Abstracts of Presentations   Thomas Carr, Ph.D. Michigan State University. On the Functional Architecture of Language and Reading: Mental Operations, Biological Preparation, and Cultural Engineering. The enduring legacy of Mike Posner's career as a cognitive psychologist and cognitive neuroscientist centers on a set of ideas that have become fundamental -- in no small part due to Mike's own work -- in understanding the human mind, its intellectual capacities, and how these capacities are supported by the developing brain. Perceiving, thinking, and acting can be understood as sequences of mental operations mediating between sensory inputs and overt actions. These sequences of mental operations are governed by attentional operations that control the selection of inputs, the computation of decisions, and the selection and execution of actions in the service of specific task-defined goals. Biology prepares people to learn some tasks, but cultural engineering forces people to go far beyond biological preparation, working hard to master quite complicated tasks that nature never imagined and hence did not build into the biological repertoire of prepared task performances. These culturally-engineered tasks place greater burdens on attentional resources, greater demands on instructional support, and show greater individual variation in achieved skill level. Finally, all of these issues can be studied with the same methodology, consisting of a carefully crafted combination of reaction-time analyses of task performance ("mental chronometry") and neuroimaging analyses of brain function (using PET, fMRI, and ERP). I will illustrate this set of ideas using work on visual word recognition, reading, writing, and language production, addressing four questions: (1) What initial architectural changes must be made to turn a language-using child into a beginning reader? (2) What is the functional architecture of the mature reading system? (3) How does the functional architecture of the reading system compare to those of speaking and listening? (4) How can cognitive and neural theories of attention, automaticity, and practice be applied to repairing "broken" language and reading systems -- that is, how can they inform aphasia rehabilitation?   BJ Casey, Ph.D. Associate Professor of Psychology in Psychiatry and Neuroscience, Sackler Institute for Developmental Psychobiology. The Development, Disruption and Neurobiological Basis of Cognitive Control. One key feature of cognitive and behavioral development is the gradual ability to override one behavior in favor of another or to suppress attention to irrelevant information in favor of more relevant information. BJ Casey will present an overview of her work examining the normal development of this ability, its neural basis and is disruption in developmental disorders. She will describe behavioral paradigms that parametrically manipulate the degree of interfering, irrelevant information, thereby increasing the demands for overriding an attentional or behavioral response (i.e. cognitive control). Behavioral and imaging results will be presented that emphasize the structural and functional connectivity of brain systems including the prefrontal cortex and basal ganglia, assumed to play a role in cognitive control. Specifically she will present findings from structural magnetic resonance imaging (MRI), diffusion tensor imaging, and functional MRI that help constrain current theories on the cognitive and neural basis of cognitive control and its development. Finally, studies examining genetic variation in performance on tasks of cognitive control will be related to measures of structural and functional brain development. This work has significant implications at the behavioral, biological, and genetic level for developmental disorders that have as a core deficit, a problem overriding or suppressing inappropriate thoughts and behaviors like Attention Deficit-Hyperactivity Disorder, Obsessive Compulsive Disorder and Tourette Syndrome.   Dr. Stanislas Dehaene. Institut National de la Santé, (INSERM), Service Hospitalier Frederic Joliot, France. The Neural Bases of Subliminal Word Priming and Conscious Word Recognition. Psychologists have long reported that words that are made invisible by forward and backward masking are nevertheless processed at a high level. This raises two questions : What is the depth of subliminal processing of words ? And why do they remain inaccessible to consciousness? Neuroimaging methods have been used to address both questions. The cerebral bases of subliminal processing can be studied either directly by contrasting prime-present with prime-absent trials, or indirectly by identifying regions that show a reduced activation for repeated prime-target pairs relative to non-repeated trials. The results reveal that multiple areas (fusiform gyrus, intraparietal sulcus, and motor cortex) can be activated by subliminal stimuli, in direct correspondence with behavioral manifestations of priming at the lexical, semantic, and motor level. Subliminal words, however, fail to elicit the intense and distributed pattern of frontal, parietal and cingulate activity which is seen when words are unmasked and become consciously identifiable. Those data fit with the hypothesis of a conscious neuronal workspace, which postulates that a visual stimulus becomes reportable when its neural representation in posterior areas is amplified and made available, via long-distance neural connections, to multiple distant sites.   John Duncan, Ph.D. MRC Cognition and Brain Sciences Unit, Cambridge. An Adaptive Coding Model of Neural Function in Prefrontal Cortex. Data from human neuroimaging and monkey electrophysiology are used to motivate a new model of prefrontal function, the adaptive coding model. Imaging data show that much the same frontal regions - the cortex surrounding the inferior frontal sulcus, the frontal operculum/anterior insula, and the dorsal anterior cingulate - are activated by increasing demands in a wide variety of cognitive domains, including perception, response selection, working memory, problem solving and executive control. Similarly, monkey studies show conspicuous activity in lateral prefrontal cortex related to many different tasks. Such activity produces a dense, distributed description of inputs, outputs, rewards and other relevant events. New data are presented to show strong attentional selectivity in frontal neurons, with effective filtering out of stimulus distinctions immaterial to a current task. According to the adaptive coding model, neurons in selected frontal regions adapt their properties to code just that information of relevance to current behaviour. In turn, this selectivity gives support to coding of related information in posterior brain systems, in this way acting as a global attentional controller. The model casts light on a number of related problems, including broad cognitive disorganization following frontal lobe damage, and the phenomenon of "general intelligence" in normal cognition.   Martha J. Farah, Ph. D. Professor of Psychology and Director, Center for Cognitive Neuroscience, University of Pennsylvania. Neurocognitive Development in Childhood Poverty. Starting as early as preschool, and persisting throughout the lifespan, children from low socioeconomic backgrounds score below their middle SES counterparts on virtually all measures of school achievement and intelligence. Furthermore, the size of the SES gap is substantial, on the order of a standard deviation or more in many cases (see Smith et al., 1997, for a review). In this talk I will summarize what we have learned about the underlying neurocognitive effects of poverty, including which neurocognitive systems are most affected and what aspects of poverty (including noneconomic aspects such as lead, depression and stress) are responsible. In so doing, I will draw upon the conceptual framework first introduced into cognitive psychology by Mike Posner (see Posner et al., 1987), in which the mind can be parsed into neurally distinct subsystems. I will also attempt to address an issue that Mike has more recently highlighted, namely variation in neurocognitive development, by identifying factors in the child's environment that predict neurocognitive outcome.   Mark Johnson, Ph.D. School of Psychology, Birkbeck College. Three Views on Human Functional Brain Development. I will review three different perspectives on the development of functioning of the human brain. First, a maturational view in which the aim is to relate the maturation of individual brain regions to changes in cognitive and behavioral abilities. Second, an interactive specialisation view in which the focus is on the changing patterns of interactions between regions, and how these enable the emergence of new cognitive functions. Third, a skill learning view in which parallels are made between the neural consequences of adult (perceptual and motor) skill learning, and changes in brain processing during infancy. The merits or otherwise of these three perspectives will be analyzed in relation to empirical evidence from our laboratory about brain functioning in infants while they perform perceptual and motor tasks.   Ray Klein, Ph.D. Department of Psychology, Dalhousie University. Development and Individuality in the Timecourse of Inhibition of Return More efficient information processing is the immediate consequence of the capture of attention by a peripheral object or event. Yet when attention is removed from this location, less efficient processing is observed there, as if, after having shifted away, attention is inhibited from returning. By discouraging orienting toward previously attended objects and locations, this inhibition of return (IOR) is thought to function as a search or foraging facilitator. In a cue-target paradigm, the timecourse of this crossover from facilitation to inhibition is known to vary with the nature of the target task. This variation can be explained by assuming that the observer adopts an attentional control setting suitable for performing the target task and that such settings cannot be rapidly altered. Thus, with the setting put in place for the target task applying to the cue, the more attention is required to perform the target task the more strongly it will be allocated to the cue, the longer attention will dwell on the cue and therefore, the later inhibition will be observed. Here I will explore an extension of this line of thinking from task differences to individual differences. Individuals with underdeveloped or degraded voluntary control over attention should be less likely to, or slower to, disengage attention from an uninformative peripheral cue - unless disengagement is elicited exogenously by a post-cue event. Support for this proposal comes from new developmental studies of the timecourse of exogenous cuing with or without a flash back to fixation, and from analyses of the literatures on the time course of exogenous cuing in aging and schizophrenia.   Helen Neville, Ph.D. Department of Psychology, University of Oregon. Specificity and Plasticity in Human Brain Development. I will review ERP and fMRI results of visual, auditory and language processing in normal adults and in those who have had different sensory and/or language experience. Taken together these studies suggest that within vision and audition and language different neural systems display different "plasticity profiles" i.e. considerable variability in the degree to which and the timeperiods when they are modified by early experience. Within vision, early auditory deprivation has most marked effects on the organization of systems important in processing motion information. Within the visual and auditory systems sensory deprivation has more effects on the representation of the peripheral than of the central fields. In addition, different subsystems within language display varying degrees of modifiability by experience. The acquisition of lexical semantics appears relatively robust and invariant even in individuals with markedly different timing and modality of language input. By contrast, systems active during grammatical and phonological processing display marked effects of alterations in the timing and nature of early language input. These results converge with other lines of evidence that suggest it is important to distinguish these different aspects of processing, they raise specific hypotheses about different mechanisms of neuroplasiticity and they raise hypotheses about the initial development of these different systems. Parallel studies of normal infants and children, and of those with abnormal development provide further evidence for the roles of genetic factors and experience in human neurobehavioral development. The results of these several different types of experiments provide evidence that some systems within the human brain retain the ability to change, adapt, and learn throughout life, while other aspects of human neural and behavioral development display multiple, specific and different critical periods.   Marcus Raichle, M.D. Departments of Radiology and Neurology, Washington University School of Medicine. Images of Mind: A Perspective The field of cognitive neuroscience has emerged over the past decade as one of the most rapidly growing areas of neuroscience. Central to the work in this area has been the emergence of new imaging techniques capable of examining the functional activity of the normal human brain. The success of these imaging techniques has, in no small measure, been due to the influence of the experimental techniques of cognitive psychology when applied in conjunction with functional brain imaging. This wedding of techniques from two separate disciplines was brought about when Michael Posner entered this arena of research in the early 1980's. The field is greatly in his debt for the seminal contributions he made. Looking to the future, this work is now tackling important problems in all domains of psychology, normal as well as abnormal. This presentation will focus on some of the most exciting areas of research that are opening up in what is not only called cognitive neuroscience but also, recently, social neuroscience as well.   Mary Rothbart, Ph.D. Distinguished Professor, University of Oregon. The Development of Effortful Control. Temperament studies have shown that care givers can consistently describe a dimension of self control or regulation in their toddlers that is called effortful control. Systems of effortful control allow approach to situations in the face of immediate cues for punishment, and avoidance of situations in the face of immediate cues for reward. The programming of effortful control is critical to socialization. Studies with adults have shown a specific frontal network is involved in tasks in which the person is required to resolve conflict between simultaneous stimulus events as in the Stroop effect. High density EEG studies of adults and four year old children show activation of this frontal network in conflict tasks appropriate for use with children. We have examined the development of the ability to resolve conflict in children from 2.5 to 7 years of age. It was found both that the ability to resolve conflict was correlated with effortful control. In turn effortful control has been shown to be related to the ability to delay reward, the development of theory of mind and the acquisition of conscience. This result forges connections between temperamental differences in effortful control as observed by parents in the behavior of their children and a specific anatomical network related to executive attention.