Changes in spontaneous EEG activity indicate a special kind of information processing in concept learning

Abstract

Some findings in the literature suggest that a high amount of spectral power in spontaneous EEG α 1 band (7.5–10.0 Hz) may be associated with tasks demanding extensive monitoring of stimulus information and combining features for a match with internal concepts (“exploration”). EEG recordings were obtained from 9 subjects involved in a concept-learning task. They had to match visually presented objects with a concept built up by hypothesis and to respond by pressing a “yes” or “no” key. Epochs of EEG data were analyzed with epoch center-times at 500 and 250 ms before response execution. In the case of “yes” responses, when subjects could match their hypothesis positively with combined features of the presented object increased α 1, spectral power was found. Also α 1, power was larger immediately after disconfirming feedback than after confirming feedback. Additionally, α 2 spectral power (10.5–12.5 Hz) was found to be larger 250 ms after confirming feedback than after disconfirming feedback. It is argued that α 1 power seems to reflect those mental processes which are involving in combining features and matching them to a concept in mind. The increase in α 2 power after confirming feedback is interpreted in terms of general processing demands imposed during task performance.