FIRST INTERNATIONAL SOCIETY FOR GERONTECHNOLOGY

MASTERCLASS IN GERONTECHNOLOGY

TUE, EINDHOVEN, NL MAY 22-23 2006

Methodologies in Compensation Studies

James L. Fozard, Ph.D.

School of Aging Studies

University of South Florida

Tampa, FL 33260

For electronic copy of slides, send me an e-mail request at

fozard@tampabay.rr.com

Tools for planning compensatory interventions

• Four steps are involved– Identify the domain(s) of human activity that is

the target of the intervention—health, housing, communication, transportation, work and leisure

– Identify the typical age of the target population and the relation of age to stage of secular development of technology to be used

– Identify the target and site of the intervention

Gerontechnology Matrix: 4 types of technological interventions in 5 domains of human activity

 

  

Technology Intervention

Domain of Human Activity

Health & Self-esteem

Housing & Daily Activities

Communication & Governance

Mobility & Transport

Work & Leisure  

Enhancement & Satisfaction

 

Prevention & Engagement  

 Compensation & Assistance

Care & Organization

  

Environment

Person

Social Built Natural

Receptors Internal Effectors Structures

Interface

Future

Past

Time

Humanaging

Secularchange

System Output Measure

LESSON: BOTH age-related and secular changes affect system output dynamics

Putting the 4 gerontechnology interventions to work

Fozard, JL Impacts of technology interventions on health and self-esteem. Gerontechnology, 2005, 4, 63-76.

• The diagrams relating the interactions between people and their environments are just the first step in planning environmental interventions

• The next steps include identifying the– Desired impact, e.g. prevention vs. compensation– Target of intervention– Site and placement of technology– Timing of intervention

Fozard, Fig.2

IMPACT?Prevention

Compensation

Care/organization

Enhance

FUNCTION?Physical

Cognitive

Emotional/Social

SystemOutput

Environ- ment

Person

IMPACT?EnhancePreventCompensateCare/organization

TARGET?PhysicalMentalEmotional/social

INTERVENE:TYPE, SITE?Person:Train, motivateSelectPersonalityDemographics

Environment:Built, social, naturalDevice on personDevice: located near or remotely

Time

Planning Practical Application of Gerontechnology Concepts

Technology for Compensation in Perceptual-Motor Functioning

• There is some evidence for using technology to reduce or delay the impact of presbycusis on age related hearing loss

• The evidence for using technology for vision and complex perceptual motor function is less clear

• Presentation will focus on vision

Hearing: Compensation 1

• Improve Auditory Image Quality– Amplification by hearing aids and direct signal

transmission, aural rehabilitation

• Reduce temporal distortion from reverberation and time compression of signals

Hearing: Compensation 2

• Reverberation– Clearly age-related—interventions available

• Schieber F, Fozard JL, Gordon-Salant S, Weiffenbach J Optimizing the sensory-perceptual environment of older adults Int J Indust Ergon 1991;7:133-162

• Speech too fast, e.g, speech compressed– Clearly age-related—one intervention is processor

to slow broadcast speech without frequency distortion

Mutsuhashi T Human-friendly broadcasting technology NHK R&D 1998;50:53-59

Hearing: Compensation 3

• Reverberation and time compression often occur together in public places

• Useful to have guidelines to set goals for both factors

• Gordon-Salant and Fitzgibbons describe effort to create equal audibility index

Equivalent S/N Ratio: Age and Hearing Impairement Effects

• Gordon-Salant, S., Fitzgibbons, P.J. J Speech Hearing Research 1995,38, 706-13.

• % correct word recognition in SPIN test measured in Young (18-40) and Old (65-76) with Normal (N)—HL no more than 15dB at 250-4000Hz or Hearing Impaired (HI)—mild to moderate sensorineural hearing loss.

Equivalent S/N Ratio: Age and Hearing Impairement Effects

Equivalent S/N Ratio Defined:

% Correct Data of Young-N Group in Noise at different S/N ratios used in Equation relating S/N to % Correct.

Predicted S/N ratios used to compare effects of Age and Hearing Impairment under 4 levels of speech compression and 4 levels of reverberation—higher Equivalent S/N ratio=better performance.

Equivalent S/N Ratios for 0-60% Time Compression(N-HI)

0

5

10

15

20

25

0 30 40 50 60

Time Compression (%)

S/N

Young N

Old N

Young HI

Old HI

Equivalent S/N Ratios for 0-0.6 Reverberation (N-HI)

0

5

10

15

20

25

0 0.2 0.3 0.4 0.6

Reverberation Time (sec)

S/N

Young N

Old N

Young HI

Old HI

Clusters of Equivalent S/N Ratios for N and HI Listeners

COMPRESSION (T30-T-60 ) AND REVERB (R.2-R.6) WITH EQUIVALENT S/N RATIOS

N 0 T3 T4 R.2 T5 R.3 R.4 T6 R.6

S/N 19 19 19 19 13 13 13 8 8

HI 0 R.2 T3 R.3 T4 T5 R.4 R.6 T6

S/N 15 12 12 8 8 8 8 3 3

From:Gordon-Salant S and Fitzgibbons PJ J Speech Hear Res 1995;38:711

Compensation: Vision 1

• Improve visual image quality – Increase illumination, contrast, letter size

improve target quality, reduce glare, and requirements for light/dark adaptation

• Decrease requirements for fast adaptation and speed in complex visual tasks. – Target magnification, longer presentation

times, cueing

Compensation: Vision 2

• The loss of sensitivity with age extends across visible spectrum:– Discrimination between white light and

mixture of white light and monochromatic light (420-680 nm) showed that older adults were less able to discriminate color at 2 levels of illumination after controlling for pupil size, retinal luminance etc.

• Kraft JM, Werner JS Aging and the satuation of colors. 1.. Colorimetric purity discrimination J Opt Soc Am 1999;16:223-230.

Color Discrimination for 2 Age and Luminance Levels

0

0.5

1

1.5

2

2.5

3

Log(1/Pc)

420 500 570 640 420 500 570 640

Wavelength (nm)

30-10

74-10

30-250

74-250

Data from Kraft JM and Werner JS, 1999

Compensation: Visual acuity in clinical testing conditions

• Longitudinal data on monocular acuity (better eye) obtained with standard apparatus confirms earlier published data showing that presenting acuity changes little until the 70s for both men and women

• Example of resolution acuity comes from data from the Baltimore Longitudinal Study of Aging. Same finding with letter acuity.

20 30 40 50 60 70 80 Age

Squares=men;Circles=women Data from BLSA, unpublished

Estimated US % w/Acuity<0,5: 4 4 9 16

SnellenFraction

Compensation: Visual Acuity

• In everyday situations, poor illumination, contrast and target characteristics greatly reduce acuity and contrast sensitivity of older persons.

• Examples from Japan and the Netherlands follow. Both illustrate lighting and contrast needed to reduce/eliminate age differences.

Visual acuity measured by letter or Landolt Ring increases as much as 80% with luminance and brings oldest group almost to level of youngest at lower luminance levels.

Data from Research Institute of Human Engineering for Quality Life, Osaka Japan, 1999.

Illumination and Contrast Effects on Readability of Type

• Steenbekkers LPA (1998) Visual contrast sensitivity. In LPA Steenbekkers CEM van Beijsterveldt (Eds) Design-relevant characteristics of ageing users. Delft, NL: Delft University of Technology Press, pp.131-136.

• Size of lower case Times Roman type needed to read standard passages by Dutch adults in four age groups was measured. Three levels of illumination (10,100,1000 lx) and 4 levels of contrast (10, 33, 100 black on white and 100 white on black used.

Type Size Needed to Read Illumination, Contrast Effects

Illum 10 lux 100 lux 1000 luxAge 25 75 25 75 25 75Cont-rast10 10.0 12.6 4.0 8.0 3.2 6.333 5.0 10.0 4.0 8.0 3.2 6.3100 4.0 8.0 3.2 6.3 3.2 5.0100 3.2 8.0 3.2 5.0 3.2 4.0

Need Multiple Approaches to Improving Image Quality

• Applied research on equivalent visibility functions across age--using combinations of illumination, contrast, and targets

• Consumer education: Mockups of kitchen, home office etc. that allow older people to see how to improve personal lighting etc. Mockups could be in lighting stores, Optician stores, senior centers etc.

Need Multiple Approaches to Improving Image Quality

• Consumer services: Small portable lighting aids in restaurants for menus and bills; better design of price tags, directions and prices of merchandise.

• Improved use of electronic reading devices: flexible print size and contrast.

• Device to automatically change focal lengths of lens for presbyopic viewers.

• Greater use of digital hearing aids that selectively amplify frequencies and suppress very high intensity signals

Vision: Compensation in Complex Tasks

• When improving visual information helps performance in complex task depends on specifics of task requirements for– attention and search– visual guidance of control movements– maintenance of balance and gait.

• Behavioral slowing with age results in a reduction of reserve capacity needed for complex behavior

Vision: Compensation in Complex Tasks

• Visually controlled movements• Elderly adults require relatively more time to

complete a repetitive movement task as difficulty increases. For small and long movements, smaller targets mean longer times.

• Welford AT, Norris AH, Shock NW Speed and accuracy of movement and their changes with age Acta Psychol 1969;30:3-15.Brogmus GE (1997) Effects of age and sex on speed and accuracy of hand movements and the refinements they suggest for Fitts’Law. In WA Rogers (Ed) Designing for an aging population. Santa Monica CA: Human Factors and Ergonomics Society, pp.25-29.

Data from Brogmus, 1991. Women performed better than men. 15 year longitudinal followup of men showed an initial practice effect followed by poorer performance because of greater variability in location of spots in the target space.

Visually Controlled Movements

• The slowing of making single and repetitive movements occurs mostly in the last segment of the movement. Practice does not help reduce age difference in speed.

• Target magnification, control damping, improved contrast provide best ways of improving performance in tasks like moving the computer screen cursor with a mouse control.

• Seidler-Dobrin RD, Stelmach GE. (1996) Practice and visual feedback in the elderly. In G Huber (Ed) Healthy aging, activity and sports. Heidelberg

GE:Health Promotion Publications, Pp.109-117.

Vision: Compensation Driving

• Self reports by current and former drivers identify same visual problems found in laboratory studies; in one study complaints correlate with age declines in carefully measured contrast sensitivity.

• Kline DW, Kline TJB, Fozard JL, Kosnick W, Schieber F, Sekuler R Aging and driving: the problems of older drivers. J Gerontol 1992;47:27-34

• Schieber F, Kline DW, Kline TJB, Fozard JL The relationship between contrast sensitivity and the visual problems of older drivers. Warrendale PA: Society of Automotive Engineers Technical Paper 920613 1992 pp 1-7

Ratings 1-3: none to moderate difficulty. Age trends in all 7 complaints predicted by contrast sensitivity data

From Schieber et al 1992

Vision: Compensation: Driving

• As in static visual environments, illumination levels and glare profoundly affect visibility for signs and objects while driving

• Compensations include better sign lighting and increased size of sign symbols

• Schieber F, Kline DW Age differences in the legibility of symbol highway signs as a function of luminance and glare level. Proceedings of the Human Factors and Ergonomics Society 38th Annual Meeting 1994 133-135

• Dewar RE, Kline DW Mark I, Schieber F Symbol signing design for older drivers. Final Report, DTFH-61-C-0018 McLean VA: Federal Highway Administration, 1994

Vision: Compensation: Driving

• Steering task study and illumination• Old adults are involved in relatively fewer night

time automobile accidents than younger drivers.• Older adults make more steering errors in

driving simulator under poor illumination than young adults

• Owens DA, Tyrell RA Effects of luminance, blur and age on nighttime visual guidance: A test of the selective degradation hypothesis. J Exp Psychol:Appl 1999;5:1-14

30

20

10

Luminance (log cd/m2)

Steering errors in driving simulator under four luminance levels. Data from Owens and Tyrrell (1999)

Compensation: Falls and Gait

• Poor illumination, confusing information resulting from bad stair design implicated in many studies of falls and accidents.

• Architect John Templar documents these in a multivolume book.

• Population based studies show consistent relation between visual acuity and contrast sensitivity and measures of gait and history of falls and hip fractures.

• Klein BEK, Klein F, Lee KE, Cruickshanks KJ Performance-based and self-asssessed measures of visual function as related to history of falls, hip fractures and measured gait time:Beaver Dam Study Ophthalmology 1998;105:160-164.

Conclusions

• Focus has been on perceptual motor applications because these are relatively resistant to prevention based technology interventions

• Person oriented interventions such as training in how to fall without injury need more research and development attention

Conclusions

• Major choices for compensation – Choice of human or machine as provider of

intervention– Acceptability of machine intervention to user,

especially important if intervention is in home environment

– Complexity of intervention—is design within scope of ‘universal design’ or is it very idiosyncratic to this particular application??