Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale
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Randomized Controlled Trial
Audiotactile interactions beyond the space and body parts around the head.
Recent research has reported that spatial modulation effects of audiotactile interactions tend to be limited to the space and body parts around the head. The present study investigated the generality of this finding by manipulating body parts stimulated and spatial relationships between the body parts and sounds. In Experiment 1, tactile stimuli were presented randomly to either left or right cheek, hand (palm or back) placed near the head, and knee while auditory stimuli were presented to either the same or opposite side from loudspeakers close to the head. ⋯ The sounds delivered from near the head exerted a greater influence on tactile spatial discrimination performance as compared with the sound delivered from far from the head. Furthermore, the back of the hand was more influenced by the auditory stimuli than the palm when the hands were placed near the sounds. These results suggest that the spatial modulation effects of audiotactile interactions can occur beyond the space and body surface around the head.
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Randomized Controlled Trial
Psychophysical testing of spatial and temporal dimensions of endogenous analgesia: conditioned pain modulation and offset analgesia.
The endogenous analgesia (EA) system is psychophysically evaluated using various paradigms, including conditioned pain modulation (CPM) and offset analgesia (OA) testing, respectively, the spatial and temporal filtering processes of noxious information. Though both paradigms assess the function of the EA system, it is still unknown whether they reflect the same aspects of EA and consequently whether they provide additive or equivalent data. Twenty-nine healthy volunteers (15 males) underwent 5 trials of different stimulation conditions in random order including: (1) the classic OA three-temperature stimulus train ('OA'); (2) a three-temperature stimulus train as control for the OA ('OAcon'); (3) a constant temperature stimulus ('constant'); (4) the classic parallel CPM ('CPM'); and (5) a combination of OA and CPM ('OA + CPM'). ⋯ Furthermore, a correlation was found between OA and CPM (r = 0.62, P = 0.01) at the time of maximum OA effect. The additive effect found suggests that the two paradigms represent at least partially different aspects of EA. The moderate association between the CPM and OA magnitudes indicates, on the other hand, some commonality of their underlying mechanisms.