bluuebunny/crossref_metadata_2025_split huggingface dataset:
Language and Reading in the Right Hemisphere: Highways or Byways of the Brain?
Authors: Baynes Kathleen 
Published: February 2008

Abstract
The literature pertaining to the representation of language in the right hemisphere of hemispherectomy and callosotomy patients is reviewed to ascertain whether it provides an empirical basis for the assertions that (1) the right hemisphere participates in the recovery of language in aphasia, (2) the right hemisphere mediates the reading errors of deep dyslexic and pure alexic patients, and (3) the right hemisphere plays a fixed role in normal reading processes. At present, there appears to be some support for the first assertion, limited support for the second (if individual variation in representation can be accepted), and disconfirming evidence for the third in the data from these populations.
Music Perception and Cognition Following Bilateral Lesions of Auditory Cortex
Authors: Tramo Mark Jude , Bharucha Jamshed J. , Musiek Frank E. 
Published: February 2008

Abstract
We present experimental and anatomical data from a case study of impaired auditory perception following bilateral hemispheric strokes. To consider the cortical representation of sensory, perceptual, and cognitive functions mediating tonal information processing in music, pure tone sensation thresholds, spectral intonation judgments, and the associative priming of spectral intonation judgments by harmonic context were examined, and lesion localization was analyzed quantitatively using straight-line two-dimensional maps of the cortical surface reconstructed from magnetic resonance images.
Despite normal pure tone sensation thresholds at 250–8000 Hz, the perception of tonal spectra was severely impaired, such that harmonic structures (major triads) were almost uniformly judged to sound dissonant; yet, the associative priming of spectral intonation judgments by harmonic context was preserved, indicating that cognitive representations of tonal hierarchies in music remained intact and accessible. Brainprints demonstrated complete bilateral lesions of the transverse gyri of Heschl and partial lesions of the right and left superior temporal gyri involving 98 and 20% of their surface areas, respectively. In the right hemisphere, there was partial sparing of the planum temporale, temporoparietal junction, and inferior parietal cortex. In the left hemisphere, all of the superior temporal region anterior to the transverse gyrus and parts of the planum temporale, temporoparietal junction, inferior parietal cortex, and insula were spared.
These observations suggest that (1) sensory, perceptual, and cognitive functions mediating tonal information processing in music are neurologically dissociable; (2) complete bilateral lesions of primary auditory cortex combined with partial bilateral lesions of auditory association cortex chronically impair tonal consonance perception; (3) cognitive functions that hierarchically structure pitch information and generate harmonic expectancies during music perception do not rely on the integrity of primary auditory cortex; and (4) musical priming may be mediated by broadly tuned subcomponents of the thala-mocortical auditory system.
The Perception of Structure from Visual Motion in Monkey and Man
Authors: Siegel R. M. , Andersen R. A. 
Published: February 2008

Abstract
The ability to perceive structure using motion information was examined using a reaction time task with two primate species. Homo sapien and Macaca mulatta subjects were quantitatively tested under identical conditions to detect the change from a control unstructured to a test structured motion stimulus. The structures underlying the test were rotations of a plane, expansion of a plane, and a rotation of a three-dimensional cylinder. On many of the stimulus conditions, the two species performed similarly, although there were some species differences. These differences may be due to the extensive training of the monkeys or the use of different cognitive strategies by the human subjects. These data provide support for the existence of a neural mechanism that uses flow fields to construct two- or three-dimensional surface representations.
Preserved Priming of Novel Objects in Patients with Memory Disorders
Authors: Schacter Daniel L. , Cooper Lynn A. , Tharan Mindy , Rubens Alan B. 
Published: February 2008

Abstract
Amnesic patients perform poorly on explicit memory tests that require conscious recollection of recent experiences, but frequently show preserved facilitations of performance or priming effects on implicit memory tasks that do not require conscious recollection. We examined implicit memory for novel visual objects on an object decision test in which subjects decide whether structurally possible and impossible objects could exist in three-dimensional form. Patients with organic memory disorders showed robust priming effects on this task---object decision accuracy was higher for previously studied objects than for nonstudied objects---and the magnitude of priming did not differ from matched control subjects or college students. However, patients showed impaired explicit memory for novel visual objects on a recognition test. We argue that priming is mediated by the structural description system, a subsystem of the perceptual representation system, that operates at a presemantic level and is preserved in amnesic patients.
Syntactically Based Sentence Processing Classes: Evidence from Event-Related Brain Potentials
Authors: Neville Helen , Nicol Janet L. , Barss Andrew , Forster Kenneth I. , Garrett Merrill F. 
Published: February 2008

Abstract
Theoretical considerations and diverse empirical data from clinical, psycholinguistic, and developmental studies suggest that language comprehension processes are decomposable into separate subsystems, including distinct systems for semantic and grammatical processing. Here we report that event-related potentials (ERPs) to syntactically well-formed but semantically anomalous sentences produced a pattern of brain activity that is distinct in timing and distribution from the patterns elicited by syntactically deviant sentences, and further, that different types of syntactic deviance produced distinct ERP patterns.
Forty right-handed young adults read sentences presented at 2 words/sec while ERPs were recorded from over several positions between and within the hemispheres. Half of the sentences were semantically and grammatically acceptable and were controls for the remainder, which contained sentence medial words that violated (1) semantic expectations, (2) phrase structure rules, or (3) WH-movement constraints on Specificity and (4) Subjacency. As in prior research, the semantic anomalies produced a negative potential, N400, that was bilaterally distributed and was largest over posterior regions. The phrase structure violations enhanced the N125 response over anterior regions of the left hemisphere, and elicited a negative response (300-500 msec) over temporal and parietal regions of the left hemisphere. Violations of Specificity constraints produced a slow negative potential, evident by 125 msec, that was also largest over anterior regions of the left hemisphere. Violations of Subjacency constraints elicited a broadly and symmetrically distributed positivity that onset around 200 msec. The distinct timing and distribution of these effects provide biological support for theories that distinguish between these types of grammatical rules and constraints and more generally for the proposal that semantic and grammatical processes are distinct subsystems within the language faculty.
Deficits in Selective Attention Following Bilateral Anterior Cingulotomy
Authors: Janer Kevin W. , Pardo José V. 
Published: February 2008

Abstract
Positron emission tomographic (PET) studies of normal humans undergoing specific cognitive activation paradigms have identified a region of the anterior cingulate cortex as a component of an anterior, midline attentional system involved in high-level processing selection. However, deficits in attention have not been demonstrated in patients following bilateral anterior cingulotomy, a procedure that results in lesions of adjacent anterior cingulate cortex. Task paradigms used in PET studies that recruit the anterior cingulate cortex were applied to normal, control subjects and to a patient before and after cingulotomy to provide highly sensitive and functionally targeted reaction time measures of attentional performance. In contrast to unchanged performance in several neuropsychological measures, this patient demonstrated specific deficits in attention during the subacute postoperative period, which resolved spontaneously several months after surgery. Such impairment is consistent with the evolving view of the anterior cingulate's involvement in high-level processing selection. These data show the feasibility of using information from PET activation studies of normals in the design of novel chronometric tasks useful for probing abnormalities in specific cognitive operations associated with discrete cortical regions.
Role of Anterior and Posterior Attention Networks in Hemispheric Asymmetries during Lexical Decisions
Authors: Nakagawa Atsuko 
Published: February 2008

Abstract
The role of the left and right hemisphere was examined during semantic priming by antonyms, remote associates, and unrelated words. Targets presented directly to the left hemisphere showed an early facilitation and a late developing inhibition, while targets presented directly to the right hemisphere showed a late developing facilitation of strong and weak associations and little evidence of inhibition. When a visual cue was given prior to each target word, reaction times were facilitated equally in both visual fields and for all prime target relationships. When the priming task was combined with shadowing, reaction times generally increased and all evidence of inhibition in left hemisphere processing disappeared. This supported the idea that the inhibition found in the left hemisphere was due to its interaction with the anterior attention network.
Right Hemisphere Processing Superiority During Sustained Visual Attention
Authors: Whitehead Roger 
Published: February 2008

Abstract
Normal subjects showed a right hemisphere processing superiority in reaction times to visual stimuli under conditions of sustained visual attention. This asymmetry was predicted based on findings in studies of blood flow, clinical populations, and physiology on lateralization of the noradrenergic system. The asymmetry was eliminated when an auditory event was delivered simultaneously with the visual target suggesting a common pathway between voluntary sustained alerting and more automatic alerting effects of external stimuli. The act of sustaining alertness also interacted with covert orienting of attention as would be expected if alerting influenced the efficiency of covert shifts of attention.
The Development of Inhibition of Return in Early Infancy
Authors: Clohessy Anne Boylan , Posner Michael I. , Rothbart Mary K. , Vecera Shaun P. 
Published: February 2008

Abstract
The posterior visual spatial attention system involves a number of separable computations that allow orienting to visual locations. We have studied one of these computations, inhibition of return, in 3-, 4-, 6-, 12-, and 18--month-old infants and adults. Our results indicate that this computation develops rapidly between 3 and 6 months, in conjunction with the ability to program eye movements to specific locations. These findings demonstrate that an attention computation involving the mid-brain eye movement system develops after the third month of life. We suggest how this development might influence the infant's ability to represent and expect visual objects.
Impaired Velocity Perception in Patients with Lesions of the Cerebellum
Authors: Ivry* Richard B. , Diener H. C. 
Published: February 2008

Abstract
In three psychophysical experiments, cerebellar patients were impaired in making perceptual judgments of the velocity of moving stimuli. Performance was normal when the judgment concerned the position of the stimuli (Experiment 1). The dissociation between the velocity and position tasks suggests the cerebellar group was selectively impaired in velocity perception. EOG data were obtained in Experiments 2 and 3 to assess whether the deficit was oculomotor in origin. Perceptual errors were not correlated with the occurrence of intrusive eye movements. These results provide a novel demonstration of the role of the cerebellum in perceptual functions that require precise timing.
Lateralized Control of Eye Movements in Attention Deficit Hyperactivity Disorder
Authors: Rothlind Johannes C. , Posner Michael I. , Schaughency Elizabeth A. 
Published: February 2008

Abstract
How does a complex syndrome that involves abnormalities in impulse control and sustained attention influence simple oculomotor responses to visual stimuli? We found that normal children, like adults, were faster in moving their eyes in directions controlled by the right cerebral hemisphere under conditions where there was no warning of the impending target. ADHD children did not show this asymmetry. We speculate that this result reflects a deficit in the vigilance network that serves to maintain the alert state.
Facilitation of Working Memory in Humans by a D2 Dopamine Receptor Agonist
Authors: Luciana Monica , Depue Richard A. , Arbisi Paul , Leon Arthur 
Published: February 2008

Abstract
Recent studies on the neurobiology of cognition have focused on the ability of the prefrontal cortex (PFC) to support processes of working memory, i.e, mnemonic processes by which information relevant for a correct response is temporarily maintained to be reevaluated or updated on a trial-by-trial basis. Of most recent interest is the role played by dopamine (DA) in spatial working memory processes of the principal sulcal region of the PFC. Although D1 DA receptors appear to modulate these mnemonic processes in monkeys, several lines of research suggest that D2 DA receptors could also be relevant to cognitive functions. Therefore, we assessed the effects of a specific D2 receptor agonist (bromocriptine) and placebo on visuospatial delayed response performance in human subjects. During delay periods of 0 or 8 sec, subjects were required to remember the spatial location of rapidly presented visual cues displayed in peripheral vision within a 360° circumference. The extent to which D2 receptor activation by bromocriptine facilitated working memory in the 8–sec delay condition relative to placebo performance was assessed. As a means of providing validation of bromocriptine's D2 receptor effect, maximum inhibition of prolactin (PRL) secretion, which is inhibited specifically by activation of D2 receptor sites, was determined. Additionally, tasks having no working memory component were administered to rule out nonspecific effects of bromocriptine on sensory, arousal, attentional, and motor factors. Results demonstrated a significant facilitatory effect of bromocriptine on spatial delayed response performance (i.e., 8–sec delay performance). Results could not be explained by nonspecific effects of bromocriptine. Thus, findings of this study suggest that spatial working memory is facilitated by D2 receptor activation. The role that DA may play in human cognitive processes is discussed within the larger theoretical framework of DA's general role in the facilitation of goal-directed behavior. In the case of cognition, DA may facilitate processes that serve to guide motivated behavior through complex environments.
Is Cognitive Neuropsychology Plausible? The Perils of Sitting on a One-Legged Stool
Authors: Kosslyn Stephen M. , Intriligator James M. 
Published: February 2008

Abstract
We distinguish between strong and weak cognitive neuropsychology, with the former attempting to provide direct insights into the nature of information processing and the latter having the more modest goal of providing constraints on such theories. We argue that strong cognitive neuropsychology, although possible, is unlikely to succeed and that researchers will fare better by combining behavioral, computational, and neural investigations. Arguments offered by Caramazza (1992) in defense of strong neuropsychology are analyzed, and examples are offered to illustrate the power of alternative points of view.
Savings in Relearning Face—Name Associations as Evidence for “Covert Recognition” in Prosopagnosia
Authors: Wallace Marcie A. , Farah Martha J. 
Published: February 2008

Abstract
Prosopagnosic patients appear to be impaired at recognizing faces. However, recent evidence for “covert recognition” in prosopagnosia has been taken to suggest that the impairment is not in face recognition per se, but rather in conscious access to face recognition. The most widely used test for covert recognition of faces in prosopagnosia is the face-name relearning task, in which some prosopagnosics have been found to learn correct names for previously familiar faces more easily than incorrect names. Although this phenomenon is consistent with face recognition operating normally but out of reach of conscious awareness, it may also be consistent with an impairment in face recognition per se. Perhaps savings in relearning is sufficiently sensitive to the residual information contained in degraded face representations that are not detectable by overt measures of recognition. If so, then we should expect to observe this same savings in relearning when overt recognition is obliterated for reasons other than brain damage. In the present study, we used forgetting of face-name associations in normal subjects as a way of degrading recognition ability. We found the same dissociation between overt recognition performance and savings in relearning as observed in prosopagnosic patients. This implies that the performance of prosopagnosic patients in these tasks does not demand explanation in terms other than an impairment in face recognition per se.
Multiple Memory Systems: What and Why
Authors: Nadel Lynn 
Published: February 2008

AbstractEvidence from a variety of domains converges on the view that there are multiple learning/memory systems, but there is no clear understanding of what these systems are, and why they should exist. I review an hypothesis about multiple memory systems postulated by O'Keefe and Nadel (The hippocampus ac a Cognitive map, Oxford: Clarendon Press, 1978), in particular our assertions about the nature of two kinds of systems (the locale and taxon systems), and what differentiates them from each other. I concentrate on our assumption that systems differ in terms of the type of information they process, rather than in terms of the temporal duration over which they function. Our “content-driven” dichotomy is contrasted with several other current views, none of which appears to explain extant data, or provides clear predictions about when one or the other kind of system would be engaged. Finally, 1 briefly consider why such distinct systems might have evolved.
Variations in Synaptic Plasticity and Types of Memory in Corticohippocampal Networks
Authors: Lynch Gary , Granger Richard 
Published: February 2008

AbstractIf Synaptic long-term potentiation (LTP) represents a memory storage mechanism, its induction and expression characteristics may constitute rules governing encoding and read-out of memory in cortical circuitry, The presence of variants of the LTP effect in different anatomical networks provides grounds for predictions about the types of memory operations to which potentiation contributes. Computer modeling studies incorporating the complex rules for LTP induction and the characteristics of expressed potentiation can be used to make such predictions specific. We review ttie types of synaptic plasticity found in the successive stages of the corticohippocampal pathway, and present results indicating that LTP does participate in definably different forms of memory, suggesting a classification of memory types differing somewhat from categories deduced from behavioral studies. Specifically, the results suggest that subtypes of memory operate serially, in an “assembly line” of specialized functions, each of which adds a unique aspect to the processing of memories. The effects of lesions on the encoding versus expression of memory can be interpreted from the perspective of this hypothesis.
MEM: Mechanisms of Recollection
Authors: Johnson Marcia K. 
Published: February 2008

AbstractThe MEM framework (Johnson, 1991a, b; Johnson & Hirst, 1992; Johnson & Multhaup, 1992) consists of a relatively small set of component cognitive processes configured into memory subsystems. Here MEM is used to discuss “recollection,” particularly the mechanisms by which aspects of experience become bound together to yield the phenomenal experience of contextually specific, event-like memories. I consider how central aspects of complex events are bound to each other and propose that these same cognitive activities operate to bind central and contextual elements into “episodic” memories. Attention is particularly focused on the role of reactivation in establishing complex memories and in strengthening or consolidating them over time.
Toward a Noncomputational Cognitive Neuroscience
Authors: Globus Gordon G. 
Published: February 2008

Abstract
The near universally accepted theory that the brain processes information persists in current neural network theory where there is "subsymbolic" computation (Smolensky, 1988) on distributed representations. This theory of brain information processing may suffice for simplifying models simulated in silicon but not for living neural nets where there is ongoing chemical tuning of the input/output transfer function at the nodes, connection weights, network parameters, and connectivity. Here the brain continually changes itself as it intersects with information from the outside. An alternative theory to information processing is developed in which the brain permits and supports "participation" of self and other as constraints on the dynamically evolving, self-organizing whole. The noncomputational process of "differing and deferring" in nonlinear dynamic neural systems is contrasted with Black's (1991) account of molecular information processing. State hyperspace for the noncomputational process of nonlinear dynamical systems, unlike classical systems, has a fractal dimension. The noncomputational model is supported by suggestive evidence for fractal properties of the brain.
Visual Processing without Awareness: Evidence from Unilateral Neglect
Authors: Berti Anna , Rizzolatti Giacomo 
Published: February 2008

Abstract
Can visual processing be carried out without visual awareness of the presented objects? In the present study we addressed this problem in patients with severe unilateral neglect. The patients were required to respond as fast as possible to target stimuli (pictures of animals and fruits) presented to the normal field by pressing one of the two keys according to the category of the targets. We then studied the influence of priming stimuli, again pictures of animals or fruits, presented to the neglected field on the responses to targets. By combining different pairs of primes and targets, three different experimental conditions were obtained. In the first condition, "Highly congruent," the target and prime stimuli belonged to the same category and were physically identical; in the second condition, "Congruent," the stimuli represented two elements of the same category but were physically dissimilar; in the third condition, "Noncongruent," the stimuli represented one exemplar from each of the two categories of stimuli. The results showed that the responses were facilitated not only in the Highly congruent condition, but also in the Congruent one. This finding suggests that patients with neglect are able to process stimuli presented to the neglected field to a categorical level of representation even when they deny the stimulus presence in the affected field. The implications of this finding for psychological and physiological theory of neglect and visual cognition are discussed.