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Articles 301 - 330 of 380
Full-Text Articles in Neurosciences
Habituation Of Reflexive And Motivated Behavior In Mice With Deficient Bk Channel Function., Marei Typlt, Magdalena Mirkowski, Erin Azzopardi, Peter Ruth, Peter K D Pilz, Susanne Schmid
Habituation Of Reflexive And Motivated Behavior In Mice With Deficient Bk Channel Function., Marei Typlt, Magdalena Mirkowski, Erin Azzopardi, Peter Ruth, Peter K D Pilz, Susanne Schmid
Brain and Mind Institute Researchers' Publications
Habituation is considered the most basic form of learning. It describes the decrease of a behavioral response to a repeated non-threatening sensory stimulus and therefore provides an important sensory filtering mechanism. While some neuronal pathways mediating habituation are well described, underlying cellular/molecular mechanisms are not yet fully understood. In general, there is an agreement that short-term and long-term habituation are based on different mechanisms. Historically, a distinction has also been made between habituation of motivated versus reflexive behavior. In recent studies in invertebrates the large conductance voltage- and calcium-activated potassium (BK) channel has been implicated to be a key player …
Mice With Deficient Bk Channel Function Show Impaired Prepulse Inhibition And Spatial Learning, But Normal Working And Spatial Reference Memory., Marei Typlt, Magdalena Mirkowski, Erin Azzopardi, Lukas Ruettiger, Peter Ruth, Susanne Schmid
Mice With Deficient Bk Channel Function Show Impaired Prepulse Inhibition And Spatial Learning, But Normal Working And Spatial Reference Memory., Marei Typlt, Magdalena Mirkowski, Erin Azzopardi, Lukas Ruettiger, Peter Ruth, Susanne Schmid
Brain and Mind Institute Researchers' Publications
Genetic variations in the large-conductance, voltage- and calcium activated potassium channels (BK channels) have been recently implicated in mental retardation, autism and schizophrenia which all come along with severe cognitive impairments. In the present study we investigate the effects of functional BK channel deletion on cognition using a genetic mouse model with a knock-out of the gene for the pore forming α-subunit of the channel. We tested the F1 generation of a hybrid SV129/C57BL6 mouse line in which the slo1 gene was deleted in both parent strains. We first evaluated hearing and motor function to establish the suitability of this …
Synaptic Scaffold Evolution Generated Components Of Vertebrate Cognitive Complexity, Jess Nithianantharajah, Noboru H. Komiyama, Andrew Mckechanie, Mandy Johnstone, Douglas H. Blackwood, David St.Clair, Richard D. Emes, Louie N. Van De Lagemaat, Lisa M. Saksida, Timothy J. Bussey, Seth G. Grant
Synaptic Scaffold Evolution Generated Components Of Vertebrate Cognitive Complexity, Jess Nithianantharajah, Noboru H. Komiyama, Andrew Mckechanie, Mandy Johnstone, Douglas H. Blackwood, David St.Clair, Richard D. Emes, Louie N. Van De Lagemaat, Lisa M. Saksida, Timothy J. Bussey, Seth G. Grant
Brain and Mind Institute Researchers' Publications
The origins and evolution of higher cognitive functions, including complex forms of learning, attention and executive functions, are unknown. A potential mechanism driving the evolution of vertebrate cognition early in the vertebrate lineage (550 million years ago) was genome duplication and subsequent diversification of postsynaptic genes. Here we report, to our knowledge, the first genetic analysis of a vertebrate gene family in cognitive functions measured using computerized touchscreens. Comparison of mice carrying mutations in each of the four Dlg paralogs showed that simple associative learning required Dlg4, whereas Dlg2 and Dlg3 diversified to have opposing functions in complex cognitive …
Errors In Device Localization In Mri Using Z-Frames., Jeremy Cepek, Blaine A Chronik, Aaron Fenster
Errors In Device Localization In Mri Using Z-Frames., Jeremy Cepek, Blaine A Chronik, Aaron Fenster
Brain and Mind Institute Researchers' Publications
The use of a passive MRI-visible tracking frame is a common method of localizing devices in MRI space for MRI-guided procedures. One of the most common tracking frame designs found in the literature is the z-frame, as it allows six degree-of-freedom pose estimation using only a single image slice. Despite the popularity of this design, it is susceptible to errors in pose estimation due to various image distortion mechanisms in MRI. In this paper, the absolute error in using a z-frame to localize a tool in MRI is quantified over various positions of the z-frame relative to the MRI isocenter, …
Language, Reading, And Math Learning Profiles In An Epidemiological Sample Of School Age Children., Lisa M D Archibald, Janis Oram Cardy, Marc F Joanisse, Daniel Ansari
Language, Reading, And Math Learning Profiles In An Epidemiological Sample Of School Age Children., Lisa M D Archibald, Janis Oram Cardy, Marc F Joanisse, Daniel Ansari
Brain and Mind Institute Researchers' Publications
Dyscalculia, dyslexia, and specific language impairment (SLI) are relatively specific developmental learning disabilities in math, reading, and oral language, respectively, that occur in the context of average intellectual capacity and adequate environmental opportunities. Past research has been dominated by studies focused on single impairments despite the widespread recognition that overlapping and comorbid deficits are common. The present study took an epidemiological approach to study the learning profiles of a large school age sample in language, reading, and math. Both general learning profiles reflecting good or poor performance across measures and specific learning profiles involving either weak language, weak reading, weak …
Differential Effects Of Parkinson's Disease And Dopamine Replacement On Memory Encoding And Retrieval., Alex A Macdonald, Ken N Seergobin, Adrian M Owen, Ruzbeh Tamjeedi, Oury Monchi, Hooman Ganjavi, Penny A Macdonald
Differential Effects Of Parkinson's Disease And Dopamine Replacement On Memory Encoding And Retrieval., Alex A Macdonald, Ken N Seergobin, Adrian M Owen, Ruzbeh Tamjeedi, Oury Monchi, Hooman Ganjavi, Penny A Macdonald
Brain and Mind Institute Researchers' Publications
Increasingly memory deficits are recognized in Parkinson's disease (PD). In PD, the dopamine-producing cells of the substantia nigra (SN) are significantly degenerated whereas those in the ventral tegmental area (VTA) are relatively spared. Dopamine-replacement medication improves cognitive processes that implicate the SN-innervated dorsal striatum but is thought to impair those that depend upon the VTA-supplied ventral striatum, limbic and prefrontal cortices. Our aim was to examine memory encoding and retrieval in PD and how they are affected by dopamine replacement. Twenty-nine PD patients performed the Rey Auditory Verbal Learning Test (RAVLT) and a non-verbal analogue, the Aggie Figures Learning Test …
Algorithmic Decomposition Of Shuffle On Words, Franziska Biegler, Mark Daley, Ian Mcquillan
Algorithmic Decomposition Of Shuffle On Words, Franziska Biegler, Mark Daley, Ian Mcquillan
Brain and Mind Institute Researchers' Publications
We investigate shuffle-decomposability into two words. We give an algorithm which takes as input a DFA M (under certain conditions) and determines the unique candidate decomposition into words u and v such that L(M) = u v ifM is shuffle decomposable, in time O(|u| + |v|). Even though this algorithm does not determine whether or not the DFA is shuffle decomposable, the sublinear time complexity of only determining the two words under the assumption of decomposability is surprising given the complexity of shuffle, and demonstrates an interesting property of the operation. We also show that for given words u and …
Expanding The Basic Science Debate: The Role Of Physics Knowledge In Interpreting Clinical Findings., Mark Goldszmidt, John Paul Minda, Sarah L Devantier, Aimee L Skye, Nicole N Woods
Expanding The Basic Science Debate: The Role Of Physics Knowledge In Interpreting Clinical Findings., Mark Goldszmidt, John Paul Minda, Sarah L Devantier, Aimee L Skye, Nicole N Woods
Brain and Mind Institute Researchers' Publications
Current research suggests a role for biomedical knowledge in learning and retaining concepts related to medical diagnosis. However, learning may be influenced by other, non-biomedical knowledge. We explored this idea using an experimental design and examined the effects of causal knowledge on the learning, retention, and interpretation of medical information. Participants studied a handout about several respiratory disorders and how to interpret respiratory exam findings. The control group received the information in standard "textbook" format and the experimental group was presented with the same information as well as a causal explanation about how sound travels through lungs in both the …
Psychophysical And Neural Evidence For Emotion-Enhanced Perceptual Vividness, Rebecca M. Todd, Deborah Talmi, Taylor W. Schmitz, Josh Susskind, Adam K. Anderson
Psychophysical And Neural Evidence For Emotion-Enhanced Perceptual Vividness, Rebecca M. Todd, Deborah Talmi, Taylor W. Schmitz, Josh Susskind, Adam K. Anderson
Brain and Mind Institute Researchers' Publications
Highly emotional events are associated with vivid "flashbulb" memories. Here we examine whether the flashbulb metaphor characterizes a previously unknown emotion-enhanced vividness (EEV) during initial perceptual experience. Using a magnitude estimation procedure, human observers estimated the relative magnitude of visual noise overlaid on scenes. After controlling for computational metrics of objective visual salience, emotional salience was associated with decreased noise, or heightened perceptual vividness, demonstrating EEV, which predicted later memory vividness. Event-related potentials revealed a posterior P2 component at ~200 ms that was associated with both increased emotional salience and decreased objective noise levels, consistent with EEV. Blood oxygenation level-dependent …
Gonadotropin-Releasing Hormone Plasticity: A Comparative Perspective., T J Stevenson, T P Hahn, S A Macdougall-Shackleton, G F Ball
Gonadotropin-Releasing Hormone Plasticity: A Comparative Perspective., T J Stevenson, T P Hahn, S A Macdougall-Shackleton, G F Ball
Brain and Mind Institute Researchers' Publications
Gonadotropin-releasing hormone 1 (GnRH1) is a key regulator of the reproductive neuroendocrine system in vertebrates. Recent developments have suggested that GnRH1 neurons exhibit far greater plasticity at the cellular and molecular levels than previously thought. Furthermore, there is growing evidence that sub-populations of GnRH1 neurons in the preoptic area are highly responsive to specific environmental and hormonal conditions. In this paper we discuss findings that reveal large variation in GnRH1 mRNA and protein expression that are regulated by social cues, photoperiod, and hormonal feedback. We draw upon studies using histochemistry and immediate early genes (e.g., c-FOS/ZENK) to illustrate that specific …
Perceptual Fluency Can Be Used As A Cue For Categorization Decisions., Sarah J Miles, John Paul Minda
Perceptual Fluency Can Be Used As A Cue For Categorization Decisions., Sarah J Miles, John Paul Minda
Brain and Mind Institute Researchers' Publications
Learning in the prototype distortion task is thought to involve perceptual learning in which category members experience an enhanced visual response (Ashby & Maddox. Annual Review of Psychology, 56, 149-178, 2005). This response likely leads to more-efficient processing, which in turn may result in a feeling of perceptual fluency for category members. We examined the perceptual-fluency hypothesis by manipulating fluency independently from category membership. We predicted that when perceptual fluency was induced using subliminal priming, this fluency would be misattributed to category membership and would affect categorization decisions. In a prototype distortion task, the participants were more likely to judge …
Behavioral And Fmri Evidence That Cognitive Ability Modulates The Effect Of Semantic Context On Speech Intelligibility, Adriana A Zekveld, Mary Rudner, Ingrid Johnsrude, Dirk J Heslenfeld, Jerker Rönnberg
Behavioral And Fmri Evidence That Cognitive Ability Modulates The Effect Of Semantic Context On Speech Intelligibility, Adriana A Zekveld, Mary Rudner, Ingrid Johnsrude, Dirk J Heslenfeld, Jerker Rönnberg
Brain and Mind Institute Researchers' Publications
Text cues facilitate the perception of spoken sentences to which they are semantically related (Zekveld, Rudner, et al., 2011). In this study, semantically related and unrelated cues preceding sentences evoked more activation in middle temporal gyrus (MTG) and inferior frontal gyrus (IFG) than nonword cues, regardless of acoustic quality (speech in noise or speech in quiet). Larger verbal working memory (WM) capacity (reading span) was associated with greater intelligibility benefit obtained from related cues, with less speech-related activation in the left superior temporal gyrus and left anterior IFG, and with more activation in right medial frontal cortex for related versus …
Greater Benefits Of Multisensory Integration During Complex Sensorimotor Transformations., Verena N Buchholz, Samanthi C Goonetilleke, W Pieter Medendorp, Brian D Corneil
Greater Benefits Of Multisensory Integration During Complex Sensorimotor Transformations., Verena N Buchholz, Samanthi C Goonetilleke, W Pieter Medendorp, Brian D Corneil
Brain and Mind Institute Researchers' Publications
Multisensory integration enables rapid and accurate behavior. To orient in space, sensory information registered initially in different reference frames has to be integrated with the current postural information to produce an appropriate motor response. In some postures, multisensory integration requires convergence of sensory evidence across hemispheres, which would presumably lessen or hinder integration. Here, we examined orienting gaze shifts in humans to visual, tactile, or visuotactile stimuli when the hands were either in a default uncrossed posture or a crossed posture requiring convergence across hemispheres. Surprisingly, we observed the greatest benefits of multisensory integration in the crossed posture, as indexed …
Resting-State Connectivity Identifies Distinct Functional Networks In Macaque Cingulate Cortex., R Matthew Hutchison, Thilo Womelsdorf, Joseph S Gati, L Stan Leung, Ravi S Menon, Stefan Everling
Resting-State Connectivity Identifies Distinct Functional Networks In Macaque Cingulate Cortex., R Matthew Hutchison, Thilo Womelsdorf, Joseph S Gati, L Stan Leung, Ravi S Menon, Stefan Everling
Brain and Mind Institute Researchers' Publications
Subregions of the cingulate cortex represent prominent intersections in the structural networks of the primate brain. The relevance of the cingulate to the structure and dynamics of large-scale networks ultimately requires a link to functional connectivity. Here, we map fine-grained functional connectivity across the complete extent of the macaque (Macaca fascicularis) cingulate cortex and delineate subdivisions pertaining to distinct identifiable networks. In particular, we identified 4 primary networks representing the functional spectrum of the cingulate: somatomotor, attention-orienting, executive, and limbic. The cingulate nodes of these networks originated from separable subfields along the rostral-to-caudal axis and were characterized by positive and …
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 …
Rapid Perceptual Learning Of Noise-Vocoded Speech Requires Attention, Julia Jones Huyck, Ingrid Johnsrude
Rapid Perceptual Learning Of Noise-Vocoded Speech Requires Attention, Julia Jones Huyck, Ingrid Johnsrude
Brain and Mind Institute Researchers' Publications
Humans are able to adapt to unfamiliar forms of speech (such as accented, time-compressed, or noise-vocoded speech) quite rapidly. Can such perceptual learning occur when attention is directed away from the speech signal? Here, participants were simultaneously exposed to noise-vocoded sentences, auditory distractors, and visual distractors. One group attended to the speech, listening to each sentence and reporting what they heard. Two other groups attended to either the auditory or visual distractors, performing a target-detection task. Only the attend-speech group benefited from the exposure when subsequently reporting noise-vocoded sentences. Thus, attention to noise-vocoded speech appears necessary for learning.
Discriminating Famous From Fictional Names Based On Lifetime Experience: Evidence In Support Of A Signal-Detection Model Based On Finite Mixture Distributions., Ben Bowles, Iain M Harlow, Melissa M Meeking, Stefan Köhler
Discriminating Famous From Fictional Names Based On Lifetime Experience: Evidence In Support Of A Signal-Detection Model Based On Finite Mixture Distributions., Ben Bowles, Iain M Harlow, Melissa M Meeking, Stefan Köhler
Brain and Mind Institute Researchers' Publications
It is widely accepted that signal-detection mechanisms contribute to item-recognition memory decisions that involve discriminations between targets and lures based on a controlled laboratory study episode. Here, the authors employed mathematical modeling of receiver operating characteristics (ROC) to determine whether and how a signal-detection mechanism contributes to discriminations between moderately famous and fictional names based on lifetime experience. Unique to fame judgments is a lack of control over participants' previous exposure to the stimuli deemed "targets" by the experimenter; specifically, if they pertain to moderately famous individuals, participants may have had no prior exposure to a substantial proportion of the …
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 …
Specific Contributions Of Ventromedial, Anterior Cingulate, And Lateral Prefrontal Cortex For Attentional Selection And Stimulus Valuation., Daniel Kaping, Martin Vinck, R Matthew Hutchison, Stefan Everling, Thilo Womelsdorf
Specific Contributions Of Ventromedial, Anterior Cingulate, And Lateral Prefrontal Cortex For Attentional Selection And Stimulus Valuation., Daniel Kaping, Martin Vinck, R Matthew Hutchison, Stefan Everling, Thilo Womelsdorf
Brain and Mind Institute Researchers' Publications
Attentional control ensures that neuronal processes prioritize the most relevant stimulus in a given environment. Controlling which stimulus is attended thus originates from neurons encoding the relevance of stimuli, i.e. their expected value, in hand with neurons encoding contextual information about stimulus locations, features, and rules that guide the conditional allocation of attention. Here, we examined how these distinct processes are encoded and integrated in macaque prefrontal cortex (PFC) by mapping their functional topographies at the time of attentional stimulus selection. We find confined clusters of neurons in ventromedial PFC (vmPFC) that predominantly convey stimulus valuation information during attention shifts. …
Paradoxical Reversal Learning Enhancement By Stress Or Prefrontal Cortical Damage: Rescue With Bdnf., Carolyn Graybeal, Michael Feyder, Emily Schulman, Lisa M Saksida, Timothy J Bussey, Jonathan L Brigman, Andrew Holmes
Paradoxical Reversal Learning Enhancement By Stress Or Prefrontal Cortical Damage: Rescue With Bdnf., Carolyn Graybeal, Michael Feyder, Emily Schulman, Lisa M Saksida, Timothy J Bussey, Jonathan L Brigman, Andrew Holmes
Brain and Mind Institute Researchers' Publications
Stress affects various forms of cognition. We found that moderate stress enhanced late reversal learning in a mouse touchscreen-based choice task. Ventromedial prefrontal cortex (vmPFC) lesions mimicked the effect of stress, whereas orbitofrontal and dorsolateral striatal lesions impaired reversal. Stress facilitation of reversal was prevented by BDNF infusion into the vmPFC. These findings suggest a mechanism by which stress-induced vmPFC dysfunction disinhibits learning by alternate (for example, striatal) systems.
Principles Of Sensorimotor Learning., Daniel M Wolpert, Jörn Diedrichsen, J Randall Flanagan
Principles Of Sensorimotor Learning., Daniel M Wolpert, Jörn Diedrichsen, J Randall Flanagan
Brain and Mind Institute Researchers' Publications
The exploits of Martina Navratilova and Roger Federer represent the pinnacle of motor learning. However, when considering the range and complexity of the processes that are involved in motor learning, even the mere mortals among us exhibit abilities that are impressive. We exercise these abilities when taking up new activities - whether it is snowboarding or ballroom dancing - but also engage in substantial motor learning on a daily basis as we adapt to changes in our environment, manipulate new objects and refine existing skills. Here we review recent research in human motor learning with an emphasis on the computational …
The Levels Of Analysis Revisited., Scott A Macdougall-Shackleton
The Levels Of Analysis Revisited., Scott A Macdougall-Shackleton
Brain and Mind Institute Researchers' Publications
The term levels of analysis has been used in several ways: to distinguish between ultimate and proximate levels, to categorize different kinds of research questions and to differentiate levels of reductionism. Because questions regarding ultimate function and proximate mechanisms are logically distinct, I suggest that distinguishing between these two levels is the best use of the term. Integrating across levels in research has potential risks, but many benefits. Consideration at one level can help generate novel hypotheses at the other, define categories of behaviour and set criteria that must be addressed. Taking an adaptationist stance thus strengthens research on proximate …
Prefrontal Cortex Deactivation In Macaques Alters Activity In The Superior Colliculus And Impairs Voluntary Control Of Saccades, Michael J. Koval, Stephen G. Lombar, Stefan Everling
Prefrontal Cortex Deactivation In Macaques Alters Activity In The Superior Colliculus And Impairs Voluntary Control Of Saccades, Michael J. Koval, Stephen G. Lombar, Stefan Everling
Brain and Mind Institute Researchers' Publications
The cognitive control of action requires both the suppression of automatic responses to sudden stimuli and the generation of behavior specified by abstract instructions. Though patient, functional imaging and neurophysiological studies have implicated the dorsolateral prefrontal cortex (dlPFC) in these abilities, the mechanism by which the dlPFC exerts this control remains unknown. Here we examined the functional interaction of the dlPFC with the saccade circuitry by deactivating area 46 of the dlPFC and measuring its effects on the activity of single superior colliculus neurons in monkeys performing a cognitive saccade task. Deactivation of the dlPFC reduced preparatory activity and increased …
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 …
Differential Effects Of Dopaminergic Therapies On Dorsal And Ventral Striatum In Parkinson's Disease: Implications For Cognitive Function., Penny A Macdonald, Oury Monchi
Differential Effects Of Dopaminergic Therapies On Dorsal And Ventral Striatum In Parkinson's Disease: Implications For Cognitive Function., Penny A Macdonald, Oury Monchi
Brain and Mind Institute Researchers' Publications
Cognitive abnormalities are a feature of Parkinson's disease (PD). Unlike motor symptoms that are clearly improved by dopaminergic therapy, the effect of dopamine replacement on cognition seems paradoxical. Some cognitive functions are improved whereas others are unaltered or even hindered. Our aim was to understand the effect of dopamine replacement therapy on various aspects of cognition. Whereas dorsal striatum receives dopamine input from the substantia nigra (SN), ventral striatum is innervated by dopamine-producing cells in the ventral tegmental area (VTA). In PD, degeneration of SN is substantially greater than cell loss in VTA and hence dopamine-deficiency is significantly greater in …
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 …
Failing To Ignore: Paradoxical Neural Effects Of Perceptual Load On Early Attentional Selection In Normal Aging, Taylor W. Schmitz, Frederick H.T. Cheng, Eve De Rosa
Failing To Ignore: Paradoxical Neural Effects Of Perceptual Load On Early Attentional Selection In Normal Aging, Taylor W. Schmitz, Frederick H.T. Cheng, Eve De Rosa
Brain and Mind Institute Researchers' Publications
We examined visual selective attention under perceptual load - simultaneous presentation of task-relevant and -irrelevant information - in healthy young and older adult human participants to determine whether age differences are observable at early stages of selection in the visual cortices. Participants viewed 50/50 superimposed face/place images and judged whether the faces were male or female, rendering places perceptible but task-irrelevant. Each stimulus was repeated, allowing us to index dynamic stimulus-driven competition from places. Consistent with intact early selection in young adults, we observed no adaptation to unattended places in parahippocampal place area (PPA) and significant adaptation to attended faces …
Neural Reuse: A Fundamental Organizational Principle Of The Brain, Michael Anderson
Neural Reuse: A Fundamental Organizational Principle Of The Brain, Michael Anderson
Brain and Mind Institute Researchers' Publications
An emerging class of theories concerning the functional structure of the brain takes the reuse of neural circuitry for various cognitive purposes to be a central organizational principle. According to these theories, it is quite common for neural circuits established for one purpose to be exapted (exploited, recycled, redeployed) during evolution or normal development, and be put to different uses, often without losing their original functions. Neural reuse theories thus differ from the usual understanding of the role of neural plasticity (which is, after all, a kind of reuse) in brain organization along the following lines: According to neural reuse, …
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, …
Deficits In Attention To Emotional Stimuli Distinguish Youth With Severe Mood Dysregulation From Youth With Bipolar Disorder., Brendan A Rich, Melissa A Brotman, Daniel P Dickstein, Derek G V Mitchell, R James R Blair, Ellen Leibenluft
Deficits In Attention To Emotional Stimuli Distinguish Youth With Severe Mood Dysregulation From Youth With Bipolar Disorder., Brendan A Rich, Melissa A Brotman, Daniel P Dickstein, Derek G V Mitchell, R James R Blair, Ellen Leibenluft
Brain and Mind Institute Researchers' Publications
Studying attention in the context of emotional stimuli may aid in differentiating pediatric bipolar disorder (BD) from severe mood dysregulation (SMD). SMD is characterized by chronic irritability, arousal, and hyper-reactivity; SMD youth frequently receive a BD diagnosis although they do not meet DSM-IV criteria for BD because they lack manic episodes. We compared 57 BD (14.4 +/- 2.9 years old, 56% male), 41 SMD (12.6 +/- 2.6 years old, 66% male), and 33 control subjects (13.7 +/- 2.5 years old, 52% male) using the Emotional Interrupt task, which examines how attention is impacted by positive, negative, or neutral distracters. We …