A5007892684- EEG and Brain-Computer Interfaces
- Transcranial Magnetic Stimulation Studies
- Neural dynamics and brain function
- Functional Brain Connectivity Studies
- Advanced MRI Techniques and Applications
- Neuroscience and Music Perception
- Atomic and Subatomic Physics Research
- Muscle activation and electromyography studies
- Blind Source Separation Techniques
- Neural and Behavioral Psychology Studies
- Motor Control and Adaptation
- Visual perception and processing mechanisms
- Hearing Loss and Rehabilitation
- Neuroscience and Neural Engineering
- Neurological disorders and treatments
- Advanced Neuroimaging Techniques and Applications
- Vestibular and auditory disorders
- Optical Imaging and Spectroscopy Techniques
- Electrical and Bioimpedance Tomography
- Multisensory perception and integration
- Neural Networks and Applications
- Face Recognition and Perception
- Advanced NMR Techniques and Applications
- Music and Audio Processing
- Non-Invasive Vital Sign Monitoring
Aalto University
2016-2025
Helsinki University Hospital
2015-2024
University of Helsinki
2015-2024
Weizmann Institute of Science
2023
University of Padua
2022
Imaging Center
2021
Hospital District of Helsinki and Uusimaa
2000-2019
Finnish Brain Research and Rehabilitation Center Neuron
2008
BM-Science
2005-2007
Nexstim (Finland)
2003-2006
Magnetoencephalography (MEG) is a noninvasive technique for investigating neuronal activity in the living human brain. The time resolution of method better than 1 ms and spatial discrimination is, under favorable circumstances, 2-3 mm sources cerebral cortex. In MEG studies, weak 10 fT-1 pT magnetic fields produced by electric currents flowing neurons are measured with multichannel SQUID (superconducting quantum interference device) gradiometers. sites cortex that activated stimulus can be...
The human brain spontaneously generates neural oscillations with a large variability in frequency, amplitude, duration, and recurrence. Little, however, is known about the long-term spatiotemporal structure of complex patterns ongoing activity. A central unresolved issue whether fluctuations oscillatory activity reflect memory dynamics system for more than few seconds. We investigated temporal correlations network normal at time scales ranging from seconds to several minutes. Ongoing during...
Abstract Transcranial magnetic stimulation (TMS) was applied to motor areas in the left language‐dominant hemisphere while right‐handed human subjects made lexical decisions on words related actions. Response times referring leg actions (e.g. kick ) were compared with those movements involving arms and hands pick ). TMS of hand influenced processing arm differentially, as documented by a significant interaction factors Stimulation site Word category. Arm area led faster than word responses...
MOTOR and visual cortices of normal volunteers were activated by transcranial magnetic stimulation. The electrical brain activity resulting from the brief electromagnetic pulse was recorded with high-resolution electroencephalography (HR-EEG) located using inversion algorithms. stimulation left sensorimotor hand area elicited an immediate response at stimulated site. activation had spread to adjacent ipsilateral motor areas within 5–10 ms homologous regions in opposite hemisphere 20 ms....
Life or death in hostile environments depends crucially on one's ability to detect and gate novel sounds awareness, such as that of a twig cracking under the paw stalking predator noisy jungle. Two distinct auditory cortex processes have been thought underlie this phenomenon: (i) attenuation so-called N1 response with repeated stimulation (ii) elicitation mismatch negativity (MMN) by changes repetitive aspects stimulation. This division has based previous studies suggesting that, unlike for...
The brain basis of action words may be neuron ensembles binding language- and action-related information that are dispersed over both cortical areas. This predicts fast spreading neuronal activity from language areas to specific sensorimotor when semantically related different parts the body being perceived. To test this, neurophysiological imaging was applied reveal spatiotemporal patterns elicited by with meaning. Spoken referring actions involving face or leg were presented while subjects...
The presence of various ongoing oscillations in the brain is correlated with behavioral states such as restful wakefulness or drowsiness. However, even when subjects aim to maintain a high level vigilance, exhibit large amplitude variability on time scales hundreds milliseconds seconds, suggesting that functional state local cortical networks continuously changing. How this volatility influences perception sensory stimuli has remained essentially unknown. We investigated relationship between...
The combination of transcranial magnetic stimulation (TMS) with simultaneous electroencephalography (EEG) provides us the possibility to non-invasively probe brain's excitability, time-resolved connectivity and instantaneous state. Early attempts combine TMS EEG suffered from huge electromagnetic artifacts seen in as a result electric field induced by stimulus pulses. To deal this problem, TMS-compatible systems have been developed. However, even amplifiers that are either immune or recover...
Learning to speak a new language requires the formation of recognition patterns for speech sounds specific newly acquired language. The present study demonstrates dynamic nature cortical memory representations phonemes in adults by using mismatch negativity (MMN) event-related potential. We studied Hungarian and Finnish subjects, dividing Hungarians into naive (no knowledge Finnish) fluent (in group. found that MMN contrast between two was elicited but not Hungarians. This result indicates...
Whole-head magnetoencephalographic (MEG) responses to repeating standard tones and infrequent slightly higher deviant complex novel sounds were recorded together with event-related brain potentials (ERPs). Deviant elicited the mismatch negativity (MMN) component of ERP its MEG counterpart (MMNm) both when auditory stimuli attended they ignored. MMNm generators located bilateral superior planes temporal lobes where preattentive discrimination appears occur. A subsequent positive P3a was by a...
Abstract To better understand the neuronal effects of transcranial magnetic stimulation (TMS), we studied how TMS‐evoked brain responses depend on intensity. We measured electroencephalographic (EEG) to motor‐cortex TMS, estimated intensity dependence overall response, and compared it a theoretical model for activity. Left right motor cortices seven volunteers were stimulated at intensities 60, 80, 100, 120% threshold (MT). A figure‐of‐eight coil (diameter each loop 4 cm) was used focal...