SENSATION & PERCEPTION INTRODUCTION

SENSATION & PERCEPTION: *In our everyday experiences, sensation & perception blend into one continuous process. SENSATION: The process by which our sensory receptors & nervous system receive and represent stimulus energies from our environment. PERCEPTION: the process of organizing & interpreting sensory information enabling us to recognize meaningful objects and events.

TWO TYPES OF PROCESSING: *Bottom-up: analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information -we process this way when we have no prior knowledge; we start at the bottom & work our way up *Top-down: information processing guided by higher- level mental processes; as when we construct perceptions drawing on our experience and expectations. -we process this way when we have prior knowledge; we start at the top and have to work to process details

*Using bottom-up processing enables our sensory systems to detect the lines, angles & colors that form the horses rider & surroundings.

*Using top-down processing we consider the painting’s title, notice the apprehensive expressions & then direct our attention the aspects of the painting that will give those observations meaning.

TOP-DOWN PROCESSING Aoccdrnig to rscheearch at Cmabrigde Uinervtisy, it deosn’t mttaer in what oredr the ltteers in a wrod are, the olny iprmoetnt tihng is that the frist and lsat ltteer be at the rghit pclae. The rset can be a total mses and you can still raed it wouthit a porbelm. This is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the word as a wlohe. *Our experience & expectations enable us to immediately perceive the scrambled letters as meaningful words & sentences.

How are we affected by selective attention? * Selective Attention: the focusing of conscious awareness on a particular stimulus. -Your conscious awareness focuses on only a very limited aspect of all that you experience. It’s estimated that your 5 senses take in 11,000,000 bits of info per second…of which you consciously process about 40. *i.e.: Until this second, you’ve been unaware that your shoes are pressing against your feet…& now suddenly your attention spotlight shifts. *i.e.:the cocktail party effect-your ability to attend to only one voice among many…but another voice speaks your name at a party & your cognitive radar will bring that voice into your consciousness *People with ADHD seem to lack the ability to be selectively attentive. Instead of filtering out unimportant stimuli in order to focus on more important ones, they attend to all stimuli in the environment, making it difficult to process info correctly

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What you just witnessed was Inattentional Blindess: *With your attention directed elsewhere, you fail to see the gorilla… *i.e.: Turning into a parking lot, a driver fails to see a bicyclist riding down the sidewalk. The driver only hears a thud & first sees the cyclist on the ground near her left front fender. *i.e.: A pilot and his crew see a light flashing on their control panel. They become so concerned with its possible cause they don’t notice the plane approach ground or even hear the alarm. The crash kills 100 people.

Change Blindness: “Mindsight – A Sixth Sense?” Ronald Rensink (2004) proposed & conducted research on whether we can be aware of and even use visual information without consciously “seeing”. A distinct, fast-acting mode of visual perception leads us to sense rather than see a change in a scene. Flicker test with two buttons…sense & see the change… Approximately 30% of participants could sense a change before they could see it.

Ask Yourself::::: Can you recall a recent time when, your attention focused on one thing, you were oblivious to something else? *PAIN *SOMEONE’S APPROACH *BACKGROUND MUSIC