Memory reactivation effects independent of reconsolidation

Memory reactivation is an important process resulting from reexposure to salient training-related information whereby a memory is brought from an inactive to an active state. Reactivation is the first stage of memory retrieval but can result from the exposure to salient cues without any behavioral output. Such cue-induced reactivation, although frequently used by neuroscientists to study reconsolidation, has seldom been considered as a process in its own right and studied as such. This review presents arguments indicating that memory reactivation has two main consequences: (1) to enhance the accessibility of the target memory and (2) to make the memory malleable. Accordingly, reactivation creates a transient state during which the content of the memory is easily accessible and can be modified and/or updated. As both of these aspects can be observed shortly after memory reactivation, this review emphasizes that reconsolidation is not necessarily required for these processes and calls attention to reactivation as a factor in the dynamics of the memory.     

Neither separate nor equivalent: Relationships between feature representations within bound objects

Evidence suggests that binding, or encoding a feature with respect to other features in time and space, can convey cognitive advantages. However, evidence across many kinds of stimuli and paradigms presents a mixed picture, alternatively showing cognitive costs or cognitive advantages associated with maintaining bound representations. We examined memory for colored letters drawn from similar and distinct color sets under circumstances that encouraged or discouraged the maintenance of color-letter binding. Our results confirmed previous change recognition research showing feature recognition improvement under explicit instructions to maintain binding. Color memory improved during binding, showing a reduced detrimental effect of feature similarity on retrieval, particularly when the letter served as the retrieval cue for a letter-color object. We found that feature recognition improved when two conditions were met: 1) relationships between features were to-be-remembered, and 2) the feature conjunction was relevant at test. Our results further suggest that this feature advantage arises because the encoded relationship between the features facilitates retrieval, not because features and objects are represented simultaneously in separate buffers.     

Effects of impoverished environmental conditions on working memory performance

This cross-cultural study investigates the impact of background experience on four verbal and visuo-spatial working memory (WM) tasks. A total of 84 children from low-income families were recruited from the following groups: (1) Portuguese immigrant children from Luxembourg impoverished in terms of language experience; (2) Brazilian children deprived in terms of scholastic background; (3) Portuguese children from Portugal with no disadvantage in either scholastic or language background. Children were matched on age, gender, fluid intelligence, and socioeconomic status and completed four simple and complex span tasks of WM and a vocabulary measure. Results indicate that, despite large differences in their backgrounds and language abilities, the groups exhibited comparable performance on the visuo-spatial tasks dot matrix and odd-one-out and on the verbal simple span task digit recall. Group differences emerged on the verbal complex span task counting recall with children from Luxembourg and Portugal outperforming children from disadvantaged schools in Brazil. The study suggests that whereas contributions of prior knowledge to digit span, dot matrix, and odd-one-out are likely to be minimal, background experience can affect performance on counting recall. Implications for testing WM capacity in children growing up in poverty are discussed.     

Book Reviews

Abstract

Johnson, J.V., & Hohansson, G. (Eds.)- (1991). The psychosocial work environment: Work organization, democratization and health. Essays in memory of Bertil Gar dell. New York: Baywood. pp. 335. ISBN 0-89503-078-0 (hardback). ISBN 0-89503-077-2 (paperback).

Shackel, B., & Richardson, S. (Eds.) (1991). Human factors of informatics usability. Cambridge: Cambridge University Press. Pp. 438. ISBN 0-521-36570-8. Hardback £35.00

Frese, M., & Brodbeck, F.C. (1989). Computer in Büro und Verwaltung. Berlin: Springer. Pp. 237. ISBN: 3-540-50774-4. DM 88. Published in German.     

Emotional job demands and burnout among oncology care providers

Abstract

Recent studies by Söderfeldt et al. (1996) and de Jonge et al. (1999) have demonstrated that Karasek's operationalization of job demands in his well-known Job Demands-Control (JD-C) Model (Karasek, 1979), i.e. quantitative demands, cannot capture the complexities of working with patients or clients in health care work. In the current study on burnout among 816 Dutch oncology care providers, the “traditional” JD-C Model was extended by including two types of emotional job demands. Moreover, “susceptibility to emotional contagion” was included as a potential moderator of the relationship between emotional job demands and burnout. Emotional job demands significantly contributed to the prediction of burnout, after controlling for quantitative job demands and job control. In addition, care providers' susceptibility to emotional contagion moderated the relationship between “confrontation with death and dying” and burnout. Care providers high in susceptibility to emotional contagion were more “vulnerable” to the stress associated with high emotional demands than their counterparts.     

Humor in Teams: Multilevel Relationships Between Humor Climate,Inclusion, Trust,and Citizenship Behaviors

Purpose

This study examines the cross-level influence of positive and offensive leader humor climates on employee inclusion and citizenship behaviors, and the moderating effect of trust in such relationships.

Design/Methodology/Approach

We collected data from a sample of 225 respondents nested within 23 teams from a Canadian financial organization. A multilevel confirmatory analysis was used to provide evidence that variables of this study are distinct and a HLM analysis to test the hypotheses.

Findings

We find that employees’ perception of inclusion is influenced much more by an offensive humor climate than by a positive one. The results also suggest that the perception of inclusion plays a significant intermediary role in the influence of humor climates on citizenship behavior. Finally, trust in leaders acts as an important contingent condition in the effectiveness of a humor climate.

Implications

Use of humor does not always pay. Offensive humor by supervisor is a risky strategy that may undermine the beneficial effects of positive humor climate, increase employee exclusion and weaker individual performance.

Originality/Value

Our study shows the utility of using micro- and macro-approaches, and more specifically, the relevance of adopting an integrative multilevel view of the effect of a humor environment in predicting individual inclusion and citizenship behaviors.

     

When distractors and to-be-remembered items compete for the control of action: a new perspective on serial memory for spatial information

In serial memory for spatial information, performance is impaired when distractors are interpolated between to-be-remembered (TBR) stimuli (Tremblay, Nicholls, Parmentier, & Jones, 2005). The so-called sandwich effect, combined with the use of eye tracking, served as a tool for examining the role of the oculomotor system in serial memory for spatial information. Participants had to recall the order in which sequences of TBR locations were presented. In some trials, to-be-ignored blue dots were presented after each TBR location. Our results show that response locations shift toward the location of the distractors, and this deviation is related to the eye movement deviation toward the distractor location. These results suggest that TBR and to-be-ignored locations are encoded onto a common map that could lie within the oculomotor system. Interference in memory for spatial information is interpreted in light of a model of oculomotor behavior (Godijn & Theeuwes, 2002b).     

The neurocognition of conduct disorder behaviors: specificity to physical aggression and theft after controlling for ADHD symptoms

There is growing evidence that among the different conduct disorder (CD) behaviors, physical aggression, but not theft, links to low neurocognitive abilities. Specifically, physical aggression has consistently been found to be negatively related to neurocognitive abilities, whereas theft has been shown to be either positively or not related to neurocognition. The specificity of these links needs further examination because attention deficit hyperactivity disorder (ADHD) links to both physical aggression and neurocognitive variation. The development of self-reported physical aggression and theft, from age 11 to 17 years, was studied in a prospective at-risk male cohort via a dual process latent growth curve model. Seven neurocognitive tests at age 20 were regressed on the growth parameters of physical aggression and theft. The links between neurocognition and the growth parameters of physical aggression and theft were adjusted for ADHD symptoms at ages 11 and 15 (parent, child and teacher reports). Results indicated that verbal abilities were negatively related to physical aggression while they were positively associated with theft. However, inductive reasoning was negatively associated with increases in theft across adolescence. Symptoms of ADHD accounted for part of the neurocognitive test links with physical aggression but did not account for the associations with theft. These differences emphasize the importance of examining specific CD behaviors to better understand their neurodevelopmental mechanisms. They also suggest that youth who engage in different levels of physical aggression or theft behaviors may require different preventive and corrective interventions.     

The role of recollection in source memory: an examination of schizophrenia patients and their first-degree relatives

Source recognition memory deficits have repeatedly been observed in people with schizophrenia (SZ), and have also recently been observed in their first-degree relatives. These deficits have been hypothesized to result, at least in part, from impairments in the conscious recollection process. Although other processes are clearly also affected in SZ, it has been proposed that impairments in the conscious recollection process could be a parsimonious explanation for the source memory deficits observed in their relatives. Here, we tested 25 patients with SZ and 34 of their non-affected parents, as well as two groups of matched healthy controls, on a short-term associative memory task that shares the characteristics of standard source recognition tasks but minimizes the need for recollection of stored information from memory. This task was administered in order to determine if deficits can still be observed in these people when involvement of the conscious recollection process is minimized. We observed deficits on our short-term source memory task in people with SZ, but their first-degree relatives did not share this deficit. These results support the idea that multiple memory processes supporting associative/source memory are affected in SZ, whereas the source memory deficits previously observed in relatives of SZ seem specific to tasks that rely on the conscious recollection process.