PubMed · 5054122
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
R Boudrot. 1972. An alpha detection and feedback control system.. https://doi.org/10.1111/j.1469-8986.1972.tb01795.x
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
This study shows that incorrect responses are preceded by different EEG characteristics than correct responses, and that these differences appear in specific brain regions that participate in each particular task. EEGs were recorded in children during three different tasks: color discrimination (CDT), verbal working memory (VWM), and word categorization task (WCT). EEG segments previous to the presentation of the stimulus were analysed. Incorrect responses were preceded by lower EEG power values at 7.8 Hz in posterior temporal and right parietal leads in CDT, 8.59 and 9.36 Hz in frontal areas in VWM, and 10.72 Hz in the left hemisphere in WCT. In the former task > 1.56 Hz power in frontal areas prior to an incorrect response was also observed.
It is well known that the rhythmic activity within the alpha band in the central area may be composed of two different types of rhythms: (i) the Rolandic mu rhythm, representing the intrinsic activity of the sensorimotor area, and (ii) rhythmic activity believed to be generated within parieto-occipital areas and to extend into central regions through volume conduction (the 'classical alpha rhythm'). In this paper we clearly demonstrate that this second type of rhythmic activity is not due to volume conduction from parieto-occipital areas. We also demonstrate the significant impact of the coexistence of these two types of rhythms on the interpretation of interhemispheric coherence measurements.
Auditory event-related potentials mismatch negativity (MMN) and N100 were recorded from seven subjects while they read text and watched emotionally negative, neutral, and positive pictures varying in valence and arousal. The MMN reflects automatic detection of change in auditory stimulus stream. Functionally different N100 is triggered by onset of various auditory stimuli. The N100 was stabile during all visual conditions. The MMN was very similar during text reading, and neutral and negative slide viewing, but was significantly attenuated during viewing of positively valenced slides. We suggest that visual emotional information of high positive valence and low arousal is a signal of nonthreatening and nonappetitive environment. This kind of environment probably reduces the need for auditory change detection.