Sen Exam 1

checkerboard-shadow illusion (same grey but it seems lighter, same colour properties)

The checkerboard-shadow illusion refers to the phenomenon where two squares of the same gray color appear to be different due to the surrounding shadows

Anderson’s Lightness Illusion

- Anderson's Lightness Illusion is a visual illusion that involves the perception of lightness or darkness in an image.

Face Recognition - The ability to identify and recognize faces.

- The ability to identify and recognize faces.

Object Recognition - The ability to identify and recognize objects.

- The ability to identify and recognize objects.

Light is made of photons

- Light consists of particles called photons.

Every photon has a wavelength

- Each photon has a specific wavelength.

nm is a nanometre (1 billionth)

- nm is an abbreviation for nanometer, which is equal to one billionth of a meter.

Shorter wavelengths are blue and longer are red

- Shorter wavelengths correspond to the color blue, while longer wavelengths correspond to the color red.

Spectrum of Sunlight

The range of wavelengths present in sunlight.

Some light blue is scattered, a lot of blue light gets scattered and mostly reddish-orange light remains

- Blue light is scattered more than other colors, resulting in a reddish-orange hue remaining.

Bee spectral sensitivity (Human and Bee)

- The sensitivity of bees and humans to different wavelengths of light.

Imagining a UV World

- Considering how the world would appear if we could see ultraviolet light.

Types of ways light can be reacted

Different ways in which light can interact with objects.

Reflection, reaction, and absorption

Light can be reflected, reacted upon, or absorbed by objects.

Light bends depending on our perceptions of what we are using thicker and thinner lens.

- The bending of light is influenced by the thickness and curvature of lenses.

Accommodation (focusing)

The process of adjusting the thickness of the lens to focus on objects at different distances.

Astigmatism

A visual defect caused by unequal curving of the cornea or lens, resulting in distorted vision.

Cranial Nerves - The twelve pairs of nerves that originate from the brain and control various functions of the head and neck.

The twelve pairs of nerves that originate from the brain and control various functions of the head and neck.

Olfactory (I) nerves

The first pair of cranial nerves. They conduct impulses from the olfactory epithelia in the nose to the olfactory bulb.

Optic (II) nerves

The second pair of cranial nerves. They carry visual information from the retina to the thalamus and other parts of the brain.

Oculomotor (III) nerves

The third pair of cranial nerves. They innervate most of the extrinsic muscles of the eye, as well as the muscles controlling the upper eyelid, ciliary muscle, and pupil.

Trochlear (IV) nerves

The fourth pair of cranial nerves. They innervate the superior oblique muscles of the eyeballs.

Abducens (VI) nerves

The sixth pair of cranial nerves. They innervate the lateral rectus muscle of the eyeballs.

Vestibulocochlear (VIII) nerves

The eighth pair of cranial nerves. They connect the inner ear with the brain, transmitting impulses related to hearing and spatial orientation.

Magnetic Resonance Imaging (MRI)

An imaging technology that uses strong magnetic fields to create detailed images of structures like the brain.

Functional Magnetic Resonance Imaging (fMRI)

A variant of MRI that measures localized patterns of brain activity by detecting changes in blood flow.

Blood Oxygen Level-Dependent (BOLD) Signal

- The ratio of oxygenated to deoxygenated hemoglobin used to measure brain

Swimming goggles

Protective eyewear worn while swimming to preserve the air-water boundary and maintain the focusing power of the cornea.

Rods vs

Rods are more sensitive to faint light than cones, allowing for better night vision.

Rod density

Rod density peaks away from the fovea, except at the optic disc on the nasal side.

Optimal position for light stimulus

The light stimulus should be positioned on the high-density region, about 15 degrees from the fovea.

Pigeon's eyes

Pigeons have a single focal power lens, allowing them to focus on both nearby objects on the ground and distant objects in the sky simultaneously.

Pigeon's retina

The top part of the retina receives images from nearby objects, while the bottom part receives images from distant objects.

Adapting to a sine wave grating

Adapting to a specific spatial frequency grating only fatigues channels sensitive to that grating.

Adapting to a pattern with multiple spatial frequencies

Adapting to a pattern with specific spatial frequencies fatigues neurons detecting those frequencies, resulting in decreased sensitivity.

Anatomy of the eye

The cornea is the transparent window of the eyeball, the lens focuses light onto the retina, and the retina contains rods and cones that convert light into electrical signals.

Aqueous humor

A watery fluid between the cornea and iris that helps maintain the shape of the eye and provides nutrients.

Pupil

The opening in the center of the iris that regulates the amount of light entering the eye.

Iris

The colored part of the eye that controls the size of the pupil.

Vitreous humor

A gel-like fluid between the lens and retina that helps maintain the shape of the eye and transmits light to the retina.

Cataract

A clouding of the lens in the eye, leading to decreased vision.

Refractive error

A condition where the shape of the eye prevents light from focusing correctly on the retina, resulting in blurred vision.

Melanopsin

A photopigment found in specialized cells in the retina that regulates circadian rhythms and pupillary reflexes.

Photoactivation

The process by which a molecule or biological system is activated or undergoes a change in response to light exposure.

Hyperpolarization

A change in the electrical potential across a cell membrane, making the inside of the cell more negative relative to the outside.

Graded potential

A change in the membrane potential of a cell that varies in magnitude and can be either depolarizing or hyperpolarizing.

Horizontal cell

A neuron in the retina that receives input from multiple photoreceptor cells and modulates communication between them.

Lateral inhibition

A process in which the activity of one neuron inhibits the activity of neighboring neurons, enhancing contrast and sharpness of visual signals.

Diffuse bipolar cell

A bipolar cell in the retina that receives input from multiple photoreceptor cells and distributes the signal to multiple ganglion cells.

On bipolar cell

A bipolar cell in the retina that responds to increased light intensity and transmits excitatory signals to downstream neurons.

Off bipolar cell

A bipolar cell in the retina that responds to decreased light intensity and transmits inhibitory signals to downstream neurons.

Ganglion cell

A neuron in the retina that receives visual information from bipolar cells and transmits it to the brain via the optic nerve.

P ganglion cell

A subtype of ganglion cell in the retina responsible for processing color and fine details in the visual scene.

M ganglion cell

A subtype of ganglion cell in the retina responsible for processing motion and spatial information in the visual scene.

Koniocellular cell

A ganglion cell in the retina involved in color processing and projects to different visual areas in the brain.

Optic chiasm

A structure located at the base of the brain where the optic nerves partially cross over, allowing visual information from each eye to be transmitted to the opposite side of the brain.

Optic tract

A bundle of nerve fibers carrying visual information from the optic chiasm to various visual processing centers in the brain.

Lateral geniculate nucleus

A relay station in the thalamus of the brain that receives visual information from the optic tract and relays it to the primary visual cortex.

Optic radiation

A collection of nerve fibers carrying visual information from the lateral geniculate nucleus to the primary visual cortex in the occipital lobe of the brain.

Striate cortex

The primary visual cortex located in the occipital lobe that receives and processes visual information from the optic radiation.