MH - Neur 3206 - Lecture 8 Handout.pptx

MH - Neur 3206 - Lecture 8 Handout.pptx - Lecture 8 Vision...

Info icon This preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 8: Vision Processing Beyond V1
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Announcements Review sessions with TAs for your pre-midterm exam: Last names A to D Lauren: Wednesday (October 11), 10 – 12 AM, DT 1006 Last names E to M Jessica: Tuesday (October 10), 9 – 11 AM, 3101 Richcraft Hall Last names N to Z Jawaria: Tuesday (October 10), 3 – 5 PM, Room TBA Today’s text: Second half of Chapter 10
Image of page 2
What are we going to do today? Review pre-midterm test Finish last lecture – receptive fields of striate cortex neurons Introduction to dorsal and ventral streams of cortical visual processing Dorsal “where” pathway – object location and movement Ventral “what” pathway – object recognition
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Where are we now? Review pre-midterm test Finish last lecture – receptive fields of striate cortex neurons Introduction to dorsal and ventral streams of cortical visual processing Dorsal “where” pathway – object location and movement Ventral “what” pathway – object recognition
Image of page 4
Receptive fields in striate cortex 1958, David Hubel and Torsten Wiesel Postdoctoral researchers in Stephen Kuffler’s lab Little response of striate cortex cells to spots of light? Accidental discovery: Burst of firing when inserting glass slide into slot Response to bars of light Nobel prize
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Receptive fields – orientation selectivity Cells in striate cortex respond best to bars of light rather than to spots of light In a given region of visual field Some cells prefer bars of light, some prefer bars of dark (simple cells) Orientation tuning Neurons respond more to bars of certain orientations and less to others Response rate falls off with angular difference of bar from preferred orientation Figs. 10.20
Image of page 6
Basis of receptive fields for simple cells Simple cells : often binocular, orientation-selective, elongated ON or OFF area flanked by antagonistic surround How bars instead of circular receptive fields like RGCs and LGN? Hubel and Wiesel: a cortical neuron that responds to oriented bars of light might receive input from several LGN neurons A cell that is tuned to any orientation you want could be created in cortex by connecting it up with the appropriate LGNs Neuronal interactions (e.g. – lateral inhibition) within cortex also important Figs. 10.23
Image of page 7

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Complex cell receptive fields Complex cells: Same properties as simple cells, except no distinct ON and OFF regions Phase-insensitive Enables responses to movement!
Image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern