Simons + Chabris

• People cant pay attention to everything that goes on around them at the same time - people select objects of interest
• Attention necessary for change detection
• Change blindness- individuals dont detect changes from one view to the next
• Individuals only remember objects that recieve attention
• Innatentional blindness- when attention diverted observers fail to notice unexpected object
• Visually demanding task- people become blind to distractions which improves performance
• Previous studies show precision of visual representations- ppts had to engage in continuous task whilst ignoring others at some point when an unexpected even occurred - majority of ppts not even seen event despite it being clearly visible
• One goal of study- revive empirical approach- innatentional blindness + selective looking helped form basis of study- builds on classic studies to examine inattentional blindnessfor complex events in dynamic scenes
• overcame fact that previous research did not systematically consider role of task difficulty in attention + no superimposed version with a live version
• Lab experiment- independent measures
• 5 IVs

  • Transparent/ umbrella woman
  • Transparent/ Gorilla condition
  • Opaque/ umbrella woman
  • opaque/ gorilla
  • For each of 4 displays- 4 task conditions- white- easy/hard Black- easy/hard- 16 conditions
• DV- number of ppts per condition who noticed an unexpected event
• Controlled observation- ppts watched a video+ attend white team and easy monitoring task
• 4 tapes- 75s in duration- two teams of 3 players- one in black and one in white- players moved randomly Infront of elevator doors- passing a basketball in a standardised order- bounce or arial- 44- 48s of action woman or gorilla left to right- lasted 5 seconds
• Transparent condition- separately filmed + overlayed

  Opaque- filmed together after rehearsals

  • All videos filmed+ edited the dame
  • In one recording Gorilla stopped and thumped its chest.
• 228 almost all undergrads- volunteered- given a candy bar or paid a single fee for this and another experiment- data from 36 discarded

  -139 results used- equally distributed across conditions
• 12 ppts watched video of gorilla thumping chest
• 21 experimenters tested ppts- written protocol was devised + reviewed before data collection
• All ppts tested individually + gave informed consent- were instructed to pay attention to one team, told to keep silent mental count of passes made by attended team (easy) or separate silent mental counts of bounce and aerial passes made by attended team (hard)
• After viewing the video, ppts asked to write counts on paper- asked following questions- did you notice anything unusual? Did you notice anything other than the 6 players? See a gorilla/ woman carrying an umbrella across the screen- yes responses triggered further questions- after asked if they had done similar experiments before- yes discarded
• ppts debriefed + video played on request- each session lasted 5-10 mins
• 14 ppts discarded as they knew of a similar experiment- 9 ppts discarded due to loosing count- 7 ppts incorrectly or incompletely recorded passes- 3 ppts couldn't be interpreted
• 54% noticed event- 46% failed to notice.

  Opaque condition- 33% failed to notice event in opaque
• more ppts noticed event in easy 64% vs hard 45% - effect of task difficulty greater in transparent 56% easy 27% hard per condition
• Umbrella woman noticed more often 65% than gorilla 44% regardless of variables
• little different between those attending black to white
• only 50% noticed event under controlled observation
• concluded: individuals have sustains inattentional blindness for dynamic events
• Concluded: individuals fail to notice ingoing + highly salient but unexpected event if engaged in primary monitoring task
• Concluded: inattentional blindness is a ubiquitous perceptual phenomenon
• Concluded: level of blindness depends on difficulty of primary task, individuals more likely to notice unexpected events if they are similar to events being paid attention to
• Concluded: objects can pass by focus + not be 'seen' if not paying attention to. No consious perception without attention