Medial Prefrontal Theta Bursts Precede Rapid Motor Responses during Visual Selective Attention

Abstract

After visual target stimuli presented infrequently at a covertly attended location, quicker speeded button presses immediately followed a larger positive (P3f) ramp in averaged electroencephalographic (EEG) recordings from the forehead. We show this peak in the mean response time locked to the button press to be principally composed of triphasic, primarily low-theta band (4.5 Hz) complexes preceding but only partially phase-locked to the button press, with larger complexes preceding quicker motor responses. For 10 of 15 subjects, independent component analysis of the unaveraged 31-channel data identified a temporally independent medial frontal EEG process contributing to these phenomena. Low-resolution tomographic modeling localized related components of two 253-channel data sets to medial frontal polar cortex (BA32/10). The far-frontal low-theta complexes and concomitant mean P3f positivity may index cortical activity induced by paralimbic processes involved in disinhibiting impulsive motor responses to rewarding or goal-fulfilling stimuli or events.

Brain oscillatory activity associated with task switching and feedback processing

“…These studies showed that attentional or motivational salient stimuli triggered a frontal component appearing earlier than P3b (referred to as P3f in the cited studies), which is mainly accounted for by the low-theta oscillatory activity (Delorme et al, 2007;Makeig et al, 2004). Thus, our findings showed a similar frontopolar theta component appearing after the switch and 1st pFb signals that may point out potential common neural processes taking place when participants detect salient or relevant stimuli during the task.…”

“…The theta activity effect detected after the switch and the 1st positive feedback was also found at more anterior parts of the frontal regions. Similarly, the frontopolar theta activity has been previously observed in association with target detection (Delorme, Westerfield, & Makeig, 2007; "Frontal" represents the averaged power activity of F3, Fz, and F4 electrodes. "Central" represents the averaged power activity of C3, Cz, and C4 electrodes.…”

Brain Oscillatory Activity during Spatial Navigation: Theta and Gamma Activity Link Medial Temporal and Parietal Regions

“…BSS techniques combined with source localization provide a useful tool for exploring task-related EEG (eg. Delorme et al, 2007b), as well as applications in realtime EEG fields such as neurofeedback and brain-computer interfaces (Congedo, 2006) and clinical studies comparing patients to normative databases (Congedo et al, 2010).…”

“…After decomposing the observed EEG into a number of elementary additive sources subsequent source localization is more reliable, typically capable of exact localization of single equivalent dipoles. BSS techniques have been used to enhance source localization efforts with ERP data (Marco-Pallarés et al, 2005;Grau et al, 2007), ictal EEG in epilepsy (Leal et al, 2007;2008), and task-related time-frequency domain EEG (Onton et al, 2005;Delorme et al, 2007b;Huang et al, 2008).…”

Variability of single trial brain activation predicts fluctuations in reaction time

“…(1) The temporal 'stability' of information processing is reflected by intertrial phase coherence (Delorme, Westerfield, & Makeig, 2007). Intertrial coherence is a measure of the degree to which the phase of the evoked response aligns across trials, independently of amplitude Makeig, Debener, Onton, & Delorme, 2004), thus, representing the latency variability in the evoked response of single trial P300.…”