Subject: Re: [AUDITORY] Question about criterion in 2AFC designs. From: Pierre Divenyi <pdivenyi@xxxxxxxx> Date: Mon, 16 Sep 2013 22:00:55 -0700 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>> This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. --B_3462213661_17995083 Content-type: text/plain; charset="ISO-8859-1" Content-transfer-encoding: quoted-printable Thank you Erick for reminding us of the treasure the Macmillan and Creelman book represents for anybody trying to play with psychophysics in the lab. -Pierre Divenyi On 9/16/13 6:31 PM, "Gallun, Frederick J. (Portland)" <Frederick.Gallun@xxxxxxxx> wrote: =B3For measuring response bias [in the 2AFC task], the methods [for the YN task] are entirely adequate. No sqrt(2) adjustment is necessary, because (a= s the reader may not be surprised to learn) bias in one task cannot be predicted from bias in the other.=B2 Macmillan and Creelman, Detection Theory: A User=B9s Guide, 2nd Edition, p. 170. =20 ------------------------------------------------------- Frederick (Erick) Gallun, PhD Research Investigator, NCRAR Associate Professor, Dept. of Otolaryngology, Oregon Health & Science University National Center for Rehabilitative Auditory Research Portland VA Medical Center 3710 SW US Veterans Hospital Road (NCRAR) Portland, Oregon 97239 Tel: 503-220-8262 x57472 Fax: 503-721-1402 http://www.ncrar.research.va.gov/AboutUs/Staff/Gallun.asp <http://www.ncrar.research.va.gov/AboutUs/Staff/Gallun.asp> This document is intended for the exclusive use of the recipient(s) named above. It may contain sensitive information that is protected, privileged, or confidential, and should not be disseminated, distributed, or copied to persons not authorized to receive such information. Unless otherwise noted= , this communication represents the views of the sender and not necessarily those of the VA or NCRAR. If you are not the intended recipient or feel yo= u have received this document in error, please notify the sender immediately and destroy the original. =20 From: AUDITORY - Research in Auditory Perception [mailto:AUDITORY@xxxxxxxx On Behalf Of Sam Mathias Sent: Sunday, September 15, 2013 6:57 AM To: AUDITORY@xxxxxxxx Subject: Question about criterion in 2AFC designs. =20 Dear list, =20 I think I know the answer to this question, but I'd rather be totally sure. When calculating sensitivity (d') in a 2AFC experiment, one needs to apply the sqrt(2) correction to the standard YN equation. My question is whether the same correction needs to be applied when calculating the criterion (c) in 2AFC. =20 Many thanks, =20 --=20 Dr. Samuel R. Mathias Center for Computational Neuroscience and Neural Technology Boston University 677 Beacon St., Boston, MA 02215 =20 =20 =20 --B_3462213661_17995083 Content-type: text/html; charset="ISO-8859-1" Content-transfer-encoding: quoted-printable <html><head></head><body style=3D"word-wrap: break-word; -webkit-nbsp-mode: s= pace; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); font-size:= 16px; font-family: Calibri, sans-serif; "><div>Thank you Erick for remindin= g us of the treasure the Macmillan and Creelman book represents for anybody = trying to play with psychophysics in the lab.</div><div><br></div><div>-Pier= re Divenyi</div><div><br></div><span id=3D"OLK_SRC_BODY_SECTION"><div><div>On = 9/16/13 6:31 PM, "Gallun, Frederick J. (Portland)" <<a href=3D"mailto:Frede= rick.Gallun@xxxxxxxx">Frederick.Gallun@xxxxxxxx</a>> wrote:</div></div><div><= br></div><div xmlns:v=3D"urn:schemas-microsoft-com:vml" xmlns:o=3D"urn:schemas-m= icrosoft-com:office:office" xmlns:w=3D"urn:schemas-microsoft-com:office:word" = xmlns:m=3D"http://schemas.microsoft.com/office/2004/12/omml" xmlns=3D"http://www= .w3.org/TR/REC-html40"><meta http-equiv=3D"Content-Type" content=3D"text/html; c= harset=3Dus-ascii"><meta name=3D"Generator" content=3D"Microsoft Word 14 (filtered= medium)"><style><!-- /* Font Definitions */ @xxxxxxxx {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4;} @xxxxxxxx {font-family:Tahoma; panose-1:2 11 6 4 3 5 4 4 2 4;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {margin:0in; margin-bottom:.0001pt; font-size:12.0pt; font-family:"Times New Roman","serif";} a:link, span.MsoHyperlink {mso-style-priority:99; color:blue; text-decoration:underline;} a:visited, span.MsoHyperlinkFollowed {mso-style-priority:99; color:purple; text-decoration:underline;} span.EmailStyle17 {mso-style-type:personal-reply; font-family:"Calibri","sans-serif"; color:#1F497D;} .MsoChpDefault {mso-style-type:export-only; font-family:"Calibri","sans-serif";} @xxxxxxxx WordSection1 {size:8.5in 11.0in; margin:1.0in 1.0in 1.0in 1.0in;} div.WordSection1 {page:WordSection1;} --></style><!--[if gte mso 9]><xml> <o:shapedefaults v:ext=3D"edit" spidmax=3D"1026" /> </xml><![endif]--><!--[if gte mso 9]><xml> <o:shapelayout v:ext=3D"edit"> <o:idmap v:ext=3D"edit" data=3D"1" /> </o:shapelayout></xml><![endif]--><div lang=3D"EN-US" link=3D"blue" vlink=3D"purp= le"><div class=3D"WordSection1"><p class=3D"MsoNormal"><span style=3D"font-size: 1= 1pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "> “Fo= r measuring response bias [in the 2AFC task], the methods [for the YN task] = are entirely adequate. No sqrt(2) adjustment is necessary, because (as the r= eader may not be surprised to learn) bias in one task cannot be predicted fr= om bias in the other.” <o:p></o:p></span></p><p class=3D"MsoNormal"><spa= n style=3D"font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 7= 3, 125); ">Macmillan and Creelman, Detection Theory: A User’s Guide, 2= <sup>nd</sup> Edition, p. 170.<o:p></o:p></span></p><p class=3D"MsoNormal"><sp= an style=3D"font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, = 73, 125); "><o:p> </o:p></span></p><p class=3D"MsoNormal" style=3D"mso-marg= in-top-alt:5.0pt;margin-right:0in;margin-bottom:5.0pt;margin-left:0in;text-a= utospace:none"><span style=3D"font-size: 10pt; font-family: Calibri, sans-seri= f; color: rgb(31, 73, 125); ">----------------------------------------------= ---------<o:p></o:p></span></p><p class=3D"MsoNormal" style=3D"text-autospace:no= ne"><span style=3D"font-size: 11pt; font-family: Calibri, sans-serif; color: r= gb(31, 73, 125); ">Frederick (Erick) Gallun, PhD <br>Research Investigator, = NCRAR<o:p></o:p></span></p><p class=3D"MsoNormal" style=3D"text-autospace:none">= <span style=3D"font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(3= 1, 73, 125); ">Associate Professor, Dept. of Otolaryngology, Oregon Health &= amp; Science University<o:p></o:p></span></p><p class=3D"MsoNormal" style=3D"mar= gin-top:6.0pt;text-autospace:none"><span style=3D"font-size: 11pt; font-family= : Calibri, sans-serif; color: rgb(31, 73, 125); ">National Center for Rehabi= litative Auditory Research <br>Portland VA Medical Center</span><span style=3D= "font-size: 10pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);= "><br>3710 SW US Veterans Hospital Road (NCRAR)<br>Portland, Oregon 97239<b= ><br>Tel:</b> 503-220-8262 x57472 <o:p></o:p></span></p><p class=3D"MsoN= ormal" style=3D"text-autospace:none"><span style=3D"font-size: 10pt; font-family= : Calibri, sans-serif; color: rgb(31, 73, 125); ">Fax: 503-721-1402<o:p></o:= p></span></p><p class=3D"MsoNormal" style=3D"text-autospace:none"><span style=3D"f= ont-size: 10pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "= ><a href=3D"http://www.ncrar.research.va.gov/AboutUs/Staff/Gallun.asp"><span s= tyle=3D"color:blue">http://www.ncrar.research.va.gov/AboutUs/Staff/Gallun.asp<= /span></a><o:p></o:p></span></p><p class=3D"MsoNormal" style=3D"mso-margin-top-a= lt:5.0pt;margin-right:0in;margin-bottom:5.0pt;margin-left:0in;text-autospace= :none"><span style=3D"font-size: 7.5pt; font-family: Calibri, sans-serif; colo= r: navy; ">This document is intended for the exclusive use of the recipient(= s) named above. It may contain sensitive information that is protected= , privileged, or confidential, and should not be disseminated, distributed, = or copied to persons not authorized to receive such information. Unles= s otherwise noted, this communication represents the views of the sender and= not necessarily those of the VA or NCRAR. If you are not the intended= recipient or feel you have received this document in error, please notify t= he sender immediately and destroy the original.</span><span style=3D"font-size= : 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "><o:p></= o:p></span></p><p class=3D"MsoNormal"><span style=3D"font-size: 11pt; font-famil= y: Calibri, sans-serif; color: rgb(31, 73, 125); "><o:p> </o:p></span><= /p><p class=3D"MsoNormal"><b><span style=3D"font-size: 10pt; font-family: Tahoma= , sans-serif; ">From:</span></b><span style=3D"font-size: 10pt; font-family: T= ahoma, sans-serif; "> AUDITORY - Research in Auditory Perception [<a href=3D"m= ailto:AUDITORY@xxxxxxxx">mailto:AUDITORY@xxxxxxxx</a>] <b>On B= ehalf Of </b>Sam Mathias<br><b>Sent:</b> Sunday, September 15, 2013 6:57 AM<= br><b>To:</b> <a href=3D"mailto:AUDITORY@xxxxxxxx">AUDITORY@xxxxxxxx= L.CA</a><br><b>Subject:</b> Question about criterion in 2AFC designs.<o:p></= o:p></span></p><p class=3D"MsoNormal"><o:p> </o:p></p><div><p class=3D"MsoN= ormal">Dear list,<o:p></o:p></p><div><p class=3D"MsoNormal"><o:p> </o:p><= /p></div><div><p class=3D"MsoNormal">I think I know the answer to this questio= n, but I'd rather be totally sure. When calculating sensitivity (d') in a 2A= FC experiment, one needs to apply the sqrt(2) correction to the standard YN = equation. My question is whether the same correction needs to be applied whe= n calculating the criterion (c) in 2AFC.<o:p></o:p></p></div><div><p class=3D"= MsoNormal"><o:p> </o:p></p></div><div><p class=3D"MsoNormal">Many thanks,= <o:p></o:p></p></div><div><div><p class=3D"MsoNormal"><o:p> </o:p></p></d= iv><div><p class=3D"MsoNormal">-- <br>Dr. Samuel R. Mathias<br>Center for= Computational Neuroscience and Neural Technology<br>Boston University<o:p><= /o:p></p><div><p class=3D"MsoNormal">677 Beacon St., Boston, MA 02215<o:p= ></o:p></p><div><p class=3D"MsoNormal"><o:p> </o:p></p></div><div><p clas= s=3D"MsoNormal"><o:p> </o:p></p></div></div></div><div><p class=3D"MsoNorma= l"><o:p> </o:p></p></div></div></div></div></div></div></span></body></= html> --B_3462213661_17995083--