type, the olfactory bulb, anterior olfactory nucleus, and orbitofrontal cortex, all areas of the brain that process olfaction are affected. the deficits observed in dementia include decrease in odor threshold sensitivity, odor identification and odor memory. patients with schizophrenia exhibit deficits in olfactory discrimination that are not seen in patients with other psychiatric disorders not mentioned here. rupp, et al. found that in patients with schizophrenia olfactory sensitivity and discrimination as well as higher order identification abilities are reduced. as mentioned earlier, the olfactory tubercle may be involved in the perception of odors due to the inputs received from the bulb and thus, by extension, may play a role in these psychiatric disorders. history the olfactory tubercle was first described by albert von kölliker in 1896, who studied them in rats. since then, there have been several histological and histochemical studies; done in this area to identify it in other rodents, cats, humans, non-human primates, and other species. similar studies were done by several authors to find the cell composition and innervations to and from other regions in the ot. over the years, several other methods have been employed to find the possible functions and role of the ot in the brain. these began with lesion studies and early electrophysiological recordings. improvements in technology have made it possible to now place multiple electrodes in the olfactory tubercle and record from anesthetized and even awake animals participating in behavioral tasks.