What are the specific sensory thresholds our bodies

What are the specific sensory thresholds our bodies contain? Logan D

Absolute Threshold n The smallest amount of stimulation necessary for a stimulus to be detected Normal Human Absolute Thresholds Vision: a candle flame on a clear, dark night = 30 miles Hearing: A ticking watch in a quiet room = 20 feet Taste: Tablespoon of sugar dissolved in two gallons of water = One Smell: Perfume diffused in a small house = one drop (1 part in 500 mil) Touch: Pressure of the wing of a fly falling on a cheek from. 4 inch

n. What is going on in your head if you are super sensitive to sound? Madison R

Signal Detection Theory Ø Sensation is a judgment the sensory system makes about incoming stimulation Ø A combination of sensation and decision-making processes When something goes ‘bump in the night’ you Stimulus event must decide what it is. What you decide depends on the keenness of Neural activity hearing, parents what you expect as well Thisyour is why canto hear a baby as other background noises Comparison with crying in the middle of the night but personal standard their Individual siblings don’t hear the baby Action (or no action) characteristics affect detection

Just Noticeable Difference • The minimal amount of change in a signal that is still recognizable Example How many lights must be turned off before you notice a difference • Difference threshold and JND are used interchangeably

Unnumbered Figure

Weber’s Law The JND is always large when the stimulus intensity is high, and small when the stimulus intensity is low • For Example: If the TV volume is high, you have to turn it down a lot to make the difference noticeable

• If a weightlifter adds 2 pounds to 10 pounds of weight, he’ll notice a difference. • If he adds 2 pounds to 100 pounds, he won’t notice a difference…it would take 20 pounds to do that

• Marsha was listening to her Ipod and when she turned it down turned ¼, she noticed a big difference. • Later, when she was listening to it at a much louder level, she turned it down the same amount as before, but did notice as much of a difference

• For example, if you are buying a new computer that costs $1, 000 and you want to add more memory that increases the price $200 (a 20% increase), you might consider this too much additional money to spend. However, if you were buying a $300, 000 house, a $200 feature may seem like nothing. It might take an additional $10, 000 to make you stop and think if it's too much to spend. In this example, the amount stays the same ($200), but the proportion changes and that's what makes the perceptual difference.

n. How do subliminal messages work? -Sarah Glenn

Subliminal Persuasion Use of weak stimulations to influence behavior • No controlled research has ever shown that subliminal messages delivered to a mass audience can influence people’s buying habits • But different people have different threshold levels, it may work for some, not others Subliminal means below the level of the conscious mind. The brain perceives the information in theory, but the mind does not interpret the information for meaning.

Subliminal priming can alter behavior • Winkielman, Berridge, & Wilbarger (2005): Subliminal priming can alter behavior • Exposed participants to subliminal images of happy or angry faces • Participants then tasted a new, lemon-lime flavored drink. After reporting how thirsty they were, they were told to drink as much as they wanted. • Participants exposed to happy faces consumed more than twice as much—but only if they were already thirsty • Priming may act as a “trigger, ” but only if there is a prior need, goal or drive.

Cautions regarding subliminal priming effects • • • Effects of priming are short-lived The subliminal prime must still be perceived, even if perception is without awareness No proof of commercial viability

This ad ran in Time Magazine (July, 2007) Note the drink to the left. Two olives and a straw create male genital. Note the drink in the man's hand. We have a very similar use of olives and a straw. This time the straw points right to the woman's genital.

How Are the Senses Alike? How Are They Different? The senses all operate in Each much sense organ has as the same way, but each different design, different and eachinformation extracts sends neural messages and sends ittotoitsits own specialized region of the specialized processing region brain in the brain

Can the sensory threshold of an individual vary based on their environment (ie. an individual no longer noticing a sound because they are used to it)? Devan C.

Sensory Adaptation • The diminished responsiveness of senses to prolonged stimulation • • For Example: Getting used to cold water Skin touching the chair your are sitting in The. Our heaternervous blower in the room "pays more system attention" to changing stimuli • Any change in the stimulation, such as a noise than to constant getting louder, drawsstimuli. one’s attention

• Sensory adaptation occurs due to…. The loss of responsiveness in receptor cells after stimulation has remained unchanged for a You feel the socks on your feet while when you put them on…but not for long…

Chromatic adaptation in action Look first at the image of the airplane, and fix your Fix your gaze on the dot between the blue and yellow gaze right on the dot. rectangles for 20 seconds. If you keep your eyes trained on the dot while You'll notice immediately that the lighter portions on examining the picture, you will notice that now the It's OK to blink normally, but keep your gaze fixed on the left half of theofplane havenow a definite bluish cast, lighter portions the plane look the same in the dot while your eyes are open. while those on thehalves right half of picture. the plane have a both of the definite yellowishshift castyour gaze to the dot in the After 20 seconds, airplane image