[koglist] meghívó - Dr. Olaf Hauk - Spatio-temporal brain dynamics of word recognition

Tisztelt Kollégák! Az MTA TTK Agyi Képalkotó Központ meghívására dr. Olaf Hauk, az MRC Cognition and Brain Sciences Unit (Cambridge, UK) munkatársa "Spatio-temporal brain dynamics of word recognition" címmel elo"adást fog tartani május 20-án, 16:00-tól. Szeretettel várunk mindenkit, a meghívót nyugodtan küldjék tovább a potenciális érdeklo"do"knek. Részvételi szándékukat a weiss.bela(a)ttk.mta.hu e-mail címen jelezzék. Helyszín: Magyar Tudományos Akadémia Természettudományi Kutatóközpont 1117 Budapest, Magyar tudósok körútja 2. földszinti elo"adóterem Tisztelettel, Weiss Béla, MSc, PhD MTA TTK Agyi Képalkotó Központ Abstract: We retrieve the meaning of a written word within a fraction of a second, thereby distinguishing it from more than 10000 other words in our vocabulary. Behavioural experiments have revealed a large number of variables that affect the word recognition process, and have been used to constrain models of visual word recognition. However, most behavioural measures reflect the end point of a complex decision process, and can provide only indirect evidence about the timing and ordering of the corresponding sub-processes. Furthermore, different behavioural measures, such as eye movements during reading or button presses in laboratory tasks, can yield different conclusions even for established findings such as the word frequency effect. I will present recent results from studies using behavioural measures as well as electro- and magnetoencephalography (EEG/MEG). EEG/MEG can provide insights into spatio-temporal brain dynamics with millisecond temporal resolution and reasonable spatial resolution. The results show that lexical and semantic information retrieval can start in parallel within less than a quarter of a second, as the result of a fast sweep through the ventral stream, ending in anterior temporal lobes. Lexical variables modulate brain responses at several distinct latencies, indicating for example that "the" word frequency effect is in fact spread over several stages of the word recognition process. With respect to semantics, we used a novel motor priming paradigm to demonstrate early involvement of cortical motor systems in action-word processing. Early brain responses in word recognition were found to be modulated by task demands, suggesting that early word recognition processes are more flexible and less automatic than previously thought.