===============================================================================
Vision.  Psych 131A = Bio 182.   Previous (useful) email questions answered.
-------------------------------------------------------------------------------

From gs  Thu Nov 18 22:30:28 2004 George Sperling 
To: XXXXXXXXXXXXXXXXXX
Subject: Grades
Cc: gs, hsiehji1@hotmail.com, iscofiel@uci.edu, jkwak@uci.edu, llin3@uci.edu

Hi XXXXXXXXXXXXXXXXXXX-
     Here's the direct quote from the UCI BioSci grade policy directive:

      FAILING GRADES
      The only failing grade in any undergrad course is
      an "F".  Students can retake a course if they
      receive a C- or worse, but that old grade remains
      on their transcript along with the new grade.
      Instructors should not give students a C- to
      allow them to retake the course.

      Some students mistakenly believe that a C- grade
      is a failing grade that will not allow them to
      take the next course in the Bio Core. There are
      two sources for the confusion.  Chem does not let
      students take the next course in their sequence
      without receiving at least a C.  We allow them to
      continue even if they receive an "F" in the
      previous course.  However, they do have to retake
      that course and pass it they want to graduate.
      The other source of confusion is that Bio
      requires an average "C" grade to be a student in
      good standing.  Some students think that this
      means that all of their grades must be a "C" or
      better.  However, the student could have half
      "Ds" and half "Bs" and still be fine.

-----------------------------------------------------------------------
 Prof. George Sperling                  (949) 824-6879 (Office)
 UCI Distinguished Professor            (949) 824-3772 (Adm Asst)
 Depts: Cognitive Sciences              (949) 824-2517 (Fax)
        Neurobiology and Behavior
 University of California               Email:  sperling@uci.edu
 Irvine CA 92697-5100           http://www.socsci.uci.edu/HIPLab
-----------------------------------------------------------------------
>
>
> From XXXXXXXXXXXXXXXXXXXXXX@uci.edu  Wed Nov 17 16:37:10 2004 
> Subject: Grade Question
> To: sperling@uci.edu
>
> Dear Professor Sperling,
>
> I just wanted to confirm that the grade of "D" is passing for this class.
> I have talked to two of the TA's and they both confirmed this, can you
> please verify. I am taking this class P/NP for the minor in Biological
> Sciences.
>
> Thank you,
> XXXXXXXXXXXXXXXXXXXXXXXXX
>
>
>
> cc: TAs
===============================================================================

 ===============================================================================
Vision.   Psychology 131A = BioSci 182.  Email questions answered.
Fall 2002 and earlier.
 -------------------------------------------------------------------------------

From gs  Fri Nov 29 10:06:05 2002 George Sperling

To: WillieDex23@aol.com
Subject: Final Exam Vision Course
Cc: athsu@uci.edu, gs, sonheel@uci.edu

> From WillieDex23@aol.com  Thu Nov 28 20:44:06 2002
> Subject: The Final?
> To: sperling@uci.edu
>
> Is it cumulative or just the stuff from the last midterm until the end
of
> next week?
>
> Thanks
>
 ******   The final, like all exams in Psych 131a = Bio 182 is CUMULATIVE

          Everything/anything  might be tested, from Lecture 1 to Lecture 20.

-----------------------------------------------------------------------
 Prof. George Sperling                       (949) 824-6879 (Office)
 Depts: Cognitive Sciences                   (949) 824-3772 (Adm Asst)
        Neurobiology and Behavior            (949) 824-2517 (Fax)
 University of California                    Email:  sperling@uci.edu
 Irvine CA 92697-5100                 http://www.socsci.uci.edu/HIPLab
 ===============================================================================
 ===============================================================================

From: "Tasneem Shabbir Ebrahimji" 
To: Joetta Gobell 
Subject: Re: Final grades posted on course webpage. 

Hello Joetta,

Thank you for the reply.  I checked my grades and I noticed that there are
students who have less total points then I do but they are making A-'s.
Can you please explain that.  Thanks for your time. I really enjoyed the
class and you were a big help too.

Tasneem Ebrahimji
21948528   

 -----------------

From joetta@uci.edu  Tue Dec 11 15:59:10 2001
To: Tasneem Shabbir Ebrahimji 
cc: sperling@uci.edu
Subject: Re: Final grades posted on course webpage.

Tasneem,

I'm glad you enjoyed the class.

As for your concerns regarding the grades, two students had valid excuses
for missing the second exam, and so were graded based on their standing in
the class excluding the second exam.  They clearly earned A's.

One student improved remarkably throughout the course, and did quite well
on the final.  This was taken into consideration and the student's grade
was moved up to an A-.

Happy Holidays,
Joetta

 ===============================================================================
From gs  Wed Nov 14 16:52:45 2001 George Sperling {sperling@uci.edu}
To:   Tasneem Shabbir Ebrahimji
Re:   Linear systems question
cc:   Joetta, Chai-huei
>
> From tebrahim@ea.oac.uci.edu  Tue Nov 13 15:29:35 2001
> From: "Tasneem Shabbir Ebrahimji" {TEBRAHIM@uci.edu}
> To: {sperling@uci.edu}
> Subject: Explain...
>
> Hello Professor Sperling,
>
> My name is Tasneem and i'm in your 182 Vision class. Can you please
> explain Linear systems compared to sine waves?  and how they relate to 1st
> order and 2nd order?
>
> Thank you 
>
SHORT ANSWER (for the long answer, review your lecture notes)

A linear system is one in which the principle of superposition holds
   (i.e., a->A, b->B => a+b -> A+B )
When a sinewave is the input to a linear system, the output is a sinewave
   of the same frequency.  The amplitude and phase may differ. (No other
  waveform is guaranteed to preserve its shape after a linear transformation)
First-order processes are those that act on the visual stimulus directly
  or the visual stimulus transformed by a linear system.
Second-order (visual) processes act on the visual stimulus only after it
  has been transformed by a nonlinear transformation, typically, absolute
  value or square (but it could be more complex).
   [If a sinewave is input to a NONlinear system, it generally will undergo
   a shape change.]

-----------------------------------------------------------------------
 Prof. George Sperling                       (949) 824-6879 (Office)
 Depts: Cognitive Sciences                   (949) 824-3772 (Adm Asst)
        Neurobiology and Behavior            (949) 824-2517 (Fax)
 University of California                    Email:  sperling@uci.edu
 Irvine CA 92697-5100                 http://www.socsci.uci.edu/HIPLab
-----------------------------------------------------------------------

 ===============================================================================

Old midterm2 questions are posted.  The answers are not posted.

 ===============================================================================

From gs  Tue Nov 13 00:20:55 2001 George Sperling

To: rkline@uci.edu
Subject: motion/slant/stereo
Cc: chaby@troland.hipl.uci.edu, gs@troland.hipl.uci.edu,
   joetta@troland.hipl.uci.edu

To:  Roger Kline
From: George Sperling
Re:    Question
>
> From rkline@uci.edu  Mon Nov 12 17:39:48 2001
> To: 
> Subject: question-clarification
>
> You said that the Reichardt model does the exact computation in
> Space-Time as the simple cell does in x-y (space) for stereoscopic depth
> perception.
> But I thought that the x-y space computation wouldn't use the f2-delay
> filter in the computation, like the space-time computation has to.
> Wouldn't it skip the f2 filter and just directly compare the 2 images?
> This would make their computations similar, but not exactly the same.
> Is my assumption correct or am I confused?
> (Also, is this information relevent to Question 1 ( i ) from the old =
> mid-term questions?)
>
Here's what I think I said ...
(1)
The Reichardt model does the same computation in x,t space-time
in indiscriminating motion direction as
Hubel-Weisel simple cells do in x,y in discriminating slant.
(2)
The computational problem of computing 3D structure-from-motion in
two-frame apparent motion is the same as the problem of computing stereo
depth from the disparities between the left- and right-eyes' images.
(That is, two consecutive frames in the structure from motion experiment
can be identical to two simultaneous images to the left and right eyes
in a stereo-depth experiment.)

I did not say that the solution to the two-frame motion problem and the
stereo-depth problems was the same because we don't have an accepted
theory for the solution of the structure-from-motion problem.  It is
believed that structure-from-motion is computed from motion flow fields
(versus corresponding points).  But which one, if any, of the various
proposed sfm solutions is the one used by the brain is not known. 
proposed sfm solutions is the one used by the brain is not known.


More on point 1.  By the same computation, I mean the same overall
computation, not the same component filters.  That is, a
direction-sensitive neuron that embodies one half of a Reichardt model
has a receptive field in space time just like a Hubel-Wiesel simple cell
in x,y.  Remember, to signal both positive and negative quanitites (in the
case of the Reichardt model, the opposite directions of motion) a pair of
neurons is needed--one to represent positive qunatities, another to
represent negative quantities.  In motion, a direction and its opposite,
respectively, are represented, respectively, by positive and negative
quantities, i.e., by two different neurons

-----------------------------------------------------------------------
 Prof. George Sperling                       (949) 824-6879 (Office)
 Depts: Cognitive Sciences                   (949) 824-3772 (Adm Asst)
        Neurobiology and Behavior            (949) 824-2517 (Fax)
 University of California                    Email:  sperling@uci.edu
 Irvine CA 92697-5100                 http://www.socsci.uci.edu/HIPLab
-----------------------------------------------------------------------
cc: Joetta, Chia-huei
                        
 ===============================================================================
From gs  Thu Nov  8 17:46:36 2001 George Sperling

To: ETRUONG@uci.edu
Subject: Vision class, Exam 2
Cc: chaby@troland.hipl.uci.edu, gs@troland.hipl.uci.edu,
   joetta@troland.hipl.uci.edu

To: Elizabeth Truong
From: George Sperling
Re: What's on the midterm (2)

Exam2 covers everything that's been talked about in class until Exam2 itself.
Exam2 mainly covers motion perception, depth, psychophysics, and linear
systems/channels.  There may also some questions about material previously
covered in Exam1.  After Exam2, there are only three more lectures so,
obviously, the final will be cumulative.  It would be a good idea to
start re-learning the material covered in the beginning of the course so
that it will be available when you again need it (for Exam2 and the
final).

Remember:  If you don't understand all the material in class, and if you
don't find it or can't understand it in your textbook(s), then there are
still two teaching assistants who will be conducting disucssion sections
right up to the last minute before each exam to make sure you have a
chance to learn the material if you make the effort.  -gs    
-----------------------------------------------------------------------
 Prof. George Sperling                       (949) 824-6879 (Office)
 Depts: Cognitive Sciences                   (949) 824-3772 (Adm Asst)
        Neurobiology and Behavior            (949) 824-2517 (Fax)
 University of California                    Email:  sperling@uci.edu
 Irvine CA 92697-5100                 http://www.socsci.uci.edu/HIPLab
-----------------------------------------------------------------------
cc: Joetta Chia-huei
>
> From etruong@ea.oac.uci.edu  Thu Nov  8 17:21:25 2001
> "Elizabeth Bui Truong" 
> To: 
> Subject: midterm2
>
> Hello Dr. Sperling!
>
> I would just like to know if today's lecture and any material on
motion
> will be covered on next Thursday's exam?  Or will depth be the last
topic
> you include on the exam?
>
> Thank you and take care-
> Elizabeth Truong
>  
 ===============================================================================
From rkline@uci.edu  Wed Oct 17 20:31:01 2001
To: 
Subject: Mid-Term, etc

Hi Prof. Sperling,           I have a few questions for you.

Will you be posting the answers to the Homework assignments?

    ***  Not before the midterm    See the TAs if you have difficulty.

In the Syllabus you had the Mid-Term falling after Lecture # 8.  Since
lecture 8 is on thursday 10/8, does that mean that the Mid-Term will be
this-coming = Tuesday 10/23?

    ***  YES  The Exam is scheduled for Lecture 9, October 23, TUESDAY

    -Will we be having any sort of review session?
   
    ***  Two, possible three review sessions with the TAs, some review
         in Lecture 8.

         The TAs had a review session on Wed, Oct 17, and will possibly
         have review sessions on Oct 19 (Fri) and Oct 22 (Mon) depending
         on demand.

    -Are any sample/practice exams available to model our studying =
after?
        -If not, what/how do you recommend that we focus our studies?

    *** Sample questions from previous midterms have been posted on the
        the Vision_Class website

Also, for the Mid-Term we were told to understand how to manipulate and
use the equations for photometry and also for visual angles.   
    -Of these, what do you expect us to memorize?
    -Will any of these equations and/or units be given to us on the test?

    *** ***   You must know how to compute   
***   visual angles (requires memorizing 57 or compute 360/2pi
***   candelas  (e.g., from efficiency of light bulb is 10 candelas/watt)
***   llluminance in meter-cd = lux (inverse square law)
***   luminance = reflectance x illum /pi  = cd/square-meter
***   retinal illuminance = lum x pupil area = trolands

Thank you for your time,
--Roger Kline

 ===============================================================================

From gs  Mon Oct  8 00:15:19 2001 George Sperling 
To: e124j@yahoo.com
Subject: hw-3, question 1f

>
> For question 1f)
> It seems like either a trick question or I'm misunderstanding the
> definitions.  ...
> 
       ****   Right!   This is somewhat of a "trick" question,
                       and you seem to understand it.   -gs

 ===============================================================================
> ... 
> 
> From rkline@uci.edu  Thu Oct  4 23:43:01 2001 "RKline"
> To: 
> 
> Prof. Sperling,
>     I'm sorry...I said Homework problem sheet 2 by mistake
> I meant that I didn't get a copy of Homework 3, which was handed out in
> class today
> (Thursday) and is due next Tuesday.
>     Is there any way I can get a copy of it?
> --Roger Kline 
> ... 

From gs  Fri Oct  5 00:36:01 2001 George Sperling 
To: rkline@uci.edu
Subject: HW 

To: Roger Kline
From: George Sperling
Re: HW on line

HW problems are now on webpage    http://www.socsci.uci.edu/HIPLab/Vision_Class
 -gs


 ===============================================================================

From vu22@yahoo.com  Mon Oct  1 15:13:12 2001 Poison Ivy
Subject: homework
To: sperling@uci.edu

Dear professor I can not get the Homework page to
appear on the screen I was wondering if it was posted
on the website already? I hope that it will work later
on today...
take care...
a student     

   **** Hi Poison Ivy - I've tested the page, HW Problem 1, on mac,
PC-windows, and linux computers and it works on all three platforms.
Other students seem to have been able to download the page.  So, I
think this problem may be on your end.
   BTW, I'm allergic to poison ivy, so please don't come too close.
   -gs
cc: joetta@troland.hipl.uci.edu

 ===============================================================================

From david54@home.com  Mon Oct  1 10:59:39 2001

Professor are you going to post your powerpoint slides online?

Thank you,
David Liao
             
****
From the Professor:  Sperling@uci.edu     Mon Oct  1 21:50:24 PDT 2001

I plan eventually to post the powerpoint slides but am currently in the
process of reconstructing the website.  It may be a week or two before
any slides are posted.  In the meantime, however, the lecture notes are
posted as pdf files for viewing or downloading.


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          SELECTED QUESTIONS FROM PREVIOUS YEAR(S)
 ===============================================================================

From mjjacobs@ea.oac.uci.edu  Sun Nov 12 00:28:17 2000
"Milagros Jessica Jacobs" 
To: sperling@uci.edu
Subject: lecture

HI Prof Sperling-
        I am a little confused on the contrast gain control-- is this
system used to devoid contrast when an input is between + or - 5%
-- what is the exact definition on contrast gain control for I can not
find it in the text.
Thanks you
Millie   

 ****
CONTRAST
  The contrast of a point in an image is the luminance of that point
minus the mean luminance, the result being divided by the mean luminance
of the image.
Thus the contrast of a point that is exactly mean luminance is 0 ;
the contrast of a point that is double the mean luminance is  +1 ;
the contrast of a point that has zero luminance is            -1 .

CONTRAST GAIN CONTROL
  Contrast gain control is a process that has an image as an imput and
produces the same image as output except that the point contrasts of the 
output image are reduced relative to the contrasts of the input image.
  More specifically, small input image contrasts (e.g. less than a few percent)
are unchanged in the output, large input contrasts are reduced in the output.
  Still more specifically:  Let the input contrast of a point be x, and
let the output contrast be y.  Then y= x/(1+x) 

 ===============================================================================

From lynda1213@hotmail.com  Sun Oct 15 21:36:33 2000 "Lynda Kiem" 
To: sperling@uci.edu
Subject: lecture notes

Professor Sperling,

 ...

I have a question regarding tuesday lecture 10/10, what exactly do we have 
to know about neuroscience?  Is it in the text book, if not do you have any 
reccomendations on how I can get the material to read up on what I can't 
understand.  I was not able to catch all of what you had to say about 
neurology on the eye.

  **** Usually you're responsible for what was said in lecture, although
I try to remember to warn you when I tell you things that are unessential
but interesting.  For exmaple, I talked some about the specific techniques
which have been used to attempt to discover the structure and function of
neurons.  You're responsible for the principles, not the details of the 
methods. For example, you're responsible for knowing how ON-center and
OFF-center neurons might respond too various  stimuli, but not how the
recording is actually carried out.

 ...

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