Final answer:
The special treatment given to the guitar solo on "I'm only sleeping" is the Reverb effect.
Step-by-step explanation:
The special treatment given to the guitar solo on "I'm only sleeping" is the Reverb effect. Reverb is a sound effect that creates an echo-like space, making the guitar solo sound as if it's being played in a larger room or hall. This effect adds depth and dimension to the sound, giving it a unique and atmospheric quality.