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Full-Text Articles in Psychology
Bdnf In The Dentate Gyrus Is Required For Consolidation Of "Pattern-Separated" Memories., Pedro Bekinschtein, Brianne A Kent, Charlotte A Oomen, Gregory D Clemenson, Fred H Gage, Lisa M Saksida, Timothy J Bussey
Bdnf In The Dentate Gyrus Is Required For Consolidation Of "Pattern-Separated" Memories., Pedro Bekinschtein, Brianne A Kent, Charlotte A Oomen, Gregory D Clemenson, Fred H Gage, Lisa M Saksida, Timothy J Bussey
Brain and Mind Institute Researchers' Publications
Successful memory involves not only remembering information over time, but also keeping memories distinct and less confusable. The computational process for making representations for similar input patterns more distinct from each other has been referred to as "pattern separation." In this work, we developed a set of behavioral conditions that allowed us to manipulate the load for pattern separation at different stages of memory. Thus, we provide experimental evidence that a brain-derived neurotrophic factor (BDNF)-dependent pattern separation process occurs during the encoding/storage/consolidation, but not the retrieval stage of memory processing. We also found that a spontaneous increase in BDNF in …
A Multivariate Method To Determine The Dimensionality Of Neural Representation From Population Activity., Jörn Diedrichsen, Tobias Wiestler, Naveed Ejaz
A Multivariate Method To Determine The Dimensionality Of Neural Representation From Population Activity., Jörn Diedrichsen, Tobias Wiestler, Naveed Ejaz
Brain and Mind Institute Researchers' Publications
How do populations of neurons represent a variable of interest? The notion of feature spaces is a useful concept to approach this question: According to this model, the activation patterns across a neuronal population are composed of different pattern components. The strength of each of these components varies with one latent feature, which together are the dimensions along which the population represents the variable. Here we propose a new method to determine the number of feature dimensions that best describes the activation patterns. The method is based on Gaussian linear classifiers that use only the first d most important pattern …
Skill Learning Strengthens Cortical Representations Of Motor Sequences., Tobias Wiestler, Jörn Diedrichsen
Skill Learning Strengthens Cortical Representations Of Motor Sequences., Tobias Wiestler, Jörn Diedrichsen
Brain and Mind Institute Researchers' Publications
Motor-skill learning can be accompanied by both increases and decreases in brain activity. Increases may indicate neural recruitment, while decreases may imply that a region became unimportant or developed a more efficient representation of the skill. These overlapping mechanisms make interpreting learning-related changes of spatially averaged activity difficult. Here we show that motor-skill acquisition is associated with the emergence of highly distinguishable activity patterns for trained movement sequences, in the absence of average activity increases. During functional magnetic resonance imaging, participants produced either four trained or four untrained finger sequences. Using multivariate pattern analysis, both untrained and trained sequences could …
Erps Reveal The Temporal Dynamics Of Auditory Word Recognition In Specific Language Impairment., Jeffrey G Malins, Amy S Desroches, Erin K Robertson, Randy Lynn Newman, Lisa M D Archibald, Marc F Joanisse
Erps Reveal The Temporal Dynamics Of Auditory Word Recognition In Specific Language Impairment., Jeffrey G Malins, Amy S Desroches, Erin K Robertson, Randy Lynn Newman, Lisa M D Archibald, Marc F Joanisse
Brain and Mind Institute Researchers' Publications
We used event-related potentials (ERPs) to compare auditory word recognition in children with specific language impairment (SLI group; N=14) to a group of typically developing children (TD group; N=14). Subjects were presented with pictures of items and heard auditory words that either matched or mismatched the pictures. Mismatches overlapped expected words in word-onset (cohort mismatches; see: DOLL, hear: dog), rhyme (CONE -bone), or were unrelated (SHELL -mug). In match trials, the SLI group showed a different pattern of N100 responses to auditory stimuli compared to the TD group, indicative of early auditory processing differences in SLI. However, the phonological mapping …
Dynamic And Opposing Adjustment Of Movement Cancellation And Generation In An Oculomotor Countermanding Task., Brian D Corneil, Joshua C Cheng, Samanthi C Goonetilleke
Dynamic And Opposing Adjustment Of Movement Cancellation And Generation In An Oculomotor Countermanding Task., Brian D Corneil, Joshua C Cheng, Samanthi C Goonetilleke
Brain and Mind Institute Researchers' Publications
Adaptive adjustments of strategies help optimize behavior in a dynamic and uncertain world. Previous studies in the countermanding (or stop-signal) paradigm have detailed how reaction times (RTs) change with trial sequence, demonstrating adaptive control of movement generation. Comparatively little is known about the adaptive control of movement cancellation in the countermanding task, mainly because movement cancellation implies the absence of an outcome and estimates of movement cancellation require hundreds of trials. Here, we exploit a within-trial proxy of movement cancellation based on recordings of neck muscle activity while human subjects attempted to cancel large eye-head gaze shifts. On a subset …
Two Distinct Ipsilateral Cortical Representations For Individuated Finger Movements., Jörn Diedrichsen, Tobias Wiestler, John W Krakauer
Two Distinct Ipsilateral Cortical Representations For Individuated Finger Movements., Jörn Diedrichsen, Tobias Wiestler, John W Krakauer
Brain and Mind Institute Researchers' Publications
Movements of the upper limb are controlled mostly through the contralateral hemisphere. Although overall activity changes in the ipsilateral motor cortex have been reported, their functional significance remains unclear. Using human functional imaging, we analyzed neural finger representations by studying differences in fine-grained activation patterns for single isometric finger presses. We demonstrate that cortical motor areas encode ipsilateral movements in 2 fundamentally different ways. During unimanual ipsilateral finger presses, primary sensory and motor cortices show, underneath global suppression, finger-specific activity patterns that are nearly identical to those elicited by contralateral mirror-symmetric action. This component vanishes when both motor cortices are …
Decoding The Neural Mechanisms Of Human Tool Use., Jason P Gallivan, D Adam Mclean, Kenneth F Valyear, Jody C Culham
Decoding The Neural Mechanisms Of Human Tool Use., Jason P Gallivan, D Adam Mclean, Kenneth F Valyear, Jody C Culham
Brain and Mind Institute Researchers' Publications
Sophisticated tool use is a defining characteristic of the primate species but how is it supported by the brain, particularly the human brain? Here we show, using functional MRI and pattern classification methods, that tool use is subserved by multiple distributed action-centred neural representations that are both shared with and distinct from those of the hand. In areas of frontoparietal cortex we found a common representation for planned hand- and tool-related actions. In contrast, in parietal and occipitotemporal regions implicated in hand actions and body perception we found that coding remained selectively linked to upcoming actions of the hand whereas …
The Human Brain Processes Syntax In The Absence Of Conscious Awareness., Laura Batterink, Helen J Neville
The Human Brain Processes Syntax In The Absence Of Conscious Awareness., Laura Batterink, Helen J Neville
Brain and Mind Institute Researchers' Publications
Syntax is the core computational component of language. A longstanding idea about syntactic processing is that it is generally not available to conscious access, operating autonomously and automatically. However, there is little direct neurocognitive evidence on this issue. By measuring event-related potentials while human observers performed a novel cross-modal distraction task, we demonstrated that syntactic violations that were not consciously detected nonetheless produced a characteristic early neural response pattern, and also significantly delayed reaction times to a concurrent task. This early neural response was distinct from later neural activity that was observed only to syntactic violations that were consciously detected. …
Hd-Cnv: Hotspot Detector For Copy Number Variants., Jenna L Butler, Marjorie Elizabeth Osborne Locke, Kathleen A Hill, Mark Daley
Hd-Cnv: Hotspot Detector For Copy Number Variants., Jenna L Butler, Marjorie Elizabeth Osborne Locke, Kathleen A Hill, Mark Daley
Brain and Mind Institute Researchers' Publications
SUMMARY: Copy number variants (CNVs) are a major source of genetic variation. Comparing CNVs between samples is important in elucidating their potential effects in a wide variety of biological contexts. HD-CNV (hotspot detector for copy number variants) is a tool for downstream analysis of previously identified CNV regions from multiple samples, and it detects recurrent regions by finding cliques in an interval graph generated from the input. It creates a unique graphical representation of the data, as well as summary spreadsheets and UCSC (University of California, Santa Cruz) Genome Browser track files. The interval graph, when viewed with other software …
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 …
Report Of A Deaf Child With Tourette's Disorder., Cathy J Chovaz
Report Of A Deaf Child With Tourette's Disorder., Cathy J Chovaz
Psychology
This is a case study of a deaf child with Tourette's Disorder (TD). Hearing parents and mental health clinicians unfamiliar with typical behaviors of deaf children may have difficulties differentiating the clinical presentation of symptoms of TD from the effects of deafness, as well as in implementing appropriate interventions. This case study reports the history, symptoms, diagnostic process, and treatment interventions. This is relevant for furthering the clinical knowledge of mental health professionals working with Deaf, deaf, and hard-of-hearing children and adolescents.
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 …
Acute Alcohol Consumption Impairs Controlled But Not Automatic Processes In A Psychophysical Pointing Paradigm., Kevin Johnston, Brian Timney, Melvyn A Goodale
Acute Alcohol Consumption Impairs Controlled But Not Automatic Processes In A Psychophysical Pointing Paradigm., Kevin Johnston, Brian Timney, Melvyn A Goodale
Brain and Mind Institute Researchers' Publications
Numerous studies have investigated the effects of alcohol consumption on controlled and automatic cognitive processes. Such studies have shown that alcohol impairs performance on tasks requiring conscious, intentional control, while leaving automatic performance relatively intact. Here, we sought to extend these findings to aspects of visuomotor control by investigating the effects of alcohol in a visuomotor pointing paradigm that allowed us to separate the influence of controlled and automatic processes. Six male participants were assigned to an experimental "correction" condition in which they were instructed to point at a visual target as quickly and accurately as possible. On a small …