Psychology Sensation and Perception Part 1

Psychology Sensation and Perception Part 1

Sensation and Perception

In psychology, sensation and perception are stages of processing in the sensory system, such as vision, auditory, and pain sensory systems.

Sensation and Perception

* Sensation- the process by which our sense organs receive information from the environment.

* Perception- the sorting out, interpretation, analysis, and integration of stimuli involving our sense organs and brain.

Transduction

Transduction is the process of turning environmental information into neural impulses.

Transduction

• Information gathered from your sensory organs is converted into neural impulses that are carried through the peripheral nervous system to your brain.

• After this process of "transduction" has occurred, the brain can convert the impulses into information.

Fraser's Spiral

Is it actually a spiral? The Fraiser's Spiral is an example of how our perception does not always match reality. If you trace the rings of the spiral, your finger will end where you started - forming a perfect circle.

Checker-shadow Illusion

Are squares A and B the same color? Our minds see colors relative to those around them. Next to lighter squares, square A appears dark, and next to darker squares, square B appears light.

Checker-shadow Illusion

If you still don't believe the squares are the same color, take a look at this picture.

Open Ended

Explain in your own words how Frasher's Spiral and Checker-shadow Illusion relate to psychology.

Thresholds

An edge, a boundary. One of the thresholds that interest psychologist is the absolute threshold. Human beings have absolute thresholds that are low enough to detect most of the significant events that occur in our environment.

** According to one estimate, a person with normal vision in total darkness can detect the light of a single candle 30 miles away.

Absolute Threshold

The minimum amount of stimulation a person can normally detect.

Multiple Choice

If your hearing had a lower absolute threshold, you might constantly be distracted by the sound of blood pulsing near your ears.

• True

• False

Difference Threshold

Sometimes referred to as the Just noticeable difference (JND).

Difference Threshold

The smallest amount of change in a physical stimulus that a person can detect 50% of the time. This is also called the "just noticeable difference."

Difference Threshold

• If someone turns the music up slowly, at what point do you notice it has become louder?

• If you hold a handful of sand, and someone adds one grain at a time to the pile, when do you notice it has become heavier?

• If your best friend trims a half inch off of their hair, will you notice the difference?

Multiple Choice

Why is difference threshold a significant accomplishment for modern psychology?

• helps to recognize missiles on a radar screen

• helps to detect the least amount of basil in your spaghetti sauce

• helps to detect how much does the volume have to increase before yo can tell that your stereo has gotten louder

Signal Detection Theory

A theory that predicts how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). This theory assumes that there is no single absolute threshold and that detection depends partly on a person's experience, motivation, and fatigue levels.

Signal Detection Theory

Helps us understand how quickly we can notice and correctly interpret a blip on a radar screen. The researcher old consider the nature of the screen itself (how bright are the blips?), the surrounding environment (how much "noise" or distraction is there?"), and the person doing the detecting (is he trained, motivated, healthy, and alert?).

Sigal Detection Theory

Helps us understand how quickly we can notice and correctly interpret a blip on a radar screen. The researcher would consider the nature of the screen itself (how bright are the blips?), the surrounding environment (how much "noise" or distraction is there?"), and the person doing the detecting (is he trained, motivated, healthy, and alert?).

Signal Detection Theory Formula

• Stimulus variables- How bright is the blip on the radar screen?

• Environmental variables- How much distracting noise is there in the room with the radar equipment?

• Organismic variables- Is the operator properly trained and motivated?

Multiple Choice

Why is signal detection theory a significant accomplishment for modern psychology?

• helps to recognize missiles on a radar screen

• helps to detect the least amount of basil in your spaghetti sauce

• helps to detect how loud your music is

Sensory Adaptation

Diminished sensitivity as a consequence of constant stimulation.

Example:

** Jumping into a cold swimming pool, doesn't feel cold after a while.

** Your eyes when you turn off the lights

Open Ended

How does sensory adaptation make your life easier?