Lecture 19 (chapter 5; slide 1-16)
Remember Weber; he tried to learn the internal state of people.
How do we actually perceive the external world?
Slide 2: You listen and interpret, but the mind uses previous knowledge to predict what’s about to be
Top-down influence- memory, previous influence
Sensation is the final output.
How do we get from patterns of light to seeing people?
Google perceptual illusion to see some weird stuff that can trick your visual perception.
Slide 3: You can see things fine, but you may not recognize what the meaning is.
Perception- a recognition of what you see/hear etc
Sensation- the raw inputs (ex. Colours you see)
Slide 4: Transduction- a process that changes a physical stimulus from the external world, translates it
and sends it to the neural impulse. It depends on what energy the sensors are sensible to (receptor cells;
they react to that energy)
Table 5.1- sensory systems and what energy they’re sensitive to. Some are chemical that need to
directly touch you, while others (like radiant energy) can reach you from a long distance. Muscle
systems have sensory inputs as well.
We need to realize how limited our sensory systems are (ex. The wavelength of light diagram- we’re
only sensitive to visual light). There’s more in the world that we cannot see- our sensory system is
Slide 5: Our neurons are simplified, but can process the complex environment. The computer is another
example of that; it can create and process very graphic and rich content out of just 0 and 1.
Morris code; each letter has different lengths of bars. You can tap it or hold it down. The dot and dash
can form spellings and communicate a rich message. Ex. On boats you flash lights to send messages
Slide 6: Nerve cells can either fire or not. The rate of firing sends a message to the brain as to what is
happening to the rest of the body- it shows where it originated as well. Whe