Perception of co-speech gestures in aphasic patients: A visual exploration study during the observation of dyadic conversations

Background: Co-speech gestures are part of nonverbal communication during conversations. They either support the verbal message or provide the interlocutor with additional information. Furthermore, they prompt as nonverbal cues the cooperative process of turn taking. In the present study, we investigated the influence of co-speech gestures on the perception of dyadic dialogue in aphasic patients. In particular, we analysed the impact of co-speech gestures on gaze direction (towards speaker or listener) and fixation of body parts. We hypothesized that aphasic patients, who are restricted in verbal comprehension, adapt their visual exploration strategies. Methods: Sixteen aphasic patients and 23 healthy control subjects participated in the study. Visual exploration behaviour was measured by means of a contact-free infrared eye-tracker while subjects were watching videos depicting spontaneous dialogues between two individuals. Cumulative fixation duration and mean fixation duration were calculated for the factors co-speech gesture (present and absent), gaze direction (to the speaker or to the listener), and region of interest (ROI), including hands, face, and body. Results: Both aphasic patients and healthy controls mainly fixated the speaker’s face. We found a significant co-speech gesture x ROI interaction, indicating that the presence of a co-speech gesture encouraged subjects to look at the speaker. Further, there was a significant gaze direction x ROI x group interaction revealing that aphasic patients showed reduced cumulative fixation duration on the speaker’s face compared to healthy controls. Conclusion: Co-speech gestures guide the observer’s attention towards the speaker, the source of semantic input. It is discussed whether an underlying semantic processing deficit or a deficit to integrate audio-visual information may cause aphasic patients to explore less the speaker’s face. Keywords: Gestures, visual exploration, dialogue, aphasia, apraxia, eye movements

Solar radiation over and under sea ice and photographic quantification of Ice algal aggregates during the POLARSTERN cruise ARK-XXVII/3 (IceArc) in summer 2012

The ice cover of the Arctic Ocean has been changing dramatically in the last decades and the consequences for the sea-ice associated ecosystem remain difficult to assess. Algal aggregates underneath sea ice have been described sporadically but the frequency and distribution of their occurrence is not well quantified. We used upward looking images obtained by a remotely operated vehicle (ROV) to derive estimates of ice algal aggregate biomass and to investigate their spatial distribution. During the IceArc expedition (ARK-XXVII/3) of RV Polarstern in late summer 2012, different types of algal aggregates were observed floating underneath various ice types in the Central Arctic basins. Our results show that the floe scale distribution of algal aggregates in late summer is very patchy and determined by the topography of the ice underside, with aggregates collecting in dome shaped structures and at the edges of pressure ridges. The buoyancy of the aggregates was also evident from analysis of the aggregate size distribution. Different approaches used to estimate aggregate biomass yield a wide range of results. This highlights that special care must be taken when upscaling observations and comparing results from surveys conducted using different methods or on different spatial scales.

Aprender a ser docentes con el cine de Miyazaki

El presente artículo plantea la incorporación del cine como argumento válido para la formación del profesorado. Consideramos que el cine incluye suficientes mecanismos para involucrar la educación en artes visuales, la educación en medios, y la educación musical. Entre los directores más relevantes del panorama internacional, proponemos la figura de Hayao Miyazaki. Este creador japonés ha sabido atraer a públicos de todas las edades y culturas a lo largo de su dilatada carrera profesional. La calidad técnica de los trabajos de Miyazaki va acompañada de una serie de valores que resultan muy válidos para incorporar acciones educativas de respeto al medio natural y a las tradiciones culturales. Pensamos que los maestros de educación primaria han de estar preparados para fomentar este tipo de valores entre el alumnado. Tanto la educación artística como el cine son entornos muy atractivos para lograrlo. Hemos observado y analizado a un grupo de estudiantes de grado de Maestro de primaria mientras miraban la película Ponyo en el acantilado. Planteamos un mayor uso del cine como recurso educativo (Ambrós y Breu, 2007; Fedorov, 2010). Animamos al profesorado y al alumnado a realizar nuevas lecturas críticas y personales del cine, indagando más allá del conocimiento del medio como mero entretenimiento (Clarembeaux, 2010; Hernández, 2000; Huerta, 2006)