After retrieving the upgrade module for Light Switch 01, the switch can bathe the Courier in "Smart Light", effectively increasing their Intelligence by 2, and their Science and Repairskills by 5 points each. This effect will linger for up to twelve hours, or unless the player activates the "Mood Lights" controlled by Light Switch 02.
Without the upgrade module, it is only possible to use the light switch to toggle the normal lights while the Personality Matrices are toggled off at the Sink CIU.
PC The "Smart Light" and "Mood Light" bonuses are applied to the player only when the player enter dialogue with the light switch and toggle such light. So, after the light is toggled, when the bonuses passes, just re-entering the Sink and be exposed to the light won't be enough to get the bonuses again.
In this case, to get again the bonuses of the light already toggled, it is needed to first toggle any other type of light (even normal light or lights off will work) and then toggle to the desired light again.