Binocular stimuli

The general parameters that are used to set and control binocular stimuli are described below. Most visual stimuli will default to monocular presentation to the left eye unless appropriate parameters are set.

To specify a binocular stimulus, set:

stim_form 3d_b

This specifies that the stimulus will have a binocular representation, that is, two separate 3D image arrays (one for the left and one for the right eye) may be used. This has been implemented for the following stim_type values,

• sine
• randot_stereogram
• barnoise

When stim_form is set to “3d_b”, the following parameter can be set to allow only the left or right eye to receive its component of the stimulus:

stim_monocular right    # "right", "left", "both"

In this case, the normal right eye stimulus is presented whereas the left eye stimulus is set to a blank field at the background color. The value of stim_monocular defaults to “both”, so that both eyes will receive the intended stimulus if this parameter is not specified in the .stm file.