Deep Learning based Recommender System: A Survey and New Perspectives

With the ever-growing volume of online information, recommender systems have been an effective strategy to overcome such information overload. The utility of recommender systems cannot be overstated, given its widespread adoption in many web applications, along with its potential impact to ameliorate many problems related to over-choice. In recent years, deep learning has garnered considerable interest in many research fields such as computer vision and natural language processing, owing not only to stellar performance but also the attractive property of learning feature representations from scratch. The influence of deep learning is also pervasive, recently demonstrating its effectiveness when applied to information retrieval and recommender systems research. Evidently, the field of deep learning in recommender system is flourishing. This article aims to provide a comprehensive review of recent research efforts on deep learning based recommender systems. More concretely, we provide and devise a taxonomy of deep learning based recommendation models, along with providing a comprehensive summary of the state-of-the-art. Finally, we expand on current trends and provide new perspectives pertaining to this new exciting development of the field.Comment: The paper has been accepted by ACM Computing Surveys. https://doi.acm.org/10.1145/328502

Effects of Music Training on Cortical Plasticity: : Cognitive Rehabilitation of Patients with Traumatic Brain Injury

The aim of this thesis was to explore the neuroplastic effects of playing the piano on patients with cognitive impairment following a mild traumatic brain injury (mTBI). It was hypothesised that playing the piano would stimulate neural networks to re-route neural connections and link up cortical circuits that had been functionally inhibited due to minor disruption of brain tissue. The objective of the intervention was to restore the patients’ cognitive processing to pre-injury levels. The study was designed as a pilot study with three experimental groups: (1) 7 patients with cognitive deficits following mTBI two years post-injury (Group 1), (2) 11 healthy subjects (Group 2), and (3) 12 further healthy subjects (Group 3). A between-group design and a longitudinal (pre-post-intervention) within-subject design were applied. Groups 1 and 2 were given eight weeks of piano training. A combination of cognitive and functional neuroimaging (task-based and resting-state fMRI) in addition to neuropsychological tests were performed pre- and post-intervention for all three groups. The results concurrently demonstrated in two independent analyses and fMRI datasets that longitudinal changes in functional connectivity took place within the orbitofrontal cortex (OFC) in the mTBI patient group only, showing increased connectivity between the OFC regions post-intervention involved in executive functions (EF), social cognition and emotional regulation. This finding provides support for the contribution of the OFC as a key mechanism that potentially drives the cognitive benefit of piano training in TBI, and further suggests a network of other connected frontal regions that may be linked to this. The key findings of this study could suggest a causal relationship between musical training and a functional reorganisation of neural networks that promotes enhanced cognitive performance. These results might hold promise as regards adding a novel music-based intervention to the cognitive rehabilitation of mTBI patients.Doktorgradsavhandlin

Effects of music production on cortical plasticity within cognitive rehabilitation of patients with mild traumatic brain injury

Objective: We explored the effects of playing the piano on patients with cognitive impairment after mild traumatic brain injury (mTBI) and, addressed the question if this approach would stimulate neural networks in re-routing neural connections and link up cortical circuits that had been functional inhibited due to disruption of brain tissue. Functional neuroimaging scans (fMRI) and neuropsychological tests were performed pre–post intervention. Method: Three groups participated, one mTBI group (n = 7), two groups of healthy participants, one with music training (n = 11), one baseline group without music (n = 12). The music groups participated in 8 weeks music-supported intervention. Results: The patient group revealed training-related neuroplasticity in the orbitofrontal cortex. fMRI results fit well with outcome from neuropsychological tests with significant enhancement of cognitive performance in the music groups. Ninety per cent of mTBI group returned to work post intervention. Conclusion: Here, for the first time, we demonstrated behavioural improvements and functional brain changes after 8 weeks of playing piano on patients with mTBI having attention, memory and social interaction problems. We present evidence for a causal relationship between musical training and reorganisation of neural networks promoting enhanced cognitive performance. These results add a novel music-supported intervention within rehabilitation of patients with cognitive deficits following mTBI.publishedVersio