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Pagnotta MF, Pascucci D, Plomp G. Selective attention involves a feature-specific sequential release from inhibitory gating. Neuroimage 2021; 246:118782. [PMID: 34879253 DOI: 10.1016/j.neuroimage.2021.118782] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/28/2021] [Accepted: 12/04/2021] [Indexed: 11/18/2022] Open
Abstract
Selective attention is a fundamental cognitive mechanism that allows our brain to preferentially process relevant sensory information, while filtering out distracting information. Attention is thought to flexibly gate the communication of irrelevant information through top-down alpha-rhythmic (8-12 Hz) functional connections, which influence early visual processing. However, the dynamic effects of top-down influence on downstream visual processing remain unknown. Here, we used electroencephalography to investigate local and network effects of selective attention while subjects attended to distinct features of identical stimuli. We found that attention-related changes in the functional brain network organization emerge shortly after stimulus onset, accompanied by an overall decrease of functional connectivity. Signatures of attentional selection were evident from a sequential release from alpha-band parietal gating in feature-selective areas. The directed connectivity paths and temporal evolution of this release from gating were consistent with the sensory effect of each feature, providing a neural basis for how visual processing quickly prioritizes relevant information in functionally specialized areas.
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Affiliation(s)
- Mattia F Pagnotta
- Perceptual Networks Group, Department of Psychology, University of Fribourg, Fribourg, Switzerland.
| | - David Pascucci
- Perceptual Networks Group, Department of Psychology, University of Fribourg, Fribourg, Switzerland; Laboratory of Psychophysics, Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Gijs Plomp
- Perceptual Networks Group, Department of Psychology, University of Fribourg, Fribourg, Switzerland
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2
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Nested oscillations and brain connectivity during sequential stages of feature-based attention. Neuroimage 2020; 223:117354. [PMID: 32916284 DOI: 10.1016/j.neuroimage.2020.117354] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/10/2020] [Accepted: 09/05/2020] [Indexed: 12/25/2022] Open
Abstract
Brain mechanisms of visual selective attention involve both local and network-level activity changes at specific oscillatory rhythms, but their interplay remains poorly explored. Here, we investigate anticipatory and reactive effects of feature-based attention using separate fMRI and EEG recordings, while participants attended to one of two spatially overlapping visual features (motion and orientation). We focused on EEG source analysis of local neuronal rhythms and nested oscillations and on graph analysis of connectivity changes in a network of fMRI-defined regions of interest, and characterized a cascade of attentional effects at multiple spatial scales. We discuss how the results may reconcile several theories of selective attention, by showing how β rhythms support anticipatory information routing through increased network efficiency, while reactive α-band desynchronization patterns and increased α-γ coupling in task-specific sensory areas mediate stimulus-evoked processing of task-relevant signals.
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3
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Lee SH, Baker CI. Multi-Voxel Decoding and the Topography of Maintained Information During Visual Working Memory. Front Syst Neurosci 2016; 10:2. [PMID: 26912997 PMCID: PMC4753308 DOI: 10.3389/fnsys.2016.00002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 01/08/2016] [Indexed: 01/04/2023] Open
Abstract
The ability to maintain representations in the absence of external sensory stimulation, such as in working memory, is critical for guiding human behavior. Human functional brain imaging studies suggest that visual working memory can recruit a network of brain regions from visual to parietal to prefrontal cortex. In this review, we focus on the maintenance of representations during visual working memory and discuss factors determining the topography of those representations. In particular, we review recent studies employing multi-voxel pattern analysis (MVPA) that demonstrate decoding of the maintained content in visual cortex, providing support for a “sensory recruitment” model of visual working memory. However, there is some evidence that maintained content can also be decoded in areas outside of visual cortex, including parietal and frontal cortex. We suggest that the ability to maintain representations during working memory is a general property of cortex, not restricted to specific areas, and argue that it is important to consider the nature of the information that must be maintained. Such information-content is critically determined by the task and the recruitment of specific regions during visual working memory will be both task- and stimulus-dependent. Thus, the common finding of maintained information in visual, but not parietal or prefrontal, cortex may be more of a reflection of the need to maintain specific types of visual information and not of a privileged role of visual cortex in maintenance.
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Affiliation(s)
- Sue-Hyun Lee
- Department of Bio and Brain Engineering, College of Engineering, Korea Advanced Institute of Science and Technology (KAIST)Daejeon, South Korea; Laboratory of Brain and Cognition, National Institute of Mental Health, National Institutes of HealthBethesda, MD, USA
| | - Chris I Baker
- Laboratory of Brain and Cognition, National Institute of Mental Health, National Institutes of Health Bethesda, MD, USA
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4
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Vallesi A, Arbula S, Capizzi M, Causin F, D'Avella D. Domain-independent neural underpinning of task-switching: An fMRI investigation. Cortex 2015; 65:173-83. [DOI: 10.1016/j.cortex.2015.01.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 10/07/2014] [Accepted: 01/27/2015] [Indexed: 11/17/2022]
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5
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Powell JL, Kemp GJ, García-Finaña M. Association between language and spatial laterality and cognitive ability: An fMRI study. Neuroimage 2012; 59:1818-29. [DOI: 10.1016/j.neuroimage.2011.08.040] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Revised: 07/26/2011] [Accepted: 08/15/2011] [Indexed: 10/17/2022] Open
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6
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A review of lateralization of spatial functioning in nonhuman primates. ACTA ACUST UNITED AC 2011; 67:56-72. [DOI: 10.1016/j.brainresrev.2010.11.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 10/20/2010] [Accepted: 11/01/2010] [Indexed: 11/17/2022]
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7
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Spatiotemporal dynamics of visual vertical judgments: early and late brain mechanisms as revealed by high-density electrical neuroimaging. Neuroscience 2011; 181:134-49. [DOI: 10.1016/j.neuroscience.2011.02.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 02/01/2011] [Accepted: 02/03/2011] [Indexed: 11/20/2022]
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8
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Tibber MS, Anderson EJ, Melmoth DR, Rees G, Morgan MJ. Common cortical loci are activated during visuospatial interpolation and orientation discrimination judgements. PLoS One 2009; 4:e4585. [PMID: 19238207 PMCID: PMC2642631 DOI: 10.1371/journal.pone.0004585] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2008] [Accepted: 01/17/2009] [Indexed: 11/25/2022] Open
Abstract
There is a wealth of literature on the role of short-range interactions between low-level orientation-tuned filters in the perception of discontinuous contours. However, little is known about how spatial information is integrated across more distant regions of the visual field in the absence of explicit local orientation cues, a process referred to here as visuospatial interpolation (VSI). To examine the neural correlates of VSI high field functional magnetic resonance imaging was used to study brain activity while observers either judged the alignment of three Gabor patches by a process of interpolation or discriminated the local orientation of the individual patches. Relative to a fixation baseline the two tasks activated a largely over-lapping network of regions within the occipito-temporal, occipito-parietal and frontal cortices. Activated clusters specific to the orientation task (orientation>interpolation) included the caudal intraparietal sulcus, an area whose role in orientation encoding per se has been hotly disputed. Surprisingly, there were few task-specific activations associated with visuospatial interpolation (VSI>orientation) suggesting that largely common cortical loci were activated by the two experimental tasks. These data are consistent with previous studies that suggest higher level grouping processes -putatively involved in VSI- are automatically engaged when the spatial properties of a stimulus (e.g. size, orientation or relative position) are used to make a judgement.
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Affiliation(s)
- Marc S Tibber
- Department of Optometry and Visual Science, City University, London, United Kingdom.
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9
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Early correlates of visual awareness following orientation and colour rivalry. Vision Res 2008; 48:2359-69. [DOI: 10.1016/j.visres.2008.07.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 07/25/2008] [Accepted: 07/29/2008] [Indexed: 11/18/2022]
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10
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Miller WL, Maffei V, Bosco G, Iosa M, Zago M, Macaluso E, Lacquaniti F. Vestibular Nuclei and Cerebellum Put Visual Gravitational Motion in Context. J Neurophysiol 2008; 99:1969-82. [DOI: 10.1152/jn.00889.2007] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Animal survival in the forest, and human success on the sports field, often depend on the ability to seize a target on the fly. All bodies fall at the same rate in the gravitational field, but the corresponding retinal motion varies with apparent viewing distance. How then does the brain predict time-to-collision under gravity? A perspective context from natural or pictorial settings might afford accurate predictions of gravity's effects via the recovery of an environmental reference from the scene structure. We report that embedding motion in a pictorial scene facilitates interception of gravitational acceleration over unnatural acceleration, whereas a blank scene eliminates such bias. Functional magnetic resonance imaging (fMRI) revealed blood-oxygen-level-dependent correlates of these visual context effects on gravitational motion processing in the vestibular nuclei and posterior cerebellar vermis. Our results suggest an early stage of integration of high-level visual analysis with gravity-related motion information, which may represent the substrate for perceptual constancy of ubiquitous gravitational motion.
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Abstract
Williams syndrome (WS) is a rare genetic disorder with a unique cognitive profile in which verbal abilities are markedly stronger than visuospatial abilities. This study investigated the claim that orientation coding is a specific deficit within the visuospatial domain in WS. Experiment 1 employed a simplified version of the Benton Judgement of Line Orientation task and a control, length-matching task. Results demonstrated comparable levels of orientation matching performance in the group with WS and a group of typically developing (TD) controls matched by nonverbal ability, although it is possible that floor effects masked group differences. A group difference was observed in the length-matching task due to stronger performance from the control group. Experiment 2 employed an orientation-discrimination task and a length-discrimination task. Contrary to previous reports, the results showed that individuals with WS were able to code by orientation to a comparable level as that of their matched controls. This demonstrates that, although some impairment is apparent, orientation coding does not represent a specific deficit in WS. Comparison between Experiments 1 and 2 suggests that orientation coding is vulnerable to task complexity. However, once again, this vulnerability does not appear to be specific to the population with WS, as it was also apparent in the TD controls.
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Affiliation(s)
- Emily K Farran
- School of Psychology and Clinical Language Sciences, University of Reading, England.
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12
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Stiers P, Peeters R, Lagae L, Van Hecke P, Sunaert S. Mapping multiple visual areas in the human brain with a short fMRI sequence. Neuroimage 2005; 29:74-89. [PMID: 16154766 DOI: 10.1016/j.neuroimage.2005.07.033] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2004] [Revised: 06/30/2005] [Accepted: 07/06/2005] [Indexed: 10/25/2022] Open
Abstract
It is a fundamental insight of neuroscience that the cerebral cortex is divided into spatially separated and functionally distinct areas. In this study, we tried to map a large number of visual areas in individual subjects passively viewing a simple stimulus sequence during functional magnetic resonance imaging (fMRI) at 1.5 T. The blocked stimulus sequence contrasted static object photographs with video takes of movement through natural indoor and outdoor scenes, alternated with a control fixation task. Two runs of the 5-min sequence sufficed to invoke 29 distinguishable activations, 16 (13 bilateral) of which were observed in all 10 participants. At the ventral side, object responsive activations were organized along the lateral occipital-temporal surface and near the collateral and occipital-temporal sulci. The latter activations, corresponding to the lateral occipital complex, showed a different activation profile from those near the collateral sulcus, most likely corresponding to the color constancy areas V4/V8-V4alpha. A potentially new fusiform object area was seen in 6 subjects, even more anterior than the parahippocampal place area. At the dorsal side, consistent activations were mainly related to motion stimuli and included the well-known areas V3a, VIPS, POIPS, hV5+, STS and the cingulate sulcus. There was consistent activation in the parietal-occipital sulcus, containing the areas V6a and V6. In addition, all subjects showed activation in the superior-anterior precuneus. Thus, the short stimulus sequence robustly invoked multiple visual areas and can be used to map the organization of the visual system in normal and brain-damaged individuals.
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Affiliation(s)
- Peter Stiers
- Laboratorium voor Neuropsychologie, K.U.Leuven, Faculteit Geneeskunde, Herestraat 49, O and N bus 504, B-3000 Leuven, Belgium.
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13
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Lux S, Marshall JC, Ritzl A, Zilles K, Fink GR. Neural mechanisms associated with attention to temporal synchrony versus spatial orientation: an fMRI study. Neuroimage 2003; 20 Suppl 1:S58-65. [PMID: 14597297 DOI: 10.1016/j.neuroimage.2003.09.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Previous neuropsychological and functional imaging studies have suggested that the right hemisphere is crucially involved in spatial cognition. By contrast, much less is known about the putative left hemisphere specialization for aspects of temporal cognition. Accordingly, we studied with functional magnetic resonance imaging the neural mechanisms underlying attention to stimulus onset synchrony or orientational congruence with identical pairs of geometric figures. In each trial, two rhombuses were presented, each 4 degrees peripheral to a central fixation cross, in the left and right visual hemifields. In half of the trials, subjects were asked to judge and indicate via button presses whether the rhombuses appeared simultaneously. In the other half of the trials, subjects indicated whether the orientation of the rhombuses was the same (Factor 1, task, temporal synchrony, orientation). In half of the trials, subjects responded with their right hand and in the other half with their left hand (Factor 2, hand, right, left). Data were analyzed using SPM99 and a random-effects model. Attention to orientation differentially activated right temporo-occipital cortex. Attention to stimulus onset synchrony activated left anterior superior temporal gyrus, left inferior parietal cortex, left medial frontal gyrus, and right operculum. Activation of right temporo-occipital cortex for attention to stimulus orientation is in good agreement with previous functional neuroimaging studies of stimulus orientation. More importantly, activation of a predominantly left-hemispheric network with attention to stimulus onset synchrony extends the results of previous functional imaging, psychophysical, and neuropsychological studies of temporal processing.
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Affiliation(s)
- Silke Lux
- Institute of Medicine, Research Center Jülich, 52425, Jülich, Germany.
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14
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Claeys KG, Orban GA, Dupont P, Sunaert S, Van Hecke P, De Schutter E. Involvement of multiple functionally distinct cerebellar regions in visual discrimination: a human functional imaging study. Neuroimage 2003; 20:840-54. [PMID: 14568456 DOI: 10.1016/s1053-8119(03)00366-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
We investigated the contribution of the human cerebellum to cerebral function during visual discrimination using PET and fMRI. The cognitive task was a successive discrimination of shades of brown with a parametric variation of the stimulus presentation rate and a constant task difficulty. The successive color discrimination task was contrasted to a dimming detection control task, with identical retinal input but with double the number of motor responses. Three sets of activated cerebellar and cerebral regions were observed: rate-dependent and rate-independent color discrimination networks and a motor-and-detection network. The rate-dependent color discrimination network included both an anterior and a posterior activation site in lobule-VI of the two lateral cerebellar hemispheres, whereas the rate-independent network involved a bilateral activation site in lateral Crus-I. Cerebellar sites of the motor-and-detection network were located in medial lobule-V bilaterally, in the vermis, and in posterior left Crus-I and right Crus-II. An additional fMRI study was performed to control for differences in motor output and response timing between the tasks. In this control study, the cerebellar activation sites of the rate-dependent and rate-independent color discrimination networks remained unaltered. The motor-and-detection network included cerebellar activations in posterior left Crus-I and right Crus-II, but none in lobule-V or the vermis. Thus, cerebellar activation sites of the motor-and-detection network could be subdivided into those related to a motor network and those belonging to a dimming detection network. We conclude that successive color discrimination activates multiple, functionally distinct cerebellar regions.
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Affiliation(s)
- Kristl G Claeys
- Laboratory of Theoretical Neurobiology, Born-Bunge Foundation, University of Antwerp-U.A., Universiteitsplein 1, B2610, Antwerpen, Belgium
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15
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d'Avossa G, Shulman GL, Corbetta M. Identification of cerebral networks by classification of the shape of BOLD responses. J Neurophysiol 2003; 90:360-71. [PMID: 12660356 DOI: 10.1152/jn.01040.2002] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Changes in regional blood oxygen level dependent (BOLD) signals in response to brief visual stimuli can exhibit a variety of time-courses. To demonstrate the anatomical distribution of BOLD response shapes during a match to sample task, a formal analysis of their time-courses is presented. An event-related design was used to estimate regional BOLD responses evoked by a cue word, which instructed the subject to attend to the motion or color of an upcoming target, and those evoked by a briefly presented moving target consisting of colored dots. Regional BOLD time-courses were adequately represented by the linear combination of three orthogonal waveforms. BOLD response shapes were then classified using a fuzzy clustering scheme. Three classes (sustained, phasic, and negative) best characterized cue responses. Four classes (sustained, sustained-phasic, phasic, and bi-phasic) best characterized target responses. In certain regions, the shape of the BOLD responses was modulated by the instruction to attend to the target's motion or color. A left frontal and a posterior parietal region showed sustained activity when motion was cued and transient activity when color was cued. A right thalamic and a left lateral occipital region showed sustained activity when color was cued and transient activity when motion was cued. Following the target several regions showed more sustained activity during motion than color trials. In summary, the effect of the task variable was focal following the cue and widespread following the target. We conclude that the temporal patterns of neural activity affected the shape of the BOLD signal.
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Affiliation(s)
- Giovanni d'Avossa
- Department of Neurology and Neurological Surgery, Alzheimer's Disease Research Center, Washington University, St. Louis, Missouri 63110, USA.
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16
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Isaacs EB, Edmonds CJ, Chong WK, Lucas A, Gadian DG. Cortical anomalies associated with visuospatial processing deficits. Ann Neurol 2003; 53:768-73. [PMID: 12783423 DOI: 10.1002/ana.10546] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Children born preterm provide a fruitful population for studying structure-function relationships because they often have specific functional deficits in the context of normal neurological status. We selected a group of preterm adolescents with deficits in judgment of line orientation. Despite their very low birth weight, all were neurologically normal with no consistent abnormalities on conventional magnetic resonance imaging. However, voxel-based morphometric analysis of their magnetic resonance imaging scans showed areas of decreased gray matter and increased white matter most prominently in right ventral extrastriate cortex, close to an area previously implicated in the line orientation task. We suggest that these anomalies of cortical architecture relate to impaired performance on the line orientation task.
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Affiliation(s)
- Elizabeth B Isaacs
- MRC Childhood Nutrition Research Centre, Institute of Child Health, University College, London, United Kingdom.
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17
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Dupont P, Sáry G, Peuskens H, Orban GA. Cerebral regions processing first- and higher-order motion in an opposed-direction discrimination task. Eur J Neurosci 2003; 17:1509-17. [PMID: 12713654 DOI: 10.1046/j.1460-9568.2003.02571.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Using PET, we studied the processing of different types of motion in an opposed-direction discrimination task. We used first-order motion and two types of higher-order motion (presented as moving gratings with stripes defined by flickering texture and kinetic boundaries, respectively). In these experiments, we found that all types of motion activate a common set of cortical regions when comparing a direction discrimination task to a detection of the dimming of the fixation point. This set includes left hV3A, bilateral hMT/V5+ and regions in the middle occipital gyrus, bilateral activations in the posterior and anterior parts of the intraparietal sulcus, bilateral precentral gyrus, medial frontal cortex and regions in the cerebellum. No significant differences were observed between different types of motion, even at low statistical thresholds. From this we conclude that, under our experimental conditions, the same cerebral regions are involved in the processing of first-order and higher-order motion in an opposed-direction discrimination task.
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Affiliation(s)
- P Dupont
- K.U.Leuven, Laboratorium voor Neuro- en Psychofysiologie; Campus Gasthuisberg, B-3000 Leuven, Belgium
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18
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Hopf JM, Vogel E, Woodman G, Heinze HJ, Luck SJ. Localizing visual discrimination processes in time and space. J Neurophysiol 2002; 88:2088-95. [PMID: 12364530 DOI: 10.1152/jn.2002.88.4.2088] [Citation(s) in RCA: 167] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous studies of visual processing in humans using event-related potentials (ERPs) have demonstrated that task-related modulations of an early component called the "N1" wave (140-200 ms) reflect the operation of a voluntary discrimination process. Specifically, this component is larger in tasks requiring target discrimination than in tasks requiring simple detection. The present study was designed to localize this discriminative process in both time and space by means of combined magnetoencephalographic (MEG) and ERP recordings. Discriminative processing led to differential ERP and MEG activity beginning within 150 ms of stimulus onset. Source localization of the combined ERP/MEG data was performed using anatomical constraints from structural magnetic resonance images. These analyses revealed highly reliable and focused activity in regions of inferior occipital-temporal cortex. These findings indicate that the earliest measurable correlates of discriminative operations in the visual system appear as neural activity in circumscribed regions of the ventral processing stream.
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Affiliation(s)
- Jens-Max Hopf
- Department of Neurology II, Otto-von-Guericke University, D-39120 Magdeburg, Germany.
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Lalonde J, Chaudhuri A. Task-dependent transfer of perceptual to memory representations during delayed spatial frequency discrimination. Vision Res 2002; 42:1759-69. [PMID: 12127108 DOI: 10.1016/s0042-6989(02)00111-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Discrimination thresholds were obtained using a delayed spatial frequency discrimination task. In Experiment 1, we found that presentation of a mask 3 s before onset of a reference Gabor patch caused a selective, spatial frequency dependent interference in a subsequent discrimination task. However, a 10 s interval abolished this masking effect. In Experiment 2, the mask was associated with a second spatial frequency discrimination task so that a representation of the mask had to be coded into short-term perceptual memory. This experiment was performed to assess whether absence of masking in the 10 s condition of Experiment 1 might be due to decay of the mask information in the perceptual or the memory representational domain. The presence of this second discrimination task now caused similar interference effects on the primary discrimination task at both the 3 s and 10 s interstimulus intervals (ISI) conditions. Finally, to test the robustness of the masking effect, the nature of the secondary masking task was changed from a spatial frequency discrimination task to an orientation discrimination task in Experiment 3. The masking effect was now abolished in both the 3 and 10 s ISI conditions. Together, the results from these experiments are consistent with the idea of a two-level perceptual memory mechanism. The results also suggest that stimulus representations during a perceptual discrimination task are shared between the perceptual and memory representation domains in a task-dependent manner.
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Affiliation(s)
- Jasmin Lalonde
- Department of Psychology, McGill University, 1205 Dr. Penfield Avenue, Montréal, Que., Canada H3A 1B1.
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20
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Fias W, Dupont P, Reynvoet B, Orban GA. The quantitative nature of a visual task differentiates between ventral and dorsal stream. J Cogn Neurosci 2002; 14:646-58. [PMID: 12126505 DOI: 10.1162/08989290260045873] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The aim of the present positron emission tomography (PET) study was to investigate how visual processing in dorsal and ventral streams depends on the quantitative nature of the task. In the same-different task, participants identified the presence of an orientation difference between two gratings, presented centrally in succession. In the quantification task, participants estimated the magnitude of the difference and compared it to a fixed standard. Detection of dimming of the fixation point was used as a control task. Visual input, motor responses, and performance were equated across tasks. Subtracting same-different from quantification yielded significant activation in the left superior parietal lobule and left ventral premotor cortex, consistent with results obtained in number-processing tasks. The reverse subtraction yielded activation in the right inferior temporal gyrus, in agreement with earlier results. These results demonstrate that a single attribute can be processed either in the ventral or dorsal stream, depending on the cognitive operations required by the tasks.
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21
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Proverbio AM, Esposito P, Zani A. Early involvement of the temporal area in attentional selection of grating orientation: an ERP study. BRAIN RESEARCH. COGNITIVE BRAIN RESEARCH 2002; 13:139-51. [PMID: 11867258 DOI: 10.1016/s0926-6410(01)00103-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The aim of the present study was to investigate the neural mechanisms of stimulus orientation selection in humans by recording event-related potentials (ERPs) of the brain with a 32-channel montage. Stimuli were isoluminant black-and-white gratings (3 cpd) having an orientation of 50, 70, 90, 110 and 130, randomly presented in the foveal portion (2 of visual angle) of the central visual field. The task consisted in selectively attending and responding to one of the five grating orientations, while ignoring the others. ERP results showed that orientation selection affected neural processing starting already at an early post-stimulus latency. The P1 component (80-140 ms) measured at temporal area, which might well be reflecting the activity of the ventral stream (i.e. 'WHAT' system) of the visual pathways, showed an enhanced amplitude for target orientations. These effects increased with progressive neural processing over time as reflected by selection negativity (SN) and P300 components. In addition, both reaction times (RTs) and ERPs showed a strong 'oblique' effect, very probably reflecting the perceptual predominance of orthogonal versus oblique stimulus orientation in the human visual system: RTs were much faster, and SN and P300 components much larger, to gratings presented vertically than in other orientations.
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Affiliation(s)
- Alice Mado Proverbio
- Department of Psychology, University of Milano-Bicocca, Piazza dell'Ateneo Nuovo, 1, 20126 Milan, Italy.
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Bennett PJ, Sekuler AB, McIntosh AR, Della-Maggiore V. The effects of aging on visual memory: evidence for functional reorganization of cortical networks. Acta Psychol (Amst) 2001; 107:249-73. [PMID: 11388138 DOI: 10.1016/s0001-6918(01)00037-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Recent evidence suggests that the mature human brain is capable of substantial functional reorganization following injury. The fact that the brain retains a great deal of plasticity raises the possibility that cortical reorganization may occur during normal aging. We examined this issue by using positron emission tomography (PET) to measure the brain activity associated with short-term memory for simple visual attributes in young and old observers. A two-interval forced choice procedure was used to measure spatial frequency discrimination thresholds for sine wave gratings presented at different inter-stimulus intervals (ISI). Memory load was manipulated by varying the duration of the ISI and by presenting an irrelevant masking stimulus in the middle of the ISI. Old and young observers performed the experiment equally well. However, the neural systems correlated with good performance differed for the two age groups. The results support the hypothesis that the functional networks that underlie visual memory undergo reorganization during aging.
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Affiliation(s)
- P J Bennett
- Department of Psychology, University of Toronto, Suite 4020, 100 St. George St., Toronto, Ont. M5S 3G3, Canada
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23
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Faillenot I, Sunaert S, Van Hecke P, Orban GA. Orientation discrimination of objects and gratings compared: an fMRI study. Eur J Neurosci 2001; 13:585-96. [PMID: 11168567 DOI: 10.1046/j.1460-9568.2001.01399.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We used functional magnetic resonance imaging to compare the human brain regions involved in orientation discrimination of two-dimensional (2D) objects and gratings. The orientation discrimination tasks, identification and successive discrimination, were contrasted to a dimming detection control condition with identical retinal input. Regions involved in orientation discrimination were very similar for the two types of tasks and for the two types of stimuli and both belonged to the dorsal and ventral visual pathways. They included posterior occipital, lingual, posterior fusiform, inferior temporal, dorsal intraparietal and medial parietal regions. The main difference between the two types of stimuli was a larger activation of precuneus when 2D objects were used compared to gratings. The main difference between discrimination tasks was an enhanced activity, at the group level, in superior frontal sulcus in identification compared to successive discrimination, and at least at the single subject level, a larger activity in right fusiform cortex in successive discriminations compared to identification. Thus, in contradiction to generally accepted views, orientation discrimination of gratings and objects involve largely similar networks including both ventral and dorsal visual regions.
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Affiliation(s)
- I Faillenot
- K.U. Leuven, Faculty of Medicine, Lab. Neuro- en Psychofysiologie, Campus Gasthuisberg, B-3000 Leuven, Belgium
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Cornette L, Dupont P, Bormans G, Mortelmans L, Orban GA. Separate neural correlates for the mnemonic components of successive discrimination and working memory tasks. Cereb Cortex 2001; 11:59-72. [PMID: 11113035 DOI: 10.1093/cercor/11.1.59] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have used positron emission tomography to map the mnemonic components of two tasks at the extremes of the visual short-term/ working memory spectrum. The successive discrimination task requires only storage of a single item for very short time (ultra-short- term memory), while the 2back task requires both maintenance (i.e. storage and rehearsal) and manipulation of several items (working memory). We tested whether or not the storage component, common to the two tasks, engaged the same cerebral regions. To remove unnecessary confounds, we reduced the cues available to the subjects to a single elementary attribute, the orientation of a grating presented in central vision. This prevented subjects from using verbal strategies or vestibular cues and allowed equating of difficulty among tasks. Ultra-short-term memory for orientation engaged a large expanse of occipito-temporal cortex with a rate-dependent antero-posterior gradient: a fast trial rate engaged posterior regions, a slow trial rate anterior regions. On the other hand, working memory for orientation involved the left inferior parietal cortex, left dorsolateral prefrontal cortex and a left superior frontal sulcus region, and to a lesser degree the symmetrical right superior frontal region and a left superior parietal region. Direct comparison of the two orientation memory networks confirmed their functional segregation. We conclude that at least the storage of orientation information engages distinct regions depending on whether or not short-term memory/working memory involves rehearsal and/or manipulative processes.
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Affiliation(s)
- L Cornette
- Laboratorium voor Neuro- en Psychofysiologie, KU Leuven, Medical School, Campus Gasthuisberg, Herestraat 49, B-3000 Leuven
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25
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Abstract
Psychophysical studies of the short-term memory for attributes or dimensions of the visual stimulus that are known to be important in early visual processing (spatial frequency, orientation, contrast, motion and color) identify a low-level perceptual memory mechanism. This proposed mechanism is located early in the visual processing stream, prior to the structural description system responsible for shape priming but beyond primary visual cortex (V1); it is composed of a series of parallel, special-purpose perceptual mechanisms with independent but limited processing resources. Each mechanism is devoted to the analysis of a single dimension and is coupled to a memory store.
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Affiliation(s)
- S Magnussen
- Dept of Psychology, University of Oslo, Norway
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26
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Rosier AM, Cornette L, Dupont P, Bormans G, Mortelmans L, Orban GA. Regional brain activity during shape recognition impaired by a scopolamine challenge to encoding. Eur J Neurosci 1999; 11:3701-14. [PMID: 10564377 DOI: 10.1046/j.1460-9568.1999.00784.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the present positron emission tomography (PET) study, we examine the effect of a scopolamine-induced challenge to encoding upon the pattern of regional cerebral blood flow during recognition of a list of abstract visual shapes 3 days after encoding of these shapes. This study was conducted to test hypotheses concerning the fusiform and thalamic contributions to object recognition arising from a previous imaging study of impaired recognition. In that study, we demonstrated that activity in the fusiform cortex and the thalamus during shape recognition was modulated by memory challenges. These memory challenges included, on one hand, impaired storage as a consequence of diazepam administration during encoding, and, on the other hand, impaired retrieval caused by a perceptual challenge. Activation in the fusiform cortex decreased during impaired recognition, irrespective of the type of challenge. In contrast, thalamic activation increased only when the recognition deficit resulted from impaired memory storage. Based on these results, we hypothesized that fusiform activation during recognition reflects the matching of an incoming stimulus with a stored one, whereas thalamic activation reflects retrieval attempts. These hypotheses would receive considerable support if scopolamine, which also impairs memory storage, induced similar modulations of fusiform and thalamic activation. In the present study, we observed that a scopolamine challenge to encoding does indeed modulate the activity in the very same regions that were previously modulated by a diazepam challenge. Hence, a similar memory deficit, although primarily effected through different neurochemical pathways, was paralleled by a similar modulation of activity in the same set of nodes in the shape recognition network. In the fusiform cortex, scopolamine decreased recognition-related activity, as did the sensory challenge of retrieval. Furthermore, covariate analysis demonstrated that the level of fusiform activity linearly correlates with behavioural performance. In the thalamus, activation increased following impaired encoding. This is in accordance with the idea that enhanced thalamic activity reflects increased effort expended in retrieval. In addition, in the intraparietal sulcus, differential activation also increased following impaired memory storage, possibly reflecting enhanced visuospatial attention in an effort to compensate for impaired performance.
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Affiliation(s)
- A M Rosier
- Laboratorium voor Neuro- en Psychofysiologie, KU Leuven, Medical School, Campus Gasthuisberg, Leuven, Belgium.
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27
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Faillenot I, Decety J, Jeannerod M. Human brain activity related to the perception of spatial features of objects. Neuroimage 1999; 10:114-24. [PMID: 10498441 DOI: 10.1006/nimg.1999.0449] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The role of the parietal cortex in visuospatial analysis of object was investigated by cerebral blood flow measurements in seven objects using positron emission tomography. Data were acquired while subjects performed a matching task requiring the discrimination of simultaneously presented objects based on one of their spatial properties. Three properties were studied separately during three scanning conditions repeated twice:surface orientation, principal axis orientation, and size. Scans were also obtained during a sensorimotor control task (similar visual stimulation, same motor action, voluntary saccades toward each object) as well as during rest (no stimulation, eyes closed). Compared to rest, the three property matching tasks showed the same pattern of activation: the whole occipital lobe, the right intraparietal sulcus (IPS), and the right occipitotemporal (OT) junction. Compared to the control condition, only right IPS and OT junction were significantly activated during discrimination of the spatial properties. The IPS focus was located between the superior parietal lobule and the angular gyrus, and the OT activation overlapped the posterior part of the inferior temporal gyrus and the middle occipital gyrus. These results indicate that discrimination of spatial attributes requires the activation of both the parietal and the temporal cortices of the right hemisphere and provide further evidence that the IPS plays a critical role in visuospatial analysis of objects.
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Affiliation(s)
- I Faillenot
- INSERM U280, 151 cours Albert Thomas, 69003 Lyon, France
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