Studies of language in Alzheimer's disease have concluded that, along with a general cognitive decline, linguistic features are also negatively affected. Studies of the language of healthy elders also observe a linguistic decline, but one which, in contrast, is markedly less severe than that induced by dementia.  We examine whether the disease can be detected from the diachronic changes in written texts and, more importantly, whether it can be clearly distinguished from normal aging.

Lexical and syntactic analyses were conducted on 51 novels by three prolific literary authors: Iris Murdoch, P.D. James, and Agatha Christie. Murdoch was diagnosed with Alzheimer's disease shortly after finishing her last novel; James, at 89 years of age, continues to publish critically-acclaimed works; Christie, whose last few novels are deemed strikingly subpar compared to her previous works, presents an interesting case study of possible dementia.

The lexical analysis reveals significant patterns of decline in Murdoch's and Christie's later novels, while James's rates remain relatively consistent throughout her career. The syntactic measures, though unveiling fewer significant linear trends, discover a cubic model of change in Murdoch's novels, with a deep decline around her 50s. Our findings provide support for the hypothesis that dementia, which manifests clearly in lexical features, can be detected in writing.

Graeme Hirst (Toronto)

(Joint work with Xuan Le, Ian Lancashire, and Regina Jokel)

Ioanna Papadopoulou in the MLT programme will defend her master's thesis "GF Modern Greek Resource Grammar".

The thesis describes the implementation of the Modern Greek grammar as part of the Grammatical Framework Resource Grammar Library (RGL).

Grammatical Framework (GF) is a special-purpose language for multilingual grammar applications. The RGL is a reusable library for dealing with the morphology and syntax of a growing number of natural languages. It uses an abstract syntax, which is common for all languages, and different concrete syntaxes implemented in GF. Both GF itself and the GF Resource Grammar Library are open-source.

The Modern Greek grammar covers all morphological variations of the language and contains definitions and rules for all the categories and functions that are provided in the GF abstract syntax, managing to fulfill the multilingualism purpose of the GF, and correlate the language with the various other languages in the RGL.

For the purpose of the implementation, a morphology-driven approach was used, meaning a bottom-up method, starting from the smallest units of the language (the words) before moving to the larger units (the sentences). We discuss the number of challenges we encountered during the development process, that originate primarily from the complexity of the Modern Greek language, both in a syntactic but mainly in a morphological level, and also from the difficulty to attribute forms and structures that derive solely from a semantic level and the choice of which, in actual speech situations, depends exclusively on the speaker itself.

Supervisor: Aarne Ranta
Opponent: Sevasti Louizou
Examiner: Torbjörn Lager

Benjamin Glass and Rajsekhar Iyer in the MLT programme will defend there master's thesis "A Dialog Based Search System".

This thesis describes the creation of a chat-based dialog system for the purpose of drilling down search engine results in an easy to use manner. We describe the use of named entity recognition in facet based filtering of search results as well as n-grams for query refinement. We then evaluate the system using a survey and present the results of the evaluation.

Supervisors: Peter Ljunglöf, Svetoslav Marinov, and Alexander Berman
Opponent: Apostolos Apostolidis
Examiner: Torbjörn Lager

Apostolos Apostolidis in the MLT programme will defend his master's thesis "Text-to-Speech News Article Reader on Talkamatic Dialog Manager".

This thesis describes the development of an automatic text-to-speech News Article Reader (NAR) on Talkamatic Dialog Manager (TDM). TDM is an issue-based dialog manager developed by Talkamatic and enables the building of complex multi-modal applications. NAR is an application that provides multi-modal access to news article abstracts, basic full article reading functions and a number of preference functionalities.

NAR was built by implementing specific dialogue design techniques and adapting them to enhance the intuitiveness and efficiency of the application. It is also examined as a demonstration on how TDM's strongest features can enhance application development and how its current limitations can be overcome. Additionally, it serves as a proving ground for a stream ranking algorithm that was adapted from the Reddit one to better meet NAR's requirements. Lastly, a reflection is made on the application's usability, based on results of a number of small evaluation sessions.

Supervisors: Peter Ljunglöf and Alexander Berman
Opponent: Rajsekhar Iyer
Examiner: Torbjörn Lager