Shillingford, Brendan
The Brain's Bitter Lesson: Scaling Speech Decoding With Self-Supervised Learning
Jayalath, Dulhan, Landau, Gilad, Shillingford, Brendan, Woolrich, Mark, Jones, Oiwi Parker
The past few years have produced a series of spectacular advances in the decoding of speech from brain activity. The engine of these advances has been the acquisition of labelled data, with increasingly large datasets acquired from single subjects. However, participants exhibit anatomical and other individual differences, and datasets use varied scanners and task designs. As a result, prior work has struggled to leverage data from multiple subjects, multiple datasets, multiple tasks, and unlabelled datasets. In turn, the field has not benefited from the rapidly growing number of open neural data repositories to exploit large-scale data and deep learning. To address this, we develop an initial set of neuroscience-inspired self-supervised objectives, together with a neural architecture, for representation learning from heterogeneous and unlabelled neural recordings. Experimental results show that representations learned with these objectives scale with data, generalise across subjects, datasets, and tasks, and are also learned faster than using only labelled data. In addition, we set new benchmarks for two foundational speech decoding tasks. Taken together, these methods now unlock the potential for training speech decoding models with orders of magnitude more existing data.
Learning to learn by gradient descent by gradient descent
Andrychowicz, Marcin, Denil, Misha, Gómez, Sergio, Hoffman, Matthew W., Pfau, David, Schaul, Tom, Shillingford, Brendan, Freitas, Nando de
The move from hand-designed features to learned features in machine learning has been wildly successful. In spite of this, optimization algorithms are still designed by hand. In this paper we show how the design of an optimization algorithm can be cast as a learning problem, allowing the algorithm to learn to exploit structure in the problems of interest in an automatic way. Our learned algorithms, implemented by LSTMs, outperform generic, hand-designed competitors on the tasks for which they are trained, and also generalize well to new tasks with similar structure. We demonstrate this on a number of tasks, including simple convex problems, training neural networks, and styling images with neural art.
Cortical microcircuits as gated-recurrent neural networks
Costa, Rui, Assael, Ioannis Alexandros, Shillingford, Brendan, Freitas, Nando de, Vogels, TIm
Cortical circuits exhibit intricate recurrent architectures that are remarkably similar across different brain areas. Such stereotyped structure suggests the existence of common computational principles. However, such principles have remained largely elusive. Inspired by gated-memory networks, namely long short-term memory networks (LSTMs), we introduce a recurrent neural network in which information is gated through inhibitory cells that are subtractive (subLSTM). We propose a natural mapping of subLSTMs onto known canonical excitatory-inhibitory cortical microcircuits.
Make Up Your Mind! Adversarial Generation of Inconsistent Natural Language Explanations
Camburu, Oana-Maria, Shillingford, Brendan, Minervini, Pasquale, Lukasiewicz, Thomas, Blunsom, Phil
To increase trust in artificial intelligence systems, a growing amount of works are enhancing these systems with the capability of producing natural language explanations that support their predictions. In this work, we show that such appealing frameworks are nonetheless prone to generating inconsistent explanations, such as "A dog is an animal" and "A dog is not an animal", which are likely to decrease users' trust in these systems. To detect such inconsistencies, we introduce a simple but effective adversarial framework for generating a complete target sequence, a scenario that has not been addressed so far. Finally, we apply our framework to a state-of-the-art neural model that provides natural language explanations on SNLI, and we show that this model is capable of generating a significant amount of inconsistencies.
Sample Efficient Adaptive Text-to-Speech
Chen, Yutian, Assael, Yannis, Shillingford, Brendan, Budden, David, Reed, Scott, Zen, Heiga, Wang, Quan, Cobo, Luis C., Trask, Andrew, Laurie, Ben, Gulcehre, Caglar, Oord, Aäron van den, Vinyals, Oriol, de Freitas, Nando
We present a meta-learning approach for adaptive text-to-speech (TTS) with few data. During training, we learn a multi-speaker model using a shared conditional WaveNet core and independent learned embeddings for each speaker. The aim of training is not to produce a neural network with fixed weights, which is then deployed as a TTS system. Instead, the aim is to produce a network that requires few data at deployment time to rapidly adapt to new speakers. We introduce and benchmark three strategies: (i) learning the speaker embedding while keeping the WaveNet core fixed, (ii) fine-tuning the entire architecture with stochastic gradient descent, and (iii) predicting the speaker embedding with a trained neural network encoder. The experiments show that these approaches are successful at adapting the multi-speaker neural network to new speakers, obtaining state-of-the-art results in both sample naturalness and voice similarity with merely a few minutes of audio data from new speakers.
Cortical microcircuits as gated-recurrent neural networks
Costa, Rui Ponte, Assael, Yannis M., Shillingford, Brendan, de Freitas, Nando, Vogels, Tim P.
Cortical circuits exhibit intricate recurrent architectures that are remarkably similar across different brain areas. Such stereotyped structure suggests the existence of common computational principles. However, such principles have remained largely elusive. Inspired by gated-memory networks, namely long short-term memory networks (LSTMs), we introduce a recurrent neural network in which information is gated through inhibitory cells that are subtractive (subLSTM). We propose a natural mapping of subLSTMs onto known canonical excitatory-inhibitory cortical microcircuits. Our empirical evaluation across sequential image classification and language modelling tasks shows that subLSTM units can achieve similar performance to LSTM units. These results suggest that cortical circuits can be optimised to solve complex contextual problems and proposes a novel view on their computational function. Overall our work provides a step towards unifying recurrent networks as used in machine learning with their biological counterparts.
Cortical microcircuits as gated-recurrent neural networks
Costa, Rui, Assael, Ioannis Alexandros, Shillingford, Brendan, Freitas, Nando de, Vogels, TIm
Cortical circuits exhibit intricate recurrent architectures that are remarkably similar across different brain areas. Such stereotyped structure suggests the existence of common computational principles. However, such principles have remained largely elusive. Inspired by gated-memory networks, namely long short-term memory networks (LSTMs), we introduce a recurrent neural network in which information is gated through inhibitory cells that are subtractive (subLSTM). We propose a natural mapping of subLSTMs onto known canonical excitatory-inhibitory cortical microcircuits. Our empirical evaluation across sequential image classification and language modelling tasks shows that subLSTM units can achieve similar performance to LSTM units. These results suggest that cortical circuits can be optimised to solve complex contextual problems and proposes a novel view on their computational function. Overall our work provides a step towards unifying recurrent networks as used in machine learning with their biological counterparts.
Learning to learn by gradient descent by gradient descent
Andrychowicz, Marcin, Denil, Misha, Gómez, Sergio, Hoffman, Matthew W., Pfau, David, Schaul, Tom, Shillingford, Brendan, Freitas, Nando de
The move from hand-designed features to learned features in machine learning has been wildly successful. In spite of this, optimization algorithms are still designed by hand. In this paper we show how the design of an optimization algorithm can be cast as a learning problem, allowing the algorithm to learn to exploit structure in the problems of interest in an automatic way. Our learned algorithms, implemented by LSTMs, outperform generic, hand-designed competitors on the tasks for which they are trained, and also generalize well to new tasks with similar structure. We demonstrate this on a number of tasks, including simple convex problems, training neural networks, and styling images with neural art.