Speech segmentation in aphasia

Background: Speech segmentation is one of the initial and mandatory phases of language learning. Although some people with aphasia have shown a preserved ability to learn novel words, their speech segmentation abilities have not been explored.

Aims: We examined the ability of individuals with chronic aphasia to segment words from running speech via statistical learning. We also explored the relationships between speech segmentation and aphasia severity, and short-term memory capacity. We further examined the role of lesion location in speech segmentation and short-term memory performance.

Methods & Procedures: The experimental task was first validated with a group of young adults (n = 120). Participants with chronic aphasia (n = 14) were exposed to an artificial language and were evaluated in their ability to segment words using a speech segmentation test. Their performance was contrasted against chance level and compared to that of a group of elderly matched controls (n = 14) using group and case-by-case analyses.

Outcomes & Results: As a group, participants with aphasia were significantly above chance level in their ability to segment words from the novel language and did not significantly differ from the group of elderly controls. Speech segmentation ability in the aphasic participants was not associated with aphasia severity although it significantly correlated with word pointing span, a measure of verbal short-term memory. Case-by-case analyses identified four individuals with aphasia who performed above chance level on the speech segmentation task, all with predominantly posterior lesions and mild fluent aphasia. Their short-term memory capacity was also better preserved than in the rest of the group.

Conclusions: Our findings indicate that speech segmentation via statistical learning can remain functional in people with chronic aphasia and suggest that this initial language learning mechanism is associated with the functionality of the verbal short-term memory system and the integrity of the left inferior frontal region.     

Hybrid forum or network? The social and political construction of an international ‘technical consultation’: Male circumcision and HIV prevention

The technical consultation in Montreux, organised by World Health Organization and UNAIDS in 2007, recommended male circumcision as a method for preventing HIV transmission. This consultation came out of a long process of releasing reports and holding international and regional conferences, a process steered by an informal network. This network's relations with other parties is analysed along with its way of working and the exchanges during the technical consultation that led up to the formal adoption of a recommendation. Conducted in relation to the concepts of a ‘hybrid forum’ and ‘network’, this article shows that the decision was based on the formation and consolidation of a network of persons. They were active in all phases of this process, ranging from studies of the recommendation's efficacy, feasibility and acceptability to its adoption and implementation. In this sense, this consultation cannot be described as the constitution of a ‘hybrid forum’, which is characterised by its openness to a debate as well as a plurality of issues formulated by the actors and of resources used by them. On the contrary, little room was allowed for contradictory discussions, as if the decision had already been made before the Montreux consultation.