TY  - JOUR
A1  - Erlbeck, Helena
A1  - Kübler, Andrea
A1  - Kotchoubey, Boris
A1  - Veser, Sandra
T1  - Task instructions modulate the attentional mode affecting the auditory MMN and the semantic N400
JF  - Frontiers in Human Neuroscience
N2  - Event-related potentials (ERPs) have been proven to be a useful tool to complement clinical assessment and to detect residual cognitive functions in patients with disorders of consciousness. These ERPs are of ten recorded using passive or unspecific instructions. Patient data obtained this way are then compared to data from healthy participants, which are usually recorded using active instructions. The present study investigates the effect of attentive modulations and particularly the effect of activevs. passive instruction on the ERP components mismatch negativity (MMN) and N400. A sample of 18 healthy participants listened to three auditory paradigms: anoddball, aword priming, and a sentence paradigm. Each paradigm was presented three times with different instructions: ignoring auditory stimuli, passive listening, and focused attention on the auditory stimuli. After each task, the participants indicated their subjective effort. The N400 decreased from the focused task to the passive task, and was extinct in the ignore task. The MMN exhibited higher amplitudes in the focused and passive task compared to the ignore task. The data indicate an effect of attention on the supratemporal component of the MMN. Subjective effort was equally high in the passive and focused tasks but reduced in the ignore task. We conclude that passive listening during EEG recording is stressful and attenuates ERPs, which renders the interpretation of the results obtained in such conditions difficult.
KW  - ERP
KW  - priming
KW  - selective attention
KW  - event-related potentials
KW  - vigilance decrement
KW  - brain potentials
KW  - vegetative state
KW  - consciousness
KW  - component
KW  - predicts recovery
KW  - mismatch negativity
KW  - attention
KW  - instruction
KW  - N400
KW  - MMN
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-115553
VL  - 8
IS  - 654
ER  - 
TY  - JOUR
A1  - Gruss, L. Forest
A1  - Wieser, Matthias J.
A1  - Schweinberger, Stefan R.
A1  - Keil, Andreas
T1  - Face-evoked steady-state visual potentials: effects of presentation rate and face inversion
JF  - Frontiers in Human Neuroscience
N2  - Face processing can be explored using electrophysiological methods. Research with event-related potentials has demonstrated the so-called face inversion effect, in which the N170 component is enhanced in amplitude and latency to inverted, compared to upright, faces. The present study explored the extent to which repetitive lower-level visual cortical engagement, reflected in flicker steady-state visual evoked potentials (ssVEPs), shows similar amplitude enhancement to face inversion. We also asked if inversion-related ssVEP modulation would be dependent on the stimulation rate at which upright and inverted faces were flickered. To this end, multiple tagging frequencies were used (5, 10, 15, and 20 Hz) across two studies (n=21, n=18). Results showed that amplitude enhancement of the ssVEP for inverted faces was found solely at higher stimulation frequencies (15 and 20 Hz). By contrast, lower frequency ssVEPs did not show this inversion effect. These findings suggest that stimulation frequency affects the sensitivity of ssVEPs to face inversion.
KW  - N170
KW  - upside-down faces
KW  - selective attention
KW  - spatial attention
KW  - cortex
KW  - perception
KW  - recognition
KW  - brain
KW  - FMRI
KW  - area
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134399
VL  - 6
IS  - 316
ER  -