Early studies in macaque monkeys have found that lesions to the PFC can increase the luminance threshold (Latto & Cowey 1971) and degrade detection performance (Kamback 1973). More recently, studies in humans using transcranial magnetic stimulation have similarly found that stimulation of the PFC can impair the visibility of stimuli (Rounis et al. 2010), but also improve detection rates during visual masking (Grosbras & Paus 2003). Finally, Antoine Del Cul et al. have shown that perceptual thresholds are increased in patients with relatively small prefrontal lesions even when attentional effects are tightly controlled for (2009). However, none of these studies has shown dramatic impairments, but rather modulations of performance or perception. Total blindness has only been reported after removing the entire frontal cortex including (parts of) the underlying cingulate cortex in monkeys, and only lasted for a few days in several cases (Nakamura & Mishkin 1986). Importantly, other lesion studies in humans have not reported perceptual deficits at all (Heath et al. 1949; Markowitsch & Kessler 2000). Taken together with the fact that the PFC is also active during unconscious processing (Diaz & McCarthy 2007; Lau & Passingham 2007; van Gaal et al. 2008), not deactivated under Thiopental anesthesia (Veselis et al. 2004), but deactivated during rapid eye movement sleep when vivid (non-lucid) dreams can be experienced (Braun et al. 1998; Desseilles et al. 2011; Muzur 2002), this indicates that the evidence for a direct, specific involvement of the PFC in conscious perception is currently inconclusive at best.