Eye to Brain Pathway

• Exam 2 is on Wednesday, March 5, in class, consisting of about 35 multiple-choice questions. A Scantron form 882-E is required.

Path from Eye to Brain

• Begins with the retina leading to the optic nerve.
• Proceeds to the superior colliculus and the lateral geniculate nucleus (LGN).
• It terminates in the striate cortex.
• Visual information from the left visual field goes to the right eye and then to the right striate cortex, and vice versa.

Optic Nerve

• It is the bundle of axons carrying visual information from the eye to the brain.
• The two optic nerves converge at the optic chiasm where some fibers cross to the opposite side.

Superior Colliculus

• It is the primary visual brain area in lower animals.
• This area controls eye movements.
• It is not ideal for detailed object analysis.

Lateral Geniculate Nucleus (LGN)

• It receives input from the retina and sends projections to the primary visual cortex.
• The LGN is located in the thalamus and contains six layers.
• Two LGNs are present.

Striate Cortex

• It is responsible for the initial processing of visual information from the eyes.

Gordan Holmes's Findings

• Holmes examined WW1 veterans with brain damage using moving spots of light.
• Scotomas, or blindness patches in the visual field contralateral to the damaged hemisphere, were identified as a result of brain damage.

Topographical Mapping

• It creates a detailed visual field representation on the brain.
• This involves mapping the visual field directly onto the thalamus.
• This allows for spatially accurate processing of visual information as it travels to the visual cortex.

Cortical Magnification

• More central to the area of the retina.
• This is useful for high-acuity tasks like reading and searching.
• It can integrate visual information to rapidly direct eye movements toward a stimulus.
• It coordinates head movements alongside eye movements to focus on a target.
• Greater cortical magnification results in better acuity.

Hubel and Wiesel

• They discovered that certain neurons in the cortex respond best to a specific orientation of a bar moving in a particular direction.

Simple Cells

• Located in the Striate Cortex
• They respond best to specific bar orientations, with responses diminishing as the bar is tilted away.
• Edges and lines of specific orientations are primarily detected by them.
• They function by detecting on and off with lines and edges.

Feature Detectors

• Neurons in the striate cortex respond to specific stimulus aspects, for example orientation, movement, and size.
• Oriented lines and edges, as derived by feature detectors, form the foundation for perceiving an object.

Neural Plasticity

• It is the brain's ability to change and adapt its neural connections based on experiences.
• The response properties of neurons can be shaped by an individual’s perceptual experience.

Blakemore and Cooper (1970)

• This study with kittens demonstrates the importance of early sensory experience in shaping brain development and perception.
• It emphasizes the existence of a crucial development period, where experience shapes perception, and sensory deprivation has effects.

Visual Acuity

• This relates to spatial frequency.

Receptive Fields

• These are located in the striate cortex.

Selective Adaptation

• It is the psychologist's electrode.

Gestalt Principles

• Principles include proximity, similarity, good continuation, connectedness, closure, and common fate.
• Illusory contours are also a part of this.

Recognition by Components Theory

Biederman (1985)

Face Inversion Effect

• Involves holistic processing and priming.

Palmer (1975)

Prosopagnosia

What and Where Pathways

Dealing with Occlusion

• Includes how one deals with parts and wholes.

Templates