# [AUDITORY] question about c (Sam Mathias )

```Subject: [AUDITORY] question about c
From:    Sam Mathias  <smathias@xxxxxxxx>
Date:    Mon, 16 Sep 2013 08:40:43 -0400
List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>

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Dear list,

Just to clarify my question from yesterday.

My experiment is equivalent to two-interval, two-alternative forced choice.
On each trial listeners hear two stimuli and judge the direction of the
change between them, either "up" or "down". I believe that calculating d'
in this experiment is just the same as for the standard 2I2AFC paradigm,
which requires listeners to select an interval, 1st or 2nd.

Even though the probabilities of "up" and "down" trials are equal, I expect
response biases (e.g., to respond "up" more than "down") and I want to
calculate c for this. I'm wondering whether I should take the standard
formula for c in YN (after redefining what is meant by a "hit" as
responding up when the correct answer was up, and so on), then divide by
sqrt(2).

--
Dr. Samuel R. Mathias
Center for Computational Neuroscience and Neural Technology
Boston University
677 Beacon St., Boston, MA 02215

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<div dir=3D"ltr">Dear list,<div><br></div><div>Just to clarify my question =
from yesterday.</div><div><br></div><div>My experiment is equivalent to two=
-interval, two-alternative forced choice. On each trial listeners hear two =
stimuli and judge the direction of the change between them, either &quot;up=
&quot; or &quot;down&quot;. I believe that calculating d&#39; in this exper=
iment is just the same as for the standard 2I2AFC paradigm, which requires =
listeners to select an interval, 1st or 2nd.</div>
<div><br></div><div>Even though the probabilities of &quot;up&quot; and &qu=
ot;down&quot; trials are equal, I expect response biases (e.g., to respond =
&quot;up&quot; more than &quot;down&quot;) and I want to calculate c for th=
is. I&#39;m wondering whether I should take the standard formula for c in Y=
N (after redefining what is meant by a &quot;hit&quot; as responding up whe=
n the correct answer was up, and so on), then divide by sqrt(2).</div>
<div><br></div><div><div>--=A0<br>Dr. Samuel R. Mathias<br>Center for Compu=
tational Neuroscience and Neural Technology<br>Boston University<div>677 Be=
acon St.,=A0Boston, MA 02215<br>
<div><br></div><div><br></div></div></div>
<div dir=3D"ltr"><br></div></div></div>

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