory processes, i.e., the explicit recollection of information about a previous event and an implicit process of recognition based on an acontextual sense of familiarity. Both types of memory supposedly rely on distinct memory systems. Sleep is known to enhance the consolidation of memories, with the different sleep stages affecting different types of memory. In the present study, we used the process-dissociation procedure to compare the effects of sleep on estimates of explicit (recollection) and implicit (familiarity) memory formation on a word-list discrimination task. Subjects studied two lists of words before a 3-h retention interval of sleep or wakefulness, and recognition was tested afterward. The retention intervals were positioned either in the early night when sleep is dominated by slow-wave sleep (SWS), or in the late night, when sleep is dominated by REM sleep. Sleep enhanced explicit recognition memory, as compared with wakefulness (P < 0.05), whereas familiarity was not affected by sleep. Moreover, explicit recognition was particularly enhanced after sleep in the early-night retention interval, and especially when the words were presented with the same contextual features as during learning, i.e., in the same font (P < 0.05). The data indicate that in a task that allows separating the contribution of explicit and implicit memory, sleep particularly supports explicit memory formation. The mechanism of this effect appears to be linked to SWS.     

Spousal influence on employees’ career paths in dual ladder systems: a dyadic model

ABSTRACT

This cross-sectional field study examines the influence of employee and spousal characteristics on employees’ career-related motivations in dual ladder systems. We go beyond “constraints-based” explanations of spousal influence and focus on the degree to which the spouse has aspirations for the focal employee’s career – referred to as spousal career aspirations. Using a dyadic study design, we tested a model that specifies the influence of both partners’ career salience and materialism on an employee’s motivation for a particular career path: as manager or technical specialist. According to survey responses from a matched sample of 207 employees and their spouses, the spouse’s career salience and materialism (the latter only for women) were associated with higher levels of spousal career aspirations. In turn, those employees whose spouses aspired for them to have a career were less motivated to obtain a specialist position. Employees’ own career salience was positively associated with their motivation for a managerial position and, in combination with high levels of spousal career aspirations, pulled employees away from a career on the technical ladder. Our results shed light on the family-relatedness of career decisions and have notable implications for dual ladder organizations.     

Shifting from implicit to explicit knowledge: different roles of early- and late-night sleep

Sleep has been shown to promote the generation of explicit knowledge as indicated by the gain of insight into previously unrecognized task regularities. Here, we explored whether this generation of explicit knowledge depends on pre-sleep implicit knowledge, and specified the differential roles of slow-wave sleep (SWS) vs. rapid eye movement (REM) sleep in this process. Implicit and explicit knowledge (insight) related to a hidden regularity were assessed in an associative motor-learning task (number reduction task, NRT), which was performed in two sessions (initial practice and retest) separated by 3 h of either early-night sleep, rich in SWS, or of late-night sleep, rich in REM sleep. About half of the participants developed signs of implicit rule knowledge (i.e., speeded reaction times for responses determined by the hidden regularity) at initial practice preceding early or late sleep. Of these, half developed explicit knowledge across early-night sleep, significantly more than across late-night sleep. In contrast, late-night subjects preferentially remained on the level of implicit rule knowledge after sleep. Participants who did not develop implicit knowledge before sleep had comparable rates of transition to implicit or explicit knowledge across early and late sleep. If subjects gained explicit knowledge across sleep, this was associated with lower amounts of REM sleep, specifically in the late-night group. SWS predominant during the early night may restructure implicit memory representations in a way that allows creating an explicit representation afterward, whereas REM sleep in the late night appears to stabilize them in their implicit form.     

Social perception as induction and inference: an integrative model of intergroup differentiation, ingroup favoritism, and differential accuracy

Three general properties of social stereotypes are the perception of differences between ingroups and outgroups (intergroup differentiation), the perception of ingroups as having more desirable attributes than outgroups (ingroup favoritism), and the greater accuracy of ingroup perceptions (differential accuracy). We present and test an inductive-reasoning model that accounts for all 3 phenomena, and we explicate the relations among them. Based on empirical evidence, the model assumes that most people have a positive self-image, that they project these self-images more strongly to ingroups than to outgroups, and that their self-images are valid cues for judgments about social groups. Two minimal-group experiments using a crossed-categorization paradigm support the model and provide new evidence for underlying psychological processes.     

Preschoolers' inhibition in their home: relation to temperament

Researchers assessed 58 preschoolers' reactions to an unfamiliar person and unfamiliar objects in their familiar home environment. Children participated in a 30-min procedure designed to elicit behavioral inhibition, including (a) a free-play period with a stranger present, (b) a structured interaction with the stranger, and (c) uncertainty-eliciting tasks. Behaviors representing the child's reactions toward the mother, stranger, and novel objects were coded. Mothers completed a temperament scale. Preschoolers exhibited behaviors indicative of inhibition toward unfamiliar social and nonsocial stimuli; behaviors remained stable across increasingly intrusive episodes. The approach/withdrawal component of temperament was related to behavioral inhibition. Individual differences in mood did not appear to be related to differences in inhibition. Parent reported temperament was related to researcher-observed behaviors.     

The intergroup sensitivity effect in mergers and acquisitions: Testing the role of merger motives

Research has shown that people are more defensive to criticism when it stems from an outgroup member, compared to an ingroup member (the intergroup sensitivity effect: ISE). We conducted two online vignette experiments to examine the ISE in the context of an organizational merger and the role of merger motives for the ISE. We predicted that the ISE would also emerge in mergers and acquisitions (M&As), but people would respond less negatively to criticism from the outgroup when the motive for the merger is described as achieving synergies rather than growth. In Experiment 1 (N = 452), which did not mention any motives behind the acquisition, a significant ISE emerged. Experiment 2 (N = 587) again showed an ISE regardless of the merger motive. In both experiments, the ISE was mediated by perceptions of the outgroup criticism as less legitimate and constructive. Overall, this research points to the intergroup sensitivity effect as a relevant phenomenon during post-merger integration.     

A Longitudinal Study of Predictors of Housing Stability,Housing Quality,and Mental Health Functioning Among Single Homeless Individuals Staying in Emergency Shelters

The current study examined risk and resilience factors at multiple levels that affect homeless individuals' ability to exit homelessness and achieve housing stability. It also examined the relationship between housing status, housing quality and mental health functioning. The methodology is a longitudinal study of single homeless individuals staying in emergency shelters in a medium‐sized Canadian city who were followed for a 2 year period. Data were collected from participants at a baseline interview when they were homeless and at a 2‐year follow‐up. There were 329 participants interviewed at baseline and 197 (59.9%) participants interviewed at follow‐up. Results from a structural equation modelling analysis found that having interpersonal and community resources were predictive of achieving housing stability. Specifically, having a larger social support network, access to subsidized housing, and greater income was related to achieving housing stability. On the other hand, having a substance use problem was a risk factor associated with a failure to achieving housing stability. Being female, feeling personally empowered, having housing that is perceived of being of higher quality were directly predictive of mental health functioning at follow‐up. Findings are discussed in the context of previous research and their policy implications.     

The impact of post-learning sleep vs. wakefulness on recognition memory for faces with different facial expressions

A beneficial effect of sleep after learning, compared to wakefulness, on memory formation has been shown in many studies using a variety of tasks. However, none of these studies has specifically addressed recognition memory for faces so far. The recognition of familiar faces, together with the extraction of emotional information from facial expression, is a fundamental cognitive skill in human everyday life, for which specific neural systems and mechanisms of processing have been developed. Here, we investigated the role of post-learning sleep for later recognition memory for neutral, happy, and angry faces. Twelve healthy subjects, after judging the emotional valence of the faces in the evening (learning phase), either slept normally in the subsequent night, with sleep recorded polysomnographically (sleep condition), or remained awake (wake condition) according to a cross-over design. Recognition testing took place in the second evening after learning, i.e. after a further night of regular sleep spent at home. Sleep after learning, compared to wakefulness, enhanced memory accuracy in recognition memory. This effect was independent of the emotional valence of facial expression. The response criterion at recognition testing did not differ between sleep and wake conditions. The amount of non rapid eye movement (NonREM) sleep during post-learning sleep correlated positively with memory accuracy at recognition testing, while time in REM sleep was associated with a speeded responding to the learned faces. Results suggest that face recognition, despite its dependence on specialized brain systems, nevertheless relies on the general neural mechanisms of sleep-associated memory consolidation.