Sensation and Perception Sensation: your window to the world Perception: interpreting what comes in your window.

Introducing,….Sensation! “Seeing is believing.” For each of the following visuals, simply write down what you see. (Do not share with your neighbor.)

Analyzing what we see…. Each visual provides sensory information that gives rise to two totally different perceptual interpretations. Now, lets try it again… Write down what you see first in the next visual image.

Sensation and visual images Why is it that no matter how many times we look at the image, we tend to see the image we saw the first time we observed it? First impression = schema Have to consciously seek the other figure After practice, we can see both images, but not simultaneously

So, what is Sensation & Perception? The physical energy we detect from the environment and encode as neural impulses (what we sense and send to the brain) Perception How we select, interpret and organize our sensations (how the brain interprets it) 5.2 Top Picture—to show the difference between sensation and perception. Looks like a meaningless blotch, students will try to figure it out—stimulation/sensation is being received but not perceived. The subject is a dog, and only part of a dog. Students will probably try to see the whole dog; you cannot tell figure from ground 5.2 Bottom picture—Fraser Spiral—it looks like a spiral but is actually a set of concentric circles

In other words… Sensation provides the raw information that perception translates into our experiences

Sensation : The Forest Has Eyes sensation and perception work together to sort out complex processes The Forest Has Eyes is the title of this work---in studying it we look at the expressions on the faces, there is something foreboding about this picture, and after we have read the title we notice other things…

Sensation and Perception (Work together) Bottom-Up Processing (Sensation) Sense receptors detect stimuli and send to the brain the brain then integrates sensory information Top-Down Processing (Perception) information processing guided by higher-level mental processes How we interpret sensations- based on expectations and previous experiences Top Down is the involvement of the brain in making meaning out of stimuli. For example there are people who can see everything clearly (sensation) but cannot recognize even their own faces (perception). Placing meaning to sensations and stimuli is the act of perception

Top Down Processing Aoccdrnig to rscheearch at Cmabridge Uinervtisy, it deosn’t mttaer in what oredr the ltteers in a word 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.

Top Down Processing How were you able to immediately make sense of these scrambled words? Our experience and expectations enable us to immediately perceive the scrambled letters as meaningful words and sentences. Higher level processes guide our perceptions.

Distinguishing Between Sensation and Perception Fraser Spiral (5.2) Place one finger on any line composing the spiral. Place a finger from your other hand beside it and begin tracing the circle while holding your first finger in place. What happens?

Failures of Perception Prosopagnosia: complete sensation but incomplete perception (“face blindness”) Can sense visual information, but can’t recognize it (can’t relate stored knowledge to sensory input) Damage to temporal lobe area (recognition)

Sensation- Basic Principles Psychophysics study of how physical energy relates to our psychological experience (Or: study of interaction between sensations we receive and our experience of them.) Light- brightness Sound- volume Pressure- weight Taste- sweetness

Sensation and Perception Sensation & Perception 6/5/2018 Sensation and Perception Defining sensation and perception The riddle of separate senses. Measuring the senses. Sensory adaptation. Sensory overload. ©1999 Prentice Hall ©1999 Prentice Hall

Sensation & Perception 6/5/2018 Ambiguous Figure Colored surface can be either the outside front surface or the inside back surface Cannot simultaneously be both Brain can interpret the ambiguous cues two different ways ©1999 Prentice Hall ©1999 Prentice Hall

Sensation & Perception Processes 6/5/2018 Sensation & Perception Processes Figure 3.Davis 2 from: Kassin, S. (1998). Psychology, second edition. Upper Saddle River, NJ: Prentice Hall. ©1999 Prentice Hall ©1999 Prentice Hall