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 Neural tracking of speech mental imagery during rhythmic inner counting

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Lingxi Lu ◽  
Qian Wang ◽  
Jingwei Sheng ◽  
Zhaowei Liu ◽  
Lang Qin ◽  
...  
Keyword(s):  
Mental Imagery ◽  
Auditory Perception ◽  
Processing Time ◽  
Human Subjects ◽  
Inferior Frontal Gyrus ◽  
Temporal Cortex ◽  
Brain Regions ◽  
Neural Processing ◽  
Top Down ◽  
Rate Frequency

The subjective inner experience of mental imagery is among the most ubiquitous human experiences in daily life. Elucidating the neural implementation underpinning the dynamic construction of mental imagery is critical to understanding high-order cognitive function in the human brain. Here, we applied a frequency-tagging method to isolate the top-down process of speech mental imagery from bottom-up sensory-driven activities and concurrently tracked the neural processing time scales corresponding to the two processes in human subjects. Notably, by estimating the source of the magnetoencephalography (MEG) signals, we identified isolated brain networks activated at the imagery-rate frequency. In contrast, more extensive brain regions in the auditory temporal cortex were activated at the stimulus-rate frequency. Furthermore, intracranial stereotactic electroencephalogram (sEEG) evidence confirmed the participation of the inferior frontal gyrus in generating speech mental imagery. Our results indicate that a disassociated neural network underlies the dynamic construction of speech mental imagery independent of auditory perception.

Ontogeny of the Neural Language Network

2017 ◽  
Author(s):  
Angela D. Friederici ◽  
Noam Chomsky
Keyword(s):  
Language Acquisition ◽  
Language Processing ◽  
Inferior Frontal Gyrus ◽  
Temporal Cortex ◽  
Superior Temporal Gyrus ◽  
Brain Structures ◽  
Relevant Information ◽  
Brain Regions ◽  
Language Performance ◽  
Language Network

This chapter reviews the neural underpinning of normal language acquisition and asks not only at which age certain milestones in language acquisition are achieved, but moreover to what extent is this achievement dependent on the maturation of particular brain structures. In our recent model, the neural basis of the developing language system is described to reflect two major phases. The available data provide consistent evidence that very early on an infant is able to extract language-relevant information from the acoustic input. This first phase covers the first three years of life when language processing is largely input-driven and supported by the temporal cortex and the ventral part of the network. A second phase extends beyond age 3, when top-down processes come into play, and the left inferior frontal cortex and the dorsal part of the language network are recruited to a larger extent. Development towards full language performance beyond age 3 is dependent on maturational changes in the gray and white matter. An increased language ability is correlated with an increase in structural and functional connectivity between language-related brain regions in the left hemisphere, the inferior frontal gyrus and the posterior superior temporal gyrus/superior temporal sulcus.

scholarly journals Top-down and bottom-up influences on the left ventral occipito-temporal cortex during visual word recognition: An analysis of effective connectivity

2013 ◽  
Vol 35 (4) ◽  
pp. 1668-1680 ◽  
Author(s):  
Matthias Schurz ◽  
Martin Kronbichler ◽  
Julia Crone ◽  
Fabio Richlan ◽  
Johannes Klackl ◽  
...  
Keyword(s):  
Word Recognition ◽  
Visual Word Recognition ◽  
Effective Connectivity ◽  
Temporal Cortex ◽  
Visual Word ◽  
Top Down ◽  
Bottom Up

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 On the Role of Bilateral Brain Hypofunction and Abnormal Lateralization of Cortical Information Flow as Neural Underpinnings of Conventional Metaphor Processing Impairment in Schizophrenia: An fMRI and EEG Study

2021 ◽  
Author(s):  
Przemysław Adamczyk ◽  
Martin Jáni ◽  
Tomasz S. Ligeza ◽  
Olga Płonka ◽  
Piotr Błądziński ◽  
...  
Keyword(s):  
Information Flow ◽  
Language Processing ◽  
Time Course ◽  
Figurative Language ◽  
Neural Circuits ◽  
Effective Connectivity ◽  
Brain Regions ◽  
Blood Oxygenation ◽  
Control Group ◽  
Metaphor Processing

AbstractFigurative language processing (e.g. metaphors) is commonly impaired in schizophrenia. In the present study, we investigated the neural activity and propagation of information within neural circuits related to the figurative speech, as a neural substrate of impaired conventional metaphor processing in schizophrenia. The study included 30 schizophrenia outpatients and 30 healthy controls, all of whom were assessed with a functional Magnetic Resonance Imaging (fMRI) and electroencephalography (EEG) punchline-based metaphor comprehension task including literal (neutral), figurative (metaphorical) and nonsense (absurd) endings. The blood oxygenation level-dependent signal was recorded with 3T MRI scanner and direction and strength of cortical information flow in the time course of task processing was estimated with a 64-channel EEG input for directed transfer function. The presented results revealed that the behavioral manifestation of impaired figurative language in schizophrenia is related to the hypofunction in the bilateral fronto-temporo-parietal brain regions (fMRI) and various differences in effective connectivity in the fronto-temporo-parietal circuit (EEG). Schizophrenia outpatients showed an abnormal pattern of connectivity during metaphor processing which was related to bilateral (but more pronounced at the left hemisphere) hypoactivation of the brain. Moreover, we found reversed lateralization patterns, i.e. a rightward-shifted pattern during metaphor processing in schizophrenia compared to the control group. In conclusion, the presented findings revealed that the impairment of the conventional metaphor processing in schizophrenia is related to the bilateral brain hypofunction, which supports the evidence on reversed lateralization of the language neural network and the existence of compensatory recruitment of alternative neural circuits in schizophrenia.

scholarly journals Auditory attention alterations in migraine: a behavioral and MEG/EEG study

2019 ◽  
Author(s):  
Rémy Masson ◽  
Yohana Lévêque ◽  
Geneviève Demarquay ◽  
Hesham ElShafei ◽  
Lesly Fornoni ◽  
...  
Keyword(s):  
Event Related Potentials ◽  
Orienting Response ◽  
List Type ◽  
Top Down ◽  
Attention Task ◽  
Bottom Up ◽  
Attentional Processes ◽  
Related Potentials ◽  
The Right ◽  
Task Irrelevant

AbstractObjectivesTo evaluate alterations of top-down and/or bottom-up attention in migraine and their cortical underpinnings.Methods19 migraineurs between attacks and 19 matched control participants performed a task evaluating jointly top-down and bottom-up attention, using visually-cued target sounds and unexpected task-irrelevant distracting sounds. Behavioral responses and MEG/EEG were recorded. Event-related potentials and fields (ERPs/ERFs) were processed and source reconstruction was applied to ERFs.ResultsAt the behavioral level, neither top-down nor bottom-up attentional processes appeared to be altered in migraine. However, migraineurs presented heightened evoked responses following distracting sounds (orienting component of the N1 and Re-Orienting Negativity, RON) and following target sounds (orienting component of the N1), concomitant to an increased recruitment of the right temporo-parietal junction. They also displayed an increased effect of the cue informational value on target processing resulting in the elicitation of a negative difference (Nd).ConclusionsMigraineurs appear to display increased bottom-up orienting response to all incoming sounds, and an enhanced recruitment of top-down attention.SignificanceThe interictal state in migraine is characterized by an exacerbation of the orienting response to attended and unattended sounds. These attentional alterations might participate to the peculiar vulnerability of the migraine brain to all incoming stimuli.HighlightsMigraineurs performed as well as healthy participants in an attention task.However, EEG markers of both bottom-up and top-down attention are increased.Migraine is also associated with a facilitated recruitment of the right temporo-parietal junction.

scholarly journals The Human Intraparietal Sulcus Modulates Task-Evoked Functional Connectivity

2019 ◽  
Vol 30 (3) ◽  
pp. 875-887
Author(s):  
Kai Hwang ◽  
James M Shine ◽  
Dillan Cellier ◽  
Mark D’Esposito
Keyword(s):  
Functional Connectivity ◽  
Temporal Cortex ◽  
Brain Regions ◽  
Intraparietal Sulcus ◽  
Top Down ◽  
Adaptive Communication ◽  
Wide Range ◽  
Functional Connectivity Strength ◽  
Ventral Temporal Cortex ◽  
Cortical Regions

Abstract Past studies have demonstrated that flexible interactions between brain regions support a wide range of goal-directed behaviors. However, the neural mechanisms that underlie adaptive communication between brain regions are not well understood. In this study, we combined theta-burst transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging to investigate the sources of top-down biasing signals that influence task-evoked functional connectivity. Subjects viewed sequences of images of faces and buildings and were required to detect repetitions (2-back vs. 1-back) of the attended stimuli category (faces or buildings). We found that functional connectivity between ventral temporal cortex and the primary visual cortex (VC) increased during processing of task-relevant stimuli, especially during higher memory loads. Furthermore, the strength of functional connectivity was greater for correct trials. Increases in task-evoked functional connectivity strength were correlated with increases in activity in multiple frontal, parietal, and subcortical (caudate and thalamus) regions. Finally, we found that TMS to superior intraparietal sulcus (IPS), but not to primary somatosensory cortex, decreased task-specific modulation in connectivity patterns between the primary VC and the parahippocampal place area. These findings demonstrate that the human IPS is a source of top-down biasing signals that modulate task-evoked functional connectivity among task-relevant cortical regions.

Multisensory objects and the orienting of spatial attention

2012 ◽  
Vol 25 (0) ◽  
pp. 90
Author(s):  
Serena Mastroberardino ◽  
Valerio Santangelo ◽  
Emiliano Macaluso
Keyword(s):  
Spatial Attention ◽  
Functional Imaging ◽  
Inferior Frontal Gyrus ◽  
Frontal Eye Fields ◽  
Imaging Data ◽  
Top Down ◽  
Task Constraints ◽  
Task Requirements ◽  
Visual Element ◽  
Task Irrelevant

The presentation of an auditory stimulus semantically-congruent with a visual element of a multi-objects display can enhance processing of that element. Here we used multisensory objects (MO) as non-informative cues in a spatial cueing paradigm, aiming to directly assess the interplay between MO integration and spatial attention. We presented two pictures (e.g., left — dog, right — cat) plus a central sound (e.g., a dog’s bark) that defined the location of the MO (left, in this example). This was followed by a target (a Gabor patch) either at the MO location or in the opposite hemifield. Subjects discriminated the orientation of the Gabor, while ignoring all task-irrelevant pictures and sounds. Further, we manipulated the task requirements including ‘easy’ or ‘difficult’ discrimination (Gabor tilt = ±5° or ±10°), and by presenting either a single unilateral Gabor (Exp. 1, ‘low’ competition) or two Gabors bilaterally (red and blue, with the target now defined by colour; Exp. 2, ‘high’ competition). Functional imaging data revealed activation of frontal regions when the target was presented on the opposite side of the MO (invalid trials). The frontal eye-fields activated irrespective of task requirements, while the inferior frontal gyrus activated only when the MO-cue was invalid and competition was low (Exp. 1 only). These findings show that MOs automatically affect the distribution of spatial attention, and that re-orienting operations on invalid trials activate dorsal and ventral frontal areas depending on top-down task constraints. Overall, the results are consistent with the hypothesis linking the integration of multisensory objects with biases of spatial attention.

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.

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