Heaviness Perception in Older Adults

Presenter Information

Alli GrunkemeyerFollow

Presenter Type

UNO Graduate Student (Doctoral)

Major/Field of Study

Biomechanics

Other

Biomechanics

Author ORCID Identifier

https://orcid.org/0000-0001-7722-2910

Advisor Information

PhD advisor, Dr. Aaron Likens

Location

CEC RM #230

Presentation Type

Oral Presentation

Start Date

22-3-2024 9:00 AM

End Date

22-3-2024 10:15 AM

Abstract

Heaviness perception is the ability to use haptic feedback from effortful touch to determine the weight of a wielded object [1]. When wielding an object with your hand, you move it in all sorts of directions, with all sorts of speeds and forces, creating all sorts of patterns of deformation of the skin and muscles. The inertia tensor is a 3 3 matrix that provides information about how the mass of an object is distributed in terms of its inertia. In this study, we sought to improve the perception of an object via wielding in young and older adults. We hypothesized (1) the age of the participant will influence accuracy in perceiving heaviness, (2) movement dynamics will influence perceptual accuracy, and (3) increasing time-to-wield will degrade perceptual accuracy.

Nineteen young and thirteen older adults were seated and wielded an occluded object with varying masses (Figure 2). There were five different mass stimuli being presented (0, 125, 250, 375, and 500 g). Subjects rated the heaviness of the object in relation to a standard object by marking their response on a scale presented at the end of each trial. For statistical analysis, we fit a series of Tweedie-Generalized linear mixed effect (LME) models with percent error as the outcome variable and fixed effects of mass, age, time-to-wield, movement dynamics, and their interactions.

In support of our first hypothesis, percent error decreased with increasing mass in older adults, and increased in younger adults. In support of our second hypothesis, as the presence of long-range correlations in the movement patterns of older adults increased, so did their percent error. In support of our third hypothesis, as the time-to-wield increased in older adults, their percent error was relatively unchanged.

As a general summary of the results, we found that percent error increased as a function of mass in younger adults. In contrast, older adults produced qualitatively different results such that decreasing the mass of the object appears to degrade their ability to perceive weight. In addition, while time-to-wield did not seem to influence percent error in older adults, the presence of long-range correlations in their movement patterns appeared to degrade perceptual accuracy. Hence, as we predicted, our results suggest that age influences one’s ability to perceive the weight of an occluded object. Other next steps involve introducing subthreshold stimulation to older adults during a wielding task.

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Mar 22nd, 9:00 AM Mar 22nd, 10:15 AM

Heaviness Perception in Older Adults

CEC RM #230

Heaviness perception is the ability to use haptic feedback from effortful touch to determine the weight of a wielded object [1]. When wielding an object with your hand, you move it in all sorts of directions, with all sorts of speeds and forces, creating all sorts of patterns of deformation of the skin and muscles. The inertia tensor is a 3 3 matrix that provides information about how the mass of an object is distributed in terms of its inertia. In this study, we sought to improve the perception of an object via wielding in young and older adults. We hypothesized (1) the age of the participant will influence accuracy in perceiving heaviness, (2) movement dynamics will influence perceptual accuracy, and (3) increasing time-to-wield will degrade perceptual accuracy.

Nineteen young and thirteen older adults were seated and wielded an occluded object with varying masses (Figure 2). There were five different mass stimuli being presented (0, 125, 250, 375, and 500 g). Subjects rated the heaviness of the object in relation to a standard object by marking their response on a scale presented at the end of each trial. For statistical analysis, we fit a series of Tweedie-Generalized linear mixed effect (LME) models with percent error as the outcome variable and fixed effects of mass, age, time-to-wield, movement dynamics, and their interactions.

In support of our first hypothesis, percent error decreased with increasing mass in older adults, and increased in younger adults. In support of our second hypothesis, as the presence of long-range correlations in the movement patterns of older adults increased, so did their percent error. In support of our third hypothesis, as the time-to-wield increased in older adults, their percent error was relatively unchanged.

As a general summary of the results, we found that percent error increased as a function of mass in younger adults. In contrast, older adults produced qualitatively different results such that decreasing the mass of the object appears to degrade their ability to perceive weight. In addition, while time-to-wield did not seem to influence percent error in older adults, the presence of long-range correlations in their movement patterns appeared to degrade perceptual accuracy. Hence, as we predicted, our results suggest that age influences one’s ability to perceive the weight of an occluded object. Other next steps involve introducing subthreshold stimulation to older adults during a wielding task.