OBJECTIVE: To explore the reactivity of the theta and alpha rhythms during visuo-spatial working memory. METHODS: One hundred and seventy-four subjects performed a delayed response task. They had to remember the spatial location of a target stimulus on a computer screen for a 1 or a 4s retention interval. The target either remained visible throughout the entire interval (sensory trials) or disappeared after 150ms (memory trials). Changes in induced band power (IBP) in the electroencephalogram (EEG) were analyzed in 4 narrow, individually adjusted frequency bands between 4 and 12Hz. RESULTS: After presentation of the target stimulus, a phasic power increase was found, irrespective of condition and delay interval, in the lower (roughly, 4-8Hz) frequency bands, with a posterior maximum. During the retention interval, sustained occipital-parietal alpha power increase and frontal theta power decrease were found. Most importantly, the memory trials showed larger IBP decreases in the theta band over frontal electrodes than the sensory trials. CONCLUSIONS: The phasic power increase following target onset is interpreted to reflect encoding of the target location. The sustained theta decrease, which is larger for memory trials, is tentatively interpreted to reflect visuo-spatial working memory processes.
OBJECTIVE: To explore the reactivity of the theta and alpha rhythms during visuo-spatial working memory. METHODS: One hundred and seventy-four subjects performed a delayed response task. They had to remember the spatial location of a target stimulus on a computer screen for a 1 or a 4s retention interval. The target either remained visible throughout the entire interval (sensory trials) or disappeared after 150ms (memory trials). Changes in induced band power (IBP) in the electroencephalogram (EEG) were analyzed in 4 narrow, individually adjusted frequency bands between 4 and 12Hz. RESULTS: After presentation of the target stimulus, a phasic power increase was found, irrespective of condition and delay interval, in the lower (roughly, 4-8Hz) frequency bands, with a posterior maximum. During the retention interval, sustained occipital-parietal alpha power increase and frontal theta power decrease were found. Most importantly, the memory trials showed larger IBP decreases in the theta band over frontal electrodes than the sensory trials. CONCLUSIONS: The phasic power increase following target onset is interpreted to reflect encoding of the target location. The sustained theta decrease, which is larger for memory trials, is tentatively interpreted to reflect visuo-spatial working memory processes.
Authors: Pascal Missonnier; François R Herrmann; Adriano Zanello; Maryse Badan Bâ; Logos Curtis; Diana Canovas; Fabrice Chantraine; Jonas Richiardi; Panteleimon Giannakopoulos; Marco C G Merlo Journal: J Psychiatry Neurosci Date: 2012-02 Impact factor: 6.186
Authors: Bradley Voytek; Matar Davis; Elena Yago; Francisco Barceló; Edward K Vogel; Robert T Knight Journal: Neuron Date: 2010-11-04 Impact factor: 17.173
Authors: Lars Michels; Kerstin Bucher; Rafael Lüchinger; Peter Klaver; Ernst Martin; Daniel Jeanmonod; Daniel Brandeis Journal: PLoS One Date: 2010-04-22 Impact factor: 3.240
Authors: A Reches; I Laufer; K Ziv; G Cukierman; K McEvoy; M Ettinger; R T Knight; A Gazzaley; A B Geva Journal: Neuroimage Date: 2013-11-21 Impact factor: 6.556