Startle intensification during painful heat.
Applying affective-motivational theories of emotions to pain presupposes that the immediate emotional reaction to pain can be conceptualized as an action disposition or an urge to escape. According to these emotion theories, an aversive emotional state should potentiate low-level reflexes with a matching affective tone. In line with this view, this study investigated whether the startle reflex, measured as the EMG peak amplitude of the eyeblink to a white noise burst, was intensified during painful heat. Twenty-four healthy volunteers were exposed twice to four heat stimuli (43, 45, 47 and 49 degrees C; 5 s duration). As predicted, an intensification of the startle reflex to the noise burst was observed during the high-intensity stimuli (47 and 49 degrees C) in comparison with the low-intensity stimuli (43 and 45 degrees C). The startle modulation was effective within a limited temporal window. Five seconds after heat offset, the startle intensification had disappeared.
Crombez
G
G
Department of Psychology, Katholieke Universiteit te Leuven, Belgium.
Baeyens
F
F
Vansteenwegen
D
D
Eelen
P
P