Capture of shrinking targets

Hoffmann, Errol R.

doi:10.1080/00140139.2011.576775

Cited by 5 publications

(6 citation statements)

References 20 publications

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“…This decrease in behavioral physiological adaptability would induce a higher error rate and lower PEP reactivity related to the mental effort (Figure 1). Behavioral adaptability should be on the MT (Hoffmann, 2011). To optimize the emergence of behavioral adaptability, the target in the present study will vanish when it reaches one pixel.…”

Section: Overview Of the Experiments And Hypothesesmentioning

confidence: 98%

“…If the target size continues to decrease (Hancock & Caird, 1993;Johnson & Hart, 1987) but never vanishes, then the movement could be made in a more relaxed manner, and the MT would increase with task difficulty (Hoffmann, Chan, & Dizmen, 2013). Hoffmann (2011) and Hoffmann et al (2013) observed that when task difficulty increased, the participants moved faster to capture the target prior to it disappearing.…”

Section: Overview Of the Experiments And Hypothesesmentioning

confidence: 99%

“…Five levels of difficulty. The experimental task was based on the pointing task of Johnson and Hart (1987), which is a modified Fitts' task (Hancock & Caird, 1993;Hoffmann, 2011). First, we computed different levels of task difficulty in accordance with the Fitts' law (Fitts, 1954).The Fitts' Index of Difficulty (ID) is a function of the amplitude (A) and the size of the target (W).…”

Section: A Modified Fitts' Task With Shrinking Targetsmentioning

confidence: 99%

“…More precisely, the shrink time reflected the time after which the target is half of its current size. Such time was determined by the Fitts' law calculation developed by Hoffmann (2011). More precisely, the shrink time corresponded to the initial target's size (W 0 ) divided by the speed of targets reduction (V sc ) : T w V S s c = 0 / .…”

Section: A Modified Fitts' Task With Shrinking Targetsmentioning

confidence: 99%

“…To ascertain that the five selected IDs produce a linear performance decrement with the shrinking targets, we conducted a pretest with 10 participants. In this pretest, we manipulated, in agreement with Hoffmann (2011), different Ts (100, 200, 400, 800, and 1600 ms) based on our five difficulty levels, and we analyzed error rate as an index of difficulty. Our analyses revealed that the error rate increased linearly according to the levels of difficulty, that is, IDs that represent task demand.…”

Section: A Modified Fitts' Task With Shrinking Targetsmentioning

confidence: 99%

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A Curvilinear Effect of Mental Workload on Mental Effort and Behavioral Adaptability: An Approach With the Pre-Ejection Period

et al. 2019

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Objective: We tested Hancock and Szalma’s mental workload model, which has never been experimentally validated at a global level with the measure of the pre-ejection period (PEP), an index of beta-adrenergic sympathetic impact. Background: Operators adapt to mental workload. When mental workload level increases, behavioral and physiological adaptability intensifies to reduce the decline in performance. However, if the mental workload exceeds an intermediate level, behavioral and physiological adaptability will decrease to protect individuals from excessive perturbations. This decrease is associated with a change in behavioral strategies and disengagement. Method: The experimental task was a modified Fitts’ task used in Hancock and Caird. Five levels of task difficulty were computed. Behavioral and physiological adaptability was indexed by the performance with speed–accuracy trade-off and PEP reactivity. Results: A curvilinear effect of task difficulty on PEP reactivity was significant, with high reactivity at the intermediate level but low reactivity at other levels. We observed a linear effect of task difficulty on error rate and a curvilinear effect on movement time. A decline in performance was noted up to the intermediate level, with a speed–accuracy trade-off above this level showing a faster movement time. Conclusion: We observed for the first time behavioral and physiological adaptability as a function of mental workload. Application: The results have important implications for the modeling of mental workload, particularly in the context of the performance-sensitive domain (car driving and air traffic control). They can help guide the design of human–computer interaction to maximize adaptive behavior, that is, the “comfort zone.”

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Section: Overview Of the Experiments And Hypothesesmentioning

confidence: 98%

Section: Overview Of the Experiments And Hypothesesmentioning

confidence: 99%

Section: A Modified Fitts' Task With Shrinking Targetsmentioning

confidence: 99%

Section: A Modified Fitts' Task With Shrinking Targetsmentioning

confidence: 99%

Section: A Modified Fitts' Task With Shrinking Targetsmentioning

confidence: 99%

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A Curvilinear Effect of Mental Workload on Mental Effort and Behavioral Adaptability: An Approach With the Pre-Ejection Period

et al. 2019

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Inertia Effects in Fitts’ Law for Movement Time

Hoffmann

Chan

Man

et al. 2022

Human-Automation Interaction

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Capture of shrinking targets with realistic shrink patterns

2013

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Previous research [Hoffmann, E. R. 2011. "Capture of Shrinking Targets." Ergonomics 54 (6): 519-530] reported experiments for capture of shrinking targets where the target decreased in size at a uniform rate. This work extended this research for targets having a shrink-size versus time pattern that of an aircraft receding from an observer. In Experiment 1, the time to capture the target in this case was well correlated in terms of Fitts' index of difficulty, measured at the time of capture of the target, a result that is in agreement with the 'balanced' model of Johnson and Hart [Johnson, W. W., and Hart, S. G. 1987. "Step Tracking Shrinking Targets." Proceedings of the human factors society 31st annual meeting, New York City, October 1987, 248-252]. Experiment 2 measured the probability of target capture for varying initial target sizes and target shrink rates constant, defined as the time for the target to shrink to half its initial size. Data of shrink time constant for 50% probability of capture were related to initial target size but did not greatly affect target capture as the rate of target shrinking decreased rapidly with time.

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Capture of shrinking targets

Cited by 5 publications

References 20 publications

A Curvilinear Effect of Mental Workload on Mental Effort and Behavioral Adaptability: An Approach With the Pre-Ejection Period

A Curvilinear Effect of Mental Workload on Mental Effort and Behavioral Adaptability: An Approach With the Pre-Ejection Period

Inertia Effects in Fitts’ Law for Movement Time

Capture of shrinking targets with realistic shrink patterns

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