Core studies: Simons & Chabris

• What does it study?

  Contemporary study of inattentional blindness.
• What was S+Cs background part 1?

  1. Moray studied auditory selective attention and S+C wanted to expand on this w/ visual selective attention and inattentional blindness, where attention is diverted to one task and observers fail to see unexpected event even if it’s in the observers point of fixation. 2. Mack and Rock: assessed this with computer-based displays, ps had to judge which arm of a cross was longer, during this a smiley face would appear and many didn’t see, but this doesn’t reflect v.s.a in real life.
• What is S+Cs background part 2?

  3. Neisser: ps had to watch basketball players passing a ball, count no passes, during this a woman with an umbrella walks across screen and most didn’t notice her. 4. but research criticised because its poor quality video so lacks evidence of inattentional blindness, S+C wanted to enhance with more representative task.
• What was S+C‘s aim?


  investigate impact of following factors on in-attentional blindness; unusualness of unexpected event, task difficulty, superimposition compared to live events in video, on detection rate.
• What was the research method for S+C?


  Lab exp in Harvard uni, independent measures of 16 conditions.
• What were the 16 conditions?


  Hard vs easy task, white t-shirt team vs black t-shirt team, opaque video vs transparent video, gorilla vs woman with umbrella.
• Describe S+C’s sample.

  228 undergraduates at Harvard university (volunteer), 36ps data discarded if they‘d seen similar task before
• What materials did S+C use?


  Four 75 second video tapes with two teams of 3 players with either black or white t-shirts. Between 44 and 48 seconds unexpected event happened (woman with umbrella or gorilla walked across screen)
• Simons and Chabris‘ procedure?


  Ps tested individually, watched clip of basketball players, told to watch either white or black team, count how many passes of ball between players made. Easy version-count all passes, hard version- separately count n.o aerial passes and n.o bounce passes. Between 44 and 48 seconds either gorilla or woman with umbrella walked across screen. Then asked surprise qs- if they saw anything unusual etc and if they’d seen anything similar before, if yes data was discarded. Then fully debriefed, inc repeat showing of video is necessary.
• What were S+C’s findings?

  sig more ps noticed umbrella lady compared to gorilla, sig more ps noticed unexpected event when task being attended to was easy compared to hard, sig more ps recognised unexpected event when task attended to was easy vs hard.
• What were S+C’s conclusions?


  When attending to a task visually similar to unexpected event we’re more likely to detect it than different event, in-attentional blindness more likely when task is hard- cognitive load increases so distractions less likely to be seen, in-attentional blindness more frequent when vids are superimposed.