Frontal midline theta oscillations during mental arithmetic: effects of stress.
Complex cognitive tasks such as mental arithmetic heavily rely on intact, well-coordinated prefrontal cortex (PFC) function. Converging evidence suggests that frontal midline theta (FMT) oscillations play an important role during the execution of such PFC-dependent tasks. Additionally, it is well-established that acute stress impairs PFC function, and recent evidence suggests that FMT is decreased under stress. In this EEG study, we investigated FMT oscillations during a mental arithmetic task that was carried out in a stressful and a neutral control condition. Our results show late-onset, sustained FMT increases during mental arithmetic. In the neutral condition FMT started to increase earlier than in the stress condition. Direct comparison of the conditions quantified this difference by showing stronger FMT increases in the neutral condition in an early time window. Between-subject correlation analysis showed that attenuated FMT under stress was related to slowed reaction times. Our results suggest that FMT is associated with stimulus independent mental processes during the natural and complex PFC-dependent task of mental arithmetic, and is a possible marker for intact PFC function that is disrupted under stress.
Affective Neuroscience and Emotion Modulation, Department of Education and Psychology, Freie Universität Berlin Berlin, Germany ; Department of Psychiatry, Charité, Campus Benjamin Franklin Berlin, Germany.
Matti
M
Gärtner
Affective Neuroscience and Emotion Modulation, Department of Education and Psychology, Freie Universität Berlin Berlin, Germany ; Department of Psychiatry, Charité, Campus Benjamin Franklin Berlin, Germany ; Department of Psychiatry, Psychotherapy and Psychosomatics, University of Zurich Zurich, Switzerland.
Simone
S
Grimm
Department of Psychiatry, Charité, Campus Benjamin Franklin Berlin, Germany.
Malek
M
Bajbouj
EEG; acute stress; frontal theta oscillations; mental arithmetic