bluuebunny/crossref_metadata_2025_split huggingface dataset:
Processing of Tactile Information in the Primate Brain
Authors: Hsiao Steven , Johnson Ken , Yoshioka Takashi 
Published: November 2003

AbstractWe discuss how the neural representation of surface features and objects are processed in the somatosensory system. Tactile perception begins with the activation of four functionally distinct cutaneous mechanoreceptive afferent systems. The SA1 system provides a high‐quality neural image of the spatial structure of surfaces and is the basis for form and texture perception. The RA system provides a neural image of motion across the skin and is important for grip control. The PC system provides a neural image of events transmitted to the hand through probes and tools. The SA2 system provides a neural image of skin stretch which plays a role in the perception of hand conformation. Information from these four systems flows centrally where it is processed by neurons in SI and SII cortex. Neurons in area 3b of SI cortex have receptive fields confined to single fingers and are selectively responsive to local spatial gradients. Neurons in SII cortex have large receptive fields that span multiple fingers on one or both hands. These neurons have complex responses and many neurons have position‐invariant responses to oriented bars. Selective attention has progressively larger effects as the information flows centrally. In SII, attention effects both the firing rates and temporal patterning of the neural responses.
Olfaction and Taste
Authors: Di Lorenzo Patricia M. , Youngentob Steven L. 
Published: November 2003

AbstractThe ability to detect and interpret the chemicals in our environment affects nearly every aspect of our survival. The flavor of our food, i.e., the combination of its taste and smell, is used both to prompt ingestion of nutrients and to protect us from ingesting or inhaling toxins. In the study of taste and olfaction, there are certain as yet unresolved questions that date from the very earliest research into these areas. For example, there is continued debate on the nature of primary stimuli, on the mechanisms of transduction, and on the ways in which stimuli are encoded and interpreted by the nervous system. In this review, the current thinking about these questions, as well as some recent data that may help to resolve them, are outlined. Data from both animal and human models are used to show how technological advances, particularly in the realm of molecular neurobiology, are providing the tools for a new and more complete understanding of how we taste and smell the chemicals in our environment.
Sex Behavior
Authors: Hull Elaine M. , Dominguez Juan M. 
Published: November 2003

AbstractSexual, as opposed to asexual, reproduction increases variability and provides a mechanism for repair of DNA and possibly reduction of pathogen specialization. Sex differentiation can be can be controlled by either environmental factors (as in some fish, amphibians, and reptiles) or by genes (as in other fish, amphibians, and reptiles, and all birds and mammals). Genetic influences on sex differentiation are typically mediated by hormones during early development; however, the specific hormones and their modes of action vary among species. Most hormonal actions require binding to intracellular receptors that act as regulators of gene transcription; however, hormones may also act rapidly via membrane receptors. Activational effects of hormones in adulthood act on the neural substrates that were differentiated during development. There is some conservation throughout evolution in the brain areas that control masculine and feminine sexual behaviors. The medial preoptic area, at the anterior end of the hypothalamus, is a major control hub for masculine behavior in all vertebrate species. Similarly, the ventromedial hypothalamus is important for feminine receptive behaviors of numerous species. Sexually relevant stimuli and motor outputs are processed by neurons that may require hormones to increase their responsiveness. The same brain areas and hormones that control sexual behavior also control other social behaviors.
Motivational Systems
Authors: McFarland Krista , Kalivas Peter W. 
Published: November 2003

AbstractThe present chapter reviews the behavioral, anatomical, and neurobiological evidence regarding the neural substrates of motivated behavior. This involves examination of motivational circuitry within the basal forebrain. The motive circuit consists of two parallel subcircuits: one predominantly associated with motor function and the other primarily associated with limbic functions. It is hypothesized that the motor circuit is critical for the production of well‐learned behavioral responses, while the limbic circuit is important for processing environmental stimuli and transmitting this information to portions of the motor circuit, thus instigating adaptive motor responses. Within this circuit, dopamine, glutamate, GABA, and neuropeptides are neurotransmitters, each conveying potentially distinct information. The present review is organized around these neruotransmitters in reference to the following hypotheses:1. Glutamate stimulates behavior and the anatomical origin of the activated glutamatergic afferents provides motor memory to provoke the appropriate behavioral response. In addition, under the appropriate conditions glutamate transmission promotes neuroplasticity permitting learning and behavioral adaptations to occur.2. Dopamine supports plasticity and learning by engaging the appropriate cellular machinery to modify neuronal communication, especially excitatory transmission.3. GABA regulates overall circuit tone and thereby serves to ‘bind’ or sustain an animal's motivational state until the goal object can be achieved.4. Neuropeptides contribute to subjective valence. Thus, the neuroanatomical and neurochemical organization of the motive circuit provides the neural basis of motivation and reinforcement and functions to elicit adaptive motor responses in the presence of motivationally significant stimuli.
Emotion
Authors: Davis Michael , Lang Peter J. 
Published: November 2003

AbstractThis chapter will present evidence to suggest that emotion is best defined, not as a single reaction, but as a process: Emotion involves multiple responses, organized according to temporal and spatial parameters. Thus, events that are positive/appetitive or aversive/threatening engage attention. They prompt information gathering, and do so more than other less motivationally relevant stimuli. Motive cues also occasion metabolic arousal, anticipatory responses that are oriented towards the engaging event, a mobilization of the organism that can lead to some action. Emotional processing can be compressed into fractions of a second or considerably extended in time. We suggest that neural networks underlying emotion include direct connections to the brain's primary motivational systems, appetitive and defensive. These neural circuits were laid down early in our evolutionary history, in primitive cortex, subcortex, and midbrain, to mediate behaviors basic to the survival of individuals and species. Unconditioned and conditioned appetitive and aversive stimuli activate these motivational circuits. They determine the general mobilization of the organism, the deployment of reflexive attentional, approach, and defensive behaviors, and mediate the formation of conditioned associations originally based on primary reinforcement.
Stress, Coping, and Immune Function
Authors: Dougall Angela Liegey , Baum Andrew 
Published: November 2003

AbstractStress is a fundamental process, characterizing individuals' interactions with their environments and responses to challenge. Appraisals of threatening or harmful challenges motivate individuals to take action to either eliminate these stressors or protect themselves from the stressor's negative impact. These appraisals and coping efforts elicit a series of specific and nonspecific cognitive, behavioral, and physiological responses. Stress responses, in turn, promote adaptation by mobilizing catabolic energies that support coping efforts. One response system that has received considerable attention is the immune system because of its role in the detection and elimination of pathogenic agents and its apparent sensitivity to stress hormones. Repeated or protracted exposures to stress appear to suppress immune system functioning and may contribute to increased vulnerability to infection and disease. Alterations in other stress response pathways appear to provide mechanisms through which many stress‐related immune changes occur. By decreasing aspects of cognitive, behavioral, and physiological responding, stress reduction interventions are used to facilitate adaptation and have important implications for decreasing vulnerability to disease processes. Continued characterization of the beneficial as well as harmful effects of stress will improve our ability to identify modifiable risk factors (e.g., lifestyle, appraisal, coping, and social resources) for the negative consequences of stress and to promote adaptation.
The Psychology and Ethology of Learning
Authors: Holland Peter C. , Ball Gregory F. 
Published: November 2003

AbstractThere are two major traditions in the study of learning in animals, a general process perspective within experimental psychology, and a view of learning as niche‐specific behavioral adaptation within ethology. Modern work in animal learning benefits from ideas that stem from each of these traditions. In this review, we develop some key ideas within each of these separate traditions, including the organization of species‐typical and how it might be modified by experience as well as a review of several influencial models in the study of animal learning such as the Rescorla‐Wagner model and more recent critiques of this model. We then discuss three case studies that show how more synthetic approaches can provide important insights into the nature of learning. We describe synthetic analyses of: (1) learning and memory processes in bird song, (2) rats, learning to anticipate food in standard laboratory conditioning tasks, and (3) sexual conditioning in Japanese quail. These analyses are characterized by concern with ethological questions of adaptive function and evolution, exploitation of analytic tools and theories developed within the general process tradition, and a unifying interest in neurobiological mechanism.
Biological Models of Associative Learning
Authors: Steinmetz Joseph E. , Kim Jeansok , Thompson Richard F. 
Published: November 2003

AbstractOver the last 100 years or so, a great deal of progress has been made in delineating the behavioral properties of simple associative learning. In addition, much progress has been made in defining the neural circuitries involved in encoding learning and memory processes in the nervous system and also some of the cellular and molecular mechanisms that underlie the encoding processes. Advances in our understanding of the behavioral and neural bases of simple associative learning are presented in this chapter. Some basic definition important for associative learning and memory are first presented, and then current data from a variety of invertebrate preparations that have proven useful for advancing our understanding of cellular and molecular correlates of learning and memory are covered. The use of simple spinal cord preparations is presented next, and this is followed by a detailed examination of fear conditioning and the brain systems involved in encoding this simple form of emotional learning. We next review the relatively large literature on classical and instrumental conditioning of discrete response. Featured in this final section of the chapter are a variety of current data about the brain systems that are involved in encoding classical eyeblink conditioning, arguably the most studied associative learning paradigm.
Memory Systems
Authors: Eichenbaum Howard 
Published: November 2003

AbstractThe idea that there are multiple memory systems in the brain has a long and interesting history. Early views, based on philosophical considerations and introspection suggested distinctions between recollective memory, habit formation, and the adoption of preferences and aversions to arbitrary stimuli. Early experimental work focused on controversies over which of these is the fundamental mechanism that underlies memory. A reconciliation of these divergent views has emerged from recent studies in the cognitive neuroscience of memory showing that these different forms of memory can be selectively disrupted by damage to distinct brain regions. This research, and parallel characterizations of neural activity in different brain areas, has shown that the three major forms of long‐term memory are supported by distinct brain systems. These include: (1) a cortical‐hippocampal circuit that mediates declarative memory, our capacity to recollect facts and events, (2) motor memory subsystems involving on a cortical‐neostriatal circuit that mediates habit formation and a brainstem‐cerebellar circuit that mediates sensori‐motor adaptations, and (3) a circuit involving subcortical and cortical pathways through the amygdala that mediates the attachment of affective status and emotional responses to previously neutral stimuli.
Primate Cognition
Authors: Hauser Marc D. 
Published: November 2003

AbstractThis chapter explores the evolution of cognition, attempting to assess the degree to which human and nonhuman primates share conceptual resources. I first lay out the logic of the comparative approach in biology, and then develop an argument concerning domain‐specific mechanisms underlying conceptual representations. In particular, I suggest that in both humans and nonhuman primates, several domains of knowledge are mediated by highly specialized mechanisms that operate over highly specific kinds of input. To buttress these claims, and showcase the power of the comparative method, I explore in detail two case studies: number and language. I argue that both systems depend upon core computational resources that evolved prior to humans. In the case of number, there are at least two core systems that are shared with other primates, and in fact other nonprimates, including rodents and birds. In the case of language, it appears that all the key perceptual mechanisms underlying speech are shared with other species, thereby suggesting that these mechanisms evolved for reasons other than speech. Where the differences appear to lie is in the domain of computation. I conclude by making some suggestions for future research on the domain‐specificity, including its evolutionary and developmental origins.
Language
Authors: Saffran Eleanor M. , Schwartz Myrna F. 
Published: November 2003

AbstractLanguage is a uniquely human capacity; hence the investigation of language function, as well as language‐brain relationships, requires the use of human subjects. In recent years, the development of methods for monitoring brain activity as people engage in cognitive tasks has provided a means of studying language‐brain relationships in normal individuals. These techniques complement the study of disruptions to language function caused by brain damage—the aphasias—which for some time served as the primary means of investigating the neural substrates of language. The breakdown patterns observed in aphasia are the focus of much of this chapter, which also reviews evidence from studies that examine language activity in the normal brain. The section on semantics describes how the understanding of objects and their names erodes in the condition known as semantic dementia. The section on language comprehension moves through the processing of spoken input from sounds to sentences. Finally, the section on production describes models of word retrieval and sentence production that aim to account for aphasic as well as nonaphasic performance. Within each section, evidence from functional imaging studies is considered alongside the lesion evidence.
Psychological Function in Computational Models of Neural Networks
Authors: O'Reilly Randall C. , Munakata Yuko 
Published: November 2003

AbstractThe overarching goal of cognitive neuroscience is to understand how the brain gives rise to thought. We describe how computer models can help accomplish this goal by simulating networks of interacting neurons and measuring cognitive function in these networks at the same time. The variables in these networks can be easily manipulated and observed, so that their effects on cognitive processes can be clearly understood. We provide an up‐to‐date review of some of the core principles and prominent applications of computational models in cognitive neuroscience. We begin with a summary of some of the main questions confronting computational modelers in cognitive neuroscience, ranging from the basic properties of individual neurons and networks thereof, up to issues surrounding how networks of neurons can subserve complex cognitive functions. We then discuss provisional answers to these questions, showing how they apply to a range of empirical data in domains including perception, learning and memory, and higher‐level cognition. Throughout, and in closing, we discuss challenges to neural network models.
Environment and Development of the Nervous System
Authors: Black James E. 
Published: November 2003

AbstractA relatively small number of species have evolved specialized brain systems that incorporate information from the environment during development to refine and better adapt the individual's brain structure. Remodeling of neural circuitry in response to experience has evolved in diverse animal species, from the honeybee to mammals, and adaptive systems can be found in numerous parts of the brain. The capacity to use experience to shape brain structure extends in mammals from the prenatal period through old age.This chapter briefly discusses the genetic contributions to the developing brain, some parts of which become specialized for learning and memory. These are not “blank slates” but rather dynamic and interactive neural structures that organize and guide plasticity. The developing nervous system helps provide and organize experience by stabilizing the visuomotor platform, rough and tumble play, exploration, and other behaviors. Affiliative behaviors between parent and child also optimize experience so that it is safe and its affective tone is stimulating but comfortable. There is thus a complex ongoing transaction during development among: brain structure, the young organism's own often playful or curious contributions to its own experience, and parental contributions.The chapter discusses two basic categories of neural plasticity:experience‐expectantdevelopment involving the readiness of the brain to receive specific types of information from the environment, andexperience‐dependentdevelopment involving the brain's adaptation to information that is unique to an individual. The former category has a species‐typical developmental period of sensitivity, as shown, for example, in studies of visual deprivation. Such processes typically overproduce synaptic connections followed by their dramatic pruning back, with synapse overproduction and pruning in prefrontal cortex seeming to occur relatively late in humans. Some information necessary for survival is unique to the individual, idiosyncratic in its timing, such that that information storage depends on the nature of the experience. A neural signal equivalent to fear or reward potentiates storage, which is not developmentally programmed but follows a lifelong pattern. Studies involving the manipulation of acrobatic training, environmental complexity, and higher education illustrate experience‐dependent processes.Clinical implications for when the neural substrate is defective or experience is inadequate or incoherent, as well as strategies for helping the injured organism get back on a normative developmental trajectory, are discussed.
Consciousness
Authors: Banks William P. , Farber Ilya 
Published: November 2003

AbstractThough unfashionable for much of the midtwentieth century, consciousness regained some respectability in the last two decades of the century and is now a hot topic for psychological research and theory. This resurgence was driven partly by the general rise of cognitive psychology and partly by more specific developments in experimental methodology and technology. Even within science, the study of consciousness is cross‐disciplinary and diverse, and so in this chapter we present work from a variety of experimental paradigms and traditions; within cognitive psychology, topics include subliminal perception, implicit cognition, and the effects of attention. Neuroscience has also become one of the major loci of work on consciousness, and so we provide an extended discussion of the relevant experimental work and of some of the latest theories about the neural basis of consciousness. We also discuss the theoretical and methodological challenges involved in applying the scientific method to subjective phenomena, and provide a brief summary of philosophical and early scientific approaches. The science of consciousness is admittedly still fragmentary, but it is remarkable how much has been discovered in a relatively short span of time, and in conclusion we offer a few predictions about the likely outlines of future progress.
Motivation
Authors: Godsil Bill P. , Tinsley Matthew R. , Fanselow Michael S. 
Published: November 2003

AbstractLearning and genetics cannot account for all the variation in behavior. The concept of motivation can be used as a construct to provide a more complete explanation of behavior. We suggest that motivation can best be defined in the context of a functional behavior system. From this perspective, the definition of motivation is explicitly related to a naturally occurring problem that the behavior system has evolved to solve. This problem‐oriented view provides a framework to organize both the stimuli that elicit motivated behavior, and the responses that address the naturally occurring problem. We focus our analysis on animal models of the functional behavior systems that organize feeding, fear, sexual and thermoregulatory behaviors.
Mood, Cognition, and Memory
Authors: Eich Eric , Forgas Joseph P. 
Published: November 2003

AbstractThe interplay between feeling and thinking, affect and cognition, has been a subject of scholarly discussion and spirited debate since antiquity. Within the past 25 years, the affect/cognition interface has also emerged as one of the most active and rapidly developing areas within psychological science. Two phenomena that have attracted much modern interest are mood congruence—the observation that a given affect state or mood promotes the processing of information that possesses a similar affective tone or valence, and mood‐dependence—the observation that information encoded in a particular mood is most retrievable in that mood, irrespective of the information's affective valence. This chapter examines the history and current status of research on mood congruence and mood dependence with a view to clarifying what is known about each of these phenomena, and why they are both worth knowing about. Particular consideration is given to the role of different information‐processing strategies in the occurrence of mood‐congruent and mood‐dependent effects, and to the way these effects may materialize in realistic everyday situations or clinical contexts.