Search

Among other mechanisms, behavioral and cognitive development entail, on the one hand, contextual scaffolding and, on the other hand, neuromodulation of adaptive neurocognitive representations across the life span. Key brain networks underlying cognition, emotion, and motivation are innervated by major transmitter systems (e.g., the catecholamines and acetylcholine). Thus, the maturation and senescence of neurotransmitter systems have direct implications for life span development. Recent progress in molecular genetics has opened new avenues for investigating neuromodulation of behavioral and cognitive development. This special section features 6 selected reviews of recent cognitive genetic evidence on the roles of dopamine and other transmitters in different domains of behavioral and cognitive development, ranging from temperament, executive control, and working memory to motivation and goal-directed behavior in different life periods. [ABSTRACT FROM AUTHOR]

Presents experiments on the forward and backward recall processes. Effect on forward recall of tasks that interfere with the formation of inter-item associations; Effect on backward recall of tasks that alter the visual-spatial characteristics of the study material; Application of Temporal Distinctiveness Theory to the study; Models of the retrieval processes.

Reports on four experiments in which the effects of an intralist distractor task were compared for forward and backward recall. Serial-order version of theory of distributed associative memory (TODAM); Disruption of forward but not backward recall by distractor task; Retrieval-based account within the framework of temporal distinctiveness theory.

Identifies six problems brought up in Mewhort et al.'s critique of Lewandowsky and Murdock's model for serial recall based on the theory of distributed associative memory (TODAM). Exaggeration of fears arising from flaws in TODAM memory component; Implementation of deblurring mechanism to answer problems arising from response selection.

Presents an alternative technique for scope evaluation to model analysis in cognitive psychology which examines the ratio between the overall interdependence among model parameters and their sensitivity. Parameter independence and sensitivity as reliable predictor of scope; Additive model's low sensitivity parameters precision; Model scope estimation.

Gains and losses in visual search were studied across the life span in a representative sample of 298 individuals from 6 to 89 years of age. Participants searched for single-feature and conjunction targets of high or low eccentricity. Search was substantially slowed early and late in life, age gradients were more pronounced in conjunction than in feature search, and all age groups were uniformly affected by eccentricity manipulations. However, developmental and aging trends were distinctly asymmetrical: Children's performance was particularly affected by the mere presence of distracters; whereas in late life, performance was particularly impaired on target-absent trials and with increasing numbers of distracters. The implications for life span theories of cognitive and attentional development and for cognitive-speed and inhibitory-control accounts are discussed. [ABSTRACT FROM AUTHOR]

Attention and working memory are fundamental for selecting and maintaining behaviorally relevant information. Not only do both processes closely intertwine at the cognitive level, but they implicate similar functional brain circuitries, namely the frontoparietal and the frontostriatal networks, which are innervated by cholinergic and dopaminergic pathways. Here we review the literature on cholinergic and dopaminergic modulations of visual-spatial attention and visual working memory processes to gain insights on aging-related changes in these processes. Some extant findings have suggested that the cholinergic system plays a role in the orienting of attention to enable the detection and discrimination of visual information, whereas the dopaminergic system has mainly been associated with working memory processes such as updating and stabilizing representations. However, since visual-spatial attention and working memory processes are not fully dissociable, there is also evidence of interacting cholinergic and dopaminergic modulations of both processes. We further review gene-cognition association studies that have shown that individual differences in visual-spatial attention and visual working memory are associated with acetylcholine- and dopamine-relevant genes. The efficiency of these 2 transmitter systems declines substantially during healthy aging. These declines, in part, contribute to age-related deficits in attention and working memory functions. We report novel data showing an effect of dopamine COMT gene on spatial updating processes in older but not in younger adults, indicating potential magnification of genetic effects in old age. [ABSTRACT FROM AUTHOR]

Older adults often experience hearing difficulties in multitalker situations. Attentional control of auditory perception is crucial in situations where a plethora of auditory inputs compete for further processing. We combined an intensity-modulated dichotic listening paradigm with attentional manipulations to study adult age differences in the interplay between perceptual saliency and attentional control of auditory processing. When confronted with two competing sources of verbal auditory input, older adults modulated their attention less flexibly and were more driven by perceptual saliency than younger adults. These findings suggest that aging severely impairs the attentional regulation of auditory perception. [ABSTRACT FROM AUTHOR]

According to a neurocomputational theory of cognitive aging, senescent changes in dopaminergic modulation lead to noisier and less differentiated processing. The authors tested a corollary hypothesis of this theory, according to which genetic predispositions of individual differences in prefrontal dopamine (DA) signaling may affect associations between memory functions, particularly in old age. Latent correlations between factors of verbal episodic memory and spatial working memory were compared between individuals carrying different allelic variants of the Catechol-O-Methyltransferase (COMT) Val158Met polymorphism, which influences DA availability in prefrontal cortex. In younger adults (n = 973), correlations between memory functions did not differ significantly among the 3 COMT genotypes (r = .35); in older adults (n = 1333), however, the correlation was significantly higher in Val homozygotes (r = .70), whose prefrontal DA availability is supposedly the lowest of all groups examined, than in heterozygotes and Met homozygotes (both rs = .29). Latent means of the episodic memory and working memory factors did not differ by COMT status within age groups. However, when restricting the analysis to the low-performing tertile of older adults (n = 443), we found that Val homozygotes showed lower levels of performance in both episodic memory and working memory than heterozygotes and Met homozygotes. In line with the neurocomputational theory, the observed dedifferentiation of memory functions in older Val homozygotes suggests that suboptimal dopaminergic modulation may underlie multiple facets of memory declines during aging. Future longitudinal work needs to test this conjecture more directly., (PsycINFO Database Record (c) 2014 APA, all rights reserved.)

Multitalker situations confront listeners with a plethora of competing auditory inputs, and hence require selective attention to relevant information, especially when the perceptual saliency of distracting inputs is high. This study augmented the classical forced-attention dichotic listening paradigm by adding an interaural intensity manipulation to investigate developmental differences in the interplay between perceptual saliency and attentional control during auditory processing between early and middle childhood. We found that older children were able to flexibly focus on instructed auditory inputs from either the right or the left ear, overcoming the effects of perceptual saliency. In contrast, younger children implemented their attentional focus less efficiently. Direct comparisons of the present data with data from a recently published study of younger and older adults from our group suggest that younger children and older adults show similar levels of performance. Critically, follow-up comparisons revealed that younger children's performance restrictions reflect difficulties in attentional control only, whereas older adults' performance deficits also reflect an exaggerated reliance on perceptual saliency. We conclude that auditory attentional control improves considerably from middle to late childhood and that auditory attention deficits in healthy aging cannot be reduced to a simple reversal of child developmental improvements.

Postural control performances of 18 younger and 18 older adults were repeatedly measured on 45 weekdays with five trials per day. This design made it possible to dissociate between long-term trends and processing fluctuations in the sensorimotor domain at moment-to-moment, trial-to-trial, and day-to-day levels. Older adults fluctuated more than younger adults at all timescales. Age differences in trial-to-trial and day-to-day processing fluctuations were reduced but remained statistically significant when controlling for fluctuations on faster timescales. We concluded that age differences in intraindividual fluctuations at the longer timescales are in part related to age differences in low-level system robustness, suggesting a cascade of effects across multiple timescales.

Many social interactions require the synchronization--be it automatically or intentionally--of one's own behavior with that of others. Using a dyadic drumming paradigm, the authors delineate lifespan differences in interpersonal action synchronization (IAS). Younger children, older children, younger adults, and older adults in same- and mixed-age dyads were instructed to drum in synchrony with their interaction partner at a constant, self-chosen tempo. Adult-only dyads showed the highest and children-only the lowest levels of IAS accuracy. It is important to note that children improved reliably in IAS accuracy when paired with older partners. The observed age-related differences in IAS accuracy remained reliable after statistically controlling for individual differences in the ability to synchronize to a metronome and for between-dyad differences in tempo. The authors conclude that IAS improves from middle childhood to adulthood and that adult interaction partners may facilitate its development., ((c) 2011 APA, all rights reserved.)

Using a population-based sample of 263 individuals ranging from 6 to 89 years of age, we investigated the gains and losses in the abilities to (a) use exogenous cues to shift attention covertly and (b) ignore conflicting information across the life span. The participants' ability to shift visual attention was tested by a typical Posner-type orienting task with valid and invalid peripheral cues. To tap conflict resolution, we asked participants to perform a color version of the Eriksen-type flanker task. The observed cross-sectional age differences in our data indicate that the ability to deal with conflicting information and the ability to covertly orient attention show different cross-sectional age gradients during childhood and that only conflict resolution mechanisms show a marked negative age difference in old age. Moreover, the data suggest that although the overall performance of the participants can, in part, be accounted for by individual differences in information processing speed, performance in the orienting and conflict task depends on factors related to the specific development of the two attentional systems in question.

Increased intraindividual variability (IIV), reflecting within-person fluctuations in behavioral performance, is commonly observed in aging as well as in select disorders including traumatic brain injury, schizophrenia, attention-deficit hyperactivity disorder (ADHD), and dementia. Much recent progress has been made toward understanding the functional significance of IIV in cognitive performance (MacDonald, Nyberg, & Bäckman, 2006) and biological information processing (Stein, Gossen, & Jones 2005), with parallel efforts devoted to investigating the links between older adults' deficient neuromodulation and their more variable neuronal and cognitive functions (Bäckman, Nyberg, Lindenberger, Li, & Farde, 2006). Despite these advances in the study of IIV, there has been little empirical examination of underlying neural correlates and virtually no synthesis of extant findings. The present review summarizes the accumulating empirical evidence linking age-related increases in IIV in cognitive performance to neural correlates at anatomical, functional, neuromodulatory, and genetic levels. Computational theories of neural dynamics (e.g., Li, Lindenberger, & Sikström, 2001) are also introduced to illustrate how age-related neuromodulatory deficiencies may contribute to increased neuronal noise and render information processing in aging neurocognitive systems to be less robust. The potential benefits of stochastic resonance and external noise are also discussed with respect to processing subthreshold stimuli (e.g., Li, von Oertzen, & Lindenberger, 2006). We conclude by highlighting important challenges and outstanding research issues that remain to be answered in the study of IIV., (PsycINFO Database Record Copyright (c) 2009 APA, all rights reserved)

Opposing scenarios about age-related increases and decreases in intraindividual variability are found in the literature: Whereas accumulating evidence indicates that cognitive functioning is characterized by an age-related increase of short-term variability, age-related decreases in variability could be expected in affective states on the basis of theories of emotion regulation and self development. We examined age differences in intraindividual variability of positive affect (PA) and negative affect (NA) and in contingencies among daily affect, daily stress, and daily events using up to 45 daily assessments of 18 young (20-30 years) and 19 older (70-80 years) adults. Whereas age groups differed little in average affect levels, older adults showed significantly less variability in PA and NA than young adults. Age differences accounted for greater variance in variability than personality factors. Multilevel modeling indicated that for young but not older adults, PA was higher (lower) on days with a positive (negative) event, and NA was lower on days with a positive event. There were no age differences in daily affect reactivity to appraised stress severity., (PsycINFO Database Record Copyright (c) 2009 APA, all rights reserved)

Working memory (WM) declines prominently during normal aging. The mechanisms underlying this decline are not fully understood. The authors analyzed performance on 2 versions of a 2-back spatial WM task to assess younger and older adults' responses to lures (i.e., nontarget items that match an item earlier in the sequence but not at the current target lag). Results demonstrate lure interference effects that are particularly pronounced among older adults. At the same time, however, older adults showed facilitation for targets. Taken together, these findings suggest that the contribution of familiarity signals to WM performance increases during normal aging.

Adult age differences in cognitive plasticity have been studied less often in working memory than in episodic memory. The authors investigated the effects of extensive working memory practice on performance improvement, transfer, and short-term maintenance of practice gains and transfer effects. Adults age 20-30 years and 70-80 years practiced a spatial working memory task with 2 levels of processing demands across 45 days for about 15 min per day. In both age groups and relative to age-matched, no-contact control groups, we found (a) substantial performance gains on the practiced task, (b) near transfer to a more demanding spatial n-back task and to numerical n-back tasks, and (c) 3-month maintenance of practice gains and near transfer effects, with decrements relative to postpractice performance among older but not younger adults. No evidence was found for far transfer to complex span tasks. The authors discuss neuronal mechanisms underlying adult age differences and similarities in patterns of plasticity and conclude that the potential of deliberate working memory practice as a tool for improving cognition in old age merits further exploration., (Copyright (c) 2009 APA, all rights reserved.)

The authors examined life-span differences in the maintenance of skilled episodic memory performance by assessing 100 individuals (10 -11, 12-13, 21-26, and 66-79 years old) 11 months after termination of an intensive multisession mnemonic training program (Y. Brehmer, S.-C. Li, V. Müller, T. von Oertzen, & U. Lindenberger, 2007). Skill maintenance was tested in 2 follow-up sessions, the first without and the second with mnemonic reinstruction. Younger and older adults' average performance levels were stable across time. In contrast, both younger and older children's memory performance improved beyond originally attained levels. Older adults' performance improved from the first to the second follow-up session, presumably profiting from instruction-induced skill reactivation. Results suggest that (a) skill maintenance is largely intact in healthy older adults, (b) older adults need environmental support to fully reactivate their former skill levels (cf. F. I. M. Craik, 1983), and (c) children adapt a skill learned 11 months ago to their increasing cognitive capabilities.

Memory plasticity, or the ability to improve one's memory performance through instruction and training, is known to decline during adulthood. However, direct comparisons among middle childhood, adulthood, and old age are lacking. The authors examined memory plasticity in an age-comparative multisession training study. One hundred and eight participants ages 9-10, 11-12, 20-25, and 65-78 years learned and practiced an imagery-based mnemonic technique to encode and retrieve words by location cues. Individuals of all ages were able to acquire and optimize use of the technique. Older adults and children showed similar baseline performance and improvement through mnemonic instruction. However, in line with tenets from life-span psychology (P. B. Baltes, 1987), children profited more from mnemonic practice and reached higher levels of final performance than did older adults.

Much of cognitive aging research concerns whether age-associated differences in various cognitive performances can be accounted for by general explanatory constructs or whether several specific processes are involved. Structural equation models have been proposed to disentangle general and specific age-associated differences in cognitive performance. This article demonstrates that existing methods that employ stepwise procedures run the risk of biasing results toward general resource accounts. An alternative model representation (i.e., the nested factor model) is proposed that affords simultaneous estimation of general and specific effects and is applied to data from the Berlin Aging Study. Using the nested factor model allowed the authors to detect that specific group factors explained 25% of the age-associated variance in addition to the general factor.

The author reviews reemerging coconstructive conceptions of development and recent empirical findings of developmental plasticity at different levels spanning several fields of developmental and life sciences. A cross-level dynamic biocultural coconstructive framework is endorsed to understand cognitive and behavioral development across the life span. This framework integrates main conceptions of earlier views into a unifying frame, viewing the dynamics of life span development as occurring simultaneously within different time scales (i.e., moment-to-moment microgenesis, life span ontogeny, and human phylogeny) and encompassing multiple levels (i.e., neurobiological, cognitive, behavioral, and sociocultural). Viewed through this metatheoretical framework, new insights of potential interfaces for reciprocal cultural and experiential influences to be integrated with behavioral genetics and cognitive neuroscience research can be more easily prescribed.