Several different types of emotion induction procedures have been used in research investigations seeking to induce emotional arousal (Gerrards-Hesse et al., 1994, Westermann et al., 1996 and Foster et al., 1999). For many of these investigations, the use of emotional memories has been frequently employed as a method of emotion induction (Schwartz et al., 1981, Roberts and Weerts, 1982, Ekman et al., 1983, Cook et al., 1988, Stemmler, 1989, Rime et al., 1990, Sidorova et al., 1992, de Jong-Meyer et al., 1993, George et al., 1995, Partiot et al., 1995, Foster et al., 1997, Foster et al., 1999, Lane et al., 1997 and Reiman et al., 1997). Research utilizing emotional memories to investigate the psychophysiological sequelae of emotional arousal has indicated that the use of this emotion induction method has consistently produced significant changes in psychophysiological response (Schwartz et al., 1981, Roberts and Weerts, 1982, Ekman et al., 1983, Cook et al., 1988, Stemmler, 1989, de Jong-Meyer et al., 1993, Foster et al., 1997 and Foster et al., 1999).
Although memories have been used extensively as an emotion induction method, the specific effects of different ages of emotional memories on the resulting changes in psychophysiological arousal have not been determined. Indeed, a thorough review of the literature failed to locate any studies that sought to investigate whether a relationship exists between the age of the emotional memories recollected and the corresponding changes in psychophysiological arousal. The possibility of such a relationship existing carries serious implications for research concerning the psychophysiological sequelae of emotions, especially when considering the fact that most investigations using emotional memories have typically placed no constraints on the age of the memory to be recalled (Schwartz et al., 1981, Roberts and Weerts, 1982, Ekman et al., 1983, Cook et al., 1988, Stemmler, 1989 and de Jong-Meyer et al., 1993). Clearly, determining whether a relationship exists between the age of emotional memories and the corresponding changes in psychophysiological arousal is an important task to be undertaken. The purpose of the present investigation was to determine whether such an influential relationship exists. Based on the assumption that more recent memories would be recalled with greater detail and more vividly, it was hypothesized that a negative relationship would be found between the age of the recalled memories and increases in both heart rate and skin conductance. Specifically, it was expected that more recent memories would be associated with greater increases in heart rate and skin conductance than older emotional memories.
