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Edward Awh - One of the best experts on this subject based on the ideXlab platform.
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sustained Attention and Spatial Attention distinctly influence long term memory encoding
Journal of Cognitive Neuroscience, 2021Co-Authors: Megan T. Debettencourt, Stephanie D. Williams, Edward K. Vogel, Edward AwhAbstract:Our Attention is critically important for what we remember. Prior measures of the relationship between Attention and memory, however, have largely treated "Attention" as a monolith. Here, across three experiments, we provide evidence for two dissociable aspects of Attention that influence encoding into long-term memory. Using Spatial cues together with a sensitive continuous report procedure, we find that long-term memory response error is affected by both trial-by-trial fluctuations of sustained Attention and prioritization via covert Spatial Attention. Furthermore, using multivariate analyses of EEG, we track both sustained Attention and Spatial Attention before stimulus onset. Intriguingly, even during moments of low sustained Attention, there is no decline in the representation of the Spatially attended location, showing that these two aspects of Attention have robust but independent effects on long-term memory encoding. Finally, sustained and Spatial Attention predicted distinct variance in long-term memory performance across individuals. That is, the relationship between Attention and long-term memory suggests a composite model, wherein distinct Attentional subcomponents influence encoding into long-term memory. These results point toward a taxonomy of the distinct Attentional processes that constrain our memories.
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Sustained Attention and Spatial Attention distinctly influence long-term memory encoding
2020Co-Authors: Megan T. Debettencourt, Stephanie D. Williams, Edward K. Vogel, Edward AwhAbstract:Abstract Our Attention is critically important for what we remember. Prior measures of the relationship between Attention and memory, however, have largely treated “Attention” as a monolith. Here, across three experiments, we provide evidence for two dissociable aspects of Attention that influence encoding into long-term memory. Using Spatial cues together with a sensitive continuous report procedure, we find that long-term memory response error is affected by both trial-by-trial fluctuations of sustained Attention and prioritization via covert Spatial Attention. Furthermore, using multivariate analyses of EEG, we track both sustained Attention and Spatial Attention prior to stimulus onset. Intriguingly, even during moments of low sustained Attention, there is no decline in the representation of the Spatially attended location, showing that these two aspects of Attention have robust but independent effects on long term memory encoding. Finally, sustained and Spatial Attention predicted distinct variance in long-term memory performance across individuals. That is, the relationship between Attention and long-term memory suggests a composite model, wherein distinct Attentional subcomponents influence encoding into long-term memory. These results point towards a taxonomy of the distinct Attentional processes that constrain our memories.
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dissecting the neural focus of Attention reveals distinct processes for Spatial Attention and object based storage in visual working memory
Psychological Science, 2019Co-Authors: Nicole Hakim, Kirsten Adam, Eren Gunseli, Edward AwhAbstract:Complex cognition relies on both on-line representations in working memory (WM), said to reside in the focus of Attention, and passive off-line representations of related information. Here, we dissected the focus of Attention by showing that distinct neural signals index the on-line storage of objects and sustained Spatial Attention. We recorded electroencephalogram (EEG) activity during two tasks that employed identical stimulus displays but varied the relative demands for object storage and Spatial Attention. We found distinct delay-period signatures for an Attention task (which required only Spatial Attention) and a WM task (which invoked both Spatial Attention and object storage). Although both tasks required active maintenance of Spatial information, only the WM task elicited robust contralateral delay activity that was sensitive to mnemonic load. Thus, we argue that the focus of Attention is maintained via a collaboration between distinct processes for covert Spatial orienting and object-based storage.
Jon Driver - One of the best experts on this subject based on the ideXlab platform.
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Spatial Attention precision and bayesian inference a study of saccadic response speed
Cerebral Cortex, 2014Co-Authors: Simone Vossel, Jon Driver, Christoph Mathys, Jean Daunizeau, Markus Bauer, Karl J Friston, Klaas E StephanAbstract:Inferring the environment's statistical structure and adapting behavior accordingly is a fundamental modus operandi of the brain. A simple form of this faculty based on Spatial Attentional orienting can be studied with Posner's location-cueing paradigm in which a cue indicates the target location with a known probability. The present study focuses on a more complex version of this task, where probabilistic context (percentage of cue validity) changes unpredictably over time, thereby creating a volatile environment. Saccadic response speed (RS) was recorded in 15 subjects and used to estimate subject-specific parameters of a Bayesian learning scheme modeling the subjects' trial-by-trial updates of beliefs. Different response models—specifying how computational states translate into observable behavior—were compared using Bayesian model selection. Saccadic RS was most plausibly explained as a function of the precision of the belief about the causes of sensory input. This finding is in accordance with current Bayesian theories of brain function, and specifically with the proposal that Spatial Attention is mediated by a precision-dependent gain modulation of sensory input. Our results provide empirical support for precision-dependent changes in beliefs about saccade target locations and motivate future neuroimaging and neuropharmacological studies of how Bayesian inference may determine Spatial Attention.
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cross modal interactions between audition touch and vision in endogenous Spatial Attention erp evidence on preparatory states and sensory modulations
Journal of Cognitive Neuroscience, 2002Co-Authors: Martin Eimer, Jose L Van Velzen, Jon DriverAbstract:Recent behavioral and event-related brain potential (ERP) studies have revealed cross-modal interactions in endogenous Spatial Attention between vision and audition, plus vision and touch. The present ERP study investigated whether these interactions reflect supramodal Attentional control mechanisms, and whether similar cross-modal interactions also exist between audition and touch. Participants directed Attention to the side indicated by a cue to detect infrequent auditory or tactile targets at the cued side. The relevant modality (audition or touch) was blocked. Attentional control processes were reflected in systematic ERP modulations elicited during cued shifts of Attention. An anterior negativity contralateral to the cued side was followed by a contralateral positivity at posterior sites. These effects were similar whether the cue signaled which side was relevant for audition or for touch. They also resembled previously observed ERP modulations for shifts of visual Attention, thus implicating supramodal mechanisms in the control of Spatial Attention. Following each cue, single auditory, tactile, or visual stimuli were presented at the cued or uncued side. Although stimuli in task-irrelevant modalities could be completely ignored, visual and auditory ERPs were nevertheless affected by Spatial Attention when touch was relevant, revealing cross-modal interactions. When audition was relevant, visual ERPs, but not tactile ERPs, were affected by Spatial Attention, indicating that touch can be decoupled from cross-modal Attention when task-irrelevant.
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Spatial Attention and crossmodal interactions between vision and touch
Neuropsychologia, 2001Co-Authors: Emiliano Macaluso, Jon DriverAbstract:In the present paper, we review several functional imaging studies investigating crossmodal interactions between vision and touch relating to Spatial Attention. We asked how the Spatial unity of a multimodal event in the external world might be represented in the brain, where signals from different modalities are initially processed in distinct brain regions. The results highlight several links between visual and tactile Spatial representations. First, we found that activity in the anterior part of the intraparietal sulcus was influenced by stimulus position independently of the modality of the stimulation. This is consistent with crossmodal interactions via sensory convergence from early modality-specific Spatial maps to higher-order multimodal regions. Second, we found that stimulation in, or Attention to, one modality could affect activity in areas dedicated to a different modality, in a Spatially-specific manner. These Spatial crossmodal effects in unimodal regions demonstrate congruous activity in anatomically distant brain areas that represent similar external locations, implicating a distributed network of Spatial representations in crossmodal integration. Finally, the results suggest that the temporo–parietal junction may be involved in aspects of controlling Spatial Attention, for both vision and touch. A multimodal Attentional system may influence activity in distinct brain areas representing common regions of space for different modalities, thus suggesting a link between Spatial Attention and crossmodal integration. © 2001 Elsevier Science Ltd. All rights reserved.
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an event related brain potential study of cross modal links in Spatial Attention between vision and touch
Psychophysiology, 2000Co-Authors: Martin Eimer, Jon DriverAbstract:Event-related potential (ERP) evidence for the existence of cross-modal links in endogenous Spatial Attention between vision and touch was obtained in an experiment where participants had to detect tactile or visual targets on the attended side and to ignore the irrelevant modality and stimuli on the unattended side. For visual ERPs, Attentional modulations of occipital P1 and N1 components were present when Attention was directed both within vision and within touch, indicating that links in Spatial Attention from touch to vision can affect early stages of visual processing. For somatosensory ERPs, Attentional negativities starting around 140 ms poststimulus were present at midline and lateral central electrodes when touch was relevant. No Attentional somatosensory ERP modulations were present when vision was relevant and tactile stimuli could be entirely ignored. However, in another task condition where responses were also required to infrequent tactile targets regardless of their location, visual-Spatial Attention modulated somatosensory ERPs. Unlike vision, touch apparently can be decoupled from Attentional orienting within another modality unless it is potentially relevant.
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modulation of human visual cortex by crossmodal Spatial Attention
Science, 2000Co-Authors: Emiliano Macaluso, Christopher D. Frith, Jon DriverAbstract:A sudden touch on one hand can improve vision near that hand, revealing crossmodal links in Spatial Attention. It is often assumed that such links involve only multimodal neural structures, but unimodal brain areas may also be affected. We tested the effect of simultaneous visuo-tactile stimulation on the activity of the human visual cortex. Tactile stimulation enhanced activity in the visual cortex, but only when it was on the same side as a visual target. Analysis of effective connectivity between brain areas suggests that touch influences unimodal visual cortex via back-projections from multimodal parietal areas. This provides a neural explanation for crossmodal links in Spatial Attention.
Mazyar Fallah - One of the best experts on this subject based on the ideXlab platform.
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microstimulation of the frontal eye field and its effects on covert Spatial Attention
Journal of Neurophysiology, 2004Co-Authors: Tirin Moore, Mazyar FallahAbstract:Many studies have established that the strength of visual perception and the strength of visual representations within visual cortex vary according to the focus of covert Spatial Attention. While it is clear that Attention can modulate visual signals, the source of this modulation remains unknown. We have examined the possibility that saccade related mechanisms provide a source of Spatial Attention by studying the effects of electrical microstimulation of the frontal eye fields (FEF) on Spatial Attention. Monkeys performed a task in which they had to detect luminance changes of a peripheral target while ignoring a flashing distracter. The target luminance change could be preceded by stimulation of the FEF at current levels below that which evoked saccadic eye movements. We found that when the target change was preceded by stimulation of FEF, the monkey could detect smaller changes in target luminance. The increased sensitivity to the target change only occurred when the target was placed in the part of the visual field represented by neurons at the stimulation site. The magnitude of improvement depended on the temporal asynchrony of the stimulation onset and the target event. No significant effect of stimulation was observed when long intervals (>300 ms) between stimulation and the target event were used, and the magnitude of the increased sensitivity decreased systematically with increasing asynchrony. At the shortest asynchrony, FEF stimulation temporally overlapped the target event and the magnitude of the improvement was comparable to that of removing the distracter from the task. These results demonstrate that transient, but potent improvements in the deployment of covert Spatial Attention can be obtained by microstimulation of FEF sites from which saccadic eye movements are also evoked.
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control of eye movements and Spatial Attention
Proceedings of the National Academy of Sciences of the United States of America, 2001Co-Authors: Tirin Moore, Mazyar FallahAbstract:Several lines of evidence suggest that planning eye movements and directing visuoSpatial Attention share overlapping brain mechanisms. This study tested whether Spatial Attention can be enhanced by altering oculomotor signals within the brain. Monkeys performed a Spatial Attention task while neurons within the frontal eye field, an oculomotor area within prefrontal cortex, were electrically stimulated below the level at which eye movements are evoked. We found that we could improve the monkey's performance with microstimulation when, but only when, the object to be attended was positioned in the space represented by the cortical stimulation site.
Andrea Facoetti - One of the best experts on this subject based on the ideXlab platform.
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visual Spatial Attention and speech segmentation are both impaired in preschoolers at familial risk for developmental dyslexia
Dyslexia, 2010Co-Authors: Andrea Facoetti, Simone Gori, Milena Ruffino, Nicola Corradi, Marco ZorziAbstract:Phonological skills are foundational of reading acquisition and impaired phonological processing is widely assumed to characterize dyslexic individuals. However, reading by phonological decoding also requires rapid selection of sublexical orthographic units through serial Attentional orienting, and recent studies have shown that visual Spatial Attention is impaired in dyslexic children. Our study investigated these different neurocognitive dysfunctions, before reading acquisition, in a sample of preschoolers including children with (N 520) and without (N 567) familial risk for developmental dyslexia. Children were tested on phonological skills, rapid automatized naming, and visual Spatial Attention. At-risk children presented deficits in both visual Spatial Attention and syllabic segmentation at the group level. Moreover, the combination of visual Spatial Attention and syllabic segmentation scores was more reliable than either single measure for the identification of at-risk children. These findings suggest that both visuo-Attentional and perisylvian-auditory dysfunctions might adversely affect reading acquisition, and may offer a new approach for early identification and remediation of developmental dyslexia. Copyright r 2010 John Wiley & Sons, Ltd.
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multisensory Spatial Attention deficits are predictive of phonological decoding skills in developmental dyslexia
Journal of Cognitive Neuroscience, 2010Co-Authors: Andrea Facoetti, Maria Luisa Lorusso, Massimo Molteni, Milena Ruffino, Anna Noemi Trussardi, Carmen Cattaneo, Raffaella Galli, Marco ZorziAbstract:Although the dominant approach posits that developmental dyslexia arises from deficits in systems that are exclusively linguistic in nature (i.e., phonological deficit theory), dyslexics show a variety of lower level deficits in sensory and Attentional processing. Although their link to the reading disorder remains contentious, recent empirical and computational studies suggest that Spatial Attention plays an important role in phonological decoding. The present behavioral study investigated exogenous Spatial Attention in dyslexic children and matched controls by measuring RTs to visual and auditory stimuli in cued-detection tasks. Dyslexics with poor nonword decoding accuracy showed a slower time course of visual and auditory (multisensory) Spatial Attention compared with both chronological age and reading level controls as well as compared with dyslexics with slow but accurate nonword decoding. Individual differences in the time course of multisensory Spatial Attention accounted for 31% of unique variance in the nonword reading performance of the entire dyslexic sample after controlling for age, IQ, and phonological skills. The present study suggests that multisensory "sluggish Attention shifting"-related to a temporoparietal dysfunction-selectively impairs the sublexical mechanisms that are critical for reading development. These findings may offer a new approach for early identification and remediation of developmental dyslexia.
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the relationship between visuo Spatial Attention and nonword reading in developmental dyslexia
Cognitive Neuropsychology, 2006Co-Authors: Andrea Facoetti, Marco Zorzi, Laurie Cestnick, Maria Luisa Lorusso, Massimo Molteni, Pierrluigi Paganoni, Carlo Umilta, Gian Gastone MascettiAbstract:Focused visuo-Spatial Attention was studied in 10 developmental dyslexic children with impaired nonword reading, 10 dyslexic children with intact nonword reading, and 12 normally reading children. Reaction times to lateralized visual stimuli in a cued detection task showed that Attentional facilitation of the target at the cued location was symmetrical in the three groups. However, dyslexics with impaired nonword reading selectively showed a lack of Attentional inhibition for targets at the uncued location in the right visual field. This result was replicated in a second group of 13 dyslexics with impaired nonword reading. Individual differences in the ability of right Attentional inhibition across the entire sample of dyslexics accounted for 17% of unique variance in nonword reading accuracy after controlling for individual differences in age, IQ, and phonological skills. A possible explanation based on the role of Spatial Attention mechanisms in the graphemic parsing process is discussed. Our results su...
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the relationship between visuo Spatial Attention and nonword reading in developmental dyslexia
Cognitive Neuropsychology, 2006Co-Authors: Andrea Facoetti, Marco Zorzi, Laurie Cestnick, Maria Luisa Lorusso, Massimo Molteni, Pierrluigi Paganoni, Carlo Umilta, Gian Gastone MascettiAbstract:Focused visuo-Spatial Attention was studied in 10 developmental dyslexic children with impaired nonword reading, 10 dyslexic children with intact nonword reading, and 12 normally reading children. Reaction times to lateralized visual stimuli in a cued detection task showed that Attentional facilitation of the target at the cued location was symmetrical in the three groups. However, dyslexics with impaired nonword reading selectively showed a lack of Attentional inhibition for targets at the uncued location in the right visual field. This result was replicated in a second group of 13 dyslexics with impaired nonword reading. Individual differences in the ability of right Attentional inhibition across the entire sample of dyslexics accounted for 17% of unique variance in nonword reading accuracy after controlling for individual differences in age, IQ, and phonological skills. A possible explanation based on the role of Spatial Attention mechanisms in the graphemic parsing process is discussed. Our results suggest that focused visuo-Spatial Attention may be crucial for nonword decoding.
Gian Gastone Mascetti - One of the best experts on this subject based on the ideXlab platform.
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the relationship between visuo Spatial Attention and nonword reading in developmental dyslexia
Cognitive Neuropsychology, 2006Co-Authors: Andrea Facoetti, Marco Zorzi, Laurie Cestnick, Maria Luisa Lorusso, Massimo Molteni, Pierrluigi Paganoni, Carlo Umilta, Gian Gastone MascettiAbstract:Focused visuo-Spatial Attention was studied in 10 developmental dyslexic children with impaired nonword reading, 10 dyslexic children with intact nonword reading, and 12 normally reading children. Reaction times to lateralized visual stimuli in a cued detection task showed that Attentional facilitation of the target at the cued location was symmetrical in the three groups. However, dyslexics with impaired nonword reading selectively showed a lack of Attentional inhibition for targets at the uncued location in the right visual field. This result was replicated in a second group of 13 dyslexics with impaired nonword reading. Individual differences in the ability of right Attentional inhibition across the entire sample of dyslexics accounted for 17% of unique variance in nonword reading accuracy after controlling for individual differences in age, IQ, and phonological skills. A possible explanation based on the role of Spatial Attention mechanisms in the graphemic parsing process is discussed. Our results su...
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the relationship between visuo Spatial Attention and nonword reading in developmental dyslexia
Cognitive Neuropsychology, 2006Co-Authors: Andrea Facoetti, Marco Zorzi, Laurie Cestnick, Maria Luisa Lorusso, Massimo Molteni, Pierrluigi Paganoni, Carlo Umilta, Gian Gastone MascettiAbstract:Focused visuo-Spatial Attention was studied in 10 developmental dyslexic children with impaired nonword reading, 10 dyslexic children with intact nonword reading, and 12 normally reading children. Reaction times to lateralized visual stimuli in a cued detection task showed that Attentional facilitation of the target at the cued location was symmetrical in the three groups. However, dyslexics with impaired nonword reading selectively showed a lack of Attentional inhibition for targets at the uncued location in the right visual field. This result was replicated in a second group of 13 dyslexics with impaired nonword reading. Individual differences in the ability of right Attentional inhibition across the entire sample of dyslexics accounted for 17% of unique variance in nonword reading accuracy after controlling for individual differences in age, IQ, and phonological skills. A possible explanation based on the role of Spatial Attention mechanisms in the graphemic parsing process is discussed. Our results suggest that focused visuo-Spatial Attention may be crucial for nonword decoding.
