Age-related changes in contrast gain related to the M and P pathways

Sarah L. Elliott, John S Werner

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Neural contributions to the age-related reduction in spatial vision are incontrovertible. Whether there are differential agerelated changes in the magnocellular (M) and parvocellular (P) pathways across the life span has not been tested extensively. We studied psychophysically the contrast gain signature of the M and P pathways for 13 younger and 13 older observers. Two separate paradigms thought to separate the M and P pathways based on their contrast gain (J. Pokorny & V. C. Smith, 1997) signature were used. A four-square array was presented as an increment or decrement on a background of 115 Td for 35 ms, with one test square presented at a slightly higher or lower retinal illumination. Using a four-alternative forced-choice procedure, the observer's task was to choose the unique square. The two paradigms differed only in the pretrial adaptation and inter-stimulus array. Data were fitted with models of contrast discrimination derived from the unique contrast gain signatures. The fitted models indicate a change in the discrimination functions with age for both the M and P pathways, revealing a shift in the contrast gain slope. Results indicate that both M and P pathways undergo age-related changes, but functional losses appear greater for the P pathway under the conditions tested.

Original languageEnglish (US)
Pages (from-to)1-15
Number of pages15
JournalJournal of Vision
Volume10
Issue number4
DOIs
StatePublished - 2010

Fingerprint

Lighting

Keywords

  • Age-related changes
  • Contrast gain
  • M and P pathways

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems

Cite this

Age-related changes in contrast gain related to the M and P pathways. / Elliott, Sarah L.; Werner, John S.

In: Journal of Vision, Vol. 10, No. 4, 2010, p. 1-15.

Research output: Contribution to journalArticle

@article{74f2e3586b4b43c891bc6e848907dd20,
title = "Age-related changes in contrast gain related to the M and P pathways",
abstract = "Neural contributions to the age-related reduction in spatial vision are incontrovertible. Whether there are differential agerelated changes in the magnocellular (M) and parvocellular (P) pathways across the life span has not been tested extensively. We studied psychophysically the contrast gain signature of the M and P pathways for 13 younger and 13 older observers. Two separate paradigms thought to separate the M and P pathways based on their contrast gain (J. Pokorny & V. C. Smith, 1997) signature were used. A four-square array was presented as an increment or decrement on a background of 115 Td for 35 ms, with one test square presented at a slightly higher or lower retinal illumination. Using a four-alternative forced-choice procedure, the observer's task was to choose the unique square. The two paradigms differed only in the pretrial adaptation and inter-stimulus array. Data were fitted with models of contrast discrimination derived from the unique contrast gain signatures. The fitted models indicate a change in the discrimination functions with age for both the M and P pathways, revealing a shift in the contrast gain slope. Results indicate that both M and P pathways undergo age-related changes, but functional losses appear greater for the P pathway under the conditions tested.",
keywords = "Age-related changes, Contrast gain, M and P pathways",
author = "Elliott, {Sarah L.} and Werner, {John S}",
year = "2010",
doi = "10.1167/10.4.4",
language = "English (US)",
volume = "10",
pages = "1--15",
journal = "Journal of Vision",
issn = "1534-7362",
publisher = "Association for Research in Vision and Ophthalmology Inc.",
number = "4",

}

TY - JOUR

T1 - Age-related changes in contrast gain related to the M and P pathways

AU - Elliott, Sarah L.

AU - Werner, John S

PY - 2010

Y1 - 2010

N2 - Neural contributions to the age-related reduction in spatial vision are incontrovertible. Whether there are differential agerelated changes in the magnocellular (M) and parvocellular (P) pathways across the life span has not been tested extensively. We studied psychophysically the contrast gain signature of the M and P pathways for 13 younger and 13 older observers. Two separate paradigms thought to separate the M and P pathways based on their contrast gain (J. Pokorny & V. C. Smith, 1997) signature were used. A four-square array was presented as an increment or decrement on a background of 115 Td for 35 ms, with one test square presented at a slightly higher or lower retinal illumination. Using a four-alternative forced-choice procedure, the observer's task was to choose the unique square. The two paradigms differed only in the pretrial adaptation and inter-stimulus array. Data were fitted with models of contrast discrimination derived from the unique contrast gain signatures. The fitted models indicate a change in the discrimination functions with age for both the M and P pathways, revealing a shift in the contrast gain slope. Results indicate that both M and P pathways undergo age-related changes, but functional losses appear greater for the P pathway under the conditions tested.

AB - Neural contributions to the age-related reduction in spatial vision are incontrovertible. Whether there are differential agerelated changes in the magnocellular (M) and parvocellular (P) pathways across the life span has not been tested extensively. We studied psychophysically the contrast gain signature of the M and P pathways for 13 younger and 13 older observers. Two separate paradigms thought to separate the M and P pathways based on their contrast gain (J. Pokorny & V. C. Smith, 1997) signature were used. A four-square array was presented as an increment or decrement on a background of 115 Td for 35 ms, with one test square presented at a slightly higher or lower retinal illumination. Using a four-alternative forced-choice procedure, the observer's task was to choose the unique square. The two paradigms differed only in the pretrial adaptation and inter-stimulus array. Data were fitted with models of contrast discrimination derived from the unique contrast gain signatures. The fitted models indicate a change in the discrimination functions with age for both the M and P pathways, revealing a shift in the contrast gain slope. Results indicate that both M and P pathways undergo age-related changes, but functional losses appear greater for the P pathway under the conditions tested.

KW - Age-related changes

KW - Contrast gain

KW - M and P pathways

UR - http://www.scopus.com/inward/record.url?scp=77956395600&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77956395600&partnerID=8YFLogxK

U2 - 10.1167/10.4.4

DO - 10.1167/10.4.4

M3 - Article

VL - 10

SP - 1

EP - 15

JO - Journal of Vision

JF - Journal of Vision

SN - 1534-7362

IS - 4

ER -