Event-Related Synchronization and Desynchronization During Affective Processing: Emergence of Valence-Related Time-Dependent Hemispheric Asymmetries in Theta and Upper Alpha Band

Abstract

Event-related desynchronization (ERD) and synchronization (ERS) in the individually defined theta, alpha-1, alpha-2, and alpha-3 frequency bands were measured in 22 healthy subjects (Ss) in response to neutral (Neut), emotionally positive (Pos), and negative (Neg) IAPS stimuli. The 62-channel EEG, facial EMG and ECG were simultaneously recorded while subjects viewed sequentially presented pictures and subjectively rated them after each presentation. The obtained findings indicate that differences induced by pictures varying in emotional valence are associated mainly with increased theta and alpha-3 synchronization activity and anterior hemispheric asymmetries. In the anterior temporal leads theta ERS revealed a significant valence by hemisphere interaction showing relatively greater right hemisphere theta ERS for Neg and left hemisphere ERS for Pos stimuli in the time window of 100-700 ms post-stimulus, whereas in the alpha-3 band Neg stimuli induced lateralized time-dependent left hemisphere ERS increased in the time window of 800-1200 ms, were not observed for Neut and Pos stimuli. The obtained results along with earlier observations on EEG correlates of affective processing challenge the notion that affective anterior hemispheric asymmetries are mainly sensitive to wide alpha frequency band. Frequency and time dependence of anterior hemispheric asymmetries in emotional valence discrimination is emphasized.

Dissociable effects of arousal and valence on prefrontal activity indexing emotional evaluation and subsequent memory: an event-related fMRI study

“…1, a left PFC region was more activated for positive than for negative pictures and a right PFC region showed the converse pattern. This finding is consistent with other evidence supporting the valence hypothesis (Aftanas et al, 2001;Canli et al, 1998;Davidson, 1995;Tomarken et al, 1992;Wheeler et al, 1993), but it extends this evidence in two ways.…”

“…Neuropsychological evidence shows that patients with left hemisphere lesions tend to experience negative emotions, such as sadness (Morris et al, 1996;Paradiso et al, 1999a), whereas patients with right hemisphere damage are biased toward experiencing positive emotions, such as euphoria (e.g., Starkstein et al, 1989). The results of some electrophysiological studies are consistent with the valence hypothesis and support the idea that this valence-related PFC lateralization may depend either on transiently induced affective states or on stable personality traits (Aftanas et al, 2001;Davidson, 1995;Davidson and Irwin, 1999;Tomarken et al, 1992;Wheeler et al, 1993).…”

“…The valence hypothesis has been primarily supported using electrophysiological methods (Aftanas et al, 2001;Davidson, 1995;Tomarken et al, 1992;Wheeler et al, 1993), which do not allow a good localization of neural sources. Evidence for the valence hypothesis was also found using fMRI (Canli et al, 1998) but using analyses that collapsed activity over a whole hemisphere.…”

Causal Mathematical Logic as a guiding framework for the prediction of “Intelligence Signals” in brain simulations

“…Reviewing older data we did find the theta and delta (ERS) appear to be present before the time of the ERD dip contradicting the general model proposed by Lemm and colleagues, (Başar-Eroglu et al, 1992;Yordanova and Kolev, 1997). This is because in the Lemm model, it is alpha which is primarily suppressed (Aftanas et al, 2001). This is not surprising as Alpha ERS has sensory input peaks which occur earlier briefly in the pre-processing to shorter ERP such as N1-P1 (Polich, 2007).…”

Exploration of Prominent Frequency Wave in EEG Signals from Brain Sensors Network

“…It is established through previous studies [9][10][11][12] that the desired results from original frequency are difficult to achieve due to some noise artifacts and existence of other unknown signal patterns. We considered five frequency bands in our research, such as delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), beta (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30), and gamma (30-50 Hz), also denoted as , , ,…”