Module 16 & 18

Sensation

Sensation

Raw info that comes from the senses

Perception

Sensation + Meaning, using knowledge, experience, and understanding of the world

Bottom-Up Processing

Info processing analyzing the raw stimuli entering thru the many sensory systems and works up to the brain.

Top-Down Processing

Info processing that draws on expectations and experiences to interpret incoming sensory info

Selective Attention

Focusing of conscious awareness on a particular stimulus

Cocktail-Party Effect

Ability to attend to one of several speech streams while ignoring others

Inattentional blindness

Failing to see visible objects when our attention is directed else where.

Change blindness

Failing to notice a change in visual stimulus

3 basic steps for sensory systems

Receive, Transform, Reliever

Receive

Sensory stimulation

Transform

that sensory stimulation into neural impulses

Reliever

the neural info to our brain

Transduction

Conversion of one form of energy into another

Trans

Across

Psychophysics

study of relationships btwn the physical characteristics of stimuli, (ex intensity), and our psych experience of them.

Absolute Threshold

Weakest amount of stimulation needed to detect a stimulus 50% of the time.

Signal-Detection Theory

Predicts how and when we detect the presence of a faint signal amid background noise.

Characteristics of Signal-Detection Theory

Assumes there is no 1 absolute threshold and depends on a person’s experience, expectations, motivation, and lvl of fatigue.

Our ability to distinguish btwn sensory stimuli takes into account

• Motivation

• expectations

Subliminal

below threshold stimuli

Difference Threshold

min amnt of diff needed to detect a change in stimulus 50% of the time.

Weber’s Law

Just Noticeable Diff (JND) is a constant proportion of the original stimulus = more stimuli needs more diff to be seen as distinct

Weber’s Law Example

holding a packet of ramen noodles, u can feel them in ur hand. Add them to a heavy bag of groceries and u won’t notice the added weight.

Sensory Adaptation

our diminishing sensitivity to an unchanging stimulus. Allows us to detect potential important changes in our surroundings while ignoring unchanging aspects of them. Ex - living in airplane layout way, go used to it and don’t notice every time plane passes by; don’t notice glasses on face

Sensory Interaction

the phenomenon where diff senses influence each other. Ex- how stuffy nose impacts the taste of food (smell impacts taste)

Synesthesia

A neurological condition where stimulating one sense involuntary triggers a sensation in another sense. Ex- Amy from Space boy saying people have flavors

Young-Helmholtz Trichromatic Theory

Any color can be created by combining light waves of the 3 primary colors (additive) which are red, green, and blue.

Opponent-Process Theory

states that opposing retinal processes enable color vision.

Where does the Opponent-Process Theory take place?

The ganglion cells

Rods

peripheral vision, black and white, highly light sensitive photoreceptors.

Cones

photoreceptors that help us disguise colors and detect fine details

Where are cones located?

in and near fovea

Ganglion cells

cells in the retina that generate action potentials

Axons of the ganglion cells form the

visual nerve

Visual nerve

carries neural impulses from eye to brain

Cocktail Party Effect Example

Hearing ur name in a loud setting