All atheists should familiarize themselves with the science of psychophysics. This is a science that relates the physical properties of stimuli (like their loudness in decibels, pitch in frequency, color in wavelenth, pressure on force per area, roughness etc.) to the quality of the conscious sensation they produce in us. It was developed in the 19th century by the German school of early experimental psychology (Wundt, Feschner et al.) which was probably the first of its kind. It later gave rise to gestalt psychology concerning perception and was overshadowed by the advent of "learning and reinforcement" schools of behaviorism. It still exists today as signal detection physiology but its clear implications for demise of "spirituality" have been largely forgotten.
It is important for us atheists to know about it because it totally undermined the idea that conscious experience is some spiritual essence beyond science. It also undermined the view of The Church that consciousness and the mind is the sacred substance or domain of God..
The psychophysicists showed that there is are lawful relationships between conscious sensation and the physical properties of stimuli. Thus the conscious experience of "loudness" is a mathematical function of the decibels of a sound stimulus. The conscious experience of "pitch" is a mathematical function of the frequency of the stimulus. The conscious sensation of "pressure" is a mathematical function of the force of a tactile stimulus divided by its area. The conscious sensation of color is a function of the wavelength of light.
It always comes as a total shock to the religious when we show them that the one nitch that they thought they can hide their last remaining vestige of spirituality or sacredness, is subject to regularity and scientific lawfulness. It drives the supernatural out of its last hiding place, consciousness.
I've attached a copy of its Wikipedia review.