scholarly journals Laminar specific fMRI reveals directed interactions in distributed networks during language processing

2019 ◽  
Vol 116 (42) ◽  
pp. 21185-21190 ◽  
Author(s):  
Daniel Sharoh ◽  
Tim van Mourik ◽  
Lauren J. Bains ◽  
Katrien Segaert ◽  
Kirsten Weber ◽  
...  
Keyword(s):  
Language Processing ◽  
Word Reading ◽  
Brain Regions ◽  
Distributed Networks ◽  
Signal Pathways ◽  
Bold Signal ◽  
Bold Response ◽  
Top Down ◽  
Bottom Up ◽  
Connectivity Patterns

Interactions between top-down and bottom-up information streams are integral to brain function but challenging to measure noninvasively. Laminar resolution, functional MRI (lfMRI) is sensitive to depth-dependent properties of the blood oxygen level-dependent (BOLD) response, which can be potentially related to top-down and bottom-up signal contributions. In this work, we used lfMRI to dissociate the top-down and bottom-up signal contributions to the left occipitotemporal sulcus (LOTS) during word reading. We further demonstrate that laminar resolution measurements could be used to identify condition-specific distributed networks on the basis of whole-brain connectivity patterns specific to the depth-dependent BOLD signal. The networks corresponded to top-down and bottom-up signal pathways targeting the LOTS during word reading. We show that reading increased the top-down BOLD signal observed in the deep layers of the LOTS and that this signal uniquely related to the BOLD response in other language-critical regions. These results demonstrate that lfMRI can reveal important patterns of activation that are obscured at standard resolution. In addition to differences in activation strength as a function of depth, we also show meaningful differences in the interaction between signals originating from different depths both within a region and with the rest of the brain. We thus show that lfMRI allows the noninvasive measurement of directed interaction between brain regions and is capable of resolving different connectivity patterns at submillimeter resolution, something previously considered to be exclusively in the domain of invasive recordings.

scholarly journals Laminar Specific fMRI Reveals Directed Interactions in Distributed Networks During Language Processing

2019 ◽  
Author(s):  
Daniel Sharoh ◽  
Tim van Mourik ◽  
Lauren J. Bains ◽  
Katrien Segaert ◽  
Kirsten Weber ◽  
...  
Keyword(s):  
Language Processing ◽  
Word Reading ◽  
Distributed Networks ◽  
Cognitive Tasks ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Top Down ◽  
Noninvasive Technique ◽  
Whole Brain ◽  
Critical Regions

AbstractLaminar resolution, functional magnetic resonance imaging (lfMRI) is a noninvasive technique with the potential to distinguish top-down and bottom-up signal contributions on the basis of laminar specific interactions between distal regions. Hitherto, lfMRI could not be demonstrated for either whole-brain distributed networks or for complex cognitive tasks. We show that lfMRI can reveal whole-brain directed networks during word reading. We identify distinct, language critical regions based on their association with the top-down signal stream and establish lfMRI for the noninvasive assessment of directed connectivity during task performance.

scholarly journals Developmental Increase in Top–Down and Bottom–Up Processing in a Phonological Task: An Effective Connectivity, fMRI Study

2009 ◽  
Vol 21 (6) ◽  
pp. 1135-1145 ◽  
Author(s):  
Tali Bitan ◽  
Jimmy Cheon ◽  
Dong Lu ◽  
Douglas D. Burman ◽  
James R. Booth
Keyword(s):  
Language Processing ◽  
Effective Connectivity ◽  
Inferior Frontal Gyrus ◽  
Temporal Cortex ◽  
Control Process ◽  
Brain Regions ◽  
Top Down ◽  
Bottom Up ◽  
Age Related ◽  
Task Irrelevant

We examined age-related changes in the interactions among brain regions in children performing rhyming judgments on visually presented words. The difficulty of the task was manipulated by including a conflict between task-relevant (phonological) information and task-irrelevant (orthographic) information. The conflicting conditions included pairs of words that rhyme despite having different spelling patterns (jazz–has), or words that do not rhyme despite having similar spelling patterns (pint–mint). These were contrasted with nonconflicting pairs that have similar orthography and phonology (dime–lime) or different orthography and phonology (press–list). Using fMRI, we examined effective connectivity among five left hemisphere regions of interest: fusiform gyrus (FG), inferior frontal gyrus (IFG), intraparietal sulcus (IPS), lateral temporal cortex (LTC), and medial frontal gyrus (MeFG). Age-related increases were observed in the influence of the IFG and FG on the LTC, but only in conflicting conditions. These results reflect a developmental increase in the convergence of bottom–up and top–down information on the LTC. In older children, top–down control process may selectively enhance the sensitivity of the LTC to bottom–up information from the FG. This may be evident especially in situations that require selective enhancement of task-relevant versus task-irrelevant information. Altogether these results provide a direct evidence for a developmental increase in top–down control processes in language processing. The developmental increase in bottom–up processing may be secondary to the enhancement of top–down processes.

Visual Attention With Cognitive Aging

2019 ◽  
Author(s):  
David J. Madden ◽  
Zachary A. Monge
Keyword(s):  
Visual Attention ◽  
Visual Processing ◽  
Cognitive Aging ◽  
Brain Regions ◽  
Object Identification ◽  
Features Selection ◽  
Top Down ◽  
Bottom Up ◽  
Attentional Functioning ◽  
Age Related

Age-related decline occurs in several aspects of fluid, speed-dependent cognition, particularly those related to attention. Empirical research on visual attention has determined that attention-related effects occur across a range of information processing components, including the sensory registration of features, selection of information from working memory, controlling motor responses, and coordinating multiple perceptual and cognitive tasks. Thus, attention is a multifaceted construct that is relevant at virtually all stages of object identification. A fundamental theme of attentional functioning is the interaction between the bottom-up salience of visual features and top-down allocation of processing based on the observer’s goals. An underlying age-related slowing is prominent throughout visual processing stages, which in turn contributes to age-related decline in some aspects of attention, such as the inhibition of irrelevant information and the coordination of multiple tasks. However, some age-related preservation of attentional functioning is also evident, particularly the top-down allocation of attention. Neuroimaging research has identified networks of frontal and parietal brain regions relevant for top-down and bottom-up attentional processing. Disconnection among these networks contributes to an age-related decline in attention, but preservation and perhaps even increased patterns of functional brain activation and connectivity also contribute to preserved attentional functioning.

scholarly journals Spared bottom-up but impaired top-down interactive effects during naturalistic language processing in schizophrenia: evidence from the visual-world paradigm

2018 ◽  
Vol 49 (08) ◽  
pp. 1335-1345 ◽  
Author(s):  
Hugh Rabagliati ◽  
Nathaniel Delaney-Busch ◽  
Jesse Snedeker ◽  
Gina Kuperberg
Keyword(s):  
Eye Tracking ◽  
Real Time ◽  
Language Processing ◽  
Interactive Effects ◽  
Top Down ◽  
Visual World ◽  
Bottom Up ◽  
Lexical Representations ◽  
Spoken Language Processing ◽  
Level Information

AbstractBackgroundPeople with schizophrenia process language in unusual ways, but the causes of these abnormalities are unclear. In particular, it has proven difficult to empirically disentangle explanations based on impairments in the top-down processing of higher level information from those based on the bottom-up processing of lower level information.MethodsTo distinguish these accounts, we used visual-world eye tracking, a paradigm that measures spoken language processing during real-world interactions. Participants listened to and then acted out syntactically ambiguous spoken instructions (e.g. ‘tickle the frog with the feather’, which could either specify how to tickle a frog, or which frog to tickle). We contrasted how 24 people with schizophrenia and 24 demographically matched controls used two types of lower level information (prosody and lexical representations) and two types of higher level information (pragmatic and discourse-level representations) to resolve the ambiguous meanings of these instructions. Eye tracking allowed us to assess how participants arrived at their interpretation in real time, while recordings of participants’ actions measured how they ultimately interpreted the instructions.ResultsWe found a striking dissociation in participants’ eye movements: the two groups were similarly adept at using lower level information to immediately constrain their interpretations of the instructions, but only controls showed evidence of fast top-down use of higher level information. People with schizophrenia, nonetheless, did eventually reach the same interpretations as controls.ConclusionsThese data suggest that language abnormalities in schizophrenia partially result from a failure to use higher level information in a top-down fashion, to constrain the interpretation of language as it unfolds in real time.

Top-down and bottom-up fMRI BOLD signal changes in response to selective attention during mechanical pressure pain

2005 ◽  
Vol 6 (3) ◽  
pp. S6
Author(s):  
T. Papageorgiou ◽  
E. Jackson ◽  
K. Anderson ◽  
S. Mahankali ◽  
C. Cleeland
Keyword(s):  
Selective Attention ◽  
Bold Signal ◽  
Top Down ◽  
Mechanical Pressure ◽  
Bottom Up ◽  
Pressure Pain ◽  
Signal Changes

scholarly journals Bottom-up Retinotopic Organization Supports Top-down Mental Imagery

2013 ◽  
Vol 7 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Ruey-Song Huang ◽  
Martin I. Sereno
Keyword(s):  
Premotor Cortex ◽  
Brain Regions ◽  
Retrosplenial Cortex ◽  
Wide Field ◽  
Top Down ◽  
Bottom Up ◽  
Retinotopic Maps ◽  
Upper Visual Field ◽  
Retinotopic Organization ◽  
High Level

Finding a path between locations is a routine task in daily life. Mental navigation is often used to plan a route to a destination that is not visible from the current location. We first used functional magnetic resonance imaging (fMRI) and surface-based averaging methods to find high-level brain regions involved in imagined navigation between locations in a building very familiar to each participant. This revealed a mental navigation network that includes the precuneus, retrosplenial cortex (RSC), parahippocampal place area (PPA), occipital place area (OPA), supplementary motor area (SMA), premotor cortex, and areas along the medial and anterior intraparietal sulcus. We then visualized retinotopic maps in the entire cortex using wide-field, natural scene stimuli in a separate set of fMRI experiments. This revealed five distinct visual streams or ‘fingers’ that extend anteriorly into middle temporal, superior parietal, medial parietal, retrosplenial and ventral occipitotemporal cortex. By using spherical morphing to overlap these two data sets, we showed that the mental navigation network primarily occupies areas that also contain retinotopic maps. Specifically, scene-selective regions RSC, PPA and OPA have a common emphasis on the far periphery of the upper visual field. These results suggest that bottom-up retinotopic organization may help to efficiently encode scene and location information in an eye-centered reference frame for top-down, internally generated mental navigation. This study pushes the border of visual cortex further anterior than was initially expected.

scholarly journals The role of the mirror neuron system in bottom-up and top-down perception of human action

2021 ◽  
Author(s):  
Lucy M. J. McGarry
Keyword(s):  
Mirror Neuron System ◽  
Mirror Neuron ◽  
Human Action ◽  
Brain Regions ◽  
Emotional Understanding ◽  
Top Down ◽  
Bottom Up ◽  
Neuron System ◽  
Movement Simulation

When we see or hear another person execute an action, we tend to automatically simulate that action. Evidence for this has been found at the neural level, specifically in parietal and premotor brain regions referred to collectively as the mirror neuron system (MNS), and the behavioural level, through an observer's tendency to mimic observed movements. This simulation process may play a key role in emotional understanding. It is currently unclear the extent to which the MNS is driven by bottom-up automatic recruitment of movement simulation, or by top-down (task driven) mechanisms. The present dissertation examines the role of the MNS in the bottom-up and top-down processing of action in the auditory and visual modalities, in response to emotional and neutral movements performed by humans. Study 1 used EEG to demonstrate that the MNS is affected by bottom-up manipulations of modality, and shows that the MNS is activated to a greater extent towards multi-modal versus unimodal sensory input. Study 2 employed an EEG paradigm utilizing a top-down emotion judgment manipulation. It was found that the left STG, part of the extended MNS, is affected by top-down manipulations of emotionality, but there were no areas in classical MNS that met the statistical threshold to be affected by top-down forces. Study 3 employed an fMRi paradigm combining bottom-up and top-down manipulations. It was found that the classical MNS was strongly affected by bottom-up differences in emotionality and modality, and minimally affected by the top-down manipulation. Together, the three studies presented in this dissertation support the premise that the classical mirror neuron system is primarily automatic. More research is needed to determine whether top-down manipulations can uniquely engage the MNS.

scholarly journals The role of the mirror neuron system in bottom-up and top-down perception of human action

2021 ◽  
Author(s):  
Lucy M. J. McGarry
Keyword(s):  
Mirror Neuron System ◽  
Mirror Neuron ◽  
Human Action ◽  
Brain Regions ◽  
Emotional Understanding ◽  
Top Down ◽  
Bottom Up ◽  
Neuron System ◽  
Movement Simulation

When we see or hear another person execute an action, we tend to automatically simulate that action. Evidence for this has been found at the neural level, specifically in parietal and premotor brain regions referred to collectively as the mirror neuron system (MNS), and the behavioural level, through an observer's tendency to mimic observed movements. This simulation process may play a key role in emotional understanding. It is currently unclear the extent to which the MNS is driven by bottom-up automatic recruitment of movement simulation, or by top-down (task driven) mechanisms. The present dissertation examines the role of the MNS in the bottom-up and top-down processing of action in the auditory and visual modalities, in response to emotional and neutral movements performed by humans. Study 1 used EEG to demonstrate that the MNS is affected by bottom-up manipulations of modality, and shows that the MNS is activated to a greater extent towards multi-modal versus unimodal sensory input. Study 2 employed an EEG paradigm utilizing a top-down emotion judgment manipulation. It was found that the left STG, part of the extended MNS, is affected by top-down manipulations of emotionality, but there were no areas in classical MNS that met the statistical threshold to be affected by top-down forces. Study 3 employed an fMRi paradigm combining bottom-up and top-down manipulations. It was found that the classical MNS was strongly affected by bottom-up differences in emotionality and modality, and minimally affected by the top-down manipulation. Together, the three studies presented in this dissertation support the premise that the classical mirror neuron system is primarily automatic. More research is needed to determine whether top-down manipulations can uniquely engage the MNS.

The Neural Basis of Successful Word Reading in Aphasia

2018 ◽  
Vol 30 (4) ◽  
pp. 514-525 ◽  
Author(s):  
Sara B. Pillay ◽  
William L. Gross ◽  
William W. Graves ◽  
Colin Humphries ◽  
Diane S. Book ◽  
...  
Keyword(s):  
Word Reading ◽  
Functional Neuroimaging ◽  
Semantic Network ◽  
Brain Activity ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Angular Gyrus ◽  
Bold Signal ◽  
Neural Basis ◽  
Successful Performance

Understanding the neural basis of recovery from stroke is a major research goal. Many functional neuroimaging studies have identified changes in brain activity in people with aphasia, but it is unclear whether these changes truly support successful performance or merely reflect increased task difficulty. We addressed this problem by examining differences in brain activity associated with correct and incorrect responses on an overt reading task. On the basis of previous proposals that semantic retrieval can assist pronunciation of written words, we hypothesized that recruitment of semantic areas would be greater on successful trials. Participants were 21 patients with left-hemisphere stroke with phonologic retrieval deficits. They read words aloud during an event-related fMRI paradigm. BOLD signals obtained during correct and incorrect trials were contrasted to highlight brain activity specific to successful trials. Successful word reading was associated with higher BOLD signal in the left angular gyrus. In contrast, BOLD signal in bilateral posterior inferior frontal cortex, SMA, and anterior cingulate cortex was greater on incorrect trials. These data show for the first time the brain regions where neural activity is correlated specifically with successful performance in people with aphasia. The angular gyrus is a key node in the semantic network, consistent with the hypothesis that additional recruitment of the semantic system contributes to successful word production when phonologic retrieval is impaired. Higher activity in other brain regions during incorrect trials likely reflects secondary engagement of attention, working memory, and error monitoring processes when phonologic retrieval is unsuccessful.

scholarly journals Top-down versus bottom-up theories of phonological acquisition: A big data approach

2017 ◽  
Author(s):  
Christina Bergmann ◽  
Sho Tsuji ◽  
Alejandrina Cristia
Keyword(s):  
Language Processing ◽  
Word Meaning ◽  
Word Segmentation ◽  
Phonological Development ◽  
Top Down ◽  
Bottom Up ◽  
Phonological Categories ◽  
Word Forms ◽  
Meta Analyses ◽  
Infant Language

Recent work has made available a number of standardized meta-analyses bearing on various aspects of infant language processing. We utilize data from two such meta-analyses (discrimination of vowel contrasts and word segmentation, i.e., recognition of word forms extracted from running speech) to assess whether the published body of empirical evidence supports a bottom-up versus a top-down theory of early phonological development by leveling the power of results from thousands of infants. We predicted that if infants can rely purely on auditory experience to develop their phonological categories, then vowel discrimination and word segmentation should develop in parallel, with the latter being potentially lagged compared to the former. However, if infants crucially rely on word form information to build their phonological categories, then development at the word level must precede the acquisition of native sound categories. Our results do not support the latter prediction. We discuss potential implications and limitations, most saliently that word forms are only one top-down level proposed to affect phonological development, with other proposals suggesting that top-down pressures emerge from lexical (i.e., word-meaning pairs) development. This investigation also highlights general procedures by which standardized meta-analyses may be reused to answer theoretical questions spanning across phenomena.

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