Louis D Matzel

Louis D Matzel
Rutgers, The State University of New Jersey | Rutgers · Department of Psychology (New Brunswick)

Ph.D.

About

141
Publications
90,025
Reads
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4,688
Citations
Introduction
We are primarily interested in individual differences, particularly those relevant to variations in intelligence and susceptibility to anxiety. Our recent work has included behavior-genetic analyses of gene/environment correlations and interactions in the emergence of individual differences. Relatedly, we are investigating the role of working memory and selective attention as core cognitive process, as well as their dependence on dopamine signalling in the prefrontal cortex.
Additional affiliations
January 1990 - December 1993
National Institutes of Health
September 1988 - July 1991
National Institute of Neurological Disorders and Strokes
National Institute of Neurological Disorders and Strokes
Position
  • IRTA Fellow
Education
August 1985 - August 1988
Binghamton University
Field of study
  • Experimental Psychology/Physiological Psychology
August 1983 - August 1985
George Mason University
Field of study
  • Experimental Psychology
August 1982 - August 1985
Independent Researcher
Independent Researcher
Field of study
  • Psychology

Publications

Publications (141)
Article
Full-text available
Intelligence can have an extremely high heritability, but also be malleable; a paradox that has been the source of continuous controversy. Here we attempt to clarify the issue, and advance a frequently overlooked solution to the paradox: Intelligence is a trait with unusual properties that create a large reservoir of hidden gene–environment (GE) ne...
Article
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In both humans and mice, performance on tests of intelligence or general cognitive ability (GCA) is related to dopamine D1 receptor-mediated activity in the prelimbic cortex, and levels of DRD1 mRNA predict the GCA of mice. Here we assessed the turnover rate of D1 receptors as well as the expression level of the D1 chaperone protein (DRiP78) in the...
Article
General cognitive ability (or general intelligence; g) is a latent variable that describes performance across a broad array of cognitive skills. This general influence on cognitive ability varies between individuals and shares a similar structure in both humans and mice. Evidence suggests that much of the variation in general intelligence is relate...
Article
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Although genetically heterogeneous laboratory mice express individual differences in general cognitive ability (c.f., "intelligence"), it is unknown whether these differences are translated into behaviors that would promote survival. Here, genetically heterogeneous laboratory CD-1 mice were administered a series of cognitive tests from which their...
Article
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General cognitive ability can be highly heritable in some species, but at the same time, is very malleable. This apparent paradox could potentially be explained by gene–environment interactions and correlations that remain hidden due to experimental limitations on human research and blind spots in animal research. Here, we shed light on this issue...
Article
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Nearly a century ago, Spearman proposed that “specific factors can be regarded as the ‘nuts and bolts’ of cognitive performance…, while the general factor is the mental energy available to power the specific engines”. Geary (2018; 2019) takes Spearman’s analogy of “mental energy” quite literally and doubles-down on the notion by proposing that a un...
Article
Most quantifiable traits exhibit some degree of heritability. The heritability of physical traits is often high, but the heritability of some personality traits and intelligence can also be highly heritable. Importantly, estimates of heritability can change dramatically depending on such variables as the age or the environmental history of the samp...
Article
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Behavioural and cognitive processes play important roles in mediating an individual's interactions with its environment. Yet, while there is a vast literature on repeatable individual differences in behaviour, relatively little is known about the repeatability of cognitive performance. To further our understanding of the evolution of cognition, we...
Article
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The typical practice of averaging group performance during extinction gives the impression that responding declines gradually and homogeneously. However, previous studies of extinction in human infants have shown that some individuals persist in responding, whereas others abruptly cease responding. As predicted by theories of control, the infants w...
Article
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Early in the 20th century, individual differences were a central focus of psychologists. By the end of that century, studies of individual differences had become far less common, and attention to these differences played little role in the development of contemporary theory. To illustrate the important role of individual differences, here we consid...
Article
Across taxonomic subfamilies, variations in intelligence ( G ) are sometimes related to brain size. However, within species, brain size plays a smaller role in explaining variations in general intelligence ( g ), and the cause-and-effect relationship may be opposite to what appears intuitive. Instead, individual differences in intelligence may refl...
Chapter
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Article
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Attention is a component of the working memory system, and as such, is responsible for protecting task-relevant information from interference. Cognitive performance (particularly outside of the laboratory) is often plagued by interference, and the source of this interference, either external or internal, might influence the expression of individual...
Article
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A common source of variance (i.e., "general intelligence") underlies an individual's performance across diverse tests of cognitive ability, and evidence indicates that the processing efficacy of working memory may serve as one such source of common variance. One component of working memory, selective attention, has been reported to co-vary with gen...
Article
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In four experiments with water-deprived rats, we examined the possibility that simultaneous associations between a conditioned stimulus (CS) and an unconditioned stimulus (US) were modulated or masked by context–US associations. In Experiment 1 we determined that simultaneous CS-US pairings administered in multiple contexts enhanced responding to t...
Article
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In a seminal paper written five decades ago, Cronbach discussed the two highly distinct approaches to scientific psychology: experimental and correlational. Today, although these two approaches are fruitfully implemented and embraced across some fields of psychology, this synergy is largely absent from other areas, such as in the study of learning...
Article
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Accumulating evidence indicates that the storage and processing capabilities of the human working memory system co-vary with individuals’ performance on a wide range of cognitive tasks. The ubiquitous nature of this relationship suggests that variations in these processes may underlie individual differences in intelligence. Here we briefly review r...
Article
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An individual’s performance across multiple cognitive tests tends to co-vary. This ubiquitous observation suggests that various cognitive domains are regulated in common, and this co-variance underlies the interpretation of many quantitative tests of “intelligence”. As in humans, we find that differences in intelligence exist across genetically het...
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From the traditional perspective of associative learning theory, the hypothesis linking modifications of synaptic transmission to learning and memory is plausible. It is less so from an information-processing perspective, in which learning is mediated by computations that make implicit commitments to physical and mathematical principles governing t...
Article
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From the traditional perspective of associative learning theory, the hypothesis linking modifications of synaptic transmission to learning and memory is plausible. It is less so from an information-processing perspective, in which learning is mediated by computations that make implicit commitments to physical and mathematical principles governing t...
Article
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Imposed social subordination, such as that which accompanies physical defeat or alienation, has been associated with impaired cognitive function in both human and non-human animals. Here we examined whether domain-specific and/or domain-general learning abilities (c.f. general intelligence) are differentially influenced by the imposition of social...
Article
Full-text available
Contemporary descriptions of human intelligence hold that this trait influences a broad range of cognitive abilities, including learning, attention, and reasoning. Like humans, individual genetically heterogeneous mice express a "general" cognitive trait that influences performance across a diverse array of learning and attentional tasks, and it ha...
Chapter
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Learning to write is a process where preverbal ideas (thoughts) are transformed into a written form. Such written forms produced vary from words to sentences to higher forms of discourse such as essays, reports, researches, reviews, poems, stories, dialogues, etc. These written forms that are generated, formed, and activated from thoughts are then...
Article
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Learning, attentional, and perseverative deficits are characteristic of cognitive aging. In this study, genetically diverse CD-1 mice underwent longitudinal training in a task asserted to tax working memory capacity and its dependence on selective attention. Beginning at 3 mo of age, animals were trained for 12 d to perform in a dual radial-arm maz...
Article
Full-text available
Humans' performance on most cognitive tasks are commonly regulated by an underlying latent variable (i.e., "general" intelligence), and the expression of this latent modulator of cognitive performance varies across individuals. While "intelligence" in humans is easily recognized, a precise definition of this trait has proven elusive, and has impede...
Article
Learning, attentional, and perseverative deficits are characteristic of cognitive aging. In this study, genetically diverse CD-1 mice underwent longitudinal training in a task asserted to tax working memory capacity and its dependence on selective attention. Beginning at 3 mo of age, animals were trained for 12 d to perform in a dual radial-arm maz...
Article
Full-text available
Genetically heterogeneous mice express a trait that is qualitatively and psychometrically analogous to general intelligence in humans, and as in humans, this trait co-varies with the processing efficacy of working memory (including its dependence on selective attention). Dopamine signaling in the prefrontal cortex (PFC) has been established to play...
Article
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In both humans and mice, the efficacy of working memory capacity and its related process, selective attention, are each strongly predictive of individuals' aggregate performance in cognitive test batteries [1-9]. Because working memory is taxed during most cognitive tasks, the efficacy of working memory may have a causal influence on individuals' p...
Article
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PEA-15 is a phosphoprotein that binds and regulates ERK MAP kinase and RSK2 and is highly expressed throughout the brain. PEA-15 alters c-Fos and CREB-mediated transcription as a result of these interactions. To determine if PEA-15 contributes to the function of the nervous system we tested mice lacking PEA-15 in a series of experiments designed to...
Article
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Learning impairments and the instability of memory are defining characteristics of cognitive aging. However, it is unclear if deficits in the expression of new memories reflect an accelerated decay of the target memory or a consequence of inefficient learning. Here, aged mice (19-21-mo old) exhibited acquisition deficits (relative to 3-5-mo old mic...
Article
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In addition to its role in axon growth and neuronal migration, the close homolog of L1 (CHL1), a member of the L1 family of cell adhesion molecules, is involved in synaptic plasticity. To date, little has been done to disassociate the role of CHL1 during adulthood from its role during development. To address this issue, mice conditionally deficient...
Article
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"General cognitive ability" describes a trait that transcends specific learning domains and impacts a wide range of cognitive skills. Individual animals (including humans) exhibit wide variations in their expression of this trait. We have previously determined that the propensity for exploration is highly correlated with the general cognitive abili...
Article
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Cell adhesion molecules, such as neuronal cell adhesion molecule (Nr-CAM), mediate cell-cell interactions in both the developing and mature nervous system. Neuronal cell adhesion molecule is believed to play a critical role in cell adhesion and migration, axonal growth, guidance, target recognition and synapse formation. Here, wild-type, heterozygo...
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A defining characteristic of age-related cognitive decline is a deficit in general cognitive performance. Here we use a testing and analysis regimen that allows us to characterize the general learning abilities of young (3-5 mo old) and aged (19-21 mo old) male and female Balb/C mice. Animals' performance was assessed on a battery of seven diverse...
Article
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It has been established that both domain-specific (e.g. spatial) as well as domain-general (general intelligence) factors influence human cognition. However, the separation of these processes has rarely been attempted in studies using laboratory animals. Previously, we have found that the performances of outbred mice across a wide range of learning...
Article
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It has previously been reported that general learning ability (GLA) correlates positively with exploratory tendencies in individual outbred mice. This finding suggests the possibility that variations in stress reactivity modulate GLA and thus its relationship to exploratory tendencies. Here, the authors investigated the potential role of stress rea...
Article
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A single factor (i.e., general intelligence) can account for much of an individuals' performance across a wide variety of cognitive tests. However, despite this factor's robustness, the underlying process is still a matter of debate. To address this question, we developed a novel battery of learning tasks to assess the general learning abilities (G...
Article
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Across multiple learning tasks (that place different sensory, motor, and information processing demands on the animals), we have found that the performance of mice is commonly regulated by a single factor ("general learning") that accounts for 30-40% of the variance across individuals and tasks. Furthermore, individuals' general learning abilities...
Article
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For at least 40 years, there has been a recurring argument concerning the nature of experimental amnesia, with one side arguing that amnesic treatments interfere with the formation of enduring memories and the other side arguing that these treatments interfere with the expression of memories that were effectively encoded. The argument appears to st...
Article
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Up to 50% of an individuals' performance across a wide variety of distinct cognitive tests can be accounted for by a single factor (i.e., "general intelligence"). Despite its ubiquity, the processes or mechanisms regulating this factor are a matter of considerable debate. Although it has been hypothesized that working memory may impact cognitive pe...
Article
Contemporary descriptions of human intelligence hold that this trait influences a broad range of cognitive abilities, including learning, attention, and reasoning. Like humans, individual genetically heterogeneous mice express a "general" cognitive trait that influences performance across a diverse array of learning and attentional tasks, and it ha...
Article
Full-text available
Human performance on diverse tests of intellect are impacted by a "general" regulatory factor that accounts for up to 50% of the variance between individuals on intelligence tests. Neurobiological determinants of general cognitive abilities are essentially unknown, owing in part to the paucity of animal research wherein neurobiological analyses are...
Article
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Using an identified synapse in the nervous system of the mollusc Hermissenda, the influence of somatic calcium accumulation on regulated synaptic transmission was investigated. Hair cells in Hermissenda project onto postsynaptic B photoreceptors where they mediate inhibitory postsynaptic potentials (IPSPs). Intracellular recordings in combination w...
Chapter
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Genetic strategies to elucidate the substrates for memory induction, maintenance, and retrieval have evolved rapidly during the previous decade. Here we review the wealth of information that has been derived from work with “transgenic” mammals, and attempt to establish a framework from which we might better appreciate the genetic and molecular cons...
Article
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In laboratory studies, the assessment of memory is typically associated with overt behavioral responses. Thus, it has been difficult to determine whether the enhancement of hippocampal sensory-evoked potentials that often accompany memory formation are the neurophysiological manifestation of a memory "trace" or are a secondary product of the behavi...
Article
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It is well established that the hippocampal formation is critically involved in the acquisition of trace memories, a paradigm in which the conditioned (CS) and unconditioned stimuli (US) are separated by a temporal gap (Solomon et al., 1986). The structure is reportedly not critical for the acquisition of delay memories, where the CS and the US ove...
Article
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Type B photoreceptors in Hermissenda exhibit increased excitability (e.g., elevated membrane resistance and lowered spike thresholds) consequent to the temporal coincidence of a light-induced intracellular Ca(2+) increase and the release of GABA from presynaptic vestibular hair cells. Convergence of these pre- and postsynaptically stimulated bioche...
Article
Accumulating evidence indicates that the storage and processing capabilities of the human working memory system co-vary with individuals' performance on a wide range of cognitive tasks. The ubiquitous nature of this relationship suggests that variations in these processes may underlie individual differences in intelligence. Here we briefly review r...
Article
The observation that retrieval returns a stable memory into a labile state cannot be readily explained by any simple version of consolidation theory. This finding has been interpreted as evidence for the need to reconsolidate a memory after reactivating it. However, as we discuss in this commentary, other behavioural observations indicate that even...
Article
Though once of central importance to psychologists and neurophysiologists alike, the elucidation of neural substrates for individual differences in learning no longer attracts a broad research effort and occupies a place of largely historical interest to the contemporary disciplines. The decline in interest in this subject ensued in part from the p...
Article
The hypothesis that an individual's capacity for learning might be predicted or influenced by basal levels of synaptic efficacy has eluded empirical tests, owing in part to the inability to compare between animals single identified synaptic responses in the mammalian brain. To overcome this limitation, we have focused our analysis on the invertebra...
Article
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Descriptions of conditioned response generation in Hermissenda stipulate that the synaptic interaction between type B and A photoreceptors should be enhanced after associative pairings of light and rotation. Although evidence from several laboratories has confirmed this assumption, the mechanism underlying this synaptic facilitation has not been el...