4 results on '"Benjamin Cowley"'
Search Results
2. Dynamic thresholds for self-organizing predictive cells
- Author
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Abdul Sattar, John Thornton, Benjamin Cowley, and Linda Main
- Subjects
0301 basic medicine ,Self-organization ,Computer science ,business.industry ,media_common.quotation_subject ,Machine learning ,computer.software_genre ,Adaptability ,Hierarchical temporal memory ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Metric (mathematics) ,Anomaly detection ,Artificial intelligence ,Sequence learning ,business ,computer ,030217 neurology & neurosurgery ,Brain function ,Generative grammar ,media_common - Abstract
It has become increasingly popular to view the brain as a prediction machine. This view has informed a number of theories of brain function, the most prominent being predictive processing, where generative hypotheses are iteratively updated by error signals. In this treatment we take a lower level approach by examining the hierarchical temporal memory framework, which views individual pyramidal cells as the primary predictive unit of a self-organizing networked sequence learning system. Within this computational framework, the cell behaviour is constrained by a number of parameters which are static and shared across all cells. To further increase the adaptability of the cells, we shift away from this paradigm by introducing the concept of dynamic thresholds. This allows for the activation threshold (the amount of activity on a distal dendrite needed to form a prediction) to be adjusted continuously and individually for each cell. As a metric we use the prior, or unconditional, probability of activity on t...
- Published
- 2017
3. Feedback Modulated Attention Within a Predictive Framework
- Author
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John Thornton and Benjamin Cowley
- Subjects
0301 basic medicine ,Cognitive science ,Predictive coding ,Computer science ,business.industry ,media_common.quotation_subject ,Cognition ,Stimulus (physiology) ,Hierarchical temporal memory ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,Connectionism ,Filter (video) ,Perception ,Artificial intelligence ,business ,030217 neurology & neurosurgery ,media_common - Abstract
Attention is both ubiquitous throughout and key to our cognitive experience. It has been shown to filter out mundane stimuli, while simultaneously communicating specific stimuli from the lowest levels of perception through to the highest levels of cognition. In this paper we present a connectionist system with mechanisms that produce both exogenous (bottom-up) and endogenous (top-down) attention. The foundational algorithm of our system is the Temporal Pooler (TP), a neocortically inspired algorithm that learns and predicts temporal sequences. We make a number of modifications to the Temporal Pooler and place it in a framework which is inspired by predictive coding. We use a novel technique in which feedback connections elicit endogenous attention by disrupting the learned representations of attended sequences. Our experiments show that this approach successfully filters attended stimuli and suppresses unattended stimuli.
- Published
- 2016
4. Epileptic Electroencephalography Profile Associates with Attention Problems in Children with Fragile X Syndrome: Review and Case Series
- Author
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Benjamin Cowley, Svetlana Kirjanen, Juhani Partanen, Maija Liisa Castrén, Behavioural Sciences, Department of Neurosciences, Kliinisen neurofysiologian yksikkö, Clinicum, Medicum, Department of Physiology, and NeuroDevDiseaseModelling
- Subjects
HYPERACTIVITY ,3124 Neurology and psychiatry ,Epilepsy ,Behavioral Neuroscience ,0302 clinical medicine ,Intellectual disability ,fragile X syndrome ,SPECIFICITY ,Original Research ,education.field_of_study ,05 social sciences ,neurofeedback ,Quantitative electroencephalography ,3. Good health ,Fragile X syndrome ,endophenotype ,Psychiatry and Mental health ,Neuropsychology and Physiological Psychology ,Neurology ,MALES ,Autism spectrum disorder ,Psychology ,electroencephalography ,medicine.medical_specialty ,515 Psychology ,Population ,attention deficit disorder ,clinical case study ,050105 experimental psychology ,lcsh:RC321-571 ,03 medical and health sciences ,QUANTITATIVE EEG ,medicine ,ADHD ,0501 psychology and cognitive sciences ,AUTISM ,Psychiatry ,education ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,METAANALYSIS ,Biological Psychiatry ,clinical case series ,3112 Neurosciences ,medicine.disease ,GENE ,Endophenotype ,Autism ,3111 Biomedicine ,DEFICIT/HYPERACTIVITY DISORDER ,030217 neurology & neurosurgery ,Neuroscience - Abstract
Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability and a variant of autism spectrum disorder (ASD). The FXS population is quite heterogeneous with respect to comorbidities, which implies the need for a personalized medicine approach, relying on biomarkers or endophenotypes to guide treatment. There is evidence that quantitative electroencephalography (EEG) endophenotype-guided treatments can support increased clinical benefit by considering the patient's neurophysiological profile. We describe a case series of 11 children diagnosed with FXS, aged one to 14 years, mean 4.6 years. Case data are based on longitudinal clinically-observed reports by attending physicians for comorbid symptoms including awake and asleep EEG profiles. We tabulate the comorbid EEG symptoms in this case series, and relate them to the literature on EEG endophenotypes and associated treatment options. The two most common endophenotypes in the data were diffuse slow oscillations and epileptiform EEG, which have been associated with attention and epilepsy respectively. This observation agrees with reported prevalence of comorbid behavioral symptoms for FXS. In this sample of FXS children, attention problems were found in 37% (4 of 11), and epileptic seizures in 45% (5 of 11). Attention problems were found to associate with the epilepsy endophenotype. From the synthesis of this case series and literature review, we argue that the evidence-based personalized treatment approach, exemplified by neurofeedback, could benefit FXS children by focusing on observable, specific characteristics of comorbid disease symptoms.
- Published
- 2016
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