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The appearance of a salient stimulus evokes a series of orienting responses including saccades and pupil size to prepare the body for appropriate action. The midbrain superior colliculus (SC) that receives critical control signals from the frontal eye field (FEF) is hypothesized to coordinate all components of orienting. It has shown recently that the FEF, together with the SC, is also importantly involved in the control of pupil size, in addition to its well‐documented role in eye movements. Although the role of the FEF in pupil size is demonstrated in monkeys, its role in human pupil responses and the coordination between pupil size and saccades remains to be established. Through applying continuous theta‐burst stimulation over the right FEF and vertex, we investigated the role of the FEF in human pupil and saccade responses evoked by a salient stimulus, and the coordination between pupil size and saccades. Our results showed that neither saccade reaction times (SRT) nor pupil responses evoked by salient stimuli were modulated by FEF stimulation. In contrast, the correlation between pupil size and SRTs in the contralateral stimulus condition was diminished with FEF stimulation, but intact with vertex stimulation. Moreover, FEF stimulation effects between saccade and pupil responses associated with salient stimuli correlated across participants. This is the first transcranial magnetic stimulation (TMS) study on the pupil orienting response, and our findings suggest that human FEF was involved in coordinating pupil size and saccades, but not involved in the control of pupil orienting responses. [ABSTRACT FROM AUTHOR]

The brain's intrinsic activity plays a fundamental role in its function. In normal conditions this activity is responsive to behavioural context, changing as an individual switches between directed tasks and task‐free conditions. A key feature of such changes is the movement of the brain between corresponding critical and sub‐critical states, with these dynamics supporting efficient cognitive processing. Breakdowns in processing efficiency can occur, however, in brain disorders such as depression. It was therefore hypothesised that depressive symptoms would be related to reduced intrinsic activity responsiveness to changes in behavioural state. This was tested in a mixed group of major depressive disorder patients (n = 26) and healthy participants (n = 37) by measuring intrinsic EEG activity temporal structure, quantified with detrended fluctuation analysis (DFA), in eyes‐closed (EC) and eyes‐open task‐free states and contrasting between the conditions. The degree to which DFA values changed between the states was found to correlate negatively with depressive symptoms. DFA values did not differ between states in those with higher symptom levels, meaning that the brain remained in a less flexible sub‐critical condition. This sub‐critical condition in the EC state was further found to correlate with levels of maladaptive rumination. This may reflect a general cognitive inflexibility resulting from a lack in neural activity reactivity that may predispose people to overly engage in self‐directed attention. These results provide an initial link between intrinsic activity reactivity and psychological features found in psychiatric disorders. [ABSTRACT FROM AUTHOR]