Integrative neurocomputational perspectives on cognitive aging, neuromodulation, and representation

doi:10.1016/S0149-7634(02)00066-0

Neuroscience & Biobehavioral Reviews

Volume 26, Issue 7, November 2002, Pages 795-808

https://doi.org/10.1016/S0149-7634(02)00066-0 Get rights and content

Abstract

Besides neuroanatomical changes, neuromodulatory mechanisms are also compromised during aging. Neural network models are suitable tools for exploring the relatively broad and homogenous neuromodulatory influences on cortical function. Computational approaches for understanding neuromodulation of the dynamic properties of cortical function and recent neurocomputational theories relating different aspects of cognitive aging with declines in neuromodulation are reviewed. Considered within an integrative cross-level neurocomputational framework, aging-related decline in dopaminergic neuromodulation reduces the fidelity of neural information and gives rise to less distinctive neural pattern representations that may underlie various facets of aging cognitive and, possibly also, sensorimotor phenomena.

Introduction

Phenomena of aging are multi-facet and multi-level. Declines in elementary cognitive, sensory, and sensorimotor functioning are ubiquitous phenomena of usual aging [18], [24], [67]. Furthermore, these declines occur at the behavioral, information processing, and neurobiological levels. The task to obtain an integrative understanding of cognitive and sensorimotor aging might benefit from a paradigm shift towards cross-level (and cross-domain) conceptions that cut across different levels and facets. Notwithstanding current empirical difficulties in addressing overarching relations across multiple levels, neurocomputational approaches provide general frameworks for theoretical investigations of the relations across neural information processing, cognition, and behavior and of the interactions between different cortical regions and functions.

In this article, we first review recent computational approaches for studying neuromodulation of cortical function. We then briefly highlight evidence of aging-related neuromodulatory and cognitive declines. An integration across these levels of phenomena are couched within a recent integrative framework, depicting a link between aging neuromodulation, neural noise, less distinctive cortical representation, and cognitive aging [40]. Possible relations between aging cognitive and sensorimotor processes are also discussed.

Section snippets

Computational approaches to neuromodulation of cortical function

Theories on the morphofunctional architecture of the brain emphasize the importance of connectivity and communication between cellular elements [65]. Cortical functioning is bounded within the brain's structural and functional organization. Furthermore, the neurochemical processes therein, affecting pattern representation and information transfer within and between the cortical regions, generate and influence the dynamical properties of cortical information processing. Neurochemical influences

Aging, cognition, and neuromodulation

Aging affects several facets of cognitive processing. People's abilities to activate, represent and maintain information in mind, to attend to relevant but ignore irrelevant information, and to process information promptly all decline with advancing age (see reviews in [18], [56], [59] and Park and Gutchess in this issue). Aging-related decline in working memory function has been found in various tasks accessing memory span. Besides the more ‘traditional’ memory capacity view, working memory

Modeling aging neuromodulation, neuronal noise, less distinctive representation, and aging cognition

As previously discussed, neuromodulation can be modeled with respect to different specificity and functionality. Dopamine's modulatory effects are diverse, depending on cortical regions and receptor types. However, a general feature of dopaminergic modulation can be conceptualized as altering the signal-to-noise ratio of neural information processing, thus regulating neurons' response sensitivity to afferent signals. One way to model this effect is adjusting the gain (G) parameter of the

Conclusions

In addition to neuroanatomical degeneration, aging-related changes in the dynamical properties of cortical function could be related to declines in neurochemical processes affecting pattern representation and information transfer within and between cortical regions. Specifically, cognitive aging may be related to declines in dopaminergic modulation in the PFC and in other subcortical brain regions. Details regarding the involvement of neuromodulation in cognitive aging deficits remain to be

Acknowledgements

The preparation of this manuscript was sponsored by the support of the Max Planck Institute for Human Development to the first author and a research grant from Humanistiska Samhällsvetenskapliga Forskningsrådet (HSFR) to the second author. The first author thanks Peter A. Frensch and Ulman Lindenberger for their contributions during previous collaborations on related research. We thank Julia Delius for helpful comments on previous versions of the manuscript.

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Integrative neurocomputational perspectives on cognitive aging, neuromodulation, and representation

Abstract

Introduction

Section snippets

Computational approaches to neuromodulation of cortical function

Aging, cognition, and neuromodulation

Modeling aging neuromodulation, neuronal noise, less distinctive representation, and aging cognition

Conclusions

Acknowledgements

Trends Cogn Sci

Curr Opin Neurobiol

Behav Brain Res

Curr Opin Neurobiol

Biol Psychol

Neurobiol Aging

Curr Opin Neurobiol

Behav Brain Res

Trends Cogn Sci

Neural Networks

Neurobiol Aging

Brain Res

Neurocomputing

Trends Cogn Sci

Neuron

Brain Res

Neural Networks

Intelligence

Cogn Brain Res

Mech Aging Dev

Artif Intell Med

Trends Cogn Sci

Brain Res Rev

computational model of information processing in the frontal cortex and basal ganglia

J Cogn Neurosci

Dopamine D1 receptor mechanisms in the cognitive performance of young adult and aged monkeys

Psychopharmacology

Age-related cognitive deficits mediated by changes in the striatal dopamine system

Am J Psychiatry

Emergence of a powerful connection between sensory and cognitive functions across the adult life span: a new window to the study of cognitive aging?

Psychol Aging

Context processing in older adults: evidence for a theory relating cognitive control to neurobiology in healthy aging

J Exp Psychol Gen

Hemispheric asymmetry reduction in older adults: the Harold model

Psychol Aging

Aging gracefully. Compensatory brain activity in high-performing older adults

Neuroimage

A model of visuospatial working memory in prefrontal cortex: recurrent network and cellular bistability

J Comput Neurosci

On the control of automatic processes: a parallel distributed processing model of the Stroop effect

Psychol Rev

Context, cortex, and dopamine: a connectionist approach to behavior and biology in Schizophrenia

Psychol Rev

The microanalyses of memory span and its development in childhood

Int J Psychol

On the transfer of information from temporary to permanent memory

Philos Trans R Soc Lond B

Aging and cognitive deficits: the role of attentional resources