Sensorimotor input as a language generalisation tool: a neurorobotics model for generation and generalisation of noun-verb combinations with sensorimotor inputs

The paper presents a neurorobotics cognitive model explaining the understanding and generalisation of nouns and verbs combinations when a vocal command consisting of a verb-noun sentence is provided to a humanoid robot. The dataset used for training was obtained from object manipulation tasks with a humanoid robot platform; it includes 9 motor actions and 9 objects placing placed in 6 different locations), which enables the robot to learn to handle real-world objects and actions. Based on the multiple time-scale recurrent neural networks, this study demonstrates its generalisation capability using a large data-set, with which the robot was able to generalise semantic representation of novel combinations of noun-verb sentences, and therefore produce the corresponding motor behaviours. This generalisation process is done via the grounding process: different objects are being interacted, and associated, with different motor behaviours, following a learning approach inspired by developmental language acquisition in infants. Further analyses of the learned network dynamics and representations also demonstrate how the generalisation is possible via the exploitation of this functional hierarchical recurrent network

Short-term fluctuations in heavy metal concentrations in Antarctic snow

Heavy metal variations in polar ice cores may reflect changes in global airborne pollution1. Reported profiles from Antarctica1–3 and Greenland4, where sampling resolution was normally larger than a year, have shown a much greater variability than can be reasonably accounted for by variations in the annually smoothed emissions of anthropogenic sources and most natural sources. Volcanism has been invoked4 to account for major features. We now report data from a finely resolved sample sequence from a remote plateau region of the Antarctic Peninsula. Variations of similar magnitude to those reported for longer time series occur also on the scale of seasonal changes and even of single snowfalls; these must be controlled by meteorological processes. We conclude that changes in large-scale transport processes and depositional mechanisms on longer tune scales may have as important a role as emission rates in generating the concentration profiles observed in deeper ice cores