, Depsipeptide 1999). However, low-current ICMS-SEF

delays self-timed but not conventional memory-guided saccades (Kunimatsu & Tanaka, 2012), and delays visually guided saccades when the animal is performing a stop-signal task that occasionally requires the saccade cancellation (Stuphorn & Schall, 2006). These results attest to the causal contribution of the SEF to more cognitively demanding tasks, presumably via the disruptive effects of ICMS-SEF on the network engaged by task demands, with greater delays reflecting a greater degree of involvement of the SEF at the time of stimulation. Recent work shows that ICMS-SEF also evokes rapid and robust recruitment of a contralateral head-turning synergy on neck muscles that begins ~30 ms after stimulation onset, preceding saccades by ~40–70 ms (Chapman et al., 2012). Stimulation of many oculomotor areas evokes an earlier response on the neck vs. saccades, due to differences in the processing of premotor cephalomotor vs. oculomotor commands (Corneil et al., 2002; Elsley et al., 2007; Farshadmanesh NVP-BEZ235 molecular weight et al., 2008). The response latency following ICMS-SEF suggests

that recruitment arises via feedforward connections from the SEF to the oculomotor brainstem (perhaps via the frontal eye fields, FEFs), and then onto the motor periphery (Chapman et al., 2012). If so, larger evoked neck muscle responses should occur

when the SEF are more active at the time of stimulation. The question we ask is whether ICMS-SEF can simultaneously disrupt some aspects of oculomotor behavior (e.g. saccades) while facilitating others (e.g. neck muscle recruitment). Such a result would reveal novel perspectives about state dependency and its application in cognitive neuroscience, emphasizing the importance of considering Amrubicin how the effects of stimulation are assessed. Here, we investigate the effects of ICMS-SEF while monkeys performed interleaved pro- or anti-saccades, requiring them to look towards or away from a peripheral cue, respectively, depending on the color of the fixation point (Fig. 1A). SEF activity is greater on anti-saccade trials (Schlag-Rey et al., 1997; Amador et al., 2004), and hence we predict greater effects, whether disruptive or facilitatory, will accompany anti-saccades. Importantly, we employ very short-duration (30 ms) ICMS-SEF, which can robustly recruit neck muscles without directly evoking saccades, allowing the animal to continue to perform the task. Short-duration ICMS can also be passed at multiple different times within a block of trials (Fig. 1A), permitting construction of a timeline of the effects of ICMS-SEF. Two male rhesus macaque monkeys (Macaca mulatta, monkeys S and Z) weighing approximately 12–14 kg performed this experiment.