98
ResultsandDiscussion
Table 1 provides the data for each of the nine conditions in this experiment. An
initial two-way ANOVA was conducted for all of the trials on which a somatosensory
stimulus was delivered, with auditory stimulus (left, right, none) and side of
somatosensory stimulus (left, right) as the two within subject factors. The main effects
of auditory stimulus and side of somatosensory stimulus were not significant (both ps >
.10). However, there was a significant interaction between these two factors (F238 =
3.27, p = .049), which was mainly due to better somatosensory localization ratés when
the auditory stimulus was on the same side as the sound (i.e., left auditory stimulus with
left somatosensory stimulus and right with right) than when they were on opposite
sides (i.e., left with right and right with left).
To further assess the nature of this interaction, side of stimu Iation was collapsed
in a subsequent one-way ANOVA, resulting in three levels of auditory stimulation with
respect to somatosensory stimulation (same side as somatosensory stimulus, opposite
side as somatosensory stimulus, none). This additional analysis further confirmed a
significant main effect of auditory stimulation on somatosensory localization accuracy
(F238 = 3.90, p = .029). As shown in Figure 2, when the sound was presented on the same
side as the somatosensory stimulus, discrimination rates (46.5%) were significantly
greater than when the sound was presented on the opposite side (42.6%; tι9 = 2.387, p
= .028) and greater than when no sound was delivered (41.6%; t29 = 2.691, p = .014).
The difference in somatosensory discrimination rates between the no sound and the
opposite sound conditions was not significant (tι9 = .495, p = .626), indicating that there