Tag Archives: top-down controls

Scanning 101: Attention Capture and Scanning (Part 2 of 3)

To be successful, scanning must result in the timely recognition of distressed and drowning victims as well as hazardous conditions and practices that require lifeguard response. In other words, scanning must lead to prompt and consistent attention capture and the correct analysis of each situation.

Bottom-Up Triggers vs. Top-Down Controls

One of the most debated issues in the study of visual attention has to do with the role played by bottom-up triggers and top-down controls in attention capture. In the context of lifeguard surveillance, top-down controls refer to the ability to select and focus on the criteria for attention capture during scanning. Bottom-up triggers refer to the capacity of certain attributes or behaviors to capture attention, irrespective of what the scanning lifeguard is focusing on or trying to find.

For example:

  • Top-down controls: When a lifeguard assumes a station, he or she should focus on the physical signs that indicate hazardous conditions, dangerous practices, and distressed and drowning victims. By keeping this focus, the lifeguard is in essence “programming” his or her senses to detect these signs.
  • Bottom-up triggers: While scanning an area of the pool, the lifeguard’s attention might be drawn away momentarily by the bright color of a swim suit or a skillful dive performed on the 1-meter diving board.

Let’s assume that both types of attention capture can and do occur during scanning. The most consistent and reliable method for scanning must be the one lifeguards can learn, control, and program their minds to look for: top-down controls. In other words, if the lifeguard understands potential hazards, the activities that lead to injury, and the behaviors of weak swimmers and distressed and drowning victims, these characteristics can lead from preattentive analysis to focused attention, reaction, and response.

In contrast, the lifeguard does not, by definition, control or program the mind for bottom-up mechanisms. These simply appear unexpectedly and, therefore, may or may not be detected during visual sweeps.

The Problem with Lifeguard Vigilant Testing

A great example of the inconsistency of bottom-up attention capture during scanning can be found in the results of so-called lifeguard vigilance testing. This testing uses a false trigger (e.g., a red shirt, red cap, floating object, or a submerged manikin or silhouette) to signal a mock rescue during an actual lifeguard shift. The lifeguard closest to the false trigger is timed from its appearance until the lifeguard recognizes it and responds, by activating the emergency action plan and entering the water to make the “rescue.”

In 2001, Ellis and Associates conducted more than 500 of these tests at 90 pools and waterparks across the United States. As reported in the 2002 article “Lifeguards Watch, but They Don’t Always See” by Joshua Brener and Michael Oostman, it took lifeguards, on average, one minute and 14 seconds to detect a manikin submerged in the pool. Brener and Oostman went on to use this average to draw the conclusion that lifeguards are not always vigilant on the job and that drowning would have occurred if the manikins had been real victims.

I strongly disagree with these conclusions. First, they are far from scientific. It is altogether possible that the lifeguards tested were doing a good job of scanning with proper top-down controls. Even though submerged manikins simulate a drowning victim, they do not look real and may be screened out during the preattentive feature recognition stage. If lifeguards are informed of vigilant testing in advance, they may be distracted from their primary responsibility to the extent they focus on finding the false trigger. And, if they are not informed of the test, their preattentive recognition of a false trigger (a fake victim) is likely to cause confusion, resulting in a delayed response.

Lifeguard vigilance testing is a bad idea because:

  • These bottom-up triggers (i.e., silhouettes, manikins, etc.) are not reliable attention capture mechanisms.
  • If lifeguards focus on these triggers, they interfere with what the lifeguard should really be looking for. This makes these tests an intrusion of a secondary task by management (i.e., a test/evaluation) while lifeguards are engaged in a primary duty (i.e., scanning the pool for real issues/victims). This violates the spirit, if not the letter, of Dr. Frank Pia’s RID Factor. Lifeguards that do better in vigilance testing may actually not be focused on the primary goal of surveillance.
  • These tests also put lifeguards and patrons at unnecessary risk from the staged rescue in less than controlled condition.  This must occur during a real rescue, but it cannot be justified for a mere test.

Using Top-Down–Control Scanning

Lifeguards can learn top-down–control scanning by:

  • Developing an understanding of what they are looking for as they scan. This includes:
    • Learning the safety rules for the swimming areas they supervise and why those rules are in place
    • Understanding how injuries occur and what characteristics make up common hazards
    • Visualizing the characteristics of distressed and drowning victims
  • Discussing with other lifeguards on their team how to enforce safety rules and handle common problems in each area
  • Focusing on these things as they scan