@article{MTMT:1121145, title = {Attention and arousal related modulation of spontaneous gamma-activity in the auditory cortex of the cat.}, url = {https://m2.mtmt.hu/api/publication/1121145}, author = {Lakatos, Péter and Szilagyi, N and Pincze, Zsuzsa and Rajkai, Csaba and Ulbert, István and Karmos, György}, doi = {10.1016/j.cogbrainres.2003.10.023}, journal-iso = {COGNITIVE BRAIN RES}, journal = {COGNITIVE BRAIN RESEARCH}, volume = {19}, unique-id = {1121145}, issn = {0926-6410}, abstract = {Sensory information processing in neocortex is associated with rhythmic synchronized gamma frequency firing of sensory cortical units and similar frequency oscillations of the field potentials. Different aspects of the gamma activity (20-80 Hz) have been suggested as correlates of attention, arousal and sensory binding. It is clear that attention has a modality selective influence, while arousal has a more general effect on the sensory systems. We used an experimental conditioning paradigm to separate these differential effects of attention and arousal on spontaneous neocortical gamma activity. We recorded field potentials with epidural electrodes placed above the auditory cortical areas of cats. The animals performed a simple instrumental alimentary conditioning task with different modality (visual and auditory) conditioned stimuli. When they attended to the auditory conditioned stimulus, both frequency and power increase of spontaneous gamma activity were detected. However when they attended visual, we found no power increase of gamma activity recorded above auditory areas, while the frequency increase was the same as in the "attend auditory" condition. We conclude that the power modulation of gamma activity is modality specific and thus can be attributed to selective attention, whereas the frequency modulation of gamma activity shows no modality specificity, it is influenced by the arousal level.}, year = {2004}, pages = {1-9}, orcid-numbers = {Ulbert, István/0000-0001-9941-9159} } @article{MTMT:1121143, title = {Frequency of gamma activity is modulated by motivation in the auditory cortex of cat.}, url = {https://m2.mtmt.hu/api/publication/1121143}, author = {Karmos, György and Lakatos, Péter and Pincze, Zsuzsa and Rajkai, Csaba and Ulbert, István}, doi = {10.1556/ABiol.53.2002.4.8}, journal-iso = {ACTA BIOL HUNG}, journal = {ACTA BIOLOGICA HUNGARICA (1983-2018)}, volume = {53}, unique-id = {1121143}, issn = {0236-5383}, abstract = {Repetitive acoustic stimuli elicit steady-state response (SSR) in the gamma-band both in humans and in mammals. Our aim was to investigate changes of the spontaneous gamma activity and the SSR in the auditory cortex of cats in the background of an instrumental conditioning situation. Epidural electrodes were chronically implanted above the auditory neocortex. The presentation rate of the clicks varied between 20 and 65/s. Spontaneous EEG and SSR were collected in three behavioral states: in an indifferent environment, in the instrumental cage while the cat was waiting for the light CS, and when she stepped on the pedal and was waiting for the meat reward. Using different repetition rate clicks we determined which stimulus rate elicited the largest SSR in these three situations. In quiet animal the highest SSR appeared at 28-30/s. Before and during the CS the optimal stimulus rate shifted to 32-38/s. The frequency of the spontaneous gamma activity changed in parallel way depending on the situation. We conclude that both the SSR and the spontaneous gamma activity reflect resonant activity of the same neuronal circuit of the auditory cortex, and it is modulated by the motivational state of the animal.}, year = {2002}, eissn = {1588-256X}, pages = {473-483}, orcid-numbers = {Ulbert, István/0000-0001-9941-9159} }