Comprehension of Co-Speech Gestures in Aphasic Patients: An Eye Movement Study.

BACKGROUND: Co-speech gestures are omnipresent and a crucial element of human interaction by facilitating language comprehension. However, it is unclear whether gestures also support language comprehension in aphasic patients. Using visual exploration behavior analysis, the present study aimed to investigate the influence of congruence between speech and co-speech gestures on comprehension in terms of accuracy in a decision task. METHOD: Twenty aphasic patients and 30 healthy controls watched videos in which speech was either combined with meaningless (baseline condition), congruent, or incongruent gestures. Comprehension was assessed with a decision task, while remote eye-tracking allowed analysis of visual exploration. RESULTS: In aphasic patients, the incongruent condition resulted in a significant decrease of accuracy, while the congruent condition led to a significant increase in accuracy compared to baseline accuracy. In the control group, the incongruent condition resulted in a decrease in accuracy, while the congruent condition did not significantly increase the accuracy. Visual exploration analysis showed that patients fixated significantly less on the face and tended to fixate more on the gesturing hands compared to controls. CONCLUSION: Co-speech gestures play an important role for aphasic patients as they modulate comprehension. Incongruent gestures evoke significant interference and deteriorate patients' comprehension. In contrast, congruent gestures enhance comprehension in aphasic patients, which might be valuable for clinical and therapeutic purposes.

Transdisciplinary co-production of knowledge in the development of organic agriculture in Switzerland

The present study analyses transdisciplinary co-production of knowledge in the development of organic farming in Switzerland by using Fleck's theory of thought styles and thought collectives. Three different phases can be identified throughout the historical development. The initial phase lasting from the beginning of the 1920s to the early 1970s contains numerous characteristics of diverse well-established definitions and concepts of transdisciplinarity and represents a successful transdisciplinary process, which has not been perceived as such in the past and present scientific discussion. The second and third phases show an increasing segregation of thought collectives, caused by internal changes such as the establishment of specialised research institutions and external processes like agriculture policy and market development. These developments led to a decreasing degree of transdisciplinarity. We observe an ambiguous trend: the continuously growing and today well-established positive societal recognition of an initially rather little accepted newcomer movement is associated with the gradual loss of its very valuable forms of knowledge co-production and the related philosophical background. In order to maintain the various forms of transdisciplinary co-production of knowledge, one has to reflect not only their results or outcome but also the whole cooperation process, which has led to these results. The understanding of the historical development and characteristic features of knowledge co-production as presented in this study will help to reinforce transdisciplinary research in organic agriculture and research on transdisciplinarity in general.