1. First of all, is it possible to adjust volume levels using inquisit? My students are in need of a setup in which participants are able to select prefered volume levels in the program.
The <sound> element has a /volume attribute which should be able to handle variables, e.g.
/ items = ("mysound.wav")
/ volume = values.myvolume
See the documentation for details. You can't make sounds louder, so set the systems volume high. But you could allow subjects to make sounds less loud.
2. My second question regards pausing - or stop/resuming - the presentation of stimuli. I need to develop a paradigm in which participants can select two buttons, a left button press which would play a video file for 25 seconds, and then stop. A right button press would play 5 seconds of the video and then stop. Well this is doable, but I need following trials to resume the video file where the last trial ended it! Any thoughts on this?
Split your video in 25s and 5s segments respectively and select them sequentially. There's no way to make Inquisit resume a video from a previous position.
3. Last, is it possible to make the computer monitor shut down using Inquisit, and start up again when I indicate it to do so? This is for another experiment, and we are considering the use of a screensize black picture. But shutting down the monitor would be preferred!
Nope, no way to control the monitor state from within Inquisit. Black picture or shape is your best option.