bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fractionating the Word Repetition Effect with Event-Related Potentials
Authors: Petten Cyma Van , Kutas Marta , Kluender Robert , Mitchiner Mark , McIsaac Heather 
Published: February 2008

Abstract
Word repetition has been a staple paradigm for both psycholinguistic and memory research; several possible loci for changes in behavioral performance have been proposed. These proposals are discussed in light of the event-related brain potential (ERP) data reported here. ERPs were recorded as subjects read nonfiction articles drawn from a popular magazine. The effects of word repetition were examined in this relatively natural context wherein words were repeated as a consequence of normal discourse structure. Three distinct components of the ERP were found to be sensitive to repetition: a positive component peaking at 200 msec poststimulus, a negative one at 400 msec (N400), and a later positivity. The components were differentially sensitive to the temporal lag between repetitions, the number of repetitions, and the normative frequency of the eliciting word. The N400 responded similarly to repetition in text as it has in experimental lists of words, but the late positivity showed a different pattern of results than in list studies.
When Metacognition Fails: Impaired Awareness of Deficit in Alzheimer's Disease
Authors: McGlynn Susan M. , Kaszniak Alfred W. 
Published: February 2008

Abstract
Two new measures were developed to assess quantitatively the degree to which patients with Alzheimer's disease (AD) are aware of their memory deficit, and to evaluate the relation between dementia severity and awareness of deficit. Results of a questionnaire measure indicated that AD patients rated their own difficulties with cognitive activities of daily life significantly lower than relatives rated patients' problems, and this discrepancy was related to patients' dementia severity. On another measure involving task performance predictions, AD patients were inaccurate in predicting their performance on most cognitive tasks when compared to both their actual performance and relatives' predictions, despite generally accurate prediction of their relatives' performance on the same tasks. These results are discussed in terms of a breakdown in metacognitive processes.
“Dead Reckoning,” Landmark Learning, and the Sense of Direction: A Neurophysiological and Computational Hypothesis
Authors: McNaughton B. L. , Chen L. L. , Markus E. J. 
Published: February 2008

Abstract
Behavioral and neurophysiological evidence strongly suggests that, within certain limits, rodents and humans can keep track of their directional heading relative to an inertial, and hence allocentric coordinate system. This “sense of direction” appears to involve the integration of angular velocity signals that arise primarily in the vestibular system. A hypothesis is proposed in which the integration process, an operation that may be difficult for neurons to implement, is replaced by a linear associative mapping, an operation that is at least theoretically easy to implement with neurons. The proposed system makes use of a set of linearly independent vectors representing the combination of the current head direction, and head angular velocity representations to “recall” the resulting head direction. It is then proposed that visual landmarks become incorporated into the directional system, enabling both the correction of cumulative error and, ultimately, the computation of novel, optimal trajectories between locations. According to the hypothesis, this occurs through the association of hippo-campal “local-view” cells (i.e., direction selective “place cells”) with “head-direction” cells located downstream in the dorsal presubiculum. The possible neurophysiological and neuroan-atomical bases for the proposed system are discussed.
High Precision Systems Require High Precision “Blueprints”: A New View Regarding the Formation of Connections in the Mammalian Visual System
Authors: Chalupa Leo M. , Dreher Bogdan 
Published: February 2008

Abstract
It is well established that early in development interconnections within the mammalian visual system are often more widespread and less precise than at maturity. The literature dealing with the formation of visual connections has largely ignored differences in developmental specificity among species differing in their phylogenetic status and/or the visual ecological niche that they occupy. Based on a review of the available evidence, we have formulated an hypothesis to account for the varying degrees of developmental specificity that characterize different visual systems. It is suggested that extremely precise systems required for high-acuity binocular vision exhibit fewer presumed developmental errors than do visual systems characterized by poorer acuity and relatively crude depth perception. The developmental implications of the hypothesis are considered, and specific experiments are proposed to further test its validity.
Short-Latency Single Unit Processing in Olfactory Cortex
Authors: McCollum Jonn , Larson John , Otto Tim , Schottler Frank , Granger Richard , Lynch Gary 
Published: February 2008

Abstract
Single-unit recording of layer II—III cells in olfactory (piriform) cortex was performed on awake, unrestrained rats actively engaged in learning novel odors in an olfactory discrimination task. Five of the 67 cells tested had very brief monophasic action potentials and high spontaneous firing rates (30–80 Hz); it is suggested that these units were interneurons. The remainder of the neurons had broader spikes and did not discharge for prolonged periods. Thirty-nine percent of the broad spike cells responded to at least one and usually more of the odors presented to the rats during either of the first two trials on which that odor was present, but, in most cases, these responses occurred only very infrequently over the course of subsequent trials. Six percent of the broad-spike group, how ever, continued firing robustly to a single odor but not to others.
From these results it appears that most cells in piriform cortex do not respond to most odors, i.e., coding is exceedingly sparse. A subgroup of the predominant broad-spike cell type does react to several odors but this response drops out with repeated exposure, perhaps because of training. However, a few members of this class (a small fraction of the total cell population) do go on responding to a particular odor, thus exhibiting a form of odor specificity. The results are discussed with regard to predictions from recently developed models of the olfactory cortex.
Components of Visual Orienting in Early Infancy: Contingency Learning, Anticipatory Looking, and Disengaging
Authors: Johnson Mark H. , Posner Michael I. , Rothbart Mary K. 
Published: February 2008

Abstract
Three aspects of the development of visual orienting in infants of 2, 3, and 4 months of age are examined in this paper. These are the age of onset and sequence of development of (1) the ability to readily disengage gaze from a stimulus, (2) the ability to consistently show “anticipatory” eye movements, and (3) the ability to use a central cue to predict the spatial location of a target. Results indicated that only the 4--month-old group was easily able to disengage from an attractive central stimulus to orient toward a simultaneously presented target. The 4--month-old group also showed more than double the percentage of “anticipatory” looks than did the other age groups. Finally, only the 4--month-old group showed significant evidence of being able to acquire the contingent relationship between a central cue and the spatial location (to the right or to the left) of a target. Measures of anticipatory looking and contingency learning were not correlated. These findings are, in general terms, consistent with the predictions of matura-tional accounts of the development of visual orienting.
Timing and Force Control Deficits in Clumsy Children
Authors: Lundy-Ekman Laurie , Ivry Richard , Keele Steven , Woollacott Marjorie 
Published: February 2008

Abstract
This study investigated the link between cognitive processes and neural structures involved in motor control. Children identified as clumsy through clinical assessment procedures were tested on tasks involving movement timing, perceptual timing, and force control. The clumsy children were divided into two groups: those with soft neurological signs associated with cerebellar dysfunction and those with soft neurological signs associated with dysfunction of the basal ganglia. A control group of age-matched children who did not exhibit evidence of clumsiness or soft neurological signs was also tested. The results showed a double dissociation between the two groups of clumsy children and the tests of timing and force. Clumsy children with cerebellar signs were more variable when attempting to tap a series of equal intervals. They were also more variable on the time perception task, indicating a deficit in motor and perceptual timing. The clumsy children with basal ganglia signs were unimpaired on the timing tasks. However, they were more variable in controlling the amplitude of isometric force pulses. These results support the hypothesis that the control of time and force are separate components of coordination and that these computations are dependent on different neural systems.
N400 to Semantically Anomalous Pictures and Words
Authors: Nigam Arti , Hoffman James E. , Simons Robert F. 
Published: February 2008

Abstract
The N400 component of the human event-related brain potential appears to be related to violations of semantic expectancy during language comprehension. The present experiment investigated whether the N400 is related specifically to activity in a language system or is an index of a conceptual system that is accessed by both pictures and words. Sentences were visually presented one word at a time with the last word being replaced in one condition by a line drawing representing the same concept (eg, the word “socks” was replaced by a picture of socks). The N400 recorded in the Pictures Condition was found to be identical to the N400 generated by words in terms of amplitude, scalp distribution, and latency. These results suggest that the N400 is an index of activity in a conceptual memory that is accessed by both pictures and words.
Event-Related Potentials and Recognition Memory for Low- and High-Frequency Words
Authors: Rugg Michael D. , Doyle Michael C. 
Published: February 2008

Abstract
Event-related potentials (ERPs) were recorded while subjects made recognition judgments on high- and low-frequency words, half of which had previously been presented in an incidental study task. Compared to high-frequency items, low-frequency words were associated with superior recognition performance, and attracted a higher proportion of confident judgments. In the case of the low-frequency words only, the region of the ERPs post-500 msec evoked by correctly classified, previously studied (old) words was more positive-going than was the same region of the EWs to nonstudied (new) words. These “old/new” ERP differences were larger from electrodes over the left than over the right hemisphere. This old/new by frequency interaction held when EWs were formed only from words that attracted confident judgments. It is argued that these data are consistent with the ideas that (1) post-500 msec “old/ new” EW differences in recognition memory tasks reflect differences in old and new words' levels of relative familiarity, and (2) the recognition memory advantage for low-frequency words results, at least in part, from the higher level of relative familiarity engendered at test by previously studied low-frequency items. The data are interpreted as providing support for “two-process” models of recognition memory.
Is Cognitive Neuropsychology Possible?
Authors: Caramazza Alfonso 
Published: February 2008

Abstract
Cognitive neuropsychology's domain of inquiry concerns the structure of normal perceptual, motor, and cognitive processes. As such, it constitutes a branch of cognitive science. Cognitive neuropsychology differs from other branches of cognitive science only by the type of observation that it uses in developing and evaluating theories of normal cognition. The data used in cognitive neuropsychology are the patterns of performance produced by brain-damged subjects. Because the basic data used in cognitive neuropsychology are the result of a biological manipulation—a brain lesion—these data will be relevant to claims about the functional organization of the brain. Hence, cognitive neuropsychology may also be considered to be a branch of cognitive neuroscience. However, in this paper I will be concerned with an assessment of research programs whose principal or only aim is to constrain theories of normal cognitive functioning through the analysis of acquired disorders of cognition. Following a brief discussion of the basic assumptions that motivate cognitive neuropsychological research, I consider Kosslyn and Van Kleeks (1990) claim that the study of brain-damaged subjects for the purpose of constraining theories of normal cognitive processing cannot lead to meaningful conclusions unless the theories are directly cast in terms of anatomical and physiological facts. I argue that these authors conflated criticisms that may apply to any empirical science with criticisms that may apply specifically to cognitive neuropsychology. Separate consideration of the criticisms specific to cognitive neuropsychology reveals that these are unfounded. The main point of this discussion is to emphasize the pragmatic character of the motivation for using impaired performance to constrain theories of normal cognition. The usefulness of cognitive neuropsychological research is illustrated through specific examples.
A Neuroethological Framework for the Representation of Minds
Authors: Brothers Leslie , Ring Brian 
Published: February 2008

AbstractThe cognition that constructs mental features such as intention, disposition, and character is an aspect of theory of mind. This aspect of representation of minds, which inherently has valence, is viewed from cognitive, evolutionary, and neural perspectives. It is proposed that this cognition is modular, and that it normally operates in association with a valence-free cognition able to represent mental states such as belief. Examples of neural activity capable of supporting the social representations macaque monkeys are believed to possess (understanding of affective displays, purposeful movement, and elemental social interactions) are presented.
An Event-Related Potential (ERP) Analysis of Semantic Congruity and Repetition Effects in Sentences
Authors: Besson Mireille , Kutas Marta , Petten Cyma Van 
Published: February 2008

Abstract
In two experiments, event-related brain potentials (ERPs) and cued-recall performance measures were used to examine the consequences of semantic congruity and repetition on the processing of words in sentences. A set of sentences, half of which ended with words that rendered them semantically incongruous, was repeated either once (eg, Experiment 1) or twice (e.g., Experiment 2). After each block of sentences, subjects were given all of the sentences and asked to recall the missing final words.
Repetition benefited the recall of both congruous and incongruous endings and reduced the amplitude and shortened the duration of the N400 component of the ERP more for (1) incongruous than congruous words, (2) open class than closed class words, and (3) low-frequency than high-frequency open class words. For incongruous sentence terminations, repetition increased the amplitude of a broad positive component subsequent to the N400.
Assuming additive factors logic and a traditional view of the lexicon, our N400 results indicate that in addition to their singular effects, semantic congruiry, repetition, and word frequency converge to influence a common stage of lexical processing. Within a parallel distributed processing framework, our results argue for substantial temporal and spatial overlap in the activation of codes subserving word recognition so as to yield the observed interactions of repetition with semantic congruity, lexical class, and word frequency effects.
Mnemonic Dissociations: The Power of Parameters
Authors: Olton David S. , Shapiro Matthew L. 
Published: February 2008

Abstract
Memory, as reflected in neural plasticity, is certainly not a functionally homogeneous process. Within the context of the mnemonic functions of the hippocampal system, this paper discusses two issues. The first concerns the appropriate conceptual approach to be taken in a neuropsychological analysis of memory. We conclude that a dimensional approach, emphasizing a quantitative analysis of individual mnemonic processes, has a significant advantage over the dichotomous classification of different types of memory. The second issue concerns the most appropriate way to describe the role of the hippocampus in mnemonic processes. On the basis of electrophysiological, neurochemical, behavioral, and computational analyses of hippocampal function, we suggest that its major role is the reduction of interference.
The Hippocampal System and Declarative Memory in Animals
Authors: Eichenbaum Howard 
Published: February 2008

AbstractTheoretical arguments and empirical data are presented in favor of the hypothesis that the hippocampal system supports a declarative memory capacity in animals as well as humans. This view is advanced by identifying two prominent characteristics of human declarative memory and by operationalizing and evaluating them using both experimental lesion and single unit recording studies on animals. First, hippocampal processing is not selective to any particular category of learning materials; instead, it supports comparisons among all kinds of information in memory, resulting in a representation of critical relations between items. Conversely, individual representations are supported outside the hippocampal system. Second, hippocampal-dependent, relational memory representations involve a flexible organization that permits inferences from memory in novel situations. Conversely, hippocampal-independent individual representations can support only repetition of procedures acquired during original learning. Correspondences between the neuropsychological and neurophysiological findings presented serve to indicate how these properties of hippocampal representation support declarative memory across behavioral paradigms and across species.
Memory and Working-with-Memory: A Component Process Model Based on Modules and Central Systems
Authors: Moscovitch Morris 
Published: February 2008

Abstract
A neuropsychological model of memory is proposed that incorporates Fodor's (1983) idea of modules and central systems. The model has four essential components: (1) a non-frontal neocortical component that consists of perceptual (and perhaps interpretative semantic) modules that mediate performance on item-specific, implicit tests of memory, (2) a modular medial temporal/hippocampal component that mediates encoding, storage, and retrieval on explicit, episodic tests of memory that are associative/cue dependent, (3) a central system, frontal-lobe component that mediates performance on explicit tests that are strategic and on procedural tests that are rule-bound, and (4) a basal ganglia component that mediates performance on sensorimotor, procedural tests of memory. The usefulness of the modular/central system construct is explored and evidence from studies of normal, amnesic, agnosic, and demented people is provided to support the model.
Computational Consequences of a Bias toward Short Connections
Authors: Jacobs Robert A. , Jordan Michael I. 
Published: February 2008

Abstract
A fundamental observation in the neurosciences is that the brain is a modular system in which different regions perform different tasks. Recent evidence, however, raises questions about the accuracy of this characterization with respect to neo-nates. One possible interpretation of this evidence is that certain aspects of the modular organization of the adult brain arise developmentally. To explore this hypothesis we wish to characterize the computational principles that underlie the development of modular systems. In previous work we have considered computational schemes that allow a learning system to discover the modular structure that is present in the environment (Jacobs, Jordan, & Barto, 1991). In the current paper we present a complementary approach in which the development of modularity is due to an architectural bias in the learner. In particular, we examine the computational consequences of a simple architectural bias toward short-range connections. We present simulations that show that systems that learn under the influence of such a bias have a number of desirable properties, including a tendency to decompose tasks into subtasks, to decouple the dynamics of recurrent subsystems, and to develop location-sensitive internal representations. Furthermore, the system's units develop local receptive and projective fields, and the system develops characteristics that are typically associated with topographic maps.
Brain Potentials during Memory Retrieval Provide Neurophysiological Support for the Distinction between Conscious Recollection and Priming
Authors: Paller Ken A. , Kutas Marta 
Published: February 2008

Abstract
Event-related brain potentials were recorded from subjects as they attempted to identify words displayed tachistoscopically. Words that had also been presented a few minutes earlier in a different context were identified more often than were words that had not been presented before. This priming effect was observed for words initially seen in an imagery task requiring size estimations as well as for words initially seen in an orthographic task requiring letter counting. Unlike priming, recall and recognition were much better for words repeated from the imagery task than from the orthographic task. Brain potentials elicited during word identification also differed as a function of task. Based on these differences, a potential from 500 to 800 msec was interpreted as an index of recollection processes. Earlier potentials may have indexed processing related to priming. These effects thus provide measures of the hypothetical processes underlying memory performance and demonstrate that recollection and priming are associated with distinct neural events.
A Neural Network Model of Cortical Activity during Reaching
Authors: Kettner Ronald , Marcario Joanne , Port Nicholas 
Published: February 2008

Abstract
A neural network model that produces many of the directional and spatial response properties that have been observed for cortical neurons in monkeys moving toward targets in space is described. These include motor cortex units with broad tuning in a single preferred direction, approximately linear variation in activity for different hold positions, and approximate invariance in preferred direction for different starting points in space. Association cortex units in the model are sometimes irregular and reminiscent of neurons observed in visually responsive brain areas such as the posterior parietal cortex. The model is also compatible with population analyses performed on motor cortical neurons. Across network units, the distribution of preferred directions is uniformly distributed in directional space, and the degree of tuning and response magnitude vary from unit to unit. A population code used to predict accurately the direction of arm movements from a large population of coarsely tuned individual neurons allows predictions using a simulated population of unit responses obtained from the neural network model. This code works for different starting locations in space using the same parameters.