, 2007). As these adjacent brain areas have also been implicated in cognitive control tasks (particularly anterior cingulate), it is not possible to entirely disambiguate their possible contribution to the deficits observed in these studies. To our knowledge there has been no report of a patient whose lesion is entirely constrained within the borders of the

pre-SMA. Here we present a young patient with a highly focal, unilateral lesion of the caudal pre-SMA. Since pre-SMA has frequently been associated with cognitive control and executive function, we chose to investigate how this might have affected performance on three standard tasks, each of which indexes a different aspect of response selection or inhibition. The STOP-signal task assesses this website the ability to inhibit an on-going response, whereas the CHANGE-signal task requires the participant to rapidly switch to a different response plan. Finally the Eriksen flanker task measures how quickly an individual is able to select between conflicting response plans that are activated simultaneously. Together these tasks employ similar stimuli with different rules, to explore specific aspects of executive function. Surprisingly we Galunisertib found that she did not display a significant

impairment when asked to stop an action (STOP task), but was significantly impaired when switching between response plans (CHANGE task). The patient also displayed Non-specific serine/threonine protein kinase no significant deficit when processing conflict at the level of the stimulus (Eriksen Flanker). Remarkably, it appears that this lesion of the caudal pre-SMA impaired the ability to rapidly switch between overt responses, whilst leaving stopping behaviour intact. We discuss these findings

in the context of the current literature and the implications for understanding the role of pre-SMA in voluntary action. Patient KP is a 28-year-old, right-handed woman who was diagnosed with epilepsy, following the onset of simple partial seizures. Following a subsequent grand mal seizure later in the year, further MRI investigations revealed a very small cavernoma (a blood vessel anomaly, also sometimes referred to as a cavernous haemangioma). This was located on the medial aspect of the right superior frontal gyrus. At the time, KP was experiencing complex partial seizures with secondary generalisations, and the cavernoma was subsequently resected. A follow-up structural scan 4 months after surgery demonstrates the focal nature of the lesion, which lies medial to the superior frontal sulcus and rostral to the paracentral sulcus. The paracentral sulcus has previously been demonstrated to be a useful landmark for the location of the supplementary eye field (SEF) (Grosbras, Lobel, Van de Moortele, LeBihan, & Berthoz, 1999), which lies at the caudal border of the pre-SMA; thus this lesion lies well within the pre-SMA. The sagittal sections in Fig.