How Accurate Is Memory For Familiar Slope?

Document Type

Poster Session

Publication Date


Published In

Journal Of Vision


Geographical slant is generally overestimated. It has been reported that these overestimations are even greater in memory than in perception (Creem & Proffitt, 1998). However, these prior studies have used imagery instructions, which may encourage biased responding. We asked two groups of undergraduates to provide verbal, and pictorial or proprioceptive slope estimates of 5 familiar campus paths ranging in actual slope from 0.5 to 8.6 deg. One set of 30 participants was led to the base of each path and made their estimates while looking at it (Perception Condition). The other set of 30 participants made estimates from memory (Memory Condition). Maps, satellite photos and verbal names for the paths were used in the memory condition to ensure that participants understood the location of the path to be judged. Half the participants in each condition were asked to hold out their unseen hand to represent the slope of the path. Hand orientation was measured precisely with a micro-inclinometer. Following this they made verbal estimates. The other half of the participants adjusted a 2D line on a computer screen to represent the slope of the path prior to making verbal estimates. All three measures showed the same patterns. For one of the shallower paths (1.2 deg), proprioceptive estimates from memory were slightly lower (2.3 deg) than the proprioceptive estimates of those viewing the path (4.0 deg), t(28) = 2.08, p = .046. For all other paths and measures, there was no evident or consistent difference between memory and perception on any of the measures. Non-verbal estimates were lower than verbal estimates, but all estimates overestimated all hills both in perception and in memory. We conclude that memory for familiar paths includes unbiased (normal) perceptual information about path inclination. Creem, S.H., & Proffitt, D.R. (1998). Psychonomic Bulletin and Review 5(1):22-36.


Vision Sciences Society Tenth Annual Meeting

Conference Dates

May 7-12, 2010

Conference Location

Naples, FL