PSYC 1200 Lecture Notes - Lecture 6: Sound Energy, Psychophysics, Absolute Threshold
20 Jun 2018
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Department
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Professor
Sensation and Perception
The process of the brain receiving new information
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Sensation- Process by which senses detect and process sensory
stimuli.
Bottom-up process
Looking at the pieces of the puzzles itself, not the puzzle
as a whole
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Perception: Process by which sensory information is actively
organized, interpreted by the brain
How we make sense of the world
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Top-down process
Looking at the whole puzzle, not the individual pieces of
the puzzle
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A lot of what we'll cover is about sensation
Getting info into the computer (your brain)
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But perception is one of the most fascinating areas of psychology
Focuses on how we make sense of the world around us
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We do not have direct access to reality through our senses
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Our brain makes sense of the incoming info via what we have
learned about the world
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"I want you to realize that there is no colour in the natural world and
no sounds -- nothing of this kind; no textures, no patterns, no
beauty, no scent… The "world out there" is synthesized in our
consciousness".
-Sir John C. Eccles. 1903-1997. Neuroscientist, Nobel Prize in
1963
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Sensation
Transduction: sensory receptors convert physical energy into neural
impulses
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The brain interprets the variety of sensations based on
Which receptors are stimulated
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Where the into goes in the brain
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Also
Intensity: rapid firing= stronger stimulus
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Note: not all physical stimuli can be detected by human sensory
capabilities
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Individual differences in what people can sense•
Use psychophysics to help us measure the differences
Absolute threshold
The weakest amount of stimulus you can detect
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Difference threshold
The smallest amount of change in a stimulus you can
detect
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Sensory adaptation
Conceptual, we don’t respond to every sense we are
exposed to, when something is constant you don’t notice
they are there
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Auditory Processing- What is Sound?
Psychological event from the movement of air molecules cause by
the vibration of an object
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Vibration moves outward from the source in a wave•
Loudness
Perception of a sound wave's amplitude or intensity
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Measured in decibels (dB)
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Amplitude: Physical strength of a wave
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Younger people can hear higher frequencies than older people
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Pitch
Perception of a sound wave's frequency
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Measured in Hertz (HZ)
1 hertz = 1 Cycle/Sec
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Frequency: Number of cycles completed by a wave on a given
amount of time
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Timbre
The complexity of a sound wave
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Distinguishes it from other of the same frequency and
amplitude
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Hearing: The Ear
Outer ear: collects sound waves•
Middle ear: Sound waves --> mechanical energy •
Inner ear: mechanical energy --> neural impulses•
The Outer Ear
Pinna: visible outer ear
Funnels sound waves to the middle ear
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Eardrum
Moves in response to sound waves
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Converts sound energy to mechanical energy
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Lecture 10/03
October 3, 2017
8:24 AM
