Longitudinal deficits to attention, executive, and working memory in subtypes of mild cognitive impairment.

Objective: Mild cognitive impairment (MCI) has emerged as a classification for a prodromal phase of cognitive decline that may precede the emergence of Alzheimer's disease (AD). Recent research suggests that attention, executive, and working memory deficits may appear much earlier in the progression of AD than traditionally conceptualized, and may be more consistently associated with the later development of AD than memory processing deficits. The present study longitudinally tracked attention, executive and working memory functions in subtypes of MCI. Method: In a longitudinal study, 52 amnestic MCI (a-MCI), 29 nonamnestic MCI (na-MCI), and 25 age- and education-matched controls undertook neuropsychological assessment of visual and verbal memory, attentional processing, executive functioning, working memory capacity, and semantic language at 10 month intervals. Results: Analysis by repeated measures ANOVA indicate that the a-MCI and na-MCI groups displayed a decline in simple sustained attention (ηp2 = .054) with a significant decline on a task of divided attention (ηp2 = .053) being evident in the a-MCI group. Stable deficits were found on other measures of attention, working memory and executive function in the a-MCI and na-MCI groups. The a-MCI group displayed stable impairments to visual and verbal memory. Conclusions: The results indicate that a-MCI and na-MCI display a stable pattern of deficits to attention, working memory, and executive function. The decline in simple sustained attention in a-MCI and n-MCI groups and to divided attention in a-MCI may be early indicators of possible transition to dementia from MCI. However, further research is required to determine this. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Relationship of early life stress and psychological functioning to blood pressure in the CARDIA study.

[Correction Notice: An erratum for this article was reported in Vol 28(4) of Health Psychology (see record 2009-10284-005). A URL for supplemental materials was included due to a production error. There are no supplemental materials for this article.] Objective: Low childhood socioeconomic status (CSES) and a harsh early family environment have been linked with health disorders in adulthood. In this study, the authors present a model to help explain these links and relate the model to blood pressure change over a 10-year period in the Coronary Artery Risk Development in Young Adults sample. Design: Participants (N = 2,738) completed measures of childhood family environment, parental education, health behavior, and adult negative emotionality. Main Outcome Measures: These variables were used to predict initial systolic and diastolic blood pressure (SBP and DBP, respectively) and the rate of blood pressure change over 10 years. Results: Structural equation modeling indicated that family environment was related to negative emotions, which in turn predicted baseline DBP and SBP and change in SBP. Parental education directly predicted change in SBP. Although African American participants had higher SBP and DBP and steeper increases over time, multiple group comparisons indicated that the strength of most pathways was similar across race and gender. Conclusion: Low CSES and harsh family environments help to explain variability in cardiovascular risk. Low CSES predicted increased blood pressure over time directly and also indirectly through associations with childhood family environment, negative emotionality, and health behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The structure of working memory abilities across the adult life span.

The present study addresses three questions regarding age differences in working memory: (1) whether performance on complex span tasks decreases as a function of age at a faster rate than performance on simple span tasks; (2) whether spatial working memory decreases at a faster rate than verbal working memory; and (3) whether the structure of working memory abilities is different for different age groups. Adults, ages 20–89 (n = 388), performed three simple and three complex verbal span tasks and three simple and three complex spatial memory tasks. Performance on the spatial tasks decreased at faster rates as a function of age than performance on the verbal tasks, but within each domain, performance on complex and simple span tasks decreased at the same rates. Confirmatory factor analyses revealed that domain-differentiated models yielded better fits than models involving domain-general constructs, providing further evidence of the need to distinguish verbal and spatial working memory abilities. Regardless of which domain-differentiated model was examined, and despite the faster rates of decrease in the spatial domain, age group comparisons revealed that the factor structure of working memory abilities was highly similar in younger and older adults and showed no evidence of age-related dedifferentiation. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Deficiencies in the detection of cognitive deficits.

Numerous studies purport to show that cardiopulmonary bypass (CPB) surgery is associated with persistent postoperative cognitive decline. In J. R. Keith et al. (2002), the authors argued that reports of post-CPB cognitive declines have often been quantified using data analysis methods that were based on tenuous assumptions and overlooked problems associated with familywise Type I errors. Four peers who are recognized for their expertise in neuropsychological outcomes research evaluated the arguments developed in the J. R. Keith et al. article, critiqued the study presented in that article, and offered suggestions for how to investigate whether cognitive decline occurs reliably after CPB. In this reply article, the authors respond to the open-peer commentaries made regarding the J. R. Keith et al. study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impaired timing precision produced by striatal D2 receptor overexpression is mediated by cognitive and motivational deficits.

Increased striatal dopamine D2 receptor activity is thought to contribute to the pathophysiology of schizophrenia. To model this condition in mice, Kellendonk et al. (2006) generated transgenic mice that selectively overexpress the D2 receptor in striatum (D2OE). Drew et al. (2007) reported that D2OE mice display deficits in interval timing and motivation. The present study further explored the impaired timing in D2OE mice. Experiment 1 assessed the role of motivation in producing timing deficits in the peak procedure and found that performance in D2OE mice was improved by increasing motivation. In addition, performance was impaired in control mice when motivation was decreased. In Experiment 2, we found that D2OE mice have no timing impairment when tested using the bisection task, a procedure in which the measure of timing performance is less influenced by motivation to respond. In Experiment 3, we also used the bisection task and found selective impairment in timing of long durations in D2OE mice. These results suggest that striatal D2 overexpression impairs timing by decreasing motivation and through its impact on working memory and/or sustained attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impaired fear memories are correlated with subregion-specific deficits in hippocampal and amygdalar LTP.

Inbred mouse strains have different genetic backgrounds that likely influence memory and long-term potentiation (LTP). LTP, a form of synaptic plasticity, is a candidate cellular mechanism for some forms of learning and memory. Strains with impaired fear memory may have selective LTP deficits in different hippocampal subregions or in the amygdala. The authors assessed fear memory in 4 inbred strains: C57BL/6NCrlBR (B6), 129S1/SvImJ (129), C3H/HeJ (C3H), and DBA/2J (D2). The authors also measured LTP in the hippocampal Schaeffer collateral (SC) and medial perforant pathways (MPP) and in the basolateral amygdala. Contextual and cued fear memory, and SC and amygdalar LTP, were intact in B6 and 129, but all were impaired in C3H and D2. MPP LTP was similar in all 4 strains. Thus, SC, but not MPP, LTP correlates with hippocampus-dependent contextual memory expression, and amygdalar LTP correlates with amygdala-dependent cued memory expression, in these inbred strains. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related deficits in mice performing working memory tasks in a water maze.

This study determined whether mice exhibit spatial working memory deficits with increased age. C57BL/6JNia mice of 3 different ages were tested in the Morris water maze with 2 protocols designed to assess immediate and delayed working memory abilities. Young mice required multiple trials in order to show improvements in the working memory task. Deficits in immediate working memory were detected in both 10- and 24- to 26-month-old mice. Reference memory deficits and declines in performance in the delayed working memory task were only seen in 24- to 26-month-olds. This increased susceptibility of immediate working memory processes to the aging process in mice may be related to their need for more rehearsal in the water maze than other species. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fear conditioning in inbred mouse strains: An analysis of the time course of memory.

Three mouse strains were examined for short- and long-term memory for Pavlovian fear conditioning measured 1 hr and 24 hr after conditioning. Both DBA/2J and CBA/J mice exhibit reduced long-term memory for contextual fear conditioning compared with C57BL/6J mice. In cued fear conditioning, however, DBA/2J mice show reduced short- and long-term memory compared with C57BL/6J mice, whereas CBA/J mice exhibit reductions only in short-term memory. These results underscore the importance of examining the time course of memory retention, and they suggest that inbred mouse strains may provide a diversity of phenotypes. The results also suggest that the processes of short- and long-term memory storage as well as contextual and cued fear conditioning are dissociable and are mediated by genetically distinct neurobiological mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Models of visuospatial and verbal memory across the adult life span.

The authors investigated the distinctiveness and interrelationships among visuospatial and verbal memory processes in short-term, working, and long-term memories in 345 adults. Beginning in the 20s, a continuous, regular decline occurs for processing-intensive tasks (e.g., speed of processing, working memory, and long-term memory), whereas verbal knowledge increases across the life span. There is little differentiation in the cognitive architecture of memory across the life span. Visuospatial and verbal working memory are distinct but highly interrelated systems with domain-specific short-term memory subsystems. In contrast to recent neuroimaging data, there is little evidence for dedifferentiation of function at the behavioral level in old compared with young adults. The authors conclude that efforts to connect behavioral and brain data yield a more complete understanding of the aging mind. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of transdermal nicotine and concurrent smoking on cognitive performance in tobacco-abstinent smokers.

Smokers experience cognitive decrements during tobacco abstinence and boosts in performance on resumption of smoking. Few studies have examined whether smoking cessation treatments such as transdermal nicotine (TN) ameliorate these decrements or attenuate the cognitive effects of smoking. Identifying the effects of nicotine on these tobacco-related changes in performance could guide the development of more efficacious treatments. The purpose of this double-blind, randomized, laboratory study was to use process-specific cognitive tasks to examine the effects of TN and tobacco smoking on attention and working memory in overnight-abstinent smokers (N = 124; 54 women). Each participant completed 4 sessions lasting 6.5 hr corresponding to 0-, 7-, 14-, or 21-mg TN doses, and smoked a single cigarette 4 hr after TN administration. Outcome measures were administered before and after smoking and included tasks measuring attention (alerting, orienting, and executive function), working memory (verbal and spatial), and psychomotor function. Analysis of variance (p     

The development of bilingual children's early spelling in English.

By using an extended version of R. Treiman, M. Cassar, and A. Zukowski's (1994) flaps spelling task (wa_er, is it t or d in water?), the authors investigated the metalinguistic awareness of 6-year-old bilingual children from 3 different language backgrounds (LBs): English-LB (English-L1, Mandarin-L2), Chinese-LB (Mandarin-L1, English L2), and Malay-LB (Bahasa Malaysia-L1, English-L2). Treiman et al. found that unilingual English-speaking children's performance was poorer on flapped words than on control words and better on /d/ flaps than on /t/ flaps, suggesting phonology is salient even for beginners. The data for bilinguals revealed predictable group differences in the use of orthographic and phonological awareness for early spellings, even though the children were all attending the same English-medium kindergarten. Possible educational implications for linguistic minority children are briefly discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Working memory in mild Alzheimer's disease and early Parkinson's disease.

Alzheimer's disease (AD) and Parkinson's disease (PD) impair working memory (WM). It is unclear, however, whether the deficits seen early in the course of these diseases are similar. To address this issue, the authors compared the performance of 22 patients with mild AD, 20 patients with early PD and without dementia, and 112 control participants on tests of inhibition, short-term memory, and 2 commonly administered tests of WM. The results suggest that although mild AD and early PD both impair WM, the deficits may be related to the interruption of different processes that contribute to WM performance. Early PD disrupted inhibitory processes, whereas mild AD did not. The WM deficits seen in patients with AD may be secondary to deficits in other cognitive capacities, including semantic memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial Working Memory Deficits in Children at Ages 3-4 Who Were Low Birth Weight, Preterm Infants.

The aim of this study was to investigate attention and perceptual and spatial working memory abilities in preterm, low birth weight preschool children without evident brain disorders as determined by normal cerebral ultrasound findings and normal motor development. The authors evaluated 19 preterm and 19 typically developing children who were matched for IQ and chronological age. Results indicated that children born prematurely without major neurological deficits and with a normal cognitive level may have specific difficulty in sustained attention, visuospatial processing, and spatial working memory when evaluated at ages 3-4. This finding is relevant for understanding the qualitative aspects of cognitive development in preterm children and the neurobiological substrate underlying this development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using the attention cascade model to probe cognitive aging.

Young and older adults searched for 2 digit targets among black letter distractors in rapid serial visual presentation. Unsurprisingly, relative to the young, the older adults performed worse on both targets and exhibited greater and longer attentional blink. The data of each group were computationally accounted for by the attention cascade model (Shih, 2008) with 7 parameters; the optimum values and 95% confidence intervals of the parameters were based on 10,000 bootstrap samples. There was no age effect on the width of the attention window or on the capacity of the consolidation processor. However, relative to the young, the older adults suffered more masking effects of the salient (and brighter) stimulus, required longer consolidation duration, and had greater and more widespread decision noise. The processing rate prior to working memory was numerically slower in older adults. Both age groups adopted inefficient strategy during the task—engaging the consolidation processor for an unnecessarily long period. Further simulations suggest that varying the duration can emulate strong or weak blinkers or nonblinkers. The attention cascade model appears a useful tool for the investigation of cognitive aging and other comparative studies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characterizing multiple memory deficits and their relation to everyday functioning in individuals with mild cognitive impairment.

The authors evaluated multiple memory processes and explored their contributions to everyday functional limitations in persons with mild cognitive impairment (MCI). Participants included individuals with amnestic MCI, nonamnestic MCI, and healthy older adults. As expected, the amnestic MCI group performed more poorly than the control and nonamnestic MCI groups on a content memory measure. Both MCI groups, however, performed more poorly than controls on the noncontent memory measures of prospective memory, temporal order memory, and source memory. Informants also reported that the MCI groups were experiencing greater difficulty than controls completing instrumental activities of daily living (IADLs). Noncontent memory measures were found to make an independent contribution to IADL performances over and above that of content memory. These findings demonstrate that impairments in memory beyond the traditionally assessed content memory are present in individuals with amnestic MCI and with nonamnestic MCI. The results further show that these noncontent memory processes, which have been linked with executive functioning, play a role in supporting IADLs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nutritional deficits during early development affect hippocampal structure and spatial memory later in life.

Development rates vary among individuals, often as a result of direct competition for food. Survival of young might depend on their learning abilities, but it remains unclear whether learning abilities are affected by nutrition during development. The authors demonstrated that compared with controls, 1-year-old Western scrub jays (Aphelocoma californica) that experienced nutritional deficits during early posthatching development had smaller hippocampi with fewer neurons and performed worse in a cache recovery task and in a spatial version of an associative learning task. In contrast, performance of nutritionally deprived birds was similar to that of controls in 2 color versions of an associative learning task. These findings suggest that nutritional deficits during early development have long-term consequences for hippocampal structure and spatial memory, which, in turn, are likely to have a strong impact on animals' future fitness (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial and object working memory deficits in Parkinson's disease are due to impairment in different underlying processes.

Working memory maintenance processes for visual-spatial and visual-object information were evaluated in patients with Parkinson's disease (PD). PD patients and controls performed a working memory task with two conditions that differed only in the aspect of the stimuli that the participant was instructed to remember: their locations or shapes. Maintenance processes were investigated by measuring accuracy over 1-s, 5-s, and 10-s delays. Results indicated that patients were impaired in maintaining object information over the delay. In contrast, the patients showed impairment on the spatial condition only when the to-be-remembered stimulus was highly similar in location to the probe, but this impairment was equivalent across the delays, suggesting that this deficit was not due to maintenance impairment. These results suggest that deficits in working memory for spatial and object information are mediated by distinct cognitive processes in nondemented patients with PD and may differ in their pathophysiological basis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychological resilience, positive emotions, and successful adaptation to stress in later life.

In 3 studies, the authors investigated the functional role of psychological resilience and positive emotions in the stress process. Studies 1a and 1b explored naturally occurring daily stressors. Study 2 examined data from a sample of recently bereaved widows. Across studies, multilevel random coefficient modeling analyses revealed that the occurrence of daily positive emotions serves to moderate stress reactivity and mediate stress recovery. Findings also indicated that differences in psychological resilience accounted for meaningful variation in daily emotional responses to stress. Higher levels of trait resilience predicted a weaker association between positive and negative emotions, particularly on days characterized by heightened stress. Finally, findings indicated that over time, the experience of positive emotions functions to assist high-resilient individuals in their ability to recover effectively from daily stress. Implications for research into protective factors that serve to inhibit the scope, severity, and diffusion of daily stressors in later adulthood are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

From infant to child: The dynamics of cognitive change in the second year of life.

The authors review several key areas of early cognitive development in which an abrupt shift in ability at the end of the second year of life has been traditionally assumed. These areas include deferred imitation, self-recognition, language, and categorization. Contrary to much conventional theorizing, the evidence shows robust continuities in all domains of early cognitive development. Where there is evidence of a reorganization of behavior that makes a new level of performance possible, dynamic-systems analyses indicate that even these may be driven by underlying processes that are continuous. Although there remain significant definitional and methodological issues to be resolved, the outcome of this review augers well for newer models in which cognitive development is viewed as a continuous, dynamic process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prenatal psychosocial stress exposure is associated with subsequent working memory performance in young women.

The aim of the present study was to examine the association between prenatal psychosocial stress exposure and subsequent prefrontal cortex-dependent working memory performance in human adults. Working memory performance was assessed using an item-recognition task under 10 mg hydrocortisone (cortisol) and placebo conditions in a sample of 32 healthy young women (mean age = 25 ± 4.34 years) whose mothers experienced a major negative life event during their pregnancy (Prenatal Stress, PS group), and in a comparison group of 27 healthy young women (mean age = 24 ± 3.4 years). The two groups did not differ in the placebo condition, however, subjects in the PS group showed longer reaction times after hydrocortisone administration compared with subjects in the comparison group (p = .02). These findings provide support for an association between prenatal stress exposure and the potential modulatory effect of cortisol on working memory performance in young adults, which may reflect compromised development of the prefrontal cortex in prenatal life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)