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Full-Text Articles in Psychology

Developmental Differences In The Influence Of Phonological Similarity On Spoken Word Processing In Mandarin Chinese., Jeffrey G Malins, Danqi Gao, Ran Tao, James R Booth, Hua Shu, Marc F Joanisse, Li Liu, Amy S Desroches Nov 2014

Developmental Differences In The Influence Of Phonological Similarity On Spoken Word Processing In Mandarin Chinese., Jeffrey G Malins, Danqi Gao, Ran Tao, James R Booth, Hua Shu, Marc F Joanisse, Li Liu, Amy S Desroches

Brain and Mind Institute Researchers' Publications

The developmental trajectory of spoken word recognition has been well established in Indo-European languages, but to date remains poorly characterized in Mandarin Chinese. In this study, typically developing children (N=17; mean age 10; 5) and adults (N=17; mean age 24) performed a picture-word matching task in Mandarin while we recorded ERPs. Mismatches diverged from expectations in different components of the Mandarin syllable; namely, word-initial phonemes, word-final phonemes, and tone. By comparing responses to different mismatch types, we uncovered evidence suggesting that both children and adults process words incrementally. However, we also observed key developmental differences in how subjects treated onset …


Striatum In Stimulus-Response Learning Via Feedback And In Decision Making., Nole M Hiebert, Andrew Vo, Adam Hampshire, Adrian M Owen, Ken N Seergobin, Penny A Macdonald Nov 2014

Striatum In Stimulus-Response Learning Via Feedback And In Decision Making., Nole M Hiebert, Andrew Vo, Adam Hampshire, Adrian M Owen, Ken N Seergobin, Penny A Macdonald

Brain and Mind Institute Researchers' Publications

Cognitive deficits are recognized in Parkinson's disease. Understanding cognitive functions mediated by the striatum can clarify some of these impairments and inform treatment strategies. The dorsal striatum, a region impaired in Parkinson's disease, has been implicated in stimulus-response learning. However, most investigations combine acquisition of associations between stimuli, responses, or outcomes (i.e., learning) and expression of learning through response selection and decision enactment, confounding these separate processes. Using neuroimaging, we provide evidence that dorsal striatum does not mediate stimulus-response learning from feedback but rather underlies decision making once associations between stimuli and responses are learned. In the experiment, 11 males …


Transcranial Magnetic Stimulation Of The Prefrontal Cortex In Awake Nonhuman Primates Evokes A Polysynaptic Neck Muscle Response That Reflects Oculomotor Activity At The Time Of Stimulation., Chao Gu, Brian D Corneil Oct 2014

Transcranial Magnetic Stimulation Of The Prefrontal Cortex In Awake Nonhuman Primates Evokes A Polysynaptic Neck Muscle Response That Reflects Oculomotor Activity At The Time Of Stimulation., Chao Gu, Brian D Corneil

Brain and Mind Institute Researchers' Publications

Transcranial magnetic stimulation (TMS) has emerged as an important technique in cognitive neuroscience, permitting causal inferences about the contribution of a given brain area to behavior. Despite widespread use, exactly how TMS influences neural activity throughout an interconnected network, and how such influences ultimately change behavior, remain unclear. The oculomotor system of nonhuman primates (NHPs) offers a potential animal model to bridge this gap. Here, based on results suggesting that neck muscle activity provides a sensitive indicator of oculomotor activation, we show that single pulses of TMS over the frontal eye fields (FEFs) in awake NHPs evoked rapid (within ∼25 …


Burning Pain Secondary To Clozapine Use: A Case Report., Bradley Linton, Rachel Fu, Penny A Macdonald, Hooman Ganjavi Oct 2014

Burning Pain Secondary To Clozapine Use: A Case Report., Bradley Linton, Rachel Fu, Penny A Macdonald, Hooman Ganjavi

Brain and Mind Institute Researchers' Publications

BACKGROUND: The first of the atypical antipsychotics introduced in the 1970s, clozapine remains the most efficacious neuroleptic to this day. However, serious and potentially fatal side effects have necessitated careful regular monitoring among prescribing clinicians. Some adverse effects (e.g. ischaemic bowel) remain under recognized, while newly identified adverse effects continue to be described in the literature.

CASE PRESENTATION: In this report, we describe a healthy 43-year old Caucasian male who experienced onset of a full body deep burning pain several months after the onset of treatment with clozapine. The pain worsened over time, ceased with cessation of treatment, and returned …


The Cost Of Moving Optimally: Kinematic Path Selection., Dinant A Kistemaker, Jeremy D Wong, Paul L Gribble Oct 2014

The Cost Of Moving Optimally: Kinematic Path Selection., Dinant A Kistemaker, Jeremy D Wong, Paul L Gribble

Brain and Mind Institute Researchers' Publications

It is currently unclear whether the brain plans movement kinematics explicitly or whether movement paths arise implicitly through optimization of a cost function that takes into account control and/or dynamic variables. Several cost functions are proposed in the literature that are very different in nature (e.g., control effort, torque change, and jerk), yet each can predict common movement characteristics. We set out to disentangle predictions of the different variables using a combination of modeling and empirical studies. Subjects performed goal-directed arm movements in a force field (FF) in combination with visual perturbations of seen hand position. This FF was designed …


Mirror Reversal And Visual Rotation Are Learned And Consolidated Via Separate Mechanisms: Recalibrating Or Learning De Novo?, Sebastian Telgen, Darius Parvin, Jörn Diedrichsen Oct 2014

Mirror Reversal And Visual Rotation Are Learned And Consolidated Via Separate Mechanisms: Recalibrating Or Learning De Novo?, Sebastian Telgen, Darius Parvin, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

Motor learning tasks are often classified into adaptation tasks, which involve the recalibration of an existing control policy (the mapping that determines both feedforward and feedback commands), and skill-learning tasks, requiring the acquisition of new control policies. We show here that this distinction also applies to two different visuomotor transformations during reaching in humans: Mirror-reversal (left-right reversal over a mid-sagittal axis) of visual feedback versus rotation of visual feedback around the movement origin. During mirror-reversal learning, correct movement initiation (feedforward commands) and online corrections (feedback responses) were only generated at longer latencies. The earliest responses were directed into a nonmirrored …


Dopaminergic Therapy Affects Learning And Impulsivity In Parkinson's Disease., Nole M Hiebert, Ken N Seergobin, Andrew Vo, Hooman Ganjavi, Penny A Macdonald Oct 2014

Dopaminergic Therapy Affects Learning And Impulsivity In Parkinson's Disease., Nole M Hiebert, Ken N Seergobin, Andrew Vo, Hooman Ganjavi, Penny A Macdonald

Brain and Mind Institute Researchers' Publications

OBJECTIVE: The aim was to examine the effect of dopaminergic medication on stimulus-response learning versus performing decisions based on learning.

METHOD: To see the effect of dopaminergic therapy on stimulus-response learning and response selection, participants with Parkinson's disease (PD) were either tested on and/or off their prescribed dose of dopaminergic therapy during different testing days. Forty participants with PD and 34 healthy controls completed the experiment on consecutive days. On Day 1, participants learned to associate abstract images with spoken, "right" or "left" responses via feedback (Session 1). On Day 2, participants recalled these responses (Session 2) and indicated the …


Developmental Stress, Condition, And Birdsong: A Case Study In Song Sparrows., Kim L Schmidt, Elizabeth A Macdougall-Shackleton, Shawn P Kubli, Scott A Macdougall-Shackleton Oct 2014

Developmental Stress, Condition, And Birdsong: A Case Study In Song Sparrows., Kim L Schmidt, Elizabeth A Macdougall-Shackleton, Shawn P Kubli, Scott A Macdougall-Shackleton

Brain and Mind Institute Researchers' Publications

Sexual-selection theory posits that ornaments and displays can reflect a signaler's condition, which in turn is affected both by recent and developmental conditions. Moreover, developmental conditions can induce correlations between sexually selected and other traits if both types of traits exhibit developmental phenotypic plasticity in response to stressors. Thus, sexually selected traits may reflect recent and/or developmental characteristics of signalers. Here, we review data on the relationships between birdsong, a sexually selected trait, and developmental and current condition of birds from a long-term study of a population of song sparrows (Melospiza melodia). Field studies of free-living birds indicate that the …


Dynamics Of Alpha Control: Preparatory Suppression Of Posterior Alpha Oscillations By Frontal Modulators Revealed With Combined Eeg And Event-Related Optical Signal, Kyle E. Mathewson, Diane M. Beck, Tony Ro, Edward L. Maclin, Kathy A. Low, Monica Fabiani, Gabriele Gratton Oct 2014

Dynamics Of Alpha Control: Preparatory Suppression Of Posterior Alpha Oscillations By Frontal Modulators Revealed With Combined Eeg And Event-Related Optical Signal, Kyle E. Mathewson, Diane M. Beck, Tony Ro, Edward L. Maclin, Kathy A. Low, Monica Fabiani, Gabriele Gratton

Publications and Research

We investigated the dynamics of brain processes facilitating conscious experience of external stimuli. Previously, we proposed that alpha (8–12 Hz) oscillations, which fluctuate with both sustained and directed attention, represent a pulsed inhibition of ongoing sensory brain activity. Here we tested the prediction that inhibitory alpha oscillations in visual cortex are modulated by top–down signals from frontoparietal attention networks. We measured modulations in phase-coherent alpha oscillations from superficial frontal, parietal, and occipital cortices using the event-related optical signal (EROS), a measure of neuronal activity affording high spatiotemporal resolution, along with concurrently recorded EEG, while participants performed a visual target detection …


“Me & My Brain”: Exposing NeuroscienceʼS Closet Dualism, Liad Mudrik, Uri Maoz Sep 2014

“Me & My Brain”: Exposing NeuroscienceʼS Closet Dualism, Liad Mudrik, Uri Maoz

Psychology Faculty Articles and Research

Our intuitive concept of the relations between brain and mind is increasingly challenged by the scientific world view. Yet, although few neuroscientists openly endorse Cartesian dualism, careful reading reveals dualistic intuitions in prominent neuroscientific texts. Here, we present the “double-subject fallacy”: treating the brain and the entire person as two independent subjects who can simultaneously occupy divergent psychological states and even have complex interactions with each other—as in “my brain knew before I did.” Although at first, such writing may appear like harmless, or even cute, shorthand, a closer look suggests that it can be seriously misleading. Surprisingly, this confused …


Sharp Emergence Of Feature-Selective Sustained Activity Along The Dorsal Visual Pathway., Diego Mendoza-Halliday, Santiago Torres, Julio C Martinez-Trujillo Sep 2014

Sharp Emergence Of Feature-Selective Sustained Activity Along The Dorsal Visual Pathway., Diego Mendoza-Halliday, Santiago Torres, Julio C Martinez-Trujillo

Brain and Mind Institute Researchers' Publications

Sustained activity encoding visual working memory representations has been observed in several cortical areas of primates. Where along the visual pathways this activity emerges remains unknown. Here we show in macaques that sustained spiking activity encoding memorized visual motion directions is absent in direction-selective neurons in early visual area middle temporal (MT). However, it is robustly present immediately downstream, in multimodal association area medial superior temporal (MST), as well as and in the lateral prefrontal cortex (LPFC). This sharp emergence of sustained activity along the dorsal visual pathway suggests a functional boundary between early visual areas, which encode sensory inputs, …


Human Premotor Areas Parse Sequences Into Their Spatial And Temporal Features., Katja Kornysheva, Jörn Diedrichsen Aug 2014

Human Premotor Areas Parse Sequences Into Their Spatial And Temporal Features., Katja Kornysheva, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

Skilled performance is characterized by precise and flexible control of movement sequences in space and time. Recent theories suggest that integrated spatio-temporal trajectories are generated by intrinsic dynamics of motor and premotor networks. This contrasts with behavioural advantages that emerge when a trained spatial or temporal feature of sequences is transferred to a new spatio-temporal combination arguing for independent neural representations of these sequence features. We used a new fMRI pattern classification approach to identify brain regions with independent vs integrated representations. A distinct regional dissociation within motor areas was revealed: whereas only the contralateral primary motor cortex exhibited unique …


Self-Injurious Behaviours Are Associated With Alterations In The Somatosensory System In Children With Autism Spectrum Disorder., Emma G Duerden, Dallas Card, S Wendy Roberts, Kathleen M Mak-Fan, M Mallar Chakravarty, Jason P Lerch, Margot J Taylor Jul 2014

Self-Injurious Behaviours Are Associated With Alterations In The Somatosensory System In Children With Autism Spectrum Disorder., Emma G Duerden, Dallas Card, S Wendy Roberts, Kathleen M Mak-Fan, M Mallar Chakravarty, Jason P Lerch, Margot J Taylor

Brain and Mind Institute Researchers' Publications

Children with autism spectrum disorder (ASD) frequently engage in self-injurious behaviours, often in the absence of reporting pain. Previous research suggests that altered pain sensitivity and repeated exposure to noxious stimuli are associated with morphological changes in somatosensory and limbic cortices. Further evidence from postmortem studies with self-injurious adults has indicated alterations in the structure and organization of the temporal lobes; however, the effect of self-injurious behaviour on cortical development in children with ASD has not yet been determined. Thirty children and adolescents (mean age = 10.6 ± 2.5 years; range 7-15 years; 29 males) with a clinical diagnosis of …


Continuous Executive Function Disruption Interferes With Application Of An Information Integration Categorization Strategy., Sarah J Miles, Kazunaga Matsuki, John Paul Minda Jul 2014

Continuous Executive Function Disruption Interferes With Application Of An Information Integration Categorization Strategy., Sarah J Miles, Kazunaga Matsuki, John Paul Minda

Brain and Mind Institute Researchers' Publications

Category learning is often characterized as being supported by two separate learning systems. A verbal system learns rule-defined (RD) categories that can be described using a verbal rule and relies on executive functions (EFs) to learn via hypothesis testing. A nonverbal system learns non-rule-defined (NRD) categories that cannot be described by a verbal rule and uses automatic, procedural learning. The verbal system is dominant in that adults tend to use it during initial learning but may switch to the nonverbal system when the verbal system is unsuccessful. The nonverbal system has traditionally been thought to operate independently of EFs, but …


Overt Responses During Covert Orienting., Brian D Corneil, Douglas P Munoz Jun 2014

Overt Responses During Covert Orienting., Brian D Corneil, Douglas P Munoz

Brain and Mind Institute Researchers' Publications

A distributed network of cortical and subcortical brain areas controls our oculomotor behavior. This network includes the superior colliculus (SC), which coordinates an ancient visual grasp reflex via outputs that ramify widely within the brainstem and spinal cord, accessing saccadic and other premotor and autonomic circuits. In this Review, we discuss recent results correlating subliminal SC activity in the absence of saccades with diverse components of the visual grasp reflex, including neck and limb muscle recruitment, pupil dilation, and microsaccade propensity. Such subtle manifestations of covert orienting are accessible in the motor periphery and may provide the next generation of …


Examining Dorsal Striatum In Cognitive Effort Using Parkinson's Disease And Fmri., Alex A Macdonald, Ken N Seergobin, Ruzbeh Tamjeedi, Adrian M Owen, Jean-Sebastien Provost, Oury Monchi, Hooman Ganjavi, Penny A Macdonald Jun 2014

Examining Dorsal Striatum In Cognitive Effort Using Parkinson's Disease And Fmri., Alex A Macdonald, Ken N Seergobin, Ruzbeh Tamjeedi, Adrian M Owen, Jean-Sebastien Provost, Oury Monchi, Hooman Ganjavi, Penny A Macdonald

Brain and Mind Institute Researchers' Publications

OBJECTIVE: Understanding cognition mediated by the striatum can clarify cognitive deficits in Parkinson's disease (PD). Previously, we claimed that dorsal striatum (DS) mediates cognitive flexibility. To refute the possibility that variation in cognitive effort confounded our observations, we reexamined our data to dissociate cognitive flexibility from effort. PD provides a model for exploring DS-mediated functions. In PD, dopamine-producing cells supplying DS are significantly degenerated. DS-mediated functions are impaired off and improved on dopamine replacement medication. Functional magnetic resonance imaging (fMRI) can confirm striatum-mediated functions.

METHODS: Twenty-two PD patients, off-on dopaminergic medication, and 22 healthy age-matched controls performed a number selection …


Pregnant Teens In Foster Care: Concepts, Issues, And Challenges In Conducting Research On Vulnerable Populations, Lisa D. Lieberman, Linda L. Bryant, Kenece Boyce, Patricia Beresford May 2014

Pregnant Teens In Foster Care: Concepts, Issues, And Challenges In Conducting Research On Vulnerable Populations, Lisa D. Lieberman, Linda L. Bryant, Kenece Boyce, Patricia Beresford

Department of Public Health Scholarship and Creative Works

Teens in foster care give birth at over twice the rate of other teens. Unique challenges exist for these vulnerable teens and babies, yet research on such populations, particularly within the systems that serve them, is limited. A demonstration project at Inwood House, a residential foster care agency in New York City, from 2000 to 2005, at the same time that the Administration for Children's Services was exploring policy and practice changes for this population, is described. Research design and implementation issues, descriptive data, and experiences provide lessons for improving the evidence base to meet the needs of pregnant teens …


The Reversal Effects Of Curcumin, An Herbal Remedy, On The Impairments Induced By Vmat-2 Inhibitor Tetrabenazine, Emily Qian, Samantha E. Yohn May 2014

The Reversal Effects Of Curcumin, An Herbal Remedy, On The Impairments Induced By Vmat-2 Inhibitor Tetrabenazine, Emily Qian, Samantha E. Yohn

Honors Scholar Theses

Substantial evidence has shown that dopamine (DA), particularly in the nucleus accumbens (NAc), is involved in behavioral activation and effort-related processes, such as overcoming work related response costs. Interference with accumbens DA transmission through administration of the vesicular monoamine transportor-2 (VMAT-2) inhibitor tetrabenazine (TBZ) produces an alteration of response allocation in the concurrent FR5/chow choice procedure, biasing animals toward the lower effort alternative. It has been suggested that these drug-induced shifts in effort-related choice behavior seen in rodents are analogous to symptoms such as psychomotor retardation, anergia, and fatigue, which can be observed in people with depression and other related …


Antioxidant Gene Therapy Against Neuronal Cell Death, Juliana Navarro-Yepes, Laura Zavala-Flores, Anandhan Annadurai, Fang Wang, Maciej Skotak, Namas Chandra, Ming Li, Aglaia Pappa, Daniel Martinez-Fong, Luz Maria Del Razo, Betzabet Quintanilla-Vega, Rodrigo Franco May 2014

Antioxidant Gene Therapy Against Neuronal Cell Death, Juliana Navarro-Yepes, Laura Zavala-Flores, Anandhan Annadurai, Fang Wang, Maciej Skotak, Namas Chandra, Ming Li, Aglaia Pappa, Daniel Martinez-Fong, Luz Maria Del Razo, Betzabet Quintanilla-Vega, Rodrigo Franco

Department of Psychology: Faculty Publications

Oxidative stress is a common hallmark of neuronal cell death associated with neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, as well as brain stroke/ischemia and traumatic brain injury. Increased accumulation of reactive species of both oxygen (ROS) and nitrogen (RNS) has been implicated inmitochondrial dysfunction, energy impairment, alterations in metal homeostasis and accumulation of aggregated proteins observed in neurodegenerative disorders, which lead to the activation/modulation of cell death mechanisms that include apoptotic, necrotic and autophagic pathways. Thus, the design of novel antioxidant strategies to selectively target oxidative stress and redox imbalance might represent important therapeutic approaches against neurological disorders. …


Effector-Independent Motor Sequence Representations Exist In Extrinsic And Intrinsic Reference Frames., Tobias Wiestler, Sheena Waters-Metenier, Jörn Diedrichsen Apr 2014

Effector-Independent Motor Sequence Representations Exist In Extrinsic And Intrinsic Reference Frames., Tobias Wiestler, Sheena Waters-Metenier, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

Many daily activities rely on the ability to produce meaningful sequences of movements. Motor sequences can be learned in an effector-specific fashion (such that benefits of training are restricted to the trained hand) or an effector-independent manner (meaning that learning also facilitates performance with the untrained hand). Effector-independent knowledge can be represented in extrinsic/world-centered or in intrinsic/body-centered coordinates. Here, we used functional magnetic resonance imaging (fMRI) and multivoxel pattern analysis to determine the distribution of intrinsic and extrinsic finger sequence representations across the human neocortex. Participants practiced four sequences with one hand for 4 d, and then performed these sequences …


A Dedicated Binding Mechanism For The Visual Control Of Movement., Alexandra Reichenbach, David W Franklin, Peter Zatka-Haas, Jörn Diedrichsen Mar 2014

A Dedicated Binding Mechanism For The Visual Control Of Movement., Alexandra Reichenbach, David W Franklin, Peter Zatka-Haas, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

The human motor system is remarkably proficient in the online control of visually guided movements, adjusting to changes in the visual scene within 100 ms [1-3]. This is achieved through a set of highly automatic processes [4] translating visual information into representations suitable for motor control [5, 6]. For this to be accomplished, visual information pertaining to target and hand need to be identified and linked to the appropriate internal representations during the movement. Meanwhile, other visual information must be filtered out, which is especially demanding in visually cluttered natural environments. If selection of relevant sensory information for online control …


Gene Co-Citation Networks Associated With Worker Sterility In Honey Bees., Emma Kate Mullen, Mark Daley, Alanna Gabrielle Backx, Graham James Thompson Mar 2014

Gene Co-Citation Networks Associated With Worker Sterility In Honey Bees., Emma Kate Mullen, Mark Daley, Alanna Gabrielle Backx, Graham James Thompson

Brain and Mind Institute Researchers' Publications

BACKGROUND: The evolution of reproductive self-sacrifice is well understood from kin theory, yet our understanding of how actual genes influence the expression of reproductive altruism is only beginning to take shape. As a model in the molecular study of social behaviour, the honey bee Apis mellifera has yielded hundreds of genes associated in their expression with differences in reproductive status of females, including genes directly associated with sterility, yet there has not been an attempt to link these candidates into functional networks that explain how workers regulate sterility in the presence of queen pheromone. In this study we use available …


Investigating The Relation Between Striatal Volume And Iq., Penny A Macdonald, Hooman Ganjavi, D Louis Collins, Alan C Evans, Sherif Karama Mar 2014

Investigating The Relation Between Striatal Volume And Iq., Penny A Macdonald, Hooman Ganjavi, D Louis Collins, Alan C Evans, Sherif Karama

Brain and Mind Institute Researchers' Publications

The volume of the input region of the basal ganglia, the striatum, is reduced with aging and in a number of conditions associated with cognitive impairment. The aim of the current study was to investigate the relation between the volume of striatum and general cognitive ability in a sample of 303 healthy children that were sampled to be representative of the population of the United States. Correlations between the WASI-IQ and the left striatum, composed of the caudate nucleus and putamen, were significant. When these data were analyzed separately for male and female children, positive correlations were significant for the …


Direct Control Of Visual Perception With Phase-Specific Modulation Of Posterior Parietal Cortex, Andrew Jaegle, Tony Ro Feb 2014

Direct Control Of Visual Perception With Phase-Specific Modulation Of Posterior Parietal Cortex, Andrew Jaegle, Tony Ro

Publications and Research

We examined the causal relationship between the phase of alpha oscillations (9–12 Hz) and conscious visual perception using rhythmic TMS (rTMS) while simultaneously recording EEG activity. rTMS of posterior parietal cortex at an alpha frequency (10 Hz), but not occipital or sham rTMS, both entrained the phase of subsequent alpha oscillatory activity and produced a phase-dependent change on subsequent visual perception, with lower discrimination accuracy for targets presented at one phase of the alpha oscillatory waveform than for targets presented at the opposite phase. By extrinsically manipulating the phase of alpha before stimulus presentation, we provide direct evidence that the …


Activation Of Mglur2/3 Receptors In The Ventro-Rostral Prefrontal Cortex Reverses Sensorimotor Gating Deficits Induced By Systemic Nmda Receptor Antagonists., Bridget Valsamis, Michael Chang, Marei Typlt, Susanne Schmid Feb 2014

Activation Of Mglur2/3 Receptors In The Ventro-Rostral Prefrontal Cortex Reverses Sensorimotor Gating Deficits Induced By Systemic Nmda Receptor Antagonists., Bridget Valsamis, Michael Chang, Marei Typlt, Susanne Schmid

Brain and Mind Institute Researchers' Publications

Prepulse inhibition (PPI) of acoustic startle is an operational measure of sensorimotor gating, which is disrupted in schizophrenia. NMDA receptor (NMDAR) antagonist induced PPI disruption has become an important pharmacological model for schizophrenia; however, knowledge of the underlying mechanism remains incomplete. This study examines the role of NMDAR in the caudal pontine reticular nucleus (PnC) and the medial prefrontal cortex (mPFC) in NMDARs antagonist induced PPI deficits, as well as the NMDA receptor subtypes involved. We administered the NMDA antagonist MK-801 locally into the caudal pontine reticular formation (PnC), where the PPI mediating pathway converges with the primary startle pathway, …


Bihemispheric Transcranial Direct Current Stimulation Enhances Effector-Independent Representations Of Motor Synergy And Sequence Learning., Sheena Waters-Metenier, Masud Husain, Tobias Wiestler, Jörn Diedrichsen Jan 2014

Bihemispheric Transcranial Direct Current Stimulation Enhances Effector-Independent Representations Of Motor Synergy And Sequence Learning., Sheena Waters-Metenier, Masud Husain, Tobias Wiestler, Jörn Diedrichsen

Brain and Mind Institute Researchers' Publications

Complex manual tasks-everything from buttoning up a shirt to playing the piano-fundamentally involve two components: (1) generating specific patterns of muscle activity (here, termed "synergies"); and (2) stringing these into purposeful sequences. Although transcranial direct current stimulation (tDCS) of the primary motor cortex (M1) has been found to increase the learning of motor sequences, it is unknown whether it can similarly facilitate motor synergy learning. Here, we determined the effects of tDCS on the learning of motor synergies using a novel hand configuration task that required the production of difficult muscular activation patterns. Bihemispheric tDCS was applied to M1 of …


Allocating Structure To Function: The Strong Links Between Neuroplasticity And Natural Selection, Michael Anderson, Barbara L. Finlay Jan 2014

Allocating Structure To Function: The Strong Links Between Neuroplasticity And Natural Selection, Michael Anderson, Barbara L. Finlay

Brain and Mind Institute Researchers' Publications

A central question in brain evolution is how species-typical behaviors, and the neural function-structure mappings supporting them, can be acquired and inherited. Advocates of brain modularity, in its different incarnations across scientific subfields, argue that natural selection must target domain-dedicated, separately modifiable neural subsystems, resulting in genetically-specified functional modules. In such modular systems, specification of neuron number and functional connectivity are necessarily linked. Mounting evidence, however, from allometric, developmental, comparative, systems-physiological, neuroimaging and neurological studies suggests that brain elements are used and reused in multiple functional systems. This variable allocation can be seen in short-term neuromodulation, in neuroplasticity over the …


Bilateral Saccadic Deficits Following Large And Reversible Inactivation Of Unilateral Frontal Eye Field., Tyler R Peel, Kevin Johnston, Stephen G Lomber, Brian D Corneil Jan 2014

Bilateral Saccadic Deficits Following Large And Reversible Inactivation Of Unilateral Frontal Eye Field., Tyler R Peel, Kevin Johnston, Stephen G Lomber, Brian D Corneil

Brain and Mind Institute Researchers' Publications

Inactivation permits direct assessment of the functional contribution of a given brain area to behavior. Previous inactivation studies of the frontal eye field (FEF) have either used large permanent ablations or reversible pharmacological techniques that only inactivate a small volume of tissue. Here we evaluated the impact of large, yet reversible, FEF inactivation on visually guided, delayed, and memory-guided saccades, using cryoloops implanted in the arcuate sulcus. While FEF inactivation produced the expected triad of contralateral saccadic deficits (increased reaction time, decreased accuracy and peak velocity) and performance errors (neglect or misdirected saccades), we also found consistent increases in reaction …


Observing Object Lifting Errors Modulates Cortico-Spinal Excitability And Improves Object Lifting Performance., Gavin Buckingham, Jeremy D Wong, Minnie Tang, Paul L Gribble, Melvyn A Goodale Jan 2014

Observing Object Lifting Errors Modulates Cortico-Spinal Excitability And Improves Object Lifting Performance., Gavin Buckingham, Jeremy D Wong, Minnie Tang, Paul L Gribble, Melvyn A Goodale

Brain and Mind Institute Researchers' Publications

Observing the actions of others has been shown to modulate cortico-spinal excitability and affect behaviour. However, the sensorimotor consequences of observing errors are not well understood. Here, participants watched actors lift identically weighted large and small cubes which typically elicit expectation-based fingertip force errors. One group of participants observed the standard overestimation and underestimation-style errors that characterise early lifts with these cubes (Error video--EV). Another group watched the same actors performing the well-adapted error-free lifts that characterise later, well-practiced lifts with these cubes (No error video--NEV). We then examined actual object lifting performance in the subjects who watched the EV …


Sensitivity Of Human Auditory Cortex To Rapid Frequency Modulation Revealed By Multivariate Representational Similarity Analysis., Marc F Joanisse, Diedre D Desouza Jan 2014

Sensitivity Of Human Auditory Cortex To Rapid Frequency Modulation Revealed By Multivariate Representational Similarity Analysis., Marc F Joanisse, Diedre D Desouza

Brain and Mind Institute Researchers' Publications

Functional Magnetic Resonance Imaging (fMRI) was used to investigate the extent, magnitude, and pattern of brain activity in response to rapid frequency-modulated sounds. We examined this by manipulating the direction (rise vs. fall) and the rate (fast vs. slow) of the apparent pitch of iterated rippled noise (IRN) bursts. Acoustic parameters were selected to capture features used in phoneme contrasts, however the stimuli themselves were not perceived as speech per se. Participants were scanned as they passively listened to sounds in an event-related paradigm. Univariate analyses revealed a greater level and extent of activation in bilateral auditory cortex in response …