Two experiments are reported in which affective modulation of the star
tle reflex elicited by monaurally presented acoustic probes was furthe
r examined. An earlier study in our laboratory obtained significant mo
dulation by affect for probes presented to the left ear, but no signif
icant effect for probes presented to the right ear. Experiment 1 repli
cated the procedures used in that experiment and obtained the same pat
tern of effects. Experiment 2 changed the presentation of monaural pro
bes from a blocked to a mixed presentation and again obtained a simila
r pattern. Modulatory differences in reflex magnitude between pleasant
and unpleasant stimuli were consistently large and reliable for refle
xes elicited by left ear probes but weak and unreliable for reflexes e
licited by right ear probes.