Browsing by Subject "SYNCHRONIZATION"

Sort by: Order: Results:

Now showing items 1-5 of 5
  • Zhdanov, Andrey; Nurminen, Jussi; Baess, Pamela; Hirvenkari, Lotta; Jousmaki, Veikko; Makela, Jyrki P.; Mandel, Anne; Meronen, Lassi; Hari, Riitta; Parkkonen, Lauri (2015)
    Hyperscanning Most neuroimaging studies of human social cognition have focused on brain activity of single subjects. More recently, "two-person neuroimaging" has been introduced, with simultaneous recordings of brain signals from two subjects involved in social interaction. These simultaneous "hyperscanning" recordings have already been carried out with a spectrum of neuroimaging modalities, such as functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and functional near-infrared spectroscopy (fNIRS). Dual MEG Setup We have recently developed a setup for simultaneous magnetoencephalographic (MEG) recordings of two subjects that communicate in real time over an audio link between two geographically separated MEG laboratories. Here we present an extended version of the setup, where we have added a video connection and replaced the telephone-landline-based link with an Internet connection. Our setup enabled transmission of video and audio streams between the sites with a one-way communication latency of about 130 ms. Our software that allows reproducing the setup is publicly available. Validation We demonstrate that the audiovisual Internet-based link can mediate real-time interaction between two subjects who try to mirror each others' hand movements that they can see via the video link. All the nine pairs were able to synchronize their behavior. In addition to the video, we captured the subjects' movements with accelerometers attached to their index fingers; we determined from these signals that the average synchronization accuracy was 215 ms. In one subject pair we demonstrate inter-subject coherence patterns of the MEG signals that peak over the sensorimotor areas contralateral to the hand used in the task.
  • Savolainen, Irina; Klippi, Anu; Launonen, Kaisa (2018)
  • Ta, Hung Xuan; Yoon, Chang No; Holm, Liisa; Han, Seung Kee (2010)
  • Haque, Hamed; Lobier, Muriel; Palva, J. Matias; Palva, Satu (2020)
    Stimuli may induce only partial consciousness—an intermediate between null and full consciousness—where the presence but not identity of an object can be reported. The differences in the neuronal basis of full and partial consciousness are poorly understood. We investigated if evoked and oscillatory activity could dissociate full from partial conscious perception. We recorded human cortical activity with magnetoencephalography (MEG) during a visual perception task in which stimulus could be either partially or fully perceived. Partial consciousness was associated with an early increase in evoked activity and theta/low-alpha-band oscillations while full consciousness was also associated with late evoked activity and beta-band oscillations. Full from partial consciousness was dissociated by stronger evoked activity and late increase in theta oscillations that were localized to higher-order visual regions and posterior parietal and prefrontal cortices. Our results reveal both evoked activity and theta oscillations dissociate partial and full consciousness.
  • Parducci, Laura; Alsos, Inger Greve; Unneberg, Per; Pedersen, Mikkel W.; Han, Lu; Lammers, Youri; Salonen, J. Sakari; Väliranta, Minna M.; Slotte, Tanja; Wohlfarth, Barbara (2019)
    The lake sediments of Hasseldala Port in south-east Sweden provide an archive of local and regional environmental conditions similar to 14.5-9.5 ka BP (thousand years before present) and allow testing DNA sequencing techniques to reconstruct past vegetation changes. We combined shotgun sequencing with plant micro- and macrofossil analyses to investigate sediments dating to the Allerod (14.1-12.7 ka BP), Younger Dryas (12.7-11.7 ka BP), and Preboreal (