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Zamboni E, Makin ADJ, Bertamini M, Morland AB. The role of task on the human brain's responses to, and representation of, visual regularity defined by reflection and rotation. Neuroimage 2024; 297:120760. [PMID: 39069225 DOI: 10.1016/j.neuroimage.2024.120760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 07/25/2024] [Accepted: 07/26/2024] [Indexed: 07/30/2024] Open
Abstract
Identifying and segmenting objects in an image is generally achieved effortlessly and is facilitated by the presence of symmetry: a principle of perceptual organisation used to interpret sensory inputs from the retina into meaningful representations. However, while imaging studies show evidence of symmetry selective responses across extrastriate visual areas in the human brain, whether symmetry is processed automatically is still under debate. We used functional Magnetic Resonance Imaging (fMRI) to study the response to and representation of two types of symmetry: reflection and rotation. Dot pattern stimuli were presented to 15 human participants (10 female) under stimulus-relevant (symmetry) and stimulus-irrelevant (luminance) task conditions. Our results show that symmetry-selective responses emerge from area V3 and extend throughout extrastriate visual areas. This response is largely maintained when participants engage in the stimulus irrelevant task, suggesting an automaticity to processing visual symmetry. Our multi-voxel pattern analysis (MVPA) results extend these findings by suggesting that not only spatial organisation of responses to symmetrical patterns can be distinguished from that of non-symmetrical (random) patterns, but also that representation of reflection and rotation symmetry can be differentiated in extrastriate and object-selective visual areas. Moreover, task demands did not affect the neural representation of the symmetry information. Intriguingly, our MVPA results show an interesting dissociation: representation of luminance (stimulus irrelevant feature) is maintained in visual cortex only when task relevant, while information of the spatial configuration of the stimuli is available across task conditions. This speaks in favour of the automaticity for processing perceptual organisation: extrastriate visual areas compute and represent global, spatial properties irrespective of the task at hand.
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Affiliation(s)
- Elisa Zamboni
- University of Nottingham, School of Psychology, Nottingham, United Kingdom; University of York, Department of Psychology, York YO10 5DD, United Kingdom; University of York, York Neuroimaging Centre, York, United Kingdom
| | - Alexis D J Makin
- University of Liverpool, Department of Psychological Sciences, Liverpool, United Kingdom
| | - Marco Bertamini
- University of Liverpool, Department of Psychological Sciences, Liverpool, United Kingdom; Università di Padova, Dipartimento di Psicologia Generale, Padova, IT, Italy
| | - Antony B Morland
- University of York, Department of Psychology, York YO10 5DD, United Kingdom; University of York, York Neuroimaging Centre, York, United Kingdom; University of York, York Biomedical Research Institute, York, United Kingdom.
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2
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Shao X, Krieger-Redwood K, Zhang M, Hoffman P, Lanzoni L, Leech R, Smallwood J, Jefferies E. Distinctive and Complementary Roles of Default Mode Network Subsystems in Semantic Cognition. J Neurosci 2024; 44:e1907232024. [PMID: 38589231 PMCID: PMC11097276 DOI: 10.1523/jneurosci.1907-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 03/05/2024] [Accepted: 04/03/2024] [Indexed: 04/10/2024] Open
Abstract
The default mode network (DMN) typically deactivates to external tasks, yet supports semantic cognition. It comprises medial temporal (MT), core, and frontotemporal (FT) subsystems, but its functional organization is unclear: the requirement for perceptual coupling versus decoupling, input modality (visual/verbal), type of information (social/spatial), and control demands all potentially affect its recruitment. We examined the effect of these factors on activation and deactivation of DMN subsystems during semantic cognition, across four task-based human functional magnetic resonance imaging (fMRI) datasets, and localized these responses in whole-brain state space defined by gradients of intrinsic connectivity. FT showed activation consistent with a central role across domains, tasks, and modalities, although it was most responsive to abstract, verbal tasks; this subsystem uniquely showed more "tuned" states characterized by increases in both activation and deactivation when semantic retrieval demands were higher. MT also activated to both perceptually coupled (scenes) and decoupled (autobiographical memory) tasks and showed stronger responses to picture associations, consistent with a role in scene construction. Core DMN consistently showed deactivation, especially to externally oriented tasks. These diverse contributions of DMN subsystems to semantic cognition were related to their location on intrinsic connectivity gradients: activation was closer to the sensory-motor cortex than deactivation, particularly for FT and MT, while activation for core DMN was distant from both visual cortex and cognitive control. These results reveal distinctive yet complementary DMN responses: MT and FT support different memory-based representations that are accessed externally and internally, while deactivation in core DMN is associated with demanding, external semantic tasks.
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Affiliation(s)
- Ximing Shao
- Department of Psychology, University of York, York, YO10 5DD, United Kingdom
| | | | - Meichao Zhang
- Department of Psychology, University of York, York, YO10 5DD, United Kingdom
- CAS Key Laboratory of Behavioural Science, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Paul Hoffman
- School of Philosophy, Psychology and Language Sciences, University of Edinburgh, Edinburgh EH8 9JZ, United Kingdom
| | - Lucilla Lanzoni
- Department of Psychology, University of York, York, YO10 5DD, United Kingdom
| | - Robert Leech
- Centre for Neuroimaging Science, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE5 9RT, United Kingdom
| | - Jonathan Smallwood
- Department of Psychology, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Elizabeth Jefferies
- Department of Psychology, University of York, York, YO10 5DD, United Kingdom
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3
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Lowndes R, Aveyard R, Welbourne LE, Wade A, Morland AB. In primary visual cortex fMRI responses to chromatic and achromatic stimuli are interdependent and predict contrast detection thresholds. Vision Res 2024; 218:108398. [PMID: 38552557 DOI: 10.1016/j.visres.2024.108398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 03/24/2024] [Accepted: 03/24/2024] [Indexed: 04/13/2024]
Abstract
Chromatic and achromatic signals in primary visual cortex have historically been considered independent of each other but have since shown evidence of interdependence. Here, we investigated the combination of two components of a stimulus; an achromatic dynamically changing check background and a chromatic (L-M or S cone) target grating. We found that combinations of chromatic and achromatic signals in primary visual cortex were interdependent, with the dynamic range of responses to chromatic contrast decreasing as achromatic contrast increased. A contrast detection threshold study also revealed interdependence of background and target, with increasing chromatic contrast detection thresholds as achromatic background contrast increased. A model that incorporated a normalising effect of achromatic contrast on chromatic responses, but not vice versa, best predicted our V1 data as well as behavioural thresholds. Further along the visual hierarchy, the dynamic range of chromatic responses was maintained when compared to achromatic responses, which became increasingly compressive.
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Affiliation(s)
- Rebecca Lowndes
- Department of Psychology, University of York, United Kingdom; York Neuroimaging Centre, University of York, United Kingdom.
| | - Richard Aveyard
- York Neuroimaging Centre, University of York, United Kingdom
| | - Lauren E Welbourne
- Department of Psychology, University of York, United Kingdom; York Neuroimaging Centre, University of York, United Kingdom
| | - Alex Wade
- Department of Psychology, University of York, United Kingdom; York Neuroimaging Centre, University of York, United Kingdom; York Biomedical Research Institute, University of York, United Kingdom
| | - Antony B Morland
- Department of Psychology, University of York, United Kingdom; York Neuroimaging Centre, University of York, United Kingdom; York Biomedical Research Institute, University of York, United Kingdom
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Multi-Echo Investigations of Positive and Negative CBF and Concomitant BOLD Changes: Positive and negative CBF and BOLD changes. Neuroimage 2022; 263:119661. [PMID: 36198353 DOI: 10.1016/j.neuroimage.2022.119661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/27/2022] [Accepted: 09/30/2022] [Indexed: 11/21/2022] Open
Abstract
Unlike the positive blood oxygenation level-dependent (BOLD) response (PBR), commonly taken as an indication of an 'activated' brain region, the physiological origin of negative BOLD signal changes (i.e. a negative BOLD response, NBR), also referred to as 'deactivation' is still being debated. In this work, an attempt was made to gain a better understanding of the underlying mechanism by obtaining a comprehensive measure of the contributing cerebral blood flow (CBF) and its relationship to the NBR in the human visual cortex, in comparison to a simultaneously induced PBR in surrounding visual regions. To overcome the low signal-to-noise ratio (SNR) of CBF measurements, a newly developed multi-echo version of a center-out echo planar-imaging (EPI) readout was employed with pseudo-continuous arterial spin labeling (pCASL). It achieved very short echo and inter-echo times and facilitated a simultaneous detection of functional CBF and BOLD changes at 3 T with improved sensitivity. Evaluations of the absolute and relative changes of CBF and the effective transverse relaxation rate,R2* the coupling ratios, and their dependence on CBF at rest, CBFrest indicated differences between activated and deactivated regions. Analysis of the shape of the respective functional responses also revealed faster negative responses with more pronounced post-stimulus transients. Resulting differences in the flow-metabolism coupling ratios were further examined for potential distinctions in the underlying neuronal contributions.
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Zhu W, Liu T, Li M, Sun X, He S. Activation of lesion projection zone in primary visual cortex is dependent on bilateral central vision loss in patients with end-stage glaucoma. Ophthalmic Physiol Opt 2022; 42:1159-1169. [PMID: 36044240 DOI: 10.1111/opo.13044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 07/26/2022] [Accepted: 07/26/2022] [Indexed: 11/29/2022]
Abstract
PURPOSE To investigate activation of the lesion projection zone (LPZ) in the primary visual cortex during end-stage glaucoma using functional magnetic resonance imaging (fMRI), as well as the relationship between fMRI responses and clinical data. METHODS Twelve subjects with bilateral end-stage glaucoma (group A), 12 with unilateral end-stage glaucoma (group B) and 12 healthy controls (group C) were enrolled. fMRI was performed under two testing stimuli conditions: passive viewing of a full-field flickering checkerboard and active viewing of a one-back task with scene images. In fMRI analysis, the primary visual cortex was divided into six regions of interest (ROIs). The beta values of the six ROIs were compared across the three groups using one-way analysis of variance under two viewing conditions. Associations between the fMRI beta value and clinical data including multifocal electroretinogram (mfERG), microperimeter-1 and optical coherence tomography were analysed by Spearman correlation. RESULTS The beta values for ROIs 1-3 representing the LPZ were significantly different between the three groups under active viewing conditions, whereas no significant changes were detected under passive viewing. In group A, there were significant differences between all six ROIs for the two viewing conditions, while no significant differences were found in groups B and C. In group A, the P-wave amplitudes of the mfERG was significantly correlated with the beta values of ROIs 1 and 2 under active viewing. In addition, the P-wave latencies of the mfERG were significantly correlated with the beta values for ROIs 2-5. No associations were found between fMRI beta values and clinical data in groups B and C. CONCLUSIONS Activation of the LPZ in the primary visual cortex was observed in patients with bilateral end-stage glaucoma under active viewing conditions. These changes were correlated with residual retinal function.
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Affiliation(s)
- Wenqing Zhu
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Tingting Liu
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Mengwei Li
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xinghuai Sun
- Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai, China
| | - Sheng He
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
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Goddard E, Carlson TA, Woolgar A. Spatial and Feature-selective Attention Have Distinct, Interacting Effects on Population-level Tuning. J Cogn Neurosci 2021; 34:290-312. [PMID: 34813647 PMCID: PMC7613071 DOI: 10.1162/jocn_a_01796] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Attention can be deployed in different ways: When searching for a taxi in New York City, we can decide where to attend (e.g., to the street) and what to attend to (e.g., yellow cars). Although we use the same word to describe both processes, nonhuman primate data suggest that these produce distinct effects on neural tuning. This has been challenging to assess in humans, but here we used an opportunity afforded by multivariate decoding of MEG data. We found that attending to an object at a particular location and attending to a particular object feature produced effects that interacted multiplicatively. The two types of attention induced distinct patterns of enhancement in occipital cortex, with feature-selective attention producing relatively more enhancement of small feature differences and spatial attention producing relatively larger effects for larger feature differences. An information flow analysis further showed that stimulus representations in occipital cortex were Granger-caused by coding in frontal cortices earlier in time and that the timing of this feedback matched the onset of attention effects. The data suggest that spatial and feature-selective attention rely on distinct neural mechanisms that arise from frontal-occipital information exchange, interacting multiplicatively to selectively enhance task-relevant information.
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Affiliation(s)
- Erin Goddard
- University of New South Wales.,Macquarie University, Sydney, New South Wales, Australia
| | - Thomas A Carlson
- Macquarie University, Sydney, New South Wales, Australia.,University of Sydney
| | - Alexandra Woolgar
- Macquarie University, Sydney, New South Wales, Australia.,University of Cambridge
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Fracasso A, Gaglianese A, Vansteensel MJ, Aarnoutse EJ, Ramsey NF, Dumoulin SO, Petridou N. FMRI and intra-cranial electrocorticography recordings in the same human subjects reveals negative BOLD signal coupled with silenced neuronal activity. Brain Struct Funct 2021; 227:1371-1384. [PMID: 34363092 PMCID: PMC9046332 DOI: 10.1007/s00429-021-02342-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 07/09/2021] [Indexed: 12/27/2022]
Abstract
Positive blood oxygenation level-dependent (BOLD) responses (PBR), as measured by functional Magnetic Resonance Imaging (fMRI), are the most utilized measurements to non-invasively map activity in the brain. Recent studies have consistently shown that BOLD responses are not exclusively positive. Negative BOLD responses (NBR) have been reported in response to specific sensory stimulations and tasks. However, the exact relationship between NBR and the underlying metabolic and neuronal demand is still under debate. In this study, we investigated the neurophysiological basis of negative BOLD using fMRI and intra-cranial electrophysiology (electrocorticography, ECoG) measurements from the same human participants. We show that, for those electrodes that responded to visual stimulation, PBR are correlated with high-frequency band (HFB) responses. Crucially, NBR were associated with an absence of HFB power responses and an unpredicted decrease in the alpha power responses.
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Affiliation(s)
- Alessio Fracasso
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, Scotland.
| | - Anna Gaglianese
- The Laboratory for Investigative Neurophysiology (The LINE), Department of Radiology, University Hospital Center, University of Lausanne, Rue Centrale 7, 1003, Lausanne, Switzerland
- Department of Radiology, Center for Image Sciences, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
- Department of Neurosurgery and Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Mariska J Vansteensel
- Department of Neurosurgery and Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Erik J Aarnoutse
- Department of Neurosurgery and Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Nick F Ramsey
- Department of Neurosurgery and Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
| | - Serge O Dumoulin
- Experimental Psychology, Helmholtz Institute, Utrecht University, Utrecht, The Netherlands
- Spinoza Center for Neuroimaging, Amsterdam, The Netherlands
- Experimental and Applied Psychology, VU University Amsterdam, Amsterdam, The Netherlands
| | - Natalia Petridou
- Department of Radiology, Center for Image Sciences, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
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8
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Mugruza-Vassallo CA, Potter DD, Tsiora S, Macfarlane JA, Maxwell A. Prior context influences motor brain areas in an auditory oddball task and prefrontal cortex multitasking modelling. Brain Inform 2021; 8:5. [PMID: 33745089 PMCID: PMC7982371 DOI: 10.1186/s40708-021-00124-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 12/21/2020] [Indexed: 11/19/2022] Open
Abstract
In this study, the relationship of orienting of attention, motor control and the Stimulus- (SDN) and Goal-Driven Networks (GDN) was explored through an innovative method for fMRI analysis considering all voxels in four experimental conditions: standard target (Goal; G), novel (N), neutral (Z) and noisy target (NG). First, average reaction times (RTs) for each condition were calculated. In the second-level analysis, 'distracted' participants, as indicated by slower RTs, evoked brain activations and differences in both hemispheres' neural networks for selective attention, while the participants, as a whole, demonstrated mainly left cortical and subcortical activations. A context analysis was run in the behaviourally distracted participant group contrasting the trials immediately prior to the G trials, namely one of the Z, N or NG conditions, i.e. Z.G, N.G, NG.G. Results showed different prefrontal activations dependent on prior context in the auditory modality, recruiting between 1 to 10 prefrontal areas. The higher the motor response and influence of the previous novel stimulus, the more prefrontal areas were engaged, which extends the findings of hierarchical studies of prefrontal control of attention and better explains how auditory processing interferes with movement. Also, the current study addressed how subcortical loops and models of previous motor response affected the signal processing of the novel stimulus, when this was presented laterally or simultaneously with the target. This multitasking model could enhance our understanding on how an auditory stimulus is affecting motor responses in a way that is self-induced, by taking into account prior context, as demonstrated in the standard condition and as supported by Pulvinar activations complementing visual findings. Moreover, current BCI works address some multimodal stimulus-driven systems.
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Affiliation(s)
- Carlos A Mugruza-Vassallo
- Grupo de Investigación de Computación Y Neurociencia Cognitiva, Facultad de Ingeniería Y Gestión, Universidad Nacional Tecnológica de Lima Sur - UNTELS, Lima, Perú.
| | - Douglas D Potter
- Neuroscience and Development Group, Arts and Science, University of Dundee, Dundee, UK
| | - Stamatina Tsiora
- School of Psychology, University of Lincoln, Lincoln, United Kingdom
| | | | - Adele Maxwell
- Neuroscience and Development Group, Arts and Science, University of Dundee, Dundee, UK
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de la Rosa N, Ress D, Taylor AJ, Kim JH. Retinotopic variations of the negative blood-oxygen-level dependent hemodynamic response function in human primary visual cortex. J Neurophysiol 2021; 125:1045-1057. [PMID: 33625949 DOI: 10.1152/jn.00676.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) measures blood-oxygen-level-dependent (BOLD) contrast that is generally assumed to be linearly related to excitatory neural activity. The positive hemodynamic response function (pHRF) is the positive BOLD response (PBR) evoked by a brief neural stimulation; the pHRF is often used as the impulse response for linear analysis of neural excitation. Many fMRI studies have observed a negative BOLD response (NBR) that is often associated with neural suppression. However, the temporal dynamics of the NBR evoked by a brief stimulus, the negative HRF (nHRF), remains unclear. Here, a unilateral visual stimulus was presented in a slow event-related design to elicit both pHRFs in the stimulus representation (SR), and nHRFs elsewhere. The observed nHRFs were not inverted versions of the pHRF previously reported. They were characterized by a stronger initial negative response followed by a significantly later positive peak. In contralateral primary visual cortex (V1), these differences varied with eccentricity from the SR. Similar nHRFs were observed in ipsilateral V1 with less eccentricity variation. Experiments with the blocked version of the same stimulus confirmed that brain regions presenting the unexpected nHRF dynamics correspond to those presenting a strong NBR. These data demonstrated that shift-invariant temporal linearity did not hold for the NBR while confirming that the PBR maintained rough linearity. Modeling indicated that the observed nHRFs can be created by suppression of both blood flow and oxygen metabolism. Critically, the nHRF can be misinterpreted as a pHRF due to their similarity, which could confound linear analysis for event-related fMRI experiments.NEW & NOTEWORTHY We investigate dynamics of the negative hemodynamic response function (nHRF), the negative blood-oxygen-level-dependent (BOLD) response (NBR) evoked by a brief stimulus, in human early visual cortex. Here, we show that the nHRFs are not inverted versions of the corresponding pHRFs. The nHRF has complex dynamics that varied significantly with eccentricity. The results also show shift-invariant temporal linearity does not hold for the NBR.
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10
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Zhang M, Varga D, Wang X, Krieger-Redwood K, Gouws A, Smallwood J, Jefferies E. Knowing what you need to know in advance: The neural processes underpinning flexible semantic retrieval of thematic and taxonomic relations. Neuroimage 2021; 224:117405. [PMID: 32992002 PMCID: PMC7779371 DOI: 10.1016/j.neuroimage.2020.117405] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/22/2020] [Accepted: 09/22/2020] [Indexed: 11/26/2022] Open
Abstract
Semantic retrieval is flexible, allowing us to focus on subsets of features and associations that are relevant to the current task or context: for example, we use taxonomic relations to locate items in the supermarket (carrots are a vegetable), but thematic associations to decide which tools we need when cooking (carrot goes with peeler). We used fMRI to investigate the neural basis of this form of semantic flexibility; in particular, we asked how retrieval unfolds differently when participants have advanced knowledge of the type of link to retrieve between concepts (taxonomic or thematic). Participants performed a semantic relatedness judgement task: on half the trials, they were cued to search for a taxonomic or thematic link, while on the remaining trials, they judged relatedness without knowing which type of semantic relationship would be relevant. Left inferior frontal gyrus showed greater activation when participants knew the trial type in advance. An overlapping region showed a stronger response when the semantic relationship between the items was weaker, suggesting this structure supports both top-down and bottom-up forms of semantic control. Multivariate pattern analysis further revealed that the neural response in left inferior frontal gyrus reflects goal information related to different conceptual relationships. Top-down control specifically modulated the response in visual cortex: when the goal was unknown, there was greater deactivation to the first word, and greater activation to the second word. We conclude that top-down control of semantic retrieval is primarily achieved through the gating of task-relevant 'spoke' regions.
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Affiliation(s)
- Meichao Zhang
- Department of Psychology, University of York, Heslington, York, UK, YO10 5DD.
| | - Dominika Varga
- Department of Psychology, University of York, Heslington, York, UK, YO10 5DD
| | - Xiuyi Wang
- Department of Psychology, University of York, Heslington, York, UK, YO10 5DD
| | | | - Andre Gouws
- Department of Psychology, University of York, Heslington, York, UK, YO10 5DD
| | - Jonathan Smallwood
- Department of Psychology, University of York, Heslington, York, UK, YO10 5DD
| | - Elizabeth Jefferies
- Department of Psychology, University of York, Heslington, York, UK, YO10 5DD.
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11
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V1 Projection Zone Signals in Human Macular Degeneration Depend on Task Despite Absence of Visual Stimulus. Curr Biol 2020; 31:406-412.e3. [PMID: 33157025 DOI: 10.1016/j.cub.2020.10.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/12/2020] [Accepted: 10/12/2020] [Indexed: 11/23/2022]
Abstract
Identifying the plastic and stable components of the visual cortex after retinal loss is an important topic in visual neuroscience and neuro-ophthalmology.1-5 Humans with juvenile macular degeneration (JMD) show significant blood-oxygen-level-dependent (BOLD) responses in the primary visual area (V1) lesion projection zone (LPZ),6 despite the absence of the feedforward signals from the degenerated retina. Our previous study7 reported that V1 LPZ responds to full-field visual stimuli during the one-back task (OBT), not during passive viewing, suggesting the involvement of task-related feedback signals. Aiming to clarify whether visual inputs to the intact retina are necessary for the LPZ responses, here, we measured BOLD responses to tactile and auditory stimuli for both JMD patients and control participants with and without OBT. Participants were instructed to close their eyes during the experiment for the purpose of eliminating retinal inputs. Without OBT, no V1 responses were detected in both groups of participants. With OBT, to the contrary, both stimuli caused substantial V1 responses in JMD patients, but not controls. Furthermore, we also found that the task-dependent activity in V1 LPZ became less pronounced when JMD patients opened their eyes, suggesting that task-related feedback signals can be partially suppressed by residual feedforward signals. Modality-independent V1 LPZ responses only in the task condition suggest that V1 LPZ responses reflect task-related feedback signals rather than reorganized feedforward visual inputs.
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12
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Wilson R, Thomas A, Mayhew SD. Spatially congruent negative BOLD responses to different stimuli do not summate in visual cortex. Neuroimage 2020; 218:116891. [DOI: 10.1016/j.neuroimage.2020.116891] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 04/23/2020] [Accepted: 04/28/2020] [Indexed: 01/07/2023] Open
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13
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Itthipuripat S, Vo VA, Sprague TC, Serences JT. Value-driven attentional capture enhances distractor representations in early visual cortex. PLoS Biol 2019; 17:e3000186. [PMID: 31398186 PMCID: PMC6703696 DOI: 10.1371/journal.pbio.3000186] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 08/21/2019] [Accepted: 07/17/2019] [Indexed: 12/22/2022] Open
Abstract
When a behaviorally relevant stimulus has been previously associated with reward, behavioral responses are faster and more accurate compared to equally relevant but less valuable stimuli. Conversely, task-irrelevant stimuli that were previously associated with a high reward can capture attention and distract processing away from relevant stimuli (e.g., seeing a chocolate bar in the pantry when you are looking for a nice, healthy apple). Although increasing the value of task-relevant stimuli systematically up-regulates neural responses in early visual cortex to facilitate information processing, it is not clear whether the value of task-irrelevant distractors influences behavior via competition in early visual cortex or via competition at later stages of decision-making and response selection. Here, we measured functional magnetic resonance imaging (fMRI) in human visual cortex while subjects performed a value-based learning task, and we applied a multivariate inverted encoding model (IEM) to assess the fidelity of distractor representations in early visual cortex. We found that the fidelity of neural representations related to task-irrelevant distractors increased when the distractors were previously associated with a high reward. This finding suggests that value-driven attentional capture begins with sensory modulations of distractor representations in early areas of visual cortex.
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Affiliation(s)
- Sirawaj Itthipuripat
- Learning Institute, King Mongkut’s University of Technology Thonburi, Bangkok, Thailand
- Futuristic Research in Enigmatic Aesthetics Knowledge Laboratory, King Mongkut’s University of Technology Thonburi, Bangkok, Thailand
- Department of Psychology and Center for Integrative and Cognitive Neuroscience, Vanderbilt University, Nashville, Tennessee, United States of America
- Neurosciences Graduate Program, University of California San Diego, La Jolla, California, United States of America
| | - Vy A. Vo
- Neurosciences Graduate Program, University of California San Diego, La Jolla, California, United States of America
| | - Thomas C. Sprague
- Neurosciences Graduate Program, University of California San Diego, La Jolla, California, United States of America
- Department of Psychology, New York University, New York, New York, United States of America
- Department of Psychological and Brain Sciences, University of California Santa Barbara, Santa Barbara, California, United States of America
| | - John T. Serences
- Neurosciences Graduate Program, University of California San Diego, La Jolla, California, United States of America
- Department of Psychology and Kavli Foundation for the Brain and Mind, University of California San Diego, La Jolla, California, United States of America
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14
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Lawrence SJ, Formisano E, Muckli L, de Lange FP. Laminar fMRI: Applications for cognitive neuroscience. Neuroimage 2019; 197:785-791. [DOI: 10.1016/j.neuroimage.2017.07.004] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 05/04/2017] [Accepted: 07/03/2017] [Indexed: 11/30/2022] Open
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15
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Itthipuripat S, Sprague TC, Serences JT. Functional MRI and EEG Index Complementary Attentional Modulations. J Neurosci 2019; 39:6162-6179. [PMID: 31127004 PMCID: PMC6668200 DOI: 10.1523/jneurosci.2519-18.2019] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 04/12/2019] [Accepted: 05/16/2019] [Indexed: 02/07/2023] Open
Abstract
Functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) are two noninvasive methods commonly used to study neural mechanisms supporting visual attention in humans. Studies using these tools, which have complementary spatial and temporal resolutions, implicitly assume they index similar underlying neural modulations related to external stimulus and internal attentional manipulations. Accordingly, they are often used interchangeably for constraining understanding about the impact of bottom-up and top-down factors on neural modulations. To test this core assumption, we simultaneously manipulated bottom-up sensory inputs by varying stimulus contrast and top-down cognitive modulations by changing the focus of spatial attention. Each of the male and female subjects participated in both fMRI and EEG sessions performing the same experimental paradigm. We found categorically different patterns of attentional modulation on fMRI activity in early visual cortex and early stimulus-evoked potentials measured via EEG (e.g., the P1 component and steady-state visually-evoked potentials): fMRI activation scaled additively with attention, whereas evoked EEG components scaled multiplicatively with attention. However, across longer time scales, a contralateral negative-going potential and oscillatory EEG signals in the alpha band revealed additive attentional modulation patterns like those observed with fMRI. These results challenge prior assumptions that fMRI and early stimulus-evoked potentials measured with EEG can be interchangeably used to index the same neural mechanisms of attentional modulations at different spatiotemporal scales. Instead, fMRI measures of attentional modulations are more closely linked with later EEG components and alpha-band oscillations. Considered together, hemodynamic and electrophysiological signals can jointly constrain understanding of the neural mechanisms supporting cognition.SIGNIFICANCE STATEMENT fMRI and EEG have been used as tools to measure the location and timing of attentional modulations in visual cortex and are often used interchangeably for constraining computational models under the assumption that they index similar underlying neural processes. However, by varying attentional and stimulus parameters, we found differential patterns of attentional modulations of fMRI activity in early visual cortex and commonly used stimulus-evoked potentials measured via EEG. Instead, across longer time scales, a contralateral negative-going potential and EEG oscillations in the alpha band exhibited attentional modulations similar to those observed with fMRI. Together, these results suggest that different physiological processes assayed by these complementary techniques must be jointly considered when making inferences about the neural underpinnings of cognitive operations.
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Affiliation(s)
- Sirawaj Itthipuripat
- Neurosciences Graduate Program,
- Learning Institute
- Futuristic Research in Enigmatic Aesthetics Knowledge Laboratory, King Mongkut's University of Technology Thonburi, Bangkok, 10140, Thailand
- Department of Psychology, Center for Integrative and Cognitive Neuroscience, and Interdisciplinary Program in Neuroscience, Vanderbilt University, Nashville, Tennessee 37235, and
| | - Thomas C Sprague
- Neurosciences Graduate Program,
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, California 93106-9660
| | - John T Serences
- Neurosciences Graduate Program
- Department of Psychology
- Kavli Foundation for the Brain and Mind, University of California, San Diego, La Jolla, California 92093
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16
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Engagement of Pulvino-cortical Feedforward and Feedback Pathways in Cognitive Computations. Neuron 2018; 101:321-336.e9. [PMID: 30553546 DOI: 10.1016/j.neuron.2018.11.023] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 09/14/2018] [Accepted: 11/12/2018] [Indexed: 01/18/2023]
Abstract
Computational modeling of brain mechanisms of cognition has largely focused on the cortex, but recent experiments have shown that higher-order nuclei of the thalamus participate in major cognitive functions and are implicated in psychiatric disorders. Here, we show that a pulvino-cortical circuit model, composed of the pulvinar and two cortical areas, captures several physiological and behavioral observations related to the macaque pulvinar. Effective connections between the two cortical areas are gated by the pulvinar, allowing the pulvinar to shift the operation regime of these areas during attentional processing and working memory and resolve conflict in decision making. Furthermore, cortico-pulvinar projections that engage the thalamic reticular nucleus enable the pulvinar to estimate decision confidence. Finally, feedforward and feedback pulvino-cortical pathways participate in frequency-dependent inter-areal interactions that modify the relative hierarchical positions of cortical areas. Overall, our model suggests that the pulvinar provides crucial contextual modulation to cortical computations associated with cognition.
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17
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Noonan MP, Crittenden BM, Jensen O, Stokes MG. Selective inhibition of distracting input. Behav Brain Res 2018; 355:36-47. [DOI: 10.1016/j.bbr.2017.10.010] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 09/02/2017] [Accepted: 10/10/2017] [Indexed: 12/22/2022]
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18
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Sprague TC, Itthipuripat S, Vo VA, Serences JT. Dissociable signatures of visual salience and behavioral relevance across attentional priority maps in human cortex. J Neurophysiol 2018; 119:2153-2165. [PMID: 29488841 DOI: 10.1152/jn.00059.2018] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Computational models posit that visual attention is guided by activity within spatial maps that index the image-computable salience and the behavioral relevance of objects in the scene. These spatial maps are theorized to be instantiated as activation patterns across a series of retinotopic visual regions in occipital, parietal, and frontal cortex. Whereas previous research has identified sensitivity to either the behavioral relevance or the image-computable salience of different scene elements, the simultaneous influence of these factors on neural "attentional priority maps" in human cortex is not well understood. We tested the hypothesis that visual salience and behavioral relevance independently impact the activation profile across retinotopically organized cortical regions by quantifying attentional priority maps measured in human brains using functional MRI while participants attended one of two differentially salient stimuli. We found that the topography of activation in priority maps, as reflected in the modulation of region-level patterns of population activity, independently indexed the physical salience and behavioral relevance of each scene element. Moreover, salience strongly impacted activation patterns in early visual areas, whereas later visual areas were dominated by relevance. This suggests that prioritizing spatial locations relies on distributed neural codes containing graded representations of salience and relevance across the visual hierarchy. NEW & NOTEWORTHY We tested a theory which supposes that neural systems represent scene elements according to both their salience and their relevance in a series of "priority maps" by measuring functional MRI activation patterns across human brains and reconstructing spatial maps of the visual scene. We found that different regions indexed either the salience or the relevance of scene items, but not their interaction, suggesting an evolving representation of salience and relevance across different visual areas.
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Affiliation(s)
- Thomas C Sprague
- Department of Psychology, New York University , New York, New York.,Neurosciences Graduate Program, University of California, San Diego, La Jolla, California
| | - Sirawaj Itthipuripat
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, California.,Learning Institute, King Mongkut's University of Technology Thonburi, Bangmod, Thung Kru, Bangkok , Thailand.,Department of Psychology, Vanderbilt University , Nashville, Tennessee
| | - Vy A Vo
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, California
| | - John T Serences
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, California.,Department of Psychology, University of California, San Diego, La Jolla, California.,Kavli Institute for Brain and Mind, University of California, San Diego, La Jolla, California
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19
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Havlicek M, Ivanov D, Roebroeck A, Uludağ K. Determining Excitatory and Inhibitory Neuronal Activity from Multimodal fMRI Data Using a Generative Hemodynamic Model. Front Neurosci 2017; 11:616. [PMID: 29249925 PMCID: PMC5715391 DOI: 10.3389/fnins.2017.00616] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 10/23/2017] [Indexed: 12/12/2022] Open
Abstract
Hemodynamic responses, in general, and the blood oxygenation level-dependent (BOLD) fMRI signal, in particular, provide an indirect measure of neuronal activity. There is strong evidence that the BOLD response correlates well with post-synaptic changes, induced by changes in the excitatory and inhibitory (E-I) balance between active neuronal populations. Typical BOLD responses exhibit transients, such as the early-overshoot and post-stimulus undershoot, that can be linked to transients in neuronal activity, but they can also result from vascular uncoupling between cerebral blood flow (CBF) and venous cerebral blood volume (venous CBV). Recently, we have proposed a novel generative hemodynamic model of the BOLD signal within the dynamic causal modeling framework, inspired by physiological observations, called P-DCM (Havlicek et al., 2015). We demonstrated the generative model's ability to more accurately model commonly observed neuronal and vascular transients in single regions but also effective connectivity between multiple brain areas (Havlicek et al., 2017b). In this paper, we additionally demonstrate the versatility of the generative model to jointly explain dynamic relationships between neuronal and hemodynamic physiological variables underlying the BOLD signal using multi-modal data. For this purpose, we utilized three distinct data-sets of experimentally induced responses in the primary visual areas measured in human, cat, and monkey brain, respectively: (1) CBF and BOLD responses; (2) CBF, total CBV, and BOLD responses (Jin and Kim, 2008); and (3) positive and negative neuronal and BOLD responses (Shmuel et al., 2006). By fitting the generative model to the three multi-modal experimental data-sets, we showed that the presence or absence of dynamic features in the BOLD signal is not an unambiguous indication of presence or absence of those features on the neuronal level. Nevertheless, the generative model that takes into account the dynamics of the physiological mechanisms underlying the BOLD response allowed dissociating neuronal from vascular transients and deducing excitatory and inhibitory neuronal activity time-courses from BOLD data alone and from multi-modal data.
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Affiliation(s)
- Martin Havlicek
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Dimo Ivanov
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Alard Roebroeck
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Kamil Uludağ
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
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20
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Towards building a more complex view of the lateral geniculate nucleus: Recent advances in understanding its role. Prog Neurobiol 2017. [DOI: 10.1016/j.pneurobio.2017.06.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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21
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Multivariate Patterns in the Human Object-Processing Pathway Reveal a Shift from Retinotopic to Shape Curvature Representations in Lateral Occipital Areas, LO-1 and LO-2. J Neurosci 2017; 36:5763-74. [PMID: 27225766 DOI: 10.1523/jneurosci.3603-15.2016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 04/08/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Representations in early visual areas are organized on the basis of retinotopy, but this organizational principle appears to lose prominence in the extrastriate cortex. Nevertheless, an extrastriate region, such as the shape-selective lateral occipital cortex (LO), must still base its activation on the responses from earlier retinotopic visual areas, implying that a transition from retinotopic to "functional" organizations should exist. We hypothesized that such a transition may lie in LO-1 or LO-2, two visual areas lying between retinotopically defined V3d and functionally defined LO. Using a rapid event-related fMRI paradigm, we measured neural similarity in 12 human participants between pairs of stimuli differing along dimensions of shape exemplar and shape complexity within both retinotopically and functionally defined visual areas. These neural similarity measures were then compared with low-level and more abstract (curvature-based) measures of stimulus similarity. We found that low-level, but not abstract, stimulus measures predicted V1-V3 responses, whereas the converse was true for LO, a double dissociation. Critically, abstract stimulus measures were most predictive of responses within LO-2, akin to LO, whereas both low-level and abstract measures were predictive for responses within LO-1, perhaps indicating a transitional point between those two organizational principles. Similar transitions to abstract representations were not observed in the more ventral stream passing through V4 and VO-1/2. The transition we observed in LO-1 and LO-2 demonstrates that a more "abstracted" representation, typically considered the preserve of "category-selective" extrastriate cortex, can nevertheless emerge in retinotopic regions. SIGNIFICANCE STATEMENT Visual areas are typically identified either through retinotopy (e.g., V1-V3) or from functional selectivity [e.g., shape-selective lateral occipital complex (LOC)]. We combined these approaches to explore the nature of shape representations through the visual hierarchy. Two different representations emerged: the first reflected low-level shape properties (dependent on the spatial layout of the shape outline), whereas the second captured more abstract curvature-related shape features. Critically, early visual cortex represented low-level information but this diminished in the extrastriate cortex (LO-1/LO-2/LOC), in which the abstract representation emerged. Therefore, this work further elucidates the nature of shape representations in the LOC, provides insight into how those representations emerge from early retinotopic cortex, and crucially demonstrates that retinotopically tuned regions (LO-1/LO-2) are not necessarily constrained to retinotopic representations.
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22
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Itthipuripat S, Cha K, Byers A, Serences JT. Two different mechanisms support selective attention at different phases of training. PLoS Biol 2017; 15:e2001724. [PMID: 28654635 PMCID: PMC5486967 DOI: 10.1371/journal.pbio.2001724] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 05/15/2017] [Indexed: 11/20/2022] Open
Abstract
Selective attention supports the prioritized processing of relevant sensory information to facilitate goal-directed behavior. Studies in human subjects demonstrate that attentional gain of cortical responses can sufficiently account for attention-related improvements in behavior. On the other hand, studies using highly trained nonhuman primates suggest that reductions in neural noise can better explain attentional facilitation of behavior. Given the importance of selective information processing in nearly all domains of cognition, we sought to reconcile these competing accounts by testing the hypothesis that extensive behavioral training alters the neural mechanisms that support selective attention. We tested this hypothesis using electroencephalography (EEG) to measure stimulus-evoked visual responses from human subjects while they performed a selective spatial attention task over the course of ~1 month. Early in training, spatial attention led to an increase in the gain of stimulus-evoked visual responses. Gain was apparent within ~100 ms of stimulus onset, and a quantitative model based on signal detection theory (SDT) successfully linked the magnitude of this gain modulation to attention-related improvements in behavior. However, after extensive training, this early attentional gain was eliminated even though there were still substantial attention-related improvements in behavior. Accordingly, the SDT-based model required noise reduction to account for the link between the stimulus-evoked visual responses and attentional modulations of behavior. These findings suggest that training can lead to fundamental changes in the way attention alters the early cortical responses that support selective information processing. Moreover, these data facilitate the translation of results across different species and across experimental procedures that employ different behavioral training regimes.
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Affiliation(s)
- Sirawaj Itthipuripat
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, California, United States of America
| | - Kexin Cha
- Department of Psychology, University of California, San Diego, La Jolla, California, United States of America
| | - Anna Byers
- Department of Psychology, University of California, San Diego, La Jolla, California, United States of America
| | - John T. Serences
- Neurosciences Graduate Program, University of California, San Diego, La Jolla, California, United States of America
- Department of Psychology, University of California, San Diego, La Jolla, California, United States of America
- Kavli Institute for Brain and Mind, University of California, San Diego, La Jolla, California, United States of America
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Perceptual Competition Promotes Suppression of Reward Salience in Behavioral Selection and Neural Representation. J Neurosci 2017; 37:6242-6252. [PMID: 28539425 DOI: 10.1523/jneurosci.0217-17.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 05/11/2017] [Accepted: 05/15/2017] [Indexed: 11/21/2022] Open
Abstract
Visual attentional selection is influenced by the value of objects. Previous studies have demonstrated that reward-associated items lead to rapid distraction and associated behavioral costs, which are difficult to override with top-down control. However, it has not been determined whether a perceptually competitive environment could render the reward-driven distraction more susceptible to top-down suppression. Here, we trained both genders of human subjects to associate two orientations with high and low magnitudes of reward. After training, we collected fMRI data while the subjects performed a categorical visual search task. The item in the reward-associated orientation served as the distractor, and the relative physical salience between the target and distractor was carefully controlled to modulate the degree of perceptual competition. The behavioral results showed faster searches in the presence of high, relative to low, reward-associated distractors. However, this effect was evident only if the physical salience of the distractor was higher than that of the target, indicating a context-dependent suppression effect of reward salience that relied on high perceptual competition. By analyzing the fMRI data in primary visual cortex, we found that the behavioral pattern of results could be predicted by the suppressed channel responses tuned to the reward-associated orientation in the distractor location, accompanied by increased responses in the midbrain dopaminergic region. Our results suggest that the learned salience of a reward plays a flexible role in solving perceptual competition, enabling the neural system to adaptively modulate the perceptual representation for behavioral optimization.SIGNIFICANCE STATEMENT The predictiveness principle in learning theory suggests that the stimulus with high predictability of reward receives priority in attentional selection. This selection bias leads to difficulties in changing approach behaviors, and thus becomes an important factor related to psychiatric disorders with attentional deficits. Here, we demonstrated that such principle is adaptively implemented in attentional suppression in visual search. We showed that the learned salience induced the suppression of the reward-associated distractor if its competition with the target was strong and could not be readily solved. This behavioral pattern was accompanied by increased midbrain fMRI activity and weakened sensory representation of the reward-associated distractor in V1. Our findings provided direct evidence that our brain flexibly uses learned regularities in attentional control.
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24
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Kalm K, Norris D. Reading positional codes with fMRI: Problems and solutions. PLoS One 2017; 12:e0176585. [PMID: 28520725 PMCID: PMC5435169 DOI: 10.1371/journal.pone.0176585] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/12/2017] [Indexed: 01/18/2023] Open
Abstract
Neural mechanisms which bind items into sequences have been investigated in a large body of research in animal neurophysiology and human neuroimaging. However, a major problem in interpreting this data arises from a fact that several unrelated processes, such as memory load, sensory adaptation, and reward expectation, also change in a consistent manner as the sequence unfolds. In this paper we use computational simulations and data from two fMRI experiments to show that a host of unrelated neural processes can masquerade as sequence representations. We show that dissociating such unrelated processes from a dedicated sequence representation is an especially difficult problem for fMRI data, which is almost exclusively the modality used in human experiments. We suggest that such fMRI results must be treated with caution and in many cases the assumed neural representation might actually reflect unrelated processes.
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Affiliation(s)
- Kristjan Kalm
- Cognition and Brain Sciences Unit, Medical Research Council, 15 Chaucer Road, Cambridge, CB2 7EF, United Kingdom
- * E-mail:
| | - Dennis Norris
- Cognition and Brain Sciences Unit, Medical Research Council, 15 Chaucer Road, Cambridge, CB2 7EF, United Kingdom
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25
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Skeide MA, Kumar U, Mishra RK, Tripathi VN, Guleria A, Singh JP, Eisner F, Huettig F. Learning to read alters cortico-subcortical cross-talk in the visual system of illiterates. SCIENCE ADVANCES 2017; 3:e1602612. [PMID: 28560333 PMCID: PMC5443643 DOI: 10.1126/sciadv.1602612] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Accepted: 03/23/2017] [Indexed: 05/22/2023]
Abstract
Learning to read is known to result in a reorganization of the developing cerebral cortex. In this longitudinal resting-state functional magnetic resonance imaging study in illiterate adults, we show that only 6 months of literacy training can lead to neuroplastic changes in the mature brain. We observed that literacy-induced neuroplasticity is not confined to the cortex but increases the functional connectivity between the occipital lobe and subcortical areas in the midbrain and the thalamus. Individual rates of connectivity increase were significantly related to the individual decoding skill gains. These findings crucially complement current neurobiological concepts of normal and impaired literacy acquisition.
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Affiliation(s)
- Michael A. Skeide
- Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstrasse 1a, 04103 Leipzig, Germany
- Corresponding author.
| | - Uttam Kumar
- Centre of Biomedical Research, Raibareli Road, 226014 Lucknow, Uttar Pradesh, India
| | - Ramesh K. Mishra
- University of Hyderabad, Prof. C.R. Rao Road, Gachibowli, 500046 Hyderabad, Telangana, India
| | - Viveka N. Tripathi
- Centre for Behavioural and Cognitive Sciences, University of Allahabad, University Road, Old Katra, 211002 Allahabad, Uttar Pradesh, India
- Department of Psychology, University of Allahabad, 211002 Allahabad, Uttar Pradesh, India
| | - Anupam Guleria
- Centre of Biomedical Research, Raibareli Road, 226014 Lucknow, Uttar Pradesh, India
| | - Jay P. Singh
- Centre for Behavioural and Cognitive Sciences, University of Allahabad, University Road, Old Katra, 211002 Allahabad, Uttar Pradesh, India
| | - Frank Eisner
- Donders Institute, Radboud University, Montessorilaan 3, 6525 HR Nijmegen, Netherlands
| | - Falk Huettig
- Psychology of Language Department, Max Planck Institute for Psycholinguistics, Wundtlaan 1, 6525 XD Nijmegen, Netherlands
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Grassi PR, Zaretskaya N, Bartels A. Scene segmentation in early visual cortex during suppression of ventral stream regions. Neuroimage 2017; 146:71-80. [DOI: 10.1016/j.neuroimage.2016.11.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 11/06/2016] [Accepted: 11/10/2016] [Indexed: 10/20/2022] Open
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27
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Williams IM, Schofield P, Khade N, Abel LA. Divided visual attention: A comparison of patients with multiple sclerosis and controls, assessed with an optokinetic nystagmus suppression task. J Clin Neurosci 2016; 34:187-192. [DOI: 10.1016/j.jocn.2016.06.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 06/22/2016] [Accepted: 06/27/2016] [Indexed: 11/28/2022]
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28
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Orchestrating Proactive and Reactive Mechanisms for Filtering Distracting Information: Brain-Behavior Relationships Revealed by a Mixed-Design fMRI Study. J Neurosci 2016; 36:988-1000. [PMID: 26791226 DOI: 10.1523/jneurosci.2966-15.2016] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Given the information overload often imparted to human cognitive-processing systems, suppression of irrelevant and distracting information is essential for successful behavior. Using a hybrid block/event-related fMRI design, we characterized proactive and reactive brain mechanisms for filtering distracting stimuli. Participants performed a flanker task, discriminating the direction of a target arrow in the presence versus absence of congruent or incongruent flanking distracting arrows during either Pure blocks (distracters always absent) or Mixed blocks (distracters on 80% of trials). Each Mixed block had either 20% or 60% incongruent trials. Activations in the dorsal frontoparietal attention network during Mixed versus Pure blocks evidenced proactive (blockwise) recruitment of a distraction-filtering mechanism. Sustained activations in right middle frontal gyrus during 60% Incongruent blocks correlated positively with behavioral indices of distraction-filtering (slowing when distracters might occur) and negatively with distraction-related behavioral costs (incongruent vs congruent trials), suggesting a role in coordinating proactive filtering of potential distracters. Event-related analyses showed that incongruent trials elicited greater reactive activations in 20% (vs 60%) Incongruent blocks for counteracting distraction and conflict, including in the insula and anterior cingulate. Context-related effects in occipitoparietal cortex consisted of greater target-evoked activations for distracter-absent trials (central-target-only) in Mixed versus Pure blocks, suggesting enhanced attentional engagement. Functional-localizer analyses in V1/V2/V3 revealed less distracter-processing activity in 60% (vs 20%) Incongruent blocks, presumably reflecting tonic suppression by proactive filtering mechanisms. These results delineate brain mechanisms underlying proactive and reactive filtering of distraction and conflict, and how they are orchestrated depending on distraction probability, thereby aiding task performance. Significance statement: Irrelevant stimuli distract people and impair their attentional performance. Here, we studied how the brain deals with distracting stimuli using a hybrid block/event-related fMRI design and a task that varied the probability of the occurrence of such distracting stimuli. The results suggest that when distraction is likely, a region in right frontal cortex proactively implements attentional control mechanisms to help filter out any distracting stimuli that might occur. In contrast, when distracting input occurs infrequently, this region is more reactively engaged to help limit the negative consequences of the distracters on behavioral performance. Our results thus help illuminate how the brain flexibly responds under differing attentional demands to engender effective behavior.
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29
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Martínez M, Valencia M, Vidorreta M, Luis EO, Castellanos G, Villagra F, Fernández‐Seara MA, Pastor MA. Trade-off between frequency and precision during stepping movements: Kinematic and BOLD brain activation patterns. Hum Brain Mapp 2016; 37:1722-37. [PMID: 26857613 PMCID: PMC6867488 DOI: 10.1002/hbm.23131] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 11/17/2015] [Accepted: 01/21/2016] [Indexed: 11/11/2022] Open
Abstract
The central nervous system has the ability to adapt our locomotor pattern to produce a wide range of gait modalities and velocities. In reacting to external pacing stimuli, deviations from an individual preferred cadence provoke a concurrent decrease in accuracy that suggests the existence of a trade-off between frequency and precision; a compromise that could result from the specialization within the control centers of locomotion to ensure a stable transition and optimal adaptation to changing environment. Here, we explore the neural correlates of such adaptive mechanisms by visually guiding a group of healthy subjects to follow three comfortable stepping frequencies while simultaneously recording their BOLD responses and lower limb kinematics with the use of a custom-built treadmill device. In following the visual stimuli, subjects adopt a common pattern of symmetric and anti-phase movements across pace conditions. However, when increasing the stimulus frequency, an improvement in motor performance (precision and stability) was found, which suggests a change in the control mode from reactive to predictive schemes. Brain activity patterns showed similar BOLD responses across pace conditions though significant differences were observed in parietal and cerebellar regions. Neural correlates of stepping precision were found in the insula, cerebellum, dorsolateral pons and inferior olivary nucleus, whereas neural correlates of stepping stability were found in a distributed network, suggesting a transition in the control strategy across the stimulated range of frequencies: from unstable/reactive at lower paces (i.e., stepping stability managed by subcortical regions) to stable/predictive at higher paces (i.e., stability managed by cortical regions). Hum Brain Mapp 37:1722-1737, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Martin Martínez
- Division of Neuroscience, Neuroimaging Laboratory, Centre for Applied Medical Research (CIMA)University of NavarraPamplona31008Spain
| | - Miguel Valencia
- Division of Neuroscience, Neurophysiology Laboratory, Centre for Applied Medical Research (CIMA)University of NavarraPamplona31008Spain
| | - Marta Vidorreta
- Division of Neuroscience, Neuroimaging Laboratory, Centre for Applied Medical Research (CIMA)University of NavarraPamplona31008Spain
| | - Elkin O. Luis
- Division of Neuroscience, Neuroimaging Laboratory, Centre for Applied Medical Research (CIMA)University of NavarraPamplona31008Spain
| | - Gabriel Castellanos
- Division of Neuroscience, Neuroimaging Laboratory, Centre for Applied Medical Research (CIMA)University of NavarraPamplona31008Spain
- Division of ResearchFundación Universitaria de Ciencias de la Salud - Hospital de San José, Bogotá D.C.Colombia
| | - Federico Villagra
- Division of Neuroscience, Neuroimaging Laboratory, Centre for Applied Medical Research (CIMA)University of NavarraPamplona31008Spain
| | - Maria A. Fernández‐Seara
- Division of Neuroscience, Neuroimaging Laboratory, Centre for Applied Medical Research (CIMA)University of NavarraPamplona31008Spain
| | - Maria A. Pastor
- Division of Neuroscience, Neuroimaging Laboratory, Centre for Applied Medical Research (CIMA)University of NavarraPamplona31008Spain
- Centro Investigación Biomédica en Red en Enfermedades Neurodegenerativas (CIBERNED)Instituto De Salud Carlos IIIMadrid28030Spain
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Sprague TC, Saproo S, Serences JT. Visual attention mitigates information loss in small- and large-scale neural codes. Trends Cogn Sci 2015; 19:215-26. [PMID: 25769502 PMCID: PMC4532299 DOI: 10.1016/j.tics.2015.02.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 01/31/2015] [Accepted: 02/06/2015] [Indexed: 01/28/2023]
Abstract
The visual system transforms complex inputs into robust and parsimonious neural codes that efficiently guide behavior. Because neural communication is stochastic, the amount of encoded visual information necessarily decreases with each synapse. This constraint requires that sensory signals are processed in a manner that protects information about relevant stimuli from degradation. Such selective processing--or selective attention--is implemented via several mechanisms, including neural gain and changes in tuning properties. However, examining each of these effects in isolation obscures their joint impact on the fidelity of stimulus feature representations by large-scale population codes. Instead, large-scale activity patterns can be used to reconstruct representations of relevant and irrelevant stimuli, thereby providing a holistic understanding about how neuron-level modulations collectively impact stimulus encoding.
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Affiliation(s)
- Thomas C Sprague
- Neurosciences Graduate Program, University of California San Diego, La Jolla, CA 92093-0109, USA.
| | - Sameer Saproo
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - John T Serences
- Neurosciences Graduate Program, University of California San Diego, La Jolla, CA 92093-0109, USA; Department of Psychology, University of California San Diego, La Jolla, CA 92093-0109, USA.
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