TEAM PROJECT 5: PSYCHOLOGY Mike, Jill, Ashley, Kel, Raina, Deepali, Grace, Josh, Janet & Alice

CHANGE DETECTION BLINDNESS

What is it? Change detection blindness is the inability to notice changes in our surroundings. People are unable to detect changes if their brains do not encode the data that they perceive. Normally, we expect a constant environment around us, and thus, we do not necessarily notice subtle changes that can occur.

Why do I care? Change detection blindness tells us how our visual/attentional system operates. By seeing where our visual/attentional system fails, we can understand the underlying mechanisms behind how our brain encodes our surroundings.

So throw me a bone here… Change Detection Blindness most commonly occurs at the movies: Films are usually taped out of sequence and spliced together to form a consecutive storyline There are often many unnoticed editing errors

Popular Examples “The Matrix” Bullet dodging sequence In the beloved motion picture, “The Wizard of Oz,” The length of Dorothy’s pigtails changes 5 times in 1 scene!!

And heeeeeeeeeere’s Dorothy!

Past Experimental Findings In 1996, Daniel Levin and Daniel Simons of Cornell University conducted a SLEW of studies in CDB. The first experiment tested subjects’ ability to detect changes in scenery and peripheral details Only 1 in 9 people noticed any change

Past Experiments cont’d… Levin and Simons’ second experiment involved a short clip with only an actor change. 33% of the subjects noticed the change A study conducted by Ronald Rensink showed that people are more likely to detect changes in vital central objects rather than minor changes (1996).

Factors influencing CDB Intentions of the observer Incidental vs. intentional Complexity of the scene Visual Dialogue and audio Type and duration of changes

Our Experiment: Goals Create a video that combines elements from aforementioned studies: Dynamic display Central and peripheral changes Instructions vs. no instructions Varying degree and duration of changes

Subjects Age 18 or older Two groups, 5 males and 5 females each A. Uninstructed - “watch the clip” B. Instructed - “pay close attention and watch for changes between cuts”

And now you are all our guinea pigs

Sign the consent form!

And now our video… Please pay attention and watch for changes between scene cuts! (please turn off all cell phones at this time )

Here’s Your Questionnaire! Did you notice any changes?

Now for the last part… Can you identify the second actress? YOU CAN DO IT!

Would you like a Debriefing Form? Please recycle

Now let’s check out the KINKS…

Just hangin’ wit MY BOYS Who cut the cheese? OOPS, I DID IT AGAIN

A QUICKIE Analysis of the Results…

No Instructions Instructions

Sample Size It was difficult to determine the statistical reliability of our findings. Ideally: a minimum of two groups of 20 Our study: a total of 20 volunteers ~ two groups of 10 Cannot extend results to the general population

HEY, how’d MY BOYS do?

SEMI-SWEET pie (graph) 15% 25% 10% 50% As good as YOUR MOMMA’s SEMI-SWEET pie (graph)

I think I’ll call him… MINI-SURACE

Take a CHILL PILL, it’s almost over…

Discussion After both viewings, the uninstructed group found 48% of the changes while the instructed subjects noticed 51% Even after both viewings, why so few detections? Richness and complexity of scene Exciting acting Limited attention capacity

Discussion cont’d Most significant change in the clip The actor change was undetected Presented subjects with pictures of the first and second actors 15% of participants judged correctly based on the face. Additionally, 10% of participants guessed correctly

Tying it together… In the initial viewing, the instructed noted 22% of the changes while the uninstructed identified only 16% of the changes Changes (i.e. painting) that altered the overall visual scene are more likely to be identified In our study, the actor change was less likely to be noticed than peripheral changes

Final Thoughts Only 50% of the total changes were detected Two viewings Further instruction Do we have a poorly designed visual system? Ability to detect change Perception We are used to continuity in our environment.