“…"animals" (Benito-Cuadrado et al, 2002;Brucki and Rocha, 2004;Kempler et al, 1998;Mathuranath et al, 2003;Ratcliff et al, 1998;Troyer, 2000), "clothes" (Pekkala et al, 2009), "fruit" (Kave, 2005;Ratcliff et al, 1998;Troyer, 2000), "supermarket" (da Silva et al, 2004;Troyer, 2000), "transportation" (Chan and Poon, 1999), "vehicles" and "vegetables" (Kave, 2005), or "profession" (Van der Elst et al, 2006)), which makes it difficult to compare or generalize the individual study results. Another problem is raised by the varying number of participants, ranging from 84 (Tomer and Levin, 1993) to 1856 subjects ( Van der Elst et al, 2006) and fluctuations based on age differences ranging from 54 to 99 years (Kempler et al, 1998) as compared to 18 to 91 years (Troyer, 2000) or 85 years of age (Kave, 2005), respectively.…”