“…While this effect has been demonstrated primarily in experiments using a variety of active-avoidance tasks (Seiden and Hanson, 1964;Hanson, 1965;Rech et al, 1966), similar effects have been reported for passive avoidance and appetitive instrumental or runway approach tasks (Carlson et al, 1965;Iwahara et al, 1968). More extensive reviews of these findings are available elsewhere (Herz, 1960;Dews and Morse, 1961;Essman, 1971;Seiden et al, 1973).…”