Effects of working memory training in young and old adults

Many cognitive abilities, including working memory and reasoning ability, decline with progressing age. In this study, we investigated whether four weeks of intensive working memory training would enhance working memory and reasoning performance in an age-comparative setting. Groups of 34 young (19–36 years) and 27 older (62–77 years) adults practiced tasks representing the three functional categories in the facet model of working memory capacity: storage and processing, relational integration, and supervision. The data were compared to those of a young and an old active control group who practiced tasks with low working memory demands. A cognitive test battery measuring near and far transfer was administered before and after training. Both age groups showed increased working memory performance in the trained tasks and in one structurally similar, but nontrained, task. Young adults also improved in a task measuring word-position binding in working memory. However, we found no far transfer to reasoning in either age group. The results provide evidence that working memory performance can be improved throughout the life span. However, in contrast to a previous study in which each facet of working memory capacity was trained separately, the present study showed that training multiple functional categories simultaneously induces less transfer.     

Personality and Memory in Old Age

We examined the impact of personality on episodic memory performance in a sample of 287 healthy adults aged 68-95 years. Extraversion and neuroticism were assessed with a standardized personality inventory. Episodic memory was assessed with an everyday task. Results from regression analyses controlling for the effects of age, gender, and education show that higher extraversion and lower neuroticism are associated with higher episodic memory performance. In addition, the strength of the correlations between neuroticism and episodic memory declined with increasing age in a male sub-sample, revealing an interaction between age and neuroticism.     

An Examination of the Value of the Generation Effect for Learning New Material

The generation effect involves an improvement in memory when learners must complete or modify materials. Several researchers have suggested that this effect involves enhanced access to learners' existing memory representations; therefore, the effect should be less effective with meaningless, low meaningful, or unfamiliar material. In the present study, the authors conducted 4 experiments in which legal nonwords were used, and they found no generation effect. In another 2 experiments in which familiar clichés were contrasted with new sentences and with unfamiliar sentences from textbooks, the results showed a greatly reduced generation effect for the new, unfamiliar material. Those findings suggest that memory strategies that depend on the generation effect will have limited effectiveness when they are applied to new or unfamiliar material.     

Number bias for the discrimination of large visual sets in infancy

This brief report attempts to resolve the claim that infants preferentially attend to continuous variables over number [e.g. Psychol. Sci. 10 (1999) 408; Cognit. Psychol.44 (2002) 33] with the finding that when continuous variables are controlled, infants as young as 6-months of age discriminate large numerical values [e.g. Psychol. Sci. 14 (2003) 396; Cognition 89 (2003) B15; Cognition 74 (2000) B1]. In two parallel experiments, we compare 6-month-old infants' ability to discriminate number and ignore continuous variables with their ability to form a representation of a cumulative surface area and ignore number. We find that infants discriminate a 2-fold change in number but fail to discriminate a 2-fold change in cumulative surface area. The results point to a more complicated relationship between discrete and continuous dimensions than implied by previous literature.     

Typical dreams: stability and gender differences

Although the variability of dream content is large, typical dream themes that occur quite often and are reported by many people can be identified (e.g., being chased, falling, flying, failing an examination, being unable to find a toilet or restroom). The present study is an investigation of the stability of the rank order of the dream themes and of gender differences in the content of dreams. The authors administered A. L. Zadra and T. A. Nielsen's (1997) Typical Dream Questionnaire to 444 participants. The findings indicated that most of the 55 dream themes occurred at least once in most of the participants' lifetimes. In addition, the correlation coefficients for the rank order of the themes were very high; that is, the relative frequencies were stable. The gender differences in the present study were in line with content analytic findings; for example, men reported dreams about physical aggression more often than did women. Overall, previous research and the present data indicate that available research results of the measurement of typical dream themes are reliable and valid. The question of the meaning of these themes or the relationship between typical dream contents and waking life experiences, however, has not yet been answered and is open to future research.     

Conflicting strategies and hemispheric suppression in a lexical decision task

The research tests the prediction of the inhibitory-interaction hypothesis that experience with a task accentuates the functional imbalance between the hemispheres. Right-handed males who were experienced readers were presented a letter string to the centre visual field for lexical decision. The string was or was not accompanied by a blinking light to the left or right visual field. It was predicted that asymmetry would be greatest for strings that spelled words, less for strings that were orthographically correct (pseudowords) and least for strings that were orthographically incorrect (nonwords) because efficient adult readers have more experience with letter strings that do than do not spell a word, and have more experience with orthographically correct than incorrect letter strings. The analysis of response times supported the prediction. Moreover, in the nonword and in early trials of the pseudoword conditions, response times were faster when one or other hemisphere was distracted than when both were engaged suggesting the hemispheres use strategies that conflict when suppression has not been accentuated by practice. As well, as the trials progressed in the pseudoword condition, asymmetry reversed before increasing suggesting that the hemispheres reduce conflict by competing for and then strengthening suppression.     

CB1 cannabinoid receptors modulate kinase and phosphatase activity during extinction of conditioned fear in mice

Cannabinoid receptors type 1 (CB1) play a central role in both short-term and long-term extinction of auditory-cued fear memory. The molecular mechanisms underlying this function remain to be clarified. Several studies indicated extracellular signal-regulated kinases (ERKs), the phosphatidylinositol 3-kinase with its downstream effector AKT, and the phosphatase calcineurin as potential molecular substrates of extinction behavior. To test the involvement of these kinase and phosphatase activities in CB1-dependent extinction of conditioned fear behavior, conditioned CB1-deficient mice (CB1(-/-)) and wild-type littermates (CB1(+/+)) were sacrificed 30 min after recall of fear memory, and activation of ERKs, AKT, and calcineurin was examined by Western blot analysis in different brain regions. As compared with CB1(+/+), the nonreinforced tone presentation 24 h after auditory-cued fear conditioning led to lower levels of phosphorylated ERKs and/or calcineurin in the basolateral amygdala complex, ventromedial prefrontal cortex, dorsal hippocampus, and ventral hippocampus of CB1(-/-). In contrast, higher levels of phosphorylated p44 ERK and calcineurin were observed in the central nucleus of the amygdala of CB1(-/-). Phosphorylation of AKT was more pronounced in the basolateral amygdala complex and the dorsal hippocampus of CB1(-/-). We propose that the endogenous cannabinoid system modulates extinction of aversive memories, at least in part via regulation of the activity of kinases and phosphatases in a brain structure-dependent manner.     

Consultation-based Academic Interventions for Children with ADHD: Effects on Reading and Mathematics Achievement

The purpose of this investigation was to evaluate the relative efficacy of two consultation-based models for designing academic interventions to enhance the educational functioning of children with attention-deficit/hyperactivity disorder (ADHD). Children (N=167) meeting DSM-IV criteria for ADHD were randomly assigned to one of two consultation groups: Individualized Academic Intervention (IAI; interventions designed using a data-based decision-making model that involved ongoing feedback to teachers) and Generic Academic Intervention (GAI; interventions designed based on consultant-teacher collaboration, representing "consultation as usual"). Teachers implemented academic interventions over 15 months. Academic outcomes (e.g., standardized achievement test, and teacher ratings of academic skills) were assessed on four occasions (baseline, 3 months, 12 months, 15 months). Hierarchical linear modeling analyses indicated significant positive growth for 8 of the 14 dependent variables; however, trajectories did not differ significantly across consultation groups. Interventions in the IAI group were delivered with significantly greater integrity; however, groups did not differ with respect to teacher ratings of treatment acceptability. The results of this study provide partial support for the effectiveness of consultation-based academic interventions in enhancing educational functioning in children with ADHD; however, the relative advantages of an individualized model over "consultation as usual" have yet to be established.     

Empirically and clinically useful decision making in psychotherapy: differential predictions with treatment response models

In the delivery of clinical services, outcomes monitoring (i.e., repeated assessments of a patient's response to treatment) can be used to support clinical decision making (i.e., recurrent revisions of outcome expectations on the basis of that response). Outcomes monitoring can be particularly useful in the context of established practice research networks. This article presents a strategy to disaggregate patients into homogeneous subgroups to generate optimal expected treatment response profiles, which can be used to predict and track the progress of patients in different treatment modalities. The study was based on data from 618 diagnostically diverse patients treated with either a cognitive-behavioral treatment protocol (n = 262) or an integrative cognitive-behavioral and interpersonal treatment protocol (n = 356). The validity of expected treatment response models to predict treatment in those 2 protocols for individual patients was evaluated. The ways such a procedure might be used in outpatient centers to learn more about patients, predict treatment response, and improve clinical practice are discussed.     

The rise and decline of prospective memory performance across the lifespan

In the present study, the trajectory of prospective memory across the lifespan was investigated in a total of 200 participants from five age groups (4- to 6-year-old children, 13- to 14-year-old adolescents, 19- to 26-year-old adults, 55- to 65-year-old adults, and 65- to 75-year-old adults). In an event-based prospective memory task the prospective and the retrospective components were assessed separately. For the prospective component, the results showed better performance for adolescents and young adults than for children and 65- to 75-year-old adults. In addition, participants belonging to the latter group were more likely to forget the retrospective component after having noticed the prospective memory targets. Overall, these results indicate that across the lifespan prospective memory performance follows a similar inverted u-shape function as is well known for retrospective episodic memory.