In conjunction with <cite>Ott et al. (2011)</cite> 's positive deceptive opinion spam dataset, we then explore the interaction between sentiment and deception with respect to three types of language features: (1) changes in first-person singular use, often attributed to psychological distancing (Newman et al., 2003) , (2) decreased spatial awareness and more narrative form, consistent with theories of reality monitoring (Johnson and Raye, 1981) and imaginative writing (Biber et al., 1999; Rayson et al., 2001) , and (3) increased negative emotion terms, often attributed to leakage cues (Ekman and Friesen, 1969) , but perhaps better explained in our case as an exaggeration of the underlying review sentiment.