Warm Up

In your notes, briefly answer the following questions:

1. How do you think you did on this test compared to the first test?2. If you think you did better, what do you think helped you this time?3. If you think you did worse, what do you think was the reason?

Scores: 39, 40, 40, 46, 47, 50, 52, 53, 54, 63, 64, 70, 75, 76, 77, 82, 82, 85, 90, 91, 96

Last test’s mean: 54This test’s mean: 65 +11 points!!

Last test’s median:45This test’s median: 64 +19 points!!

Curve:90s +4 60s +7 30s +1080s +5 50s +870s +6 40s +9

This makes the highest grade 100, and passes the lowest 60.

Related to… Sight: Visual (like “vision”)

Hearing: Auditory (like “audio”)

Taste: Gustatory (you eat with “gusto”!)

Smell: Olfactory (when you drive past

an ol’ factory it often smells

bad) Touch: Tactile (sounds like “texture”)

Balance: Vestibular

Sensation Information coming into our brain from our sensory receivers. (What comes in.)

Perception The way the brain organizes and interprets the data received by our senses (How we understand it.)

StimulusSomething that triggers a response.

Prosopagnosia (“agnosia” = ignorance, or not knowing)

Inability to recognize faces. Sensation is fine,perception just doesn’t work.

Example of Prosopagnosia: FACE BLINDNESS

Can you have sensation without perception?

Start at the ‘bottom’ with the sense receptors and individual stimuli, work ‘up’ to the brain to form

meaning.processing that begins with the sense receptors and works up to the brain’s

integration of sensory information

Letter “A” is really a set of black lines that the brain puts together to perceive as an “A.”

Starting from experiences and expectations (the ‘top’) and working ‘down’ to create perception (what we think we see.)

information processing guided by higher-level mental processes as when we construct perceptions drawing on our experience

and expectations How do you read the words below? Is it because of what you are actually

sensing? Or because of what you expect to see?

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What do you se

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Uinervtisy, it deosn't mttaer in waht oredr the

ltteers in a wrod are, the olny iprmoetnt tihng is

taht the frist and lsat ltteer be at the rghit

pclae. The rset can be a total mses and you

can sitll raed it wouthit a porbelm. Tihs is

bcuseae the huamn mnid deos not raed ervey

lteter by istlef, but the wrod as a wlohe.

Psychophysics: study of the relationship between physical characteristics of stimuli and our psychological experience of them

Stimulus We experience…light brightnesssound volumepressure weighttaste sweetness

(Why do dogs hear a dogwhistle, but we don’t?)

Absolute ThresholdMinimum stimulation needed to detect a particular stimulus 50% of the time.

Subliminal MessagesMessages presented below absolute thresholds (sub=below, liminal=threshold). Not consciously perceived.

(Technically, a ‘subliminal’ message can be something you DO perceive,

just less than 50% of the time.)

subliminal message- stimulus that lies below one’s absolute threshold for conscious awarenessWe can detect some subliminal messagesHow is that?because absolute thresholds involvedetecting the stimulus 50% of the timeDoes this mean we can be subliminally persuaded?

Some have argued that humans still “pick up” these messages that influence our “unconscious.” Do these messages have suggestive powers?

Why do people who buy “subliminal message tapes” that promise to make them more confident, or more relaxed, say they work?

Mr. Subliminal

Difference ThresholdAmount of change needed to notice that a change has occurred.

Weber’s Law: The greater or stronger the stimulus, the greater the change required to notice a difference. Two stimuli must differ by a constant minimum percentage (rather than a constant amount), to be perceived as different.

JND = just noticeable difference

Signal Detection Theory: predicts how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise)

Assumes that there is no single absolute threshold - it varies by person, and by situation.

What might a person’s detection of a stimulus depend on?

Diminished sensitivity as a consequence of constant stimulation. Your sensory receptors “get tired.”

Put a band aid on your arm and after a whileyou don’t sense it.

Quick Write: What function does sensory adaptation serve? How might it help us? (Think evolution and survival…and present day)

Different nerve cells in the visual cortex respond to specific features, such as

edges, angles, and movement.

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1. Light enters the eye through the cornea (transparent covering), and passes through the pupil (the black hole in your eye).

2. The size of the opening (pupil) is controlled by the iris (the colored part of your eye) which is a muscle that opens or closes the pupil, (dilates or constricts), causing either more or less light to get in.

3. Behind the pupil, the lens, a transparent structure, changes its curvature in a process called accommodation, and focuses the light rays into an image on the light-sensitive back surface called the retina, where image is focused.

4. Image coming through activates photoreceptors in the retina called rods (dark/light) and cones (color/detail).

5. As rods and cones set off chemical reactions they form a synapse with bipolar cells which transducts (changes) light energy into neural impulses (electrical messages/action potentials).

6. Neural impulse travels along the ganglion cells which send information up the optic nerve (bundle of neurons that take information from retina to the brain).

7. The Optic Nerve carries neural information to the Thalamus (sensory switchboard).

8. Thalamus sends information to the visual cortex, in the occipital lobe.

9. The brain then constructs what you are seeing and turns image right side up.