Psychology Reader

Gorillas in Our Midst: Sustained Inattentional Blindness for Dynamic Events

Daniel J Simons and Christopher F Chabris · 1999 · Perception

Role
Landmark empirical study · Methodological contribution
Difficulty
Moderate
Full work length
16 pages
Type
Journal article

Access

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Reading focus

Syllabus: How Do We Direct Attention and Control Thought?

Examine this study as evidence about selection and reported awareness. Compare its monitoring tasks and unexpected events with the measures of distractor interference in load theory.

A question to consider. If an observer does not report the unexpected person, what further evidence would distinguish absent conscious noticing, poor later recall, and some processing without a report?

Why this reading

An event can be visible in a scene yet go unreported by a person concentrating on another task. This study makes attention an explanatory question by varying what participants track and what unexpectedly appears.

Before you read

Inattentional blindness concerns failure to notice an unexpected event while attention is engaged elsewhere. It differs from change blindness, which concerns noticing a change. A surprise question after the task measures reported noticing; it is not a complete measure of every stage of processing.

Read for

  1. Map the variations in the counting task, attended team, unexpected event, and display to the comparisons they enable.
  2. Examine how noticing varies with task demands and the relation between the attended and unexpected objects.
  3. Consider participant exclusions, prior familiarity, and the timing of the questions when judging what the results can establish.

Consider afterwards

  1. A person misses an unexpected sign while searching a display. How would you distinguish a problem of visibility from a consequence of the assigned search task?

Editorial context

The often-repeated demonstration is only one part of a study comparing several conditions. There is no single universal percentage of people who will miss an unexpected event. Because surprise and prior knowledge matter, familiar viewers are not equivalent to the original participants. Reported noticing also leaves questions about unreported processing unresolved.