The 47th Language Lunch
Date: 2015-04-30
Location: G.07 Informatics Forum
An fMRI study of semantic diversity effects upon the semantic network
Ellise,Suffill; None; None
Semantic diversity in language has been found to increase processing costs on both a behavioural (RT) and neural basis, reflecting diversity within the mental representation required to process a concept, or narrative event. Semantic diversity refers to the range of associations and contexts of occurrence an event can be linked to (Coll-Florit & Gennari, 2011). Concept imageability has been linked to semantic diversity, with neuroimaging studies revealing differential activations across left frontal and temporal lobe regions for varying degrees of imageability in sentence comprehension (Rodríguez-Ferreiro, Gennari, Davies and Cuetos, 2011). Another aspect that has demonstrated similar behavioural effects due to semantic diversity is narrative event duration. Event duration in such narratives affects retrieval time in behavioural tasks and this has been attributed to greater semantic diversity for events of longer durations. However, little is known regarding the neural basis of representations for narrative event duration. This exploratory fMRI study aimed to investigate the neural mechanisms underlying semantic processing across the domains of imageabiltiy and event duration, and how semantic diversity may affect such processing across these domains.
Graph Regularised Hashing
Sean,Morran; None; None
Hashing has witnessed an increase in popularity over the past few years due to the promise of compact encoding and fast query time. In order to be effective hashing methods must maximally preserve the similarity between the data points in the underlying binary representation. The current best performing hashing techniques have utilised supervision. In this paper we propose a two-step iterative scheme, Graph Regularised Hashing (GRH), for incrementally adjusting the positioning of the hashing hypersurfaces to better conform to the supervisory signal: in the first step the binary bits are regularised using a data similarity graph so that similar data points receive similar bits. In the second step the regularised hashcodes form targets for a set of binary classi fiers which shift the position of each hypersurface so as to separate opposite bits with maximum margin. GRH exhibits superior retrieval accuracy to competing hashing methods.
Sampling Techniques for Streaming Cross Document Coreference Resolution
Luke,Shrimpton; None; None
We present the first truly streaming cross document coreference resolution (CDC) system. Processing infinite streams of mentions forces us to use a constant amount of memory and so we maintain a representative, fixed sized sample at all times. For the sample to be representative it should represent a large number of entities whilst taking into account both temporal recency and distant references. We introduce new sampling techniques that take into account a notion of streaming discourse (current mentions depend on previous mentions). Using the proposed sampling techniques we are able to get a CEAFe score within 5% of a non-streaming system while using only 30% of the memory.
Language learning as cognitive training: attentional improvement after a one-week intensive Gaelic course
Madeleine,Long; None; None
We investigated whether an intensive one-week language course would influence cognitive functions. We tested auditory attention in 31 participants at the beginning and end of a one-week intensive Gaelic course and compared the results to 34 matched controls, who either followed their usual routines (passive controls, n=18) or participated in a course of comparable duration and intensity but not involving foreign language learning (active controls, n=16). There was no difference between the groups in any of the measures at the beginning of the course. At the end of the course, the language but not the control group showed a significant improvement in attention switching, independent of the age of participants (age range 18-75 years). The improvement was biggest in the beginners. Our results suggest that even a short period of intensive language learning can modulate attentional functions and that all age groups can benefit from this effect.
