Gradient Staircase experiment: narrowing to non-zero angles

[Michael]

@Forkhogan

Or are the values that I set in the excel file representative of the difference away from whatever base grating angle I set?

Yes. In theory, you are always working towards some threshold difference that is close to zero. It is only meaningful to think of the threshold as being a difference from some reference value. There is nothing magical about the absolute rotation angle.

Please just provide the code you are currently using to change the Ori_grat variable, pasted into a message rather than as a screenshot, and please:

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Lastly:

@Forkhogan

The whole point of this interleaved staircase is for the participant to narrow the angles inward toward the desired angle, as opposed to merely comparing minor differences at random from the base angle. The link Michael provided seemed to provide coding info for the latter instead of the prior.

• Staircases are by nature adaptive. They don’t just present random variations. So I’m not sure what to make of this.
• I don’t think you need to use an interleaved staircase at all. Aren’t you just measuring a single threshold (the relative orientation of the stimuli)?