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The locus coeruleus‐norepinephrine (LC‐NE) system, which regulates arousal levels, is important for cognitive control, including emotional conflict resolution. Additionally, the LC‐NE system is implicated in P300 generation. If the P300 is mediated by the LC‐NE system, and considering the established correlations between LC activity and pupil dilation, P300 amplitude should correlate with task‐evoked (phasic) pupil dilation on a trial‐by‐trial basis. However, prior studies, predominantly utilizing oddball‐type paradigms, have not demonstrated correlations between concurrently recorded task‐evoked pupil dilation and P300 responses. Using a recently developed emotional face‐word Stroop task that links pupil dilation to the LC‐NE system, here, we examined both intra‐ and inter‐individual correlations between task‐evoked pupil dilation and P300 amplitude. We found that lower accuracy, slower reaction times, and larger task‐evoked pupil dilation were obtained in the incongruent compared to the congruent condition. Furthermore, we observed intra‐individual correlations between task‐evoked pupil dilation and P300 amplitude, with larger pupil dilation correlating with a greater P300 amplitude. In contrast, pupil dilation did not exhibit consistent correlations with N450 and N170 amplitudes. Baseline (tonic) pupil size also showed correlations with P300 and N170 amplitudes, with smaller pupil size corresponding to larger amplitude. Moreover, inter‐individual differences in task‐evoked pupil dilation between the congruent and incongruent conditions correlated with differences in reaction time and P300 amplitude, though these effects only approached significance. To summarize, our study provides evidence for a connection between task‐evoked pupil dilation and P300 amplitude at the single‐trial level, suggesting the involvement of the LC‐NE system in P300 generation. The locus coeruleus‐norepinephrine system is implicated in the generation of the P300. Using pupillometry as an indirect measure of locus coeruleus‐norepinephrine activity, we demonstrated intra‐individual trial‐to‐trial correlations between concurrently recorded task‐evoked pupil dilation and P300 responses in the emotional face‐word Stroop task, with larger pupil dilation correlating with a greater P300 amplitude, suggesting the involvement of the locus coeruleus‐norepinephrine system in P300 generation. [ABSTRACT FROM AUTHOR]

The amplitude modulated (AM) neural oscillation is an essential feature of neural dynamics to coordinate distant brain areas. The AM transcranial alternating current stimulation (tACS) has recently been adopted to examine various cognitive functions, but its neural mechanism remains unclear. The current study utilized the phosphene phenomenon to investigate whether, in an AM‐tACS, the AM frequency could modulate or even override the carrier frequency in phosphene percept. We measured the phosphene threshold and the perceived flash rate/pattern from 12 human subjects (four females, aged from 20–44 years old) under tACS that paired carrier waves (10, 14, 18, 22 Hz) with different envelope conditions (0, 2, 4 Hz) over the mid‐occipital and left facial areas. We also examined the phosphene source by adopting a high‐density stimulation montage. Our results revealed that (1) phosphene threshold was higher for AM‐tACS than sinusoidal tACS and demonstrated different carrier frequency functions in two stimulation montages. (2) AM‐tACS slowed down the phosphene flashing and abolished the relation between the carrier frequency and flash percept in sinusoidal tACS. This effect was independent of the intensity change of the stimulation. (3) Left facial stimulation elicited phosphene in the upper‐left visual field, while occipital stimulation elicited equally distributed phosphene. (4) The near‐eye electrodermal activity (EDA) measured under the threshold‐level occipital tACS was greater than the lowest power sufficient to elicit retinal phosphene. Our results show that AM frequency may override the carrier frequency and determine the perceived flashing frequency of AM‐tACS‐induced phosphene. [ABSTRACT FROM AUTHOR]

Repetitive transcranial magnetic stimulation (rTMS) is an alternative treatment for depression, but the neural correlates of the treatment are currently inconclusive, which might be a limit of conventional analytical methods. The present study aimed to investigate the neurophysiological evidence and potential biomarkers for rTMS and intermittent theta burst stimulation (iTBS) treatment. A total of 61 treatment‐resistant depression patients were randomly assigned to receive prolonged iTBS (piTBS; N = 19), 10 Hz rTMS (N = 20), or sham stimulation (N = 22). Each participant went through a treatment phase with resting state electroencephalography (EEG) recordings before and after the treatment phase. The aftereffects of stimulation showed that theta‐alpha amplitude modulation frequency (fam) was associated with piTBS_Responder, which involves repetitive bursts delivered in the theta frequency range, whereas alpha carrier frequency (fc) was related to 10 Hz rTMS, which uses alpha rhythmic stimulation. In addition, theta‐alpha amplitude modulation frequency was positively correlated with piTBS antidepressant efficacy, whereas the alpha frequency was not associated with the 10 Hz rTMS clinical outcome. The present study showed that TMS stimulation effects might be lasting, with changes of brain oscillations associated with the delivered frequency. Additionally, theta‐alpha amplitude modulation frequency may be as a function of the degree of recovery in TRD with piTBS treatment and also a potential EEG‐based predictor of antidepressant efficacy of piTBS in the early treatment stage, that is, first 2 weeks. [ABSTRACT FROM AUTHOR]

Children with developmental coordination disorder ( DCD) have been demonstrated to show attentional orienting deficits. The neural mechanism, however, has thus far remained elusive. Here, we measure oscillations in the EEG associated with attentional orienting to address this issue. The EEG was recorded from DCD children and typical developing ( TD) controls during an eye-gaze cueing paradigm. DCD group responded more slowly than TD group across all conditions. Additionally, TD group showed higher frontal midline theta activities in both valid and invalid conditions relative to a neutral condition, with such an effect absent in the DCD group. Theta oscillations might reflect attentional processing in relation to the cues being performed in TD group, with the lessened modulation of theta in DCD group possibly reflecting a deficit in attentional orienting. Possible explanations for the DCD- TD differences in theta oscillation and attentional orienting are discussed. [ABSTRACT FROM AUTHOR]

The interaction between goal-directed and stimulus-driven attentional control allows humans to rapidly reorient to relevant objects outside the focus of attention-a phenomenon termed contingent reorienting. Neuroimaging studies have observed activation of the ventral and dorsal attentional networks, but specific involvement of each network remains unclear. The present study aimed to determine whether both networks are critical to the processes of top-down contingent reorienting. To this end, we combined the contingent attentional capture paradigm with the use of transcranial magnetic stimulation (TMS) to interfere with temporoparietal junction (TPJ; ventral network) and frontal eye field (dorsal network) activity. The results showed that only right TPJ (rTPJ) TMS modulated contingent orienting. Furthermore, this modulation was highly dependent on visual fields: rTPJ TMS increased contingent capture in the left visual field and decreased the effect in the right visual field. These results demonstrate a critical involvement of the ventral network in attentional reorienting and reveal the spatial selectivity within such network. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]