3. Sensory and Perception (Ch 5)

Sensation
- transforming energy from outside stimuli into neural energy
Perception
- taking neural energy and creating an image of outside world

Psychophysics
- levels of intensity we can detect stimuli
- how sensitive we are to changes in stimulation
- how psychological factors influence our ability to sense stimuli
Psychological factors
- motivation, past experience and expectation that impact our ability to notice stimuli
- Signal detection theory: how people respond to different degress of stimuli
- Important to detect differences between stimuli as well as their absence or presence
Selective attention
- The amount of information we can hold in our awareness is less than what exists in the given environment
- Our ideas about reality are chosen, organized and interpreted
- Perception is constructing meaning out of sensation

Somesthesis is the body’s sense of touch and is broken down into three systems:
- the skin sense: keep bodily fluids in and germs out
- the kinesthetic sense: knowing how your body is moving without visually observing ing
- vestibular sense: keeps the body balanced, sense of balance
Olfaction is the body’s sense of smell
- Chemical compounds of a specific “smell” travel through the nose to the brain
- first processed by the olfactory bulb
- Olfactory bulb has direct connections to amygdala and hippocampus which are strongly implicated in emotion and memory
Gustation is the body’s sense of taste
- Promotes nutritional needs and protects from poisonous food
- Bitter, sweet, salty, sour and unami (savory) are the five main types of taste
Vestibular system
- sensory information pertaining to motion, equilibrium and spatial orientation
- Located in each ear- utricle, saccule and three semicircular canals
  - utricle and saccule detect gravity and linear movement
- Keeps eyes on target when head moves

What is the origin of our capacities? Nature or upbringing?
Ecological (nature)
- some abilities are present at birth and fine-tuning of perceptual processes occurs throughout the lifespan
Constructivism (nurture)
- construction of perception through learning and reliant on specific experiences

Depth Perception
- allows us to estimate distances between ourselves and objects we see
- binocular cues (both eyes): Retinal Disparity
- monocular cues (one eye): Linear Perspective
- Motion parallax: the apparent movement of stable objects when we are moving
- Interposition: when one object partially blocks out another
Perceptual cues are hardwired but our experiences also shape our perception
- sensory restriction: only has an effect in childhood when systems are forming
- suggest a critical period for certain perceptions to be developed
Processing of information occurs in:
- bottom-up: simple sensory receptors to complex neural networks
- top- down: expectations, motives and contextual cues to raw sensory data

Vision allows for the processing of visual detail through use of the eyes
- detects and interprets information from visual light
- build representation of the surrounding environment
Audition is the process of taking in sound through the ear and having it travel to the brain
- taken to language center of brain to be interpreted

3. Sensory and Perception