Ex: Walking into the kitchen smelling cinnamon rolls, the sensation being the scent
detection of the cinnamon
- Sensory receptors: specialized neurons that respond to specific types of
stimuli
Ex: light enters the eye and causes a chemical change in cells in the back of
the eye
- The cells relay messages in form of action potentials to the central nervous
system
- Transduction: conversion of sensory stimulus energy to action potential
- The five senses(touch, taste, sight, hearing and smell) are oversimplified.
Sensory systems also provide senses of balance, body position/movement,
pain and temperature
- Absolute Threshold: minimum amount of stimulus energy that has to be
present for the stimulus to be detected half of the time
When the stimulus reaches a psychological threshold strong enough to
excite sensory receptors and send nerve impulses to the brain
- Subliminal Messages: attain messages that are presented below the threshold
for conscious awareness
Below the threshold because we receive it but aren’t conscious of it
- Difference Threshold: difference in stimuli reactions, amount required to
detect a difference between them
Depends on stimulus intensity
Ex: Youre in a dark movie theater, and you notice someone's cell phone go
off, but it’d be harder to notice if you were in a bright room
, way sensory information is organized, interpreted and
consciously experienced
Ex: Walking into the kitchen smelling cinnamon rolls, the perception being
“This smells like something Grandma used to make on Christmas.”
- Bottom-up Processing: sensing basic features of stimuli and them integrating
them, sensory information from a stimulus in the environment driving a
process
Ex: Looking at your friend to focus on what they are saying, then you hear
a cup fall and break, it immediately captures your attention (you have no
choice)
- Top-Down Processing: when previous experience and expectations are used
to recognize stimuli, knowledge and expectancy driving a process
- These processes are usually goal directed, slow, deliberate, effortful and
under your control
Ex: Misplaced your keys, so you look in places they usually would be, and you
also have a big red pom pom, so you keep an eye out for something red and
similar size as you look around
Sensory Adaptation - not receiving stimuli over prolonged periods of time
Ex: Construction is being done across the street so now you have an
obnoxious blinking light radiating over your entire room. You want to to
watch TV but it’s really hard to pay attention, but after a while you don’t
even notice the light anymore
Famous Attention and Percption Study
- Conucted by Daniel Simons and Christopher Chabris (1999)
- Watched a video of people dressed in black and white passing basketballs
- Participants were asked to count the amount of times someone in white
passed the ball
- During the video a person dressed in a Gorilla costume walks passed the
teams