Quiz 1 - HCI

Input and Output

A person’s interaction with the outside world occurs through information being received and sent

Input

occurs mainly through the senses

Output

through the motor control of the effectors

Taste and Smell

do not currently play a significant role in HCI, and it is not clear whether they could be exploited at all in general computer systems, although they could have a role to play in more specialized systems

the physical reception of the stimulus from the outside world, and the processing and interpretation of that stimulus

two stages of visual perception

Light

Vision begins with

Light

is reflected from objects in the world and their image is focused upside down on the back of the eye

The cornea and lens

The _____ and _____ at the front of the eye focus the light into a sharp image on the back of the eye, the retina.

rods and cones

The retina is light sensitive and contains two types of photoreceptor

Rods

are highly sensitive to light and therefore allow us to see under a low level of illumination. However, they are unable to resolve fine detail and are subject to light saturation.

Cones

the second type of receptor in the eye. They are less sensitive to light than the rods and can therefore tolerate more light.

Fovea

the eye has approximately 6 million cones, mainly concentrated on the _______, a small area of the retina on which images are fixated.

Ganglion cells

The retina also has specialized nerve cells called ___________

X-cells

which are concentrated in the fovea and are responsible for the early detection of pattern

Y-cells

which are more widely distributed in the retina and are responsible for the early detection of movement.