Visual Processing Processing in the Retina

Slides:



Advertisements
Similar presentations
Visual Sensation & Perception How do we see?. Structure of the eye.
Advertisements

Perception Chapter 3 Light is necessary but not sufficient for vision Ganzfeld: a visual field completely lacking in contour, or luminance changes. Prolonged.
The visual system II Eye and retina. The primary visual pathway From perret-optic.ch.
Exam in 12 days in class assortment of question types including written answers.
Midterm 1 was returned in this class -mean was “a little to low” - for future, Moodle will have an Open Discussion Forum for this class to catalyze engagement.
Exam 1 week from today in class assortment of question types including written answers.
Visual Processing Structure of the Retina Lateral Inhibition Receptive Fields.
Unrelated vs. Related Color Unrelated color: color perceived to belong to an area in isolation (CIE 17.4) Related color: color perceived to belong to.
Visual Sensation & Perception How do we see?. Structure of the eye.
The Eye. A Model for Sensing  Three components: Stimulus detection – a specialized sensory neuron Reception – where neurons receive information from.
Human Sensing: The eye and visual processing Physiology and Function Martin Jagersand.
The visual system Lecture 1: Structure of the eye
RGB Models human visual system? Gives an absolute color description? Models color similarity? Linear model? Convenient for color displays?
The Visual System Into. to Neurobiology 2010.
The Visual System General plan for visual system material: How the visual input is received and transduced at the retina by photoreceptors (rods and cones)
EYES!.
LECTURE 17: VISION--ORGANIZATION AND FUNCTION OF RETINA REQUIRED READING: Kandel text, Chapter 26 central The retina is part of the central nervous system,
University Studies 15A: Consciousness I The Neurobiology of Vision.
Glaucoma & Glaucoma test Refraction Degree of cell packing in retina.
Psychology 4051 The Retina and LGN. Retino-Geniculate-Cortical Pathway.
PSYCH 2220 Sensation & Perception I Lecture 3. Keywords for lecture 2 Air-dwelling eye, water-dwelling eye, (both: mask, powerful lens, flat cornea, pinhole),
The Visual System Part 2. The Retina Photoreceptors –Rods –Cones Bipolar cells Ganglion Cells –axons converge at optic disk –axons constitute optic nerve.
THE VISUAL SYSTEM: EYE TO CORTEX Outline 1. The Eyes a. Structure b. Accommodation c. Binocular Disparity 2. The Retina a. Structure b. Completion c. Cone.
Why is this hard to read. Unrelated vs. Related Color Unrelated color: color perceived to belong to an area in isolation (CIE 17.4) Related color: color.
The Visual System: Retinal Mechanisms
The Visual System Part 2. The Retina Photoreceptor cells 4 light sensitive proteins: rods with 1 type 3 types of cones, each with a single type Receptors.
Retinal Physiology : from photon capture to spike trains, an overview Cast of characters and personalities, Who’s on first... Wiring diagrams of the most.
Visual System II: Retinal Processing. Adequate Stimulus: A stimulus of a quality and of sufficient intensity to excite a sensory receptor. Adequate Stimulus.
Dr. Raj Patel OD - Vancouver Vision Clinic
Retinal Physiology Vocabulary  Receptive Field  Spatial summation  Temporal summation  Convergent wiring  Divergent wiring  Lateral inhibition 
Vision 1. Structure of the eye Light passes through ganglion and bipolar cells, without distortion, to visual receptors –bipolar cells receive input.
1 Psychology 304: Brain and Behaviour Lecture 32.
Processing visual information - pathways
Psychology 304: Brain and Behaviour Lecture 28
Cogs 160: Neural Coding in Sensory Systems Spring, 2011 Angela Yu
Psychology 210 Lecture 4 Kevin R Smith.
Light Sensing and Vision
Retinal Circuit and Processing
Visual Sensory System.
Neurophysiology and vison
Cognitive Architectures
The Visual System Part 1.
The Visual System: From Eye to Cortex
BY DR. MUDASSAR ALI ROOMI (MBBS, M. Phil.)
The Visual System Part 2.
Anatomy of the Human Eye
The Visual System.
Rods vs cones Rods - large current change with a single photon
Early Processing in Biological Vision
THE VISUAL SYSTEM.
Ch 6: The Visual System pt 2
The Visual System: Retinal Mechanisms
Physiology of Photoreceptors Vertebrate photoreceptors hyperpolarize and produce graded potentials Photoreceptors use glutamate as transmitter.
Ascending Visual Pathways
Perception: Structures
Spatial Vision (continued)
Perceptual processes and development
Visual processing: The Devil is in the details
Aqueous Humour Vitreous Humour. Aqueous Humour Vitreous Humour.
Central Visual Pathways
Sensation & Perception
Human vision: physical apparatus
Photochemistry of Vision
Computational Vision CSCI 384, Spring 2004 Lecture 4 The Retina
Outline Announcements Human Visual Information Processing
Outline Human Visual Information Processing – cont.
Eye: Retina and Neural Mechanisms.
VISION.
Duplex retina First instance of vision as ‘multiple specialized systems that operate in parallel’ Partitions for sensitivity (rods) and resolution (cones).
Edge Detection via Lateral Inhibition
Presentation transcript:

Visual Processing Processing in the Retina On Center and Off Center Cells Higher Levels of Processing Neural Pathways Edge Effects Motion Illusions Perceptual Learning and Ambiguity

Optical Processing Level one processing occurs in the retina, the rods and cones are the first order cells, bipolar cells are 2nd order and ganglionic cells are the third. Amacrine cells and horizontal cells create both converging and diverging pathways. Rods and cones hyperpolarize when stimulated and Na channels close Horizontal cells produce graded hyperpolarizations Some bipolar cells hyperpolarize and some depolarize Some ganglionic cells hyperpolarize and some depolariize. Ganglionic cells are matched to their bipolar cells Amacrine cells respond transiently when the stimulus changes

Each ganglionic cell has a particular area of the retina that it receives information from. These visual fields are circular. The fields near the fovea are quite small so visual acuity is great. The fields are divided into two areas -- a center and a surround. There are two types of fields an on center field and an off center field. Off CenterInhibited when light in center, fires when light in surround On Cell Ganglion responds when light in center, inhibited by light in surround

Film Clip on Processing

First order – rods and cones Second – bipolar cells Third – ganglionic cells Fourth – neurons of the lateral geniculate nucleus Fifth – Simple cells of the visual cortex Sixth – Complex cells of the cortex (Brodman’s Area 17)

Simple Cell and Motion Illusions