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Articles 31 - 54 of 54
Full-Text Articles in Neurosciences
Encoding Of Sensory Prediction Errors In The Human Cerebellum., John Schlerf, Richard B Ivry, Jörn Diedrichsen
Encoding Of Sensory Prediction Errors In The Human Cerebellum., John Schlerf, Richard B Ivry, Jörn Diedrichsen
Brain and Mind Institute Researchers' Publications
A central tenet of motor neuroscience is that the cerebellum learns from sensory prediction errors. Surprisingly, neuroimaging studies have not revealed definitive signatures of error processing in the cerebellum. Furthermore, neurophysiologic studies suggest an asymmetry, such that the cerebellum may encode errors arising from unexpected sensory events, but not errors reflecting the omission of expected stimuli. We conducted an imaging study to compare the cerebellar response to these two types of errors. Participants made fast out-and-back reaching movements, aiming either for an object that delivered a force pulse if intersected or for a gap between two objects, either of which …
Distinct Patterns Of Functional And Effective Connectivity Between Perirhinal Cortex And Other Cortical Regions In Recognition Memory And Perceptual Discrimination., Edward B O'Neil, Andrea B Protzner, Cornelia Mccormick, D Adam Mclean, Jordan Poppenk, Anthony D Cate, Stefan Köhler
Distinct Patterns Of Functional And Effective Connectivity Between Perirhinal Cortex And Other Cortical Regions In Recognition Memory And Perceptual Discrimination., Edward B O'Neil, Andrea B Protzner, Cornelia Mccormick, D Adam Mclean, Jordan Poppenk, Anthony D Cate, Stefan Köhler
Brain and Mind Institute Researchers' Publications
Traditionally, the medial temporal lobe (MTL) is thought to be dedicated to declarative memory. Recent evidence challenges this view, suggesting that perirhinal cortex (PrC), which interfaces the MTL with the ventral visual pathway, supports highly integrated object representations in recognition memory and perceptual discrimination. Even with comparable representational demands, perceptual and memory tasks differ in numerous task demands and the subjective experience they evoke. Here, we tested whether such differences are reflected in distinct patterns of connectivity between PrC and other cortical regions, including differential involvement of prefrontal control processes. We examined functional magnetic resonance imaging data for closely matched …
The Effect Of Dopamine Therapy On Ventral And Dorsal Striatum-Mediated Cognition In Parkinson's Disease: Support From Functional Mri., Penny A Macdonald, Alex A Macdonald, Ken N Seergobin, Ruzbeh Tamjeedi, Hooman Ganjavi, Jean-Sebastien Provost, Oury Monchi
The Effect Of Dopamine Therapy On Ventral And Dorsal Striatum-Mediated Cognition In Parkinson's Disease: Support From Functional Mri., Penny A Macdonald, Alex A Macdonald, Ken N Seergobin, Ruzbeh Tamjeedi, Hooman Ganjavi, Jean-Sebastien Provost, Oury Monchi
Brain and Mind Institute Researchers' Publications
The central aim of our study was to elucidate functions mediated by the ventral and dorsal striatum, respectively, to better understand the cognitive effects of dopamine replacement in Parkinson's disease. We proposed that the ventral striatum underlies general learning of stimulus associations, whereas the dorsal striatum promotes integration of various influences on selecting. In Parkinson's disease, dopamine depletion is substantially less notable in the ventral relative to the dorsal striatum, and therefore greater improvements are expected for dorsal striatum-mediated functions with dopamine replacement. Using a simple selection task, we found that dopamine replacement impaired encoding and facilitation of consistent stimulus-stimulus …
Negative Associations Between Corpus Callosum Midsagittal Area And Iq In A Representative Sample Of Healthy Children And Adolescents., Hooman Ganjavi, John D Lewis, Pierre Bellec, Penny A Macdonald, Deborah P Waber, Alan C Evans, Sherif Karama, The Brain Development Cooperative Group
Negative Associations Between Corpus Callosum Midsagittal Area And Iq In A Representative Sample Of Healthy Children And Adolescents., Hooman Ganjavi, John D Lewis, Pierre Bellec, Penny A Macdonald, Deborah P Waber, Alan C Evans, Sherif Karama, The Brain Development Cooperative Group
Brain and Mind Institute Researchers' Publications
Documented associations between corpus callosum size and cognitive ability have heretofore been inconsistent potentially owing to differences in sample characteristics, differing methodologies in measuring CC size, or the use of absolute versus relative measures. We investigated the relationship between CC size and intelligence quotient (IQ) in the NIH MRI Study of Normal Brain Development sample, a large cohort of healthy children and adolescents (aged six to 18, n = 198) recruited to be representative of the US population. CC midsagittal area was measured using an automated system that partitioned the CC into 25 subregions. IQ was measured using the Wechsler …
Multiple Mechanisms Of Consciousness: The Neural Correlates Of Emotional Awareness., Jayna M Amting, Steven G Greening, Derek G V Mitchell
Multiple Mechanisms Of Consciousness: The Neural Correlates Of Emotional Awareness., Jayna M Amting, Steven G Greening, Derek G V Mitchell
Brain and Mind Institute Researchers' Publications
Emotional stimuli, including facial expressions, are thought to gain rapid and privileged access to processing resources in the brain. Despite this access, we are conscious of only a fraction of the myriad of emotion-related cues we face everyday. It remains unclear, therefore, what the relationship is between activity in neural regions associated with emotional representation and the phenomenological experience of emotional awareness. We used functional magnetic resonance imaging and binocular rivalry to delineate the neural correlates of awareness of conflicting emotional expressions in humans. Behaviorally, fearful faces were significantly more likely to be perceived than disgusted or neutral faces. Functionally, …
Intracranial Eeg Reveals A Time- And Frequency-Specific Role For The Right Inferior Frontal Gyrus And Primary Motor Cortex In Stopping Initiated Responses, Nicole Swann, Nitin Tandon, Ryan Canolty, Timothy M Ellmore, Linda K Mcevoy, Stephen Dreyer, Michael Disano, Adam R Aron
Intracranial Eeg Reveals A Time- And Frequency-Specific Role For The Right Inferior Frontal Gyrus And Primary Motor Cortex In Stopping Initiated Responses, Nicole Swann, Nitin Tandon, Ryan Canolty, Timothy M Ellmore, Linda K Mcevoy, Stephen Dreyer, Michael Disano, Adam R Aron
Faculty, Staff and Student Publications
Inappropriate response tendencies may be stopped via a specific fronto/basal ganglia/primary motor cortical network. We sought to characterize the functional role of two regions in this putative stopping network, the right inferior frontal gyrus (IFG) and the primary motor cortex (M1), using electocorticography from subdural electrodes in four patients while they performed a stop-signal task. On each trial, a motor response was initiated, and on a minority of trials a stop signal instructed the patient to try to stop the response. For each patient, there was a greater right IFG response in the beta frequency band ( approximately 16 Hz) …
Adapting To Dynamic Stimulus-Response Values: Differential Contributions Of Inferior Frontal, Dorsomedial, And Dorsolateral Regions Of Prefrontal Cortex To Decision Making., Derek G V Mitchell, Qian Luo, Shelley B Avny, Tomasz Kasprzycki, Karanvir Gupta, Gang Chen, Elizabeth C Finger, R James R Blair
Adapting To Dynamic Stimulus-Response Values: Differential Contributions Of Inferior Frontal, Dorsomedial, And Dorsolateral Regions Of Prefrontal Cortex To Decision Making., Derek G V Mitchell, Qian Luo, Shelley B Avny, Tomasz Kasprzycki, Karanvir Gupta, Gang Chen, Elizabeth C Finger, R James R Blair
Brain and Mind Institute Researchers' Publications
Dorsomedial prefrontal cortex (dmPFC), dorsolateral prefrontal cortex (dlPFC), and inferior frontal gyrus (IFG) have all been implicated in resolving decision conflict whether this conflict is generated by having to select between responses of similar value or by making selections following a reversal in reinforcement contingencies. However, work distinguishing their individual functional contributions remains preliminary. We used functional magnetic resonance imaging to delineate the functional role of these systems with regard to both forms of decision conflict. Within dmPFC and dlPFC, blood oxygen level-dependent responses increased in response to decision conflict regardless of whether the conflict occurred in the context of …
Illusory Vowels Resulting From Perceptual Continuity: A Functional Magnetic Resonance Imaging Study, Antje Heinrich, Robert P Carlyon, Matthew H Davis, Ingrid Johnsrude
Illusory Vowels Resulting From Perceptual Continuity: A Functional Magnetic Resonance Imaging Study, Antje Heinrich, Robert P Carlyon, Matthew H Davis, Ingrid Johnsrude
Brain and Mind Institute Researchers' Publications
We used functional magnetic resonance imaging to study the neural processing of vowels whose perception depends on the continuity illusion. Participants heard sequences of two-formant vowels under a number of listening conditions. In the "vowel conditions," both formants were always present simultaneously and the stimuli were perceived as speech-like. Contrasted with a range of nonspeech sounds, these vowels elicited activity in the posterior middle temporal gyrus (MTG) and superior temporal sulcus (STS). When the two formants alternated in time, the "speech-likeness" of the sounds was reduced. It could be partially restored by filling the silent gaps in each formant with …
Freesurfer-Initiated Fully-Automated Subcortical Brain Segmentation In Mri Using Large Deformation Diffeomorphic Metric Mapping., Ali R Khan, Lei Wang, Mirza Faisal Beg
Freesurfer-Initiated Fully-Automated Subcortical Brain Segmentation In Mri Using Large Deformation Diffeomorphic Metric Mapping., Ali R Khan, Lei Wang, Mirza Faisal Beg
Brain and Mind Institute Researchers' Publications
Fully-automated brain segmentation methods have not been widely adopted for clinical use because of issues related to reliability, accuracy, and limitations of delineation protocol. By combining the probabilistic-based FreeSurfer (FS) method with the Large Deformation Diffeomorphic Metric Mapping (LDDMM)-based label-propagation method, we are able to increase reliability and accuracy, and allow for flexibility in template choice. Our method uses the automated FreeSurfer subcortical labeling to provide a coarse-to-fine introduction of information in the LDDMM template-based segmentation resulting in a fully-automated subcortical brain segmentation method (FS+LDDMM). One major advantage of the FS+LDDMM-based approach is that the automatically generated segmentations generated are …
Functional Imaging Of The Auditory Processing Applied To Speech Sounds, Roy D Patterson, Ingrid Johnsrude
Functional Imaging Of The Auditory Processing Applied To Speech Sounds, Roy D Patterson, Ingrid Johnsrude
Brain and Mind Institute Researchers' Publications
In this paper, we describe domain-general auditory processes that we believe are prerequisite to the linguistic analysis of speech. We discuss biological evidence for these processes and how they might relate to processes that are specific to human speech and language. We begin with a brief review of (i) the anatomy of the auditory system and (ii) the essential properties of speech sounds. Section 4 describes the general auditory mechanisms that we believe are applied to all communication sounds, and how functional neuroimaging is being used to map the brain networks associated with domain-general auditory processing. Section 5 discusses recent …
Dominance Of The Proximal Coordinate Frame In Determining The Locations Of Hippocampal Place Cell Activity During Navigation, Jennifer J Siegel, Joshua P Neunuebel, James J Knierim
Dominance Of The Proximal Coordinate Frame In Determining The Locations Of Hippocampal Place Cell Activity During Navigation, Jennifer J Siegel, Joshua P Neunuebel, James J Knierim
Faculty, Staff and Student Publications
The place-specific activity of hippocampal cells provides downstream structures with information regarding an animal's position within an environment and, perhaps, the location of goals within that environment. In rodents, recent research has suggested that distal cues primarily set the orientation of the spatial representation, whereas the boundaries of the behavioral apparatus determine the locations of place activity. The current study was designed to address possible biases in some previous research that may have minimized the likelihood of observing place activity bound to distal cues. Hippocampal single-unit activity was recorded from six freely moving rats as they were trained to perform …
Human Parietal "Reach Region" Primarily Encodes Intrinsic Visual Direction, Not Extrinsic Movement Direction, In A Visual Motor Dissociation Task., Juan Fernandez-Ruiz, Herbert C Goltz, Joseph F X Desouza, Tutis Vilis, J Douglas Crawford
Human Parietal "Reach Region" Primarily Encodes Intrinsic Visual Direction, Not Extrinsic Movement Direction, In A Visual Motor Dissociation Task., Juan Fernandez-Ruiz, Herbert C Goltz, Joseph F X Desouza, Tutis Vilis, J Douglas Crawford
Brain and Mind Institute Researchers' Publications
Posterior parietal cortex (PPC) participates in the planning of visuospatial behaviors, including reach movements, in gaze-centered coordinates. It is not known if these representations encode the visual goal in retinal coordinates, or the movement direction relative to gaze. Here, by dissociating the intrinsic retinal stimulus from the extrinsic direction of movement, we show that PPC employs a visual code. Using delayed pointing and event-related functional magnetic resonance imaging, we identified a cluster of PPC regions whose activity was topographically (contralaterally) related to the direction of the planned movement. We then switched the normal visual-motor spatial relationship by adapting subjects to …
Do Vegetative Patients Retain Aspects Of Language Comprehension? Evidence From Fmri, Martin R Coleman, Jennifer M Rodd, Matthew H Davis, Ingrid Johnsrude, David K Menon, John D Pickard, Adrian M Owen
Do Vegetative Patients Retain Aspects Of Language Comprehension? Evidence From Fmri, Martin R Coleman, Jennifer M Rodd, Matthew H Davis, Ingrid Johnsrude, David K Menon, John D Pickard, Adrian M Owen
Brain and Mind Institute Researchers' Publications
A diagnosis of vegetative state is made if a patient demonstrates no evidence of awareness of self or environment, no evidence of sustained, reproducible, purposeful or voluntary behavioural response to sensory stimuli and critically no evidence of language comprehension. For those patients who retain peripheral motor function, rigorous behavioural assessment is usually able to determine retained function. However, some patients do not retain the ability to respond overtly to command and it is becoming increasingly accepted that assessment of these patients should include techniques, which do not rely on any 'motor action' on the part of the patient. Here, we …
Perceptual Functions Of Perirhinal Cortex In Rats: Zero-Delay Object Recognition And Simultaneous Oddity Discriminations., Susan J Bartko, Boyer D Winters, Rosemary A Cowell, Lisa M Saksida, Timothy J Bussey
Perceptual Functions Of Perirhinal Cortex In Rats: Zero-Delay Object Recognition And Simultaneous Oddity Discriminations., Susan J Bartko, Boyer D Winters, Rosemary A Cowell, Lisa M Saksida, Timothy J Bussey
Brain and Mind Institute Researchers' Publications
The perirhinal cortex (PRh) is widely accepted as having an important role in object recognition memory in humans and animals. Contrary to claims that PRh mediates declarative memory exclusively, previous evidence suggests that PRh has a role in the perceptual processing of complex objects. In the present study, we conducted an examination of the possible role of PRh in perceptual function in rats. We examined whether bilateral excitotoxic lesions of PRh or PPRh (perirhinal plus postrhinal cortices) in the rat would cause deficits in a zero-delay object-recognition task and a simultaneous oddity discrimination task. Both of these tasks measured spontaneous …
Representation Of Head-Centric Flow In The Human Motion Complex., Jeroen Goossens, Sean P Dukelow, Ravi S Menon, Tutis Vilis, Albert V Van Den Berg
Representation Of Head-Centric Flow In The Human Motion Complex., Jeroen Goossens, Sean P Dukelow, Ravi S Menon, Tutis Vilis, Albert V Van Den Berg
Brain and Mind Institute Researchers' Publications
Recent neuroimaging studies have identified putative homologs of macaque middle temporal area (area MT) and medial superior temporal area (area MST) in humans. Little is known about the integration of visual and nonvisual signals in human motion areas compared with monkeys. Through extra-retinal signals, the brain can factor out the components of visual flow on the retina that are induced by eye-in-head and head-in-space rotations and achieve a representation of flow relative to the head (head-centric flow) or body (body-centric flow). Here, we used functional magnetic resonance imaging to test whether extra-retinal eye-movement signals modulate responses to visual flow in …
A Contralateral Preference In The Lateral Occipital Area: Sensory And Attentional Mechanisms., Matthias Niemeier, Herbert C Goltz, Anil Kuchinad, Douglas B Tweed, Tutis Vilis
A Contralateral Preference In The Lateral Occipital Area: Sensory And Attentional Mechanisms., Matthias Niemeier, Herbert C Goltz, Anil Kuchinad, Douglas B Tweed, Tutis Vilis
Brain and Mind Institute Researchers' Publications
Here we examined the level of the lateral occipital (LO) area within the processing stream of the ventral visual cortex. An important determinant of an area's level of processing is whether it codes visual elements on both sides of the visual field, as do higher visual areas, or prefers those in the contralateral visual field, as do early visual areas. The former would suggest that LO, on one side, combines bilateral visual elements into a whole, while the latter suggests that it codes only the parts of forms. We showed that LO has a relative preference for visual objects in …
Double Dissociation Between The Effects Of Peri-Postrhinal Cortex And Hippocampal Lesions On Tests Of Object Recognition And Spatial Memory: Heterogeneity Of Function Within The Temporal Lobe., Boyer D Winters, Suzanna E Forwood, Rosemary A Cowell, Lisa M Saksida, Timothy J Bussey
Double Dissociation Between The Effects Of Peri-Postrhinal Cortex And Hippocampal Lesions On Tests Of Object Recognition And Spatial Memory: Heterogeneity Of Function Within The Temporal Lobe., Boyer D Winters, Suzanna E Forwood, Rosemary A Cowell, Lisa M Saksida, Timothy J Bussey
Brain and Mind Institute Researchers' Publications
It is widely believed that declarative memory is mediated by a medial temporal lobe memory system consisting of several distinct structures, including the hippocampus and perirhinal cortex. The strong version of this view assumes a high degree of functional homogeneity and serial organization within the medial temporal lobe, such that double dissociations between individual structures should not be possible. In the present study, we tested for a functional double dissociation between the hippocampus and peri-postrhinal cortex in a single experiment. Rats with bilateral excitotoxic lesions of either the hippocampus or peri-postrhinal cortex were assessed in tests of spatial memory (radial …
Somatotopic Representation Of Action Words In Human Motor And Premotor Cortex, Olaf Hauk, Ingrid Johnsrude, Friedemann Pulvermüller
Somatotopic Representation Of Action Words In Human Motor And Premotor Cortex, Olaf Hauk, Ingrid Johnsrude, Friedemann Pulvermüller
Brain and Mind Institute Researchers' Publications
Since the early days of research into language and the brain, word meaning was assumed to be processed in specific brain regions, which most modern neuroscientists localize to the left temporal lobe. Here we use event-related fMRI to show that action words referring to face, arm, or leg actions (e.g., to lick, pick, or kick), when presented in a passive reading task, differentially activated areas along the motor strip that either were directly adjacent to or overlapped with areas activated by actual movement of the tongue, fingers, or feet. These results demonstrate that the referential meaning of action words has …
Gaze-Centered Updating Of Visual Space In Human Parietal Cortex., W Pieter Medendorp, Herbert C Goltz, Tutis Vilis, J Douglas Crawford
Gaze-Centered Updating Of Visual Space In Human Parietal Cortex., W Pieter Medendorp, Herbert C Goltz, Tutis Vilis, J Douglas Crawford
Brain and Mind Institute Researchers' Publications
Single-unit recordings have identified a region in the posterior parietal cortex (PPC) of the monkey that represents and updates visual space in a gaze-centered frame. Here, using event-related functional magnetic resonance imaging, we identified an analogous bilateral region in the human PPC that shows contralateral topography for memory-guided eye movements and arm movements. Furthermore, when eye movements reversed the remembered horizontal target location relative to the gaze fixation point, this PPC region exchanged activity across the two cortical lobules. This shows that the human PPC dynamically updates the spatial goals for action in a gaze-centered frame.
The Lateral Occipital Complex Subserves The Perceptual Persistence Of Motion-Defined Groupings., Susanne Ferber, G Keith Humphrey, Tutis Vilis
The Lateral Occipital Complex Subserves The Perceptual Persistence Of Motion-Defined Groupings., Susanne Ferber, G Keith Humphrey, Tutis Vilis
Brain and Mind Institute Researchers' Publications
How are the bits and pieces of retinal information assembled and integrated to form the coherent objects that we see? One long-established principle is that elements that move as a group are linked together. For instance a fragmented line-drawing of an object, placed on a background of randomly distributed short lines, can be impossible to see. But if the object moves relative to the background, its shape is instantly recognized. Even after the motion stops, the percept of the object persists briefly before it fades into the background of random lines. Where in the brain does the percept of the …
Hierarchical Processing In Spoken Language Comprehension., Matthew H Davis, Ingrid Johnsrude
Hierarchical Processing In Spoken Language Comprehension., Matthew H Davis, Ingrid Johnsrude
Brain and Mind Institute Researchers' Publications
Understanding spoken language requires a complex series of processing stages to translate speech sounds into meaning. In this study, we use functional magnetic resonance imaging to explore the brain regions that are involved in spoken language comprehension, fractionating this system into sound-based and more abstract higher-level processes. We distorted English sentences in three acoustically different ways, applying each distortion to varying degrees to produce a range of intelligibility (quantified as the number of words that could be reported) and collected whole-brain echo-planar imaging data from 12 listeners using sparse imaging. The blood oxygenation level-dependent signal correlated with intelligibility along the …
Can Meaningful Effective Connectivities Be Obtained Between Auditory Cortical Regions?, M S Gonçalves, D A Hall, Ingrid Johnsrude, M P Haggard
Can Meaningful Effective Connectivities Be Obtained Between Auditory Cortical Regions?, M S Gonçalves, D A Hall, Ingrid Johnsrude, M P Haggard
Brain and Mind Institute Researchers' Publications
Structural equation modeling (SEM) of neuroimaging data can be evaluated both for the goodness of fit of the model and for the strength of path coefficients (as an index of effective connectivity). SEM of auditory fMRI data is made difficult by the necessary sparse temporal sampling of the time series (to avoid contamination of auditory activation by the response to scanner noise) and by the paucity of well-defined anatomical information to constrain the functional model. We used SEM (i.e., a model incorporating latent variables) to investigate how well fMRI data in four adjacent cortical fields can be described as an …
Identifying Global Anatomical Differences: Deformation-Based Morphometry, J Ashburner, C Hutton, R Frackowiak, Ingrid Johnsrude, C Price, K Friston
Identifying Global Anatomical Differences: Deformation-Based Morphometry, J Ashburner, C Hutton, R Frackowiak, Ingrid Johnsrude, C Price, K Friston
Brain and Mind Institute Researchers' Publications
The aim of this paper is to illustrate a method for identifying macroscopic anatomical differences among the brains of different populations of subjects. The method involves spatially normalizing the structural MR images of a number of subjects so that they all conform to the same stereotactic space. Multivariate statistics are then applied to the parameters describing the estimated nonlinear deformations that ensue. To illustrate the method, we compared the gross morphometry of male and female subjects. We also assessed brain asymmetry, the effect of handedness, and interactions among these effects.
Triple Dissociation Of Anterior Cingulate, Posterior Cingulate, And Medial Frontal Cortices On Visual Discrimination Tasks Using A Touchscreen Testing Procedure For The Rat., T J Bussey, J L Muir, B J Everitt, T W Robbins
Triple Dissociation Of Anterior Cingulate, Posterior Cingulate, And Medial Frontal Cortices On Visual Discrimination Tasks Using A Touchscreen Testing Procedure For The Rat., T J Bussey, J L Muir, B J Everitt, T W Robbins
Brain and Mind Institute Researchers' Publications
Four experiments examined effects of quinolinic acid-induced lesions of the anterior cingulate, posterior cingulate, and medial frontal cortices on tests of visual discrimination learning, using a new "touchscreen" testing method for rats. Anterior cingulate cortex lesions impaired acquisition of an 8-pair concurrent discrimination task, whereas posterior cingulate cortex lesions facilitated learning but selectively impaired the late stages of acquisition of a visuospatial conditional discrimination. Medial frontal cortex lesions selectively impaired reversal learning when stimuli were difficult to discriminate; lesions of anterior and posterior cingulate cortex had no effect. These results suggest roles for the anterior cingulate, posterior cingulate, and medial …