How We Collect Information From Our Environment

Definitions Sensation is collecting information from the environment taking energy/stimulation from the environment and converting it to neural impulses Perception is creating meaningful patterns out of the sensory information that we collect selecting, organizing, & interpreting sensory info. Bottom-up processing: starting with the sensory information (sensation) Then tracing the process up to the finish product (the perception) this process is not linear, but happens nearly simultaneously Top-down processing: using sensory information but also looks at how our brain (memories, emotions, experiences) influences the final product Why can two people look at the same piece of clothing and see different colors or watch the same movie but have very different experiences?

Thresholds Absolute thresholds minimum amount of stimulation necessary to “sense” it 50% of the time Signal Detection Theory this theory describes how we are able to select stimuli from our environment amongst the noise of other stimuli can be dependent on motivation, physical health, etc. ex. Mother sleeps through storm, but hears baby cry

Thresholds Subliminal stimulation – below absolute threshold (< 50% accuracy) priming – preparing someone to acknowledge a stimuli Difference threshold (Just Noticeable Difference) Minimum difference between two stimuli to recognize a difference Weber’s Law – the amount difference is a constant PROPORTION

Sensory Adaptation When stimuli don’t change: neurons fire less often over time We are less aware of an unchanging stimulus Why don’t we see “less” if we stare Our eyes are constantly moving sending new stimuli Page 202 Allows us to recognize what changes in our environment Selective attention