SENSATION & PERCEPTION

SENSATION & PERCEPTION.

SENSATION. The method in which the sensations experienced at any given moment are interpreted and organized in some meaningful fashion.

SENSATION. 1.

Pain. Pressure. Temperature. Number of Senses. 4.

An absolute threshold is the smallest intensity of a stimulus that must be present for it to be detected.

Signal Detection Theory. Signal detection theory is a method of differentiating a person’s ability to discriminate the presence and absence of a stimulus (or different stimulus intensities) from the criterion the person uses to make responses to those stimuli This refers to our attempt to focus on one particular stimulus and ignore the flood of information entering our senses..

Exercise. 7.

Sensory Adaptation. 8. [image]. [image]. [image] @Studycom.

Sensory Adaptation. Tendency of sensory receptor cells to become less responsive to a stimulus that is unchanging. It is a reduction in sensitivity to a stimulus after constant exposure to it. While sensory adaptation reduces our awareness of a stimulus, it helps free up our attention and resources to attend to other stimuli in our environment. Receptors are no longer sending signals to the brain.

PERCEPTION. Principles of perception.

[image]. [image]. EXAMPLES. 11.

Developed by German psychologists, the Gestalt laws describe how humans perceive the world around them through a psychological process known as perceptual organisation. In this process, the human mind will group stimuli (objects) into comprehensible patterns in order to readily determine their meaning The term pragnanz indicates fullness or completeness. Gestalt psychologists are of the view that the process of perception is dynamic and goes on changing until we reach a stage of perceiving with maximum meaning and completeness. Once we reach this point, the perceived gestalt remains stable. Such a stable gestalt is called a good gestalt.

[image]. [image]. [image]. 13.

Gestalt psychologists believe that the brain tends to perceive forms and figures in their complete appearance despite the absence of one or more of their parts, either hidden or totally absent. Gestalt psychologists claimed that when we receive sensations that form an incomplete or unfinished visual image or sound, we tend to overlook the incompleteness and perceive the image or sound as a complete or finished unit. This tendency to fill in the gaps is referred to as closure..

[image]. When objects are close to each other, the tendency is to perceive them together rather than separately. Even if the individual items do not have any connection with each other they will be grouped under a single pattern or perceived as a meaningful picture.

[image] o caoczo. Similar elements tend to be perceived as belonging together. Stimuli that have the same size, shape and color tend to be perceived as parts of the pattern.

17. Assignment. Principle of continuity Principle of inclusiveness.

Color – Vision & Color – Blindness. 18. [image] Gamgp 0-14 X-rays 10-10 Ultraviolet 10—8 Infrared rays I 1 10—4 Radar 10-2 Red FM IOI Shortwave 102 AM 104 electricity I 10-12 106 108 Wavelength in meters Violet Blue 400 Visible light Green 600 Yellow 500 700 Wavelength in nanometers (billionths of a meter).

A person with normal color vision is capable of distinguishing no less than 7 million different colors.

COLOR BLIND RATIO. 7% of men 4% of women. 20.

21. [image]. [image]. [image].

22. The Trichromatic Theory color green, color blue, color red Short-wavelength cone receptors Middle-wavelength cone receptors Long-wavelength cone receptors Opponent Process Theory process of excitatory and inhibitory responses These two types of cells in a red-green receptor complex can't be activated at the same time. Complementary Color Theory It seems the green receptor cells do not activate because the red cells become inhibited. cells are excited or inhibited by certain wavelengths of light..

PSYCHOLOGY OF COLORS. 23.

Your feelings about color are often deeply personal and rooted in your own experience or culture EXAMPLES ..? Supermarket psychology Psychology of brands.

Influences on Perception. Attention Process of sorting through sensations and selecting some for further processing Some sensations are automatic requiring minimal mental effort Inattentional blindness Changes in objects not receiving direct attention are not noticed Cocktail party phenomenon When you hear your name, focus follows due to assumption that other meaningful information will follow Focus Information that receives focus is remembered while other stimulation received at same time is lost Hearing words spoken into both ears at same time; only words that receive focus of attention are recalled.

Presentation. 26.

ILLUSION. 27.

illusion, a misrepresentation of a “real” sensory stimulus..

29. [image] 22.

30. [image] 33.

31. [image] Amazing Paintings of Animals on Hand 17.

Hearing. The location of the outer ears on different sides of the head helps with sound localization, the process by which we identify the direction from which a sound is coming. The two outer ears delay or amplify sounds of particular frequencies to different degrees. “Sound is the movement of air molecules brought about by a source of vibration” Sound waves are invisible ripples of high and low air pressure created by objects that vibrate or shake rapidly to and fro..

The ear converts this type of energy-in this case the energy of sound waves, into tiny electrical nerve signals The inner ear is the portion of the ear that changes the sound vibrations into a form in which they can be transmitted to the brain. Sound waves have an amplitude and frequency.

Frequency is the number of wave cycles that occur in a second Amplitude is a feature of wave patterns that allows us to distinguish between loud and soft sounds. Amplitude is the spread between the up-and-down peaks..

[image]. 35.

The sense of smell is sparked when the molecules of a substance enter the nasal passages and meet olfactory cells. The receptor neurons of the nose, which are spread across the nasal cavity. More than 1,000 separate types of receptors have been identified on those cells sense of smell ( olfaction ) permits us to detect more than 10,000 separate smells.

Airborne molecules must reach receptors in the back of the nose in order to smell. Sniffing swirls the air up into these receptors. Messages from these receptors are sent to the brain temporal lobe and to parts of the limbic system..

TASTE. The sense of taste ( gustation ) involves receptor cells that respond to four basic stimulus qualities: sweet, sour, salty, and bitter. A fifth category also exists, a flavor called umami , although there is controversy about whether it qualifies as a fundamental taste. The English“meaty” or “savory” comes close.

every taste is simply a combination of the basic flavor qualities, in the same way that the primary colors blend into a vast variety of shades The receptor cells for taste are located in roughly 10,000 taste buds , which are distributed across the tongue and other parts of the mouth and throat. The taste buds wear out and are replaced every 10 days or so..

THANK YOU ☺. 40.