According to the gate control theory of pain, the _____ opens the pain gate by sending excitation to _____.
A) mechanoreceptors; transmission cells
B) SG+; nocioceptors
C) SG-; mechanoreceptors
D) nociceptors; transmission cells
Question 2
In general, ______________ are more problematic than ________________ because they can produce spurious relationships.
a. extraneous variables; mediating variables
b. reciprocal variables; mediating variables
c. common-causal variables; extraneous variables
d. extraneous variables; common-causal variables
