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Joaquin M Fuster

Joaquin M Fuster
University of California Los Angeles Medical School

Doctor of Medicine Doctor of Philosophy

About

269
Publications
132,068
Reads
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23,619
Citations
Additional affiliations
October 2003 - present
University of California, Los Angeles
Position
  • Professor Emeritus
Description
  • Distinguished Professor in Cognitive Neuroscience Research, Consulting, Writing, Outpatient (Calif. Med. License active)
October 1967 - July 2001
Neuropsychiatric Research Institute
Neuropsychiatric Research Institute
Position
  • Professor (Full)
September 1967 - June 2003
University of California, Los Angeles
Position
  • Professor of Psychiatry and Biobehavioral Sciences

Publications

Publications (269)
Article
Full-text available
Ever since it was discovered in the monkey’s prefrontal cortex, persistent neuronal activity during the delay period of delay tasks has been considered a phenomenon of working memory. Operationally, this interpretation is correct, because during that delay those tasks require the memorization of a sensory cue, commonly visual. What is incorrect is...
Article
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Background: Repeat sports-related concussive/subconcussive injury (RC/SCI) is related to memory impairment. Objective & Methods: We sought to determine memory differences between persons with RC/SCI, moderate-to-severe single-impact traumatic brain injury (SI-TBI), and healthy controls. MRI scans from a subsample of participants with SI-TBI were us...
Article
Objective Traumatic brain injury (TBI) is associated with a number of cognitive deficits. Language factors also impact neurocognitive performance. We examined the effects of TBI and bilingualism/monolingualism on a test of attention and executive functioning (Trail Making Test; TMT). Method The sample (N = 96) consisted of 36 healthy controls (19...
Article
Objective Traumatic brain injury (TBI) affects neurocognition. Speaking multiple languages can also influence cognitive test performances. We examined the relationship between TBI and monolingualism/bilingualism on a task of attention and response inhibition (Stroop Color Word Test; SCWT). Method The sample (N = 96) consisted of 37 healthy control...
Chapter
Throughout the nervous system, posterior structures are mainly devoted to receptive functions-sensation and perception-while anterior structures are devoted to motor functions. In the cortex, that dichotomy is unclear because perception and action are intertwined in the perception-action cycle, the biocybernetic cycle that adapts the organism to it...
Chapter
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The prefrontal cortex plays a critical role in the temporal organization of behavior and language within the broad neurobiological framework of the perception–action (PA) cycle, the circular processing of information that regulates the adaptation of the organism to its environment. That temporal organizing role of the prefrontal cortex is supported...
Article
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The cognitive dynamic system (CDS) is a structured physical model and research tool inspired by certain features of the human brain. One such feature is the predictive adaptation of the organism to the future environment. From an engineering perspective, this property of the brain is of profound practical importance, particularly when the system, i...
Chapter
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The neural mechanisms of decision-making are understandable only in the structural and dynamic context of the perception–action (PA) cycle. The PA cycle is the biocybernetic processing of information that adapts the organism to its environment. That circular processing involves a variety of neural structures at several hierarchical levels, though w...
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This chapter focuses on use of neuroimaging to study parts of brains, including prefrontal cortex. By use of noninvasive methods, it is now possible to assess regional cerebral blood flow (rCBF) or metabolism, and in this manner, indirectly, the levels of neuronal activity in various parts of the brain. Functional neuroimaging provides indirect rec...
Chapter
This chapter focuses on studies of the functions of the prefrontal cortex in animals. An experimental lesion in the prefrontal cortex remains a prime tool of neuropsychology. Lesions of the prefrontal cortex elicit characteristic behavioral abnormalities. These fall into three major categories: disorders of motility, disorders of emotion and social...
Chapter
This chapter discusses the involvement of certain prefrontal areas in the collection of sensory inputs, the generation of motor outputs, and their visceral and emotional functions, all of which undoubtedly serve the eminently integrative executive functions of the frontal lobe. Electrophysiological data corroborate the connective links of the prefr...
Article
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Our perception of the world is represented in widespread, overlapping, and interactive neuronal networks of the cerebral cortex. A majority of physiological studies on the subject have focused on oscillatory synchrony as the binding mechanism for representation and transmission of neural information. Little is known, however, about the stability of...
Book
This is the fourth edition of the undisputed classic on the prefrontal cortex, the principal "executive" structure of the brain. Because of its role in such cognitive functions as working memory, planning, and decision-making, the prefrontal cortex is critically involved in the organization of behavior, language, and reasoning. Prefrontal dysfuncti...
Article
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A b s t r a c t : This article aims to summarize how the organization of knowledge and memory in the cerebral cortex, the dynamics of the perception-action cycle and the integrative functions of the prefrontal cortex bear on the integration and programming of human language. K e y w o r d s : cognits, syntax of action, hierarchy in cortex, hierarch...
Article
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The pFC enables the essential human capacities for predicting future events and preadapting to them. These capacities rest on both the structure and dynamics of the human pFC. Structurally, pFC, together with posterior association cortex, is at the highest hierarchical level of cortical organization, harboring neural networks that represent complex...
Article
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Previous studies have shown that neurons of monkey dorsolateral prefrontal cortex (DLPFC) integrate information across modalities and maintain it throughout the delay period of working-memory (WM) tasks. However, the mechanisms of this temporal integration in the DLPFC are still poorly understood. In the present study, to further elucidate the role...
Article
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Cognitive dynamic systems provide a broadly defined platform, whereby engineering learns from cognitive neuroscience, and by the same token, cognitive neuroscience learns from engineering. The first part of the paper is of a tutorial nature, addressing recent advances in cognitive perception and cognitive control, which are the dual of each other....
Article
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In the course of evolution, the prefrontal cortex develops to maximum relative mass in the human brain. That large increase in mass is attributable to the disproportionate development of connective fibers (white matter), rather than cells (gray matter). This points to connectivity as the key to the evolutionary advantage of the human prefrontal cor...
Article
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Traumatic brain injury (TBI) is associated with deficits in memory for the content of completed activities. However, TBI groups have shown variable memory for the temporal order of activities. We sought to clarify the conditions under which temporal order memory for activities is intact following TBI. Additionally, we evaluated activity source memo...
Book
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Book
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Professor Joaquín M. Fuster is an eminent cognitive neuroscientist whose research over the last five decades has made fundamental contributions to our understanding of the neural structures underlying cognition and behaviour. This book provides his view on the eternal question of whether we have free will. Based on his seminal work on the functions...
Article
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Working memory is critical to the integration of information across time in goal-directed behavior, reasoning and language, yet its neural substrate is unknown. Based on recent research, we propose a mechanism by which the brain can retain working memory for prospective use, thereby bridging time in the perception/action cycle. The essence of the m...
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The sections in this article are:
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Purpose – To show that Hayek's prescient concepts on the cerebral cortex have received substantial support from modern neuroscience. Methodology – Update the terminology of The Sensory Order to adjust it to prevalent concepts of cognitive network, plasticity, association, connectivity, and cortical dynamics. Extend his concepts of perception to oth...
Article
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Recent advances in cognitive neuroscience oblige us to change radically the traditional model of representation of memory in the cerebral cortex. The old -modular- model postulates a separate area for each form of memory (working memory, episodic memory, visual memory, auditory memory, tactile memory, etc.). In the new -reticular- paradigm, memorie...
Article
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Converging evidence from humans and nonhuman primates is obliging us to abandon conventional models in favor of a radically different, distributed-network paradigm of cortical memory. Central to the new paradigm is the concept of memory network or cognit--that is, a memory or an item of knowledge defined by a pattern of connections between neuron p...
Article
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Neurons in the cortex exhibit a number of patterns that correlate with working memory. Specifically, averaged across trials of working memory tasks, neurons exhibit different firing rate patterns during the delay of those tasks. These patterns include: 1) persistent fixed-frequency elevated rates above baseline, 2) elevated rates that decay through...
Chapter
This chapter aims to present a conceptual model of prefrontal function that, by deductive and synthetic reasoning, accommodates the empirical evidence discussed in previous chapters of the book. The model is essentially based on four general propositions for which there is now overwhelming empirical support: the entirety of the cortex of the fronta...
Chapter
This chapter introduces a book that focuses on the prefrontal cortex. The cortex of the anterior pole of the mammalian brain is commonly designated the prefrontal cortex. Prefrontal cortex is defined as the part of the cerebral cortex that receives projections from the mediodorsal nucleus of the thalamus. The precise nature of the apparently multip...
Article
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An expanding body of literature describes the existence of concerted brain activations in the absence of any external stimuli. Resting-state networks have been identified and demonstrated to be modulated during the performance of specific cognitive operations. However, despite mounting evidence the possibility still remains that those correlated si...
Article
Full-text available
The role of prefrontal cortex in working memory (WM) is well established. However, questions remain regarding the topography and “domain-specific differentiation” of different types of information processing in the cortex. While it has been theorized that dorsolateral (DPFC) and ventrolateral (VPFC) prefrontal cortex preferentially process spatial...
Article
Full-text available
The role of prefrontal cortex in working memory (WM) is well established. However, questions remain regarding the topography and “domain-specific differentiation” of different types of information processing in the cortex. While it has been theorized that dorsolateral (DPFC) and ventrolateral (VPFC) prefrontal cortex preferentially process spatial...
Article
This is the fourth edition of the undisputed classic on the prefrontal cortex, the principal "executive" structure of the brain. Because of its role in such cognitive functions as working memory, planning, and decision-making, the prefrontal cortex is critically involved in the organization of behavior, language, and reasoning. Prefrontal dysfuncti...
Book
This is the fourth edition of the undisputed classic on the prefrontal cortex, the principal "executive" structure of the brain. Because of its role in such cognitive functions as working memory, planning, and decision-making, the prefrontal cortex is critically involved in the organization of behavior, language, and reasoning. Prefrontal dysfuncti...
Article
Full-text available
This study explores the cortical cell dynamics of unimodal and cross-modal working memory (WM). Neuronal activity was recorded from parietal areas of monkeys performing delayed match-to-sample tasks with tactile or visual samples. Tactile memoranda (haptic samples) consisted of rods with differing surface features (texture or orientation of ridges)...
Article
Full-text available
Persistent elevated neuronal activity has been identified as the neuronal correlate of working memory. It is generally assumed in the literature and in computational and theoretical models of working memory that memory-cell activity is stable and replicable; however, this assumption may be an artifact of the averaging of data collected across trial...
Article
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Executive actions are represented and hierarchically organized in the cortex of the frontal lobe. The representation and coordination of an action or series of actions have the same anatomical substrate: an executive neuronal network (cognit) in forntal cortex. That network interacts structurally and dynamically with perceptual networks of posterio...
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The prevalent concept in modular models is that there are discrete cortical domains dedicated more or less exclusively to such cognitive functions as visual discrimination, language, spatial attention, face recognition, motor programming, memory retrieval, and working memory. Most of these models have failed or languished for lack of conclusive evi...
Article
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We have studied a neurodynamic model of cross-modal and cross-temporal associations. We show that a network of integrate-and-fire neurons can generate spiking activity with realistic dynamics during the delay period of a paired associates task. In particular, the activity of the model resembles reported data from single-cell recordings in the prefr...
Article
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We describe the use of near-infrared spectroscopy (NIRS) as a suitable means of assessing hemodynamic changes in the cerebral cortex of awake and behaving monkeys. NIRS can be applied to animals performing cognitive tasks in conjunction with electrophysiological methods, thus offering the possibility of investigating cortical neurovascular coupling...
Article
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Abstract Cells in the somatosensory cortex of the monkey are known to exhibit sustained elevations of firing frequency during the short-term mnemonic retention of tactile information in a haptic delay task. In this study, we examine the possibility that those firing elevations are accompanied by changes in firing pattern. Patterns are identified by...
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Presents the obitiuary for Patricia Shoer Goldman-Rakic (1937-2003), recognized not only for her contributions to neuroscience but also for her humanity. The one scientific accomplishment for Dr. Goldman- Rakic is universally recognized is her contribution to the understanding of the role of the prefrontal cortex in working memory, and because of h...
Article
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Neurons in the monkey's anterior parietal cortex (Brodmann's areas 3a, 3b, 1, and 2) have been reported to retain information from a visual cue that has been associated with a tactile stimulus in a haptic memory task. This cross-modal transfer indicates that neurons in somatosensory cortex can respond to non-tactile stimuli if they are associated w...
Article
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The neural substrate for behavioral, cognitive and linguistic actions is hierarchically organized in the cortex of the frontal lobe. In their methodologically impeccable study, Koechlin et al. reveal the neural dynamics of the frontal hierarchy in behavioral action. Progressively higher areas control the performance of actions requiring the integra...
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Single-unit data from the cortex of monkeys performing working-memory tasks support the main point of the target article. Those data, however, also indicate that the activation of long-term memory is essential to the processing of all cognitive functions. The activation of cortical long-term memory networks is a key neural mechanism in attention (w...
Article
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In phylogeny as in ontogeny, the association cortex of the frontal lobe, also known as the prefrontal cortex, is a late-developing region of the neocortex. It is also one of the cortical regions to undergo the greatest expansion in the course of both evolution and individual maturation. In the human adult, the prefrontal cortex constitutes as much...
Article
Full-text available
Memory networks are formed in the cerebral cortex by associative processes, following Hebbian principles of synaptic modulation. Sensory and motor memory networks are made of elementary representations in cell assemblies of primary sensory and motor cortex (phyletic memory). Higher-order individual memories, e.g. episodic, semantic, conceptual - ar...
Chapter
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This chapter considers the executive functions of the lateral prefrontal cortex (LPC). Topics discussed include the anatomy and connectivity of the prefrontal cortex, neuropsychology of the prefrontal cortex, temporal integration and its ancillary executive functions, and the perception-action cycle.
Book
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This book explores whether the mental order corresponds to the order of structures, events, and processes in one part of the neural order, namely, the cerebral cortex. For clarity and simplicity, this means the search for a spatial and temporal order in the cerebral cortex that matches the cognitive order in every respect. A change or difference in...
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This chapter focuses on the anatomy and developmental neurobiology of the prefrontal cortex. It begins with a discussion of issues related to the phylogenetic development and comparative anatomy of the neocortex of the frontal lobe. The chapter also deals with its ontogenetic development and the morphological changes it undergoes as a result of agi...
Chapter
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In this chapter, the executive functions of the prefrontal cortex are discussed against the background of its position in the neocortical map of cognitive representations. Lateral prefrontal areas constitute the highest stage in the cortical hierarchy of executive memories. Their neuronal networks represent schemas of sequential action, past or pla...
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This article is a transcription of an electronic symposium in which some active researchers were invited by the Brazilian Society for Neuroscience and Behavior (SBNeC) to discuss the last decade's advances in neurobiology of learning and memory. The way different parts of the brain are recruited during the storage of different kinds of memory (e.g....
Article
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Recent studies show that cells in the somatosensory cortex are involved in the short-term retention of tactile information. In addition, some somatosensory cells appear to retain visual information that has been associated with the touch of an object. The presence of such cells suggests that nontactile stimuli associated with touch have access to c...
Article
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The neuronal networks of the frontal lobe that represent motor or executive memories are probably the same networks that cooperate with other cerebral structures in the temporal organization of behavior. The prefrontal cortex, at the top of the perception-action cycle, plays a critical role in the mediation of contingencies of action across time, a...
Article
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This chapter presents a conceptual model of the representational and executive functions of the cortex of the frontal lobe derived from empirical evidence obtained principally in the monkey. According to this model, the neuronal networks of the frontal lobe that represent motor or executive memories are probably the same networks that cooperate wit...
Article
Full-text available
The prefrontal cortex is essential for the temporal integration of sensory information in behavioural and linguistic sequences. Such information is commonly encoded in more than one sense modality, notably sight and sound. Connections from sensory cortices to the prefrontal cortex support its integrative function. Here we present the first evidence...
Article
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The prefrontal cortex is one of the latest regions of the neocortex to develop, in both phylogeny and ontogeny. In the primate, the prefrontal cortex is anatomically divided into three major sectors: medial, orbital (or inferior), and dorsolateral. The dorsolateral sector is the association cortex of the convexity of the frontal lobe. Phylogenetica...
Article
Full-text available
Memory networks are formed in the cerebral cortex by associative processes, following Hebbian principles of synaptic modulation. Sensory and motor memory networks are made of elementary representations in cell assemblies of primary sensory and motor cortex (phyletic memory). Higher-order individual memories, e.g. episodic, semantic, conceptual - ar...
Article
Full-text available
Article
Full-text available