Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 2

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Sequential P3 effects in a Posner's spatial cueing paradigm: Trial-by-trial learning of the predictive value of the cue

100%
Gomez C. M., Flores A., Digiacomo M. R., Vazquez-Marrufo M.
Acta Neurobiologiae Experimentalis
|
2009
|
vol. 69
|
issue 2
155-167
EN
The neurocognitive consequences of correct or incorrect spatial prediction in a sequential S1-S2 paradigm were assessed. Sequential dependence on previous trial outcome (valid or invalid) was assessed by late Event-Related Potentials (ERPs) and behavioral responses. Two different experiments were performed, situating the target in the vertical (Experiment 1) or in the horizontal (Experiment 2) meridian. RTs and late positivities (P3a and P3b) were recorded. ERPs showed that posterior positivity (probably a P3b) was greater in invalid-valid trials than in valid-valid trials but lower than in valid-invalid trials. However, at the frontal electrodes, late positivity (probably a P3a) only appeared in valid-invalid trials, indicating that invalid trials are analyzed as novel-like stimuli. The P3b results suggest trial-by-trial learning of the predictive value of the cue, which needs to be updated as indicated by the pattern of P3b amplitudes: valid-invalid > invalid-valid > valid-valid.
2
Content available remote

Reduction of EEG power during expectancy periods in humans

88%
Gomez C. M., Vaquero E., Lopez-Mendoza D., Gonzalez-Rosa J., Vazquez-Marrufo M.
Acta Neurobiologiae Experimentalis
|
2004
|
vol. 64
|
issue 2
143-151
EN
The contingent negative variation (CNV), and the associated event-related desynchronization (ERD) on motor areas and sensory areas, and increase of alpha in the ipsilateral to the cued stimulus side, are different brain signals that reflect motor, sensory, and cognitive activations related to the expectancy of the next stimulus. However, the possibility of an overall change in EEG oscillatory activity during expectancy periods has not been directly addressed. The present report tests whether the background oscillatory activity is modulated by a warning signal. During the expectancy period, the power spectral density (PSD) between 0 and 42.9 Hz ? including delta, theta, alpha, beta, and gamma ? decreased with respect to the baseline. These results suggest that during expectancy periods there is a generalised decrease in the oscillatory activity, and that reduction of the EEG power would facilitate the phasic and oscillatory neural activities triggered by the next target stimulus.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.