Male bisexuality is particularly presumed to be non-existent, with sexual fluidity studies adding to the debate. In 2005, researchers Gerulf Rieger, Meredith L. Chivers, and J. Michael Bailey used penile plethysmography to measure the arousal of self-identified bisexual men to pornography involving only men and pornography involving only women. Participants were recruited via advertisements in gay-oriented magazines and an alternative paper. They found that the self-identified bisexual men in their sample had genital arousal patterns similar to either homosexual or heterosexual men. The authors concluded that "in terms of behavior and identity, bisexual men clearly exist", but that male bisexuality had not been shown to exist with respect to arousal or attraction. The assertion of Bailey that "for men arousal is orientation" was criticized by Fairness and Accuracy in Reporting (FAIR) as a simplification which neglects to account for behavior and self-identification. Further, some researchers hold that the technique used in the study to measure genital arousal is too crude to capture the richness (erotic sensations, affection, admiration) that constitutes sexual attraction. The National Gay and Lesbian Task Force called the study and "The New York Times" coverage of it flawed and biphobic. The American Institute of Bisexuality stated that Bailey's study was misinterpreted and misreported by both "The New York Times" and its critics. In 2011, Bailey and other researchers reported that among men with a history of several romantic and sexual relationships with members of both sexes, high levels of sexual arousal were found in response to both male and female sexual imagery. The subjects were recruited from a Craigslist group for men seeking intimacy with both members of a heterosexual couple. The authors said that this change in recruitment strategy was an important difference, but it may not have been a representative sample of bisexual-identified men. They concluded that "bisexual-identified men with bisexual arousal patterns do indeed exist", but could not establish whether such a pattern is typical of bisexual-identified men in general. Bisexual erasure (or bisexual invisibility) is the tendency to ignore, remove, falsify, or reexplain evidence of bisexuality in culture, history, academia, news media and other primary sources. In its most extreme form, bisexual erasure includes denying that bisexuality exists. It is often a manifestation of biphobia, although it does not necessarily involve overt antagonism. There is increasing inclusion and visibility of bisexuals, particularly in the LGBT community. American psychologist Beth Firestone writes that since she wrote her first book on bisexuality, in 1996, "bisexuality has gained visibility, although progress is uneven and awareness of bisexuality is still minimal or absent in many of the more remote regions of our country and internationally."