Temperament and Character Correlates of the Startle Reflex

Some literature suggests that individual temperament traits can modulate the startle reflex. There is evidence supporting Cloninger’s concept of Harm Avoidance as being predictive of individual differences in reactivity to aversive stimuli. (Corr, 1997). Since this finding, a new version Cloninger’s measure includes character subscales that like temperament, have been proposed to modify the meaning of experiences, changing emotional reactions. High scorers on the character variables are less susceptible to excessive anxiety and tend to have neurochemical profiles that are not consistent with anxiety disorders (Gillespie, 2003; Tse & Bond, 2001; Peirson et al., 1999). It was thus hypothesized that individuals scoring low on character scales would have higher startle magnitude to negative pictures. Method: 73 undergraduate students underwent a standard emotion modulated startle reflex paradigm (Lang, 1994) and completed the TCI. Results: A significant linear trend was found for the within subjects factor ‘valence’ F(1,82) = 4.2, p \u3c .05, η2 = .049 indicating that blink magnitude increased from positive to negative picture condition. A manipulation check found that in the negative condition, pictures were rated similarly negative, more arousing (t = 4.60; p t = 5.77; p \u3c .05) than the norm sample. The finding in the literature that suggests high levels of Harm Avoidance predicts an increase in the startle response to negative pictures was not supported. Implications for the TCI as being a better measure of personality in clinical populations is an issue for further research, as well as the effects of perceived control on self-reported Harm Avoidance