Laboratory Exercise on Sensory Physiology ppt

Question 1

Requires that the separate images in the right eye and left eye to be fused, to give a single view

Answer 1

bionocular vision

Question 2

also known as a near point of convergence (NPC) test, measures how well your eyes work together when focusing on nearby objects. This test can help identify convergence insufficiency, a condition that affects binocular vision.

Answer 2

Convergence of gaze test

Question 3

Convergence of gaze test procedure and results

Answer 3

distant object and near object

focus on distant object, while move the near object closer till you get double vision of the near object

if one eye is closed, double vision disappears
if two eyes are open, double vision appears

Question 4

the eye can ________ for far or near vision, by varying shapes of the lens

Answer 4

focus / accomodate

Question 5

accomodation test steps and results

Answer 5

a pin is put near the face, and the eyes will focus on an object in the distance. After, the focus should shift to the pin.

When the pin was focused, the surroundings went blurred and slightly dimmed.
when the the object at the distance was focused, the pin was blurred and disappeared

Question 6

visual illusion that occurs when the brain blocks visual processing during eye movements

Answer 6

saccadic masking

Question 7

saccadic masking test steps and results

Answer 7

looking at the mirror, the look directly into the right eye. the, look directly into the left eye

While doing the said procedure, my eyes did not move. Rather, my eyes seemed to instantly jump from one position to the other without any visible motion. ​

Question 8

represents the optic disk, a part of the retine with no photoreceptors

Answer 8

blind spot

Question 9

blind spot test steps and results

Answer 9

using paper and a white barreled pen, while looking right across the paper with one eye, the pen from the left will move to the right until it can be seen

able to identify my blind spot when the pen tip disappeared at a specific point. This happens because the optic nerve lacks photoreceptors. Marking the upper and lower limits helped estimate its size. Typically, I do not notice my blind spot because my brain fills in the missing . ​

Question 10

The eye has properties similar to those of a camera, in that the image formed on the retina is

Answer 10

inverted

Question 11

Mechanical stimulation of the retina, by pressure on the eyeball, also gives a visual response that is

Answer 11

inverted

Question 12

Light falling on the retina on one side of the eye gives a visual response in the ________ side of the visual field.

Answer 12

opposite

Question 13

Mechanical stimulation of the retina test and results

Answer 13

Gaze to the left and closing both eyes after. Gently pressing down the right side of the eye. Do the same for the other eye

There is a circular disc at the end opposite to where my finger is. The direction of the disc is opposite or the inverted movement of my finger.

Question 14

Retinal photoreceptors have a surprisingly long and slow response to light. A brief visual stimulus gives rise to a response that outlasts the stimulus long enough to give an

Answer 14

after- image

Question 15

positive after image test steps and results

Answer 15

face a bright light for 30 mins, close eyes and look again, then close

after closing eyes, there should be a bright image the same as the light seen earlier while the eyes are closed

Question 16

When you close your eyes and see a positive afterimage

Answer 16

the photoreceptor cells in your retina are still firing signals to the brain, essentially “replaying” the image you saw even though the original stimulus is gone, resulting in an afterimage that appears in the same colors as the original image, hence “positive.

Question 17

why are afterimages negative when eyes are open

Answer 17

The area of the retina that was desensitized by the bright image does not respond as well to this new light input as the rest of the retina. Instead, this area appears as a negative afterimage, a dark area that matches the original shape.

Question 18

negative after image test steps and results

Answer 18

black object on white paper, focusing on that for a while then remove

red object on white paper, focusing on that for a while then remove

The black pen gave off a faint, white glowing afterimage of the pen. The red colored pen, however, gave off a light, glowing green afterimage of the pen. It seems like the after image of colored objects are the complementary color of it.

Question 19

The sensitivity of retinal photoreceptors decreases gradually while they are being stimulated by light, and increases while they are not.

Answer 19

true

Question 20

adaptation to light and dark allows visual function over a very wide range of light intensities. It has the side effect of giving rise to ____________

Answer 20

negative after-images.

Question 21

Visual information test steps and results

Answer 21

look at pixilated image first
squint after to focus

With the lack of additional detail and pixilation, it is quite hard to confirm who the person is. After squinting or screwing, it helps me focus and reduce scattered light from the distortion. This made my brain fill in the blanks and confirm that it is Albert Einstein.

Question 22

Optical illusions

an optical illusion that makes people see gray spots at the intersections of white lines on a black background

Answer 22

The Hermann grid illusion

Question 23

Optical illusions

occur when our brains misinterpret visual cues, causing us to perceive an object as larger or smaller than it actually is, often due to the surrounding context or the arrangement of lines and shapes

Answer 23

size perception

Question 24

Optical illusions

is a type of optical illusion that consists of a two-dimensional figure which is instantly and naturally understood as representing a projection of a three-dimensional object but cannot exist as a solid object.

Answer 24

impossible geometric object

Question 25

As outlined in the Background section, about ___________ of the male population has various deficits in their ability to appreciate colors

Answer 25

5%

Question 26

is a test for red-green color deficiencies, the most common kind. It was named after its designer, Dr. Shinobu Ishihara (1879-1963), a professor at the University of Tokyo, who first published his tests in 1917. The full test consists of thirty- eight plates. Nine images are shown here.

Answer 26

Ishihara color test

Question 27

is a type of red-green color blindness that makes up approximately 80% of all color blindness cases.

Answer 27

Deutan type color blindness

Question 28

tends to see greens, yellows, oranges, reds, and browns as being more similar shades of color than normal, especially in low light you have impaired or missing red-sensing cones, or L cones

Answer 28

protan type color blindness

Question 29

you have impaired or missing green-sensing cones, or M cones

Answer 29

Deutan type color blindness

Question 30

a rare type of color blindness that makes it difficult to distinguish between blue, green, purple, red, and yellow. It's also known as tritanopia or blue-yellow color blindness.

Answer 30

tritan type color blindness

Question 31

reduced sensitivity in the blue-sensitive “S” cone cells

Answer 31

tritan type color blindness

Question 32

tactile illusion steps and results

Answer 32

Cross fingers and put the pen through the V shaped hole move the pen through it bakc and forth It feels like I am touching 2 different things ​despite only touching one pen.

Question 33

Thermal illusion steps and results

Answer 33

warm, room temp, cold water on finger each in hot and cold water after place the fingers in room temp water The hand that was submerged in cold water felt warmer when placed in lukewarm water while the hand that was submerged in hot water felt cooler when placed in lukewarm water. A similar sensation was observed with the metal and wooden rods only that the metal felt slightly cooler than the wooden rod.

Question 34

Taste and Smell test steps and results

Answer 34

closing eyes and pinching nostrils small apple in mouth next is raw potato then and onion repeat next time and allow them to breathe through nose It was difficult to differentiate the 3 foods from​ Each other based on texture as the taste is dulled ​ Due to pinching the nose.​ When no longer pinching my nose I was able to clearly​differentiate the 3 foods from each other. ​

Question 35

joint position Sense

Answer 35

closing eyes and fingers outstretched, moving the volunteers finger up and down with both large and small movements Without visual aid, the volunteer is able to generally perceive the larger movements of their finger. However, there is difficulty in detecting smaller movements as it did not largely include both joint and muscle receptors. The volunteer’s accuracy in responding to each movement can vary due to the minimality of each sensory input from the joint receptors without visual cues.

Question 36

semicircular canal test steps and results

Answer 36

Procedure 1. The volunteer should sit on the swivel chair, with both feet in the air, and close both eyes. 2. Ask the volunteer to say when a rotation is detected, and to indicate in which direction. Test the volunteer's ability to sense rotary motion, by rotating the chair at various speeds and for various durations. You should find that even very slight movements are reliably detected. The volunteer is able to detect the slight rotations of the swivel chair without visual perception. This suggests the highly sensitive properties of the semicircular canals to movement. However, multiple rotations in varying directions and speed has disoriented the volunteer’s senses, deeming a lesser reliability in the reports of the chair’s movement. This is due to the prolonged stimulation that there is a temporary disruption of the semicircular canals, influencing the volunteer’s balance and spatial awareness.

Question 37

__________ are liquid-filled channels in the temporal bone of the skull, and form part of the inner ear. They detect rotary movements of the head in three axes.

Answer 37

semicircular canals

Question 38

The semicircular canals detect rotation but do not signal the body's position. You can test this by

Answer 38

showing that the volunteer's idea of which direction he or she is facing becomes unreliable after a sequence of rotations, such as a quarter-turn in one direction and then a half-turn in the other.