Hippocampal activation, which was bilateral in both awake monkeys, was absent in two of the anesthetized monkeys and unilaterally preserved in one animal. The functional

activation in the amygdalae and hippocampus is suppressed under anesthesia or at the least severely reduced. That these areas are activated only in awake animals suggests they are involved in awake processing of faces or their properties. Figure 6 shows the mean responses of the face-selective areas to faces and to the other categories in awake and anesthetized animals. Overall response amplitudes were lower in anesthetized than awake monkeys. The reduction of the amplitude of the BOLD signal was expected given the effects of anesthesia on the vascular system. CDK inhibitor While the face-selective areas in the middle STS showed significant responses to the other object categories (t test, p < 0.05), the ventral areas, for

instance near the AMTS, were more selective to faces, given that the responses to objects were often not significantly different from zero in these areas. These results suggest that the ventral pathway is more selective for faces than the STS patches. In this study, we took advantage of the increased sensitivity of high-field (7T) SE fMRI to study face processing in the temporal lobe of awake and in the entire brain of anesthetized monkeys. First, we confirmed the face-selective activation found in earlier monkey fMRI studies, but in addition, we found and report a number of face-selective areas in the ventral and medial temporal lobe that have not been described before, such as ventral V4, see more ventral TE, TG, hippocampus, entorhinal science cortex, and parahippocampal cortex (area TF). Some of the more posterior areas may be homologous with human occipitotemporal face areas. We also scanned awake

and anesthetized animals by using the same protocol and observed that MTL activation that was present under passive viewing was mostly preserved under anesthesia (except in the hippocampus), suggesting that processes related to memory, like familiarity or recollection, are not necessarily required for functional activation in the MTL. In agreement with previous studies of face-selective activation in macaques we found extensive face-selective activation in STS, with the largest and most reproducible face-selective patches located in the middle STS, which responded to other categories as well (Pinsk et al., 2005 and Tsao et al., 2003). Activation in or near the AMTS was also found in all animals and was highly specific to faces. Selectivity of AMTS areas for faces was also identified in earlier fMRI studies (Logothetis et al., 1999 and Tsao et al., 2003) although not in all, most likely because of signal loss in the temporal lobe. Additional face-selective areas were found in area TG and ventral TE but these results were less reproducible across animals.