Spatial frequency discrimination and visual memory

Lages, M. and Treisman, M. (1996) Spatial frequency discrimination and visual memory. Investigative Ophthalmology and Visual Science, 37(3), S697.

Abstract

Purpose. Magnussen and Dyrnes (1994) claimed that Ss presented with a reference grating can employ a long-term visual memory of up to 50 hrs to discriminate differences in spatial frequency between the reference and a set of test stimuli. We investigated whether Ss performing this task use the spatial frequency information provided by the test stimuli rather than a long-term memory. Methods. A sinusoidal grating with spatial frequency of 2.5 cpd in one condition, and 5.0 cpd in another, served as a reference stimulus. This was presented for 10 secs on a calibrated CRT display linearized in luminance. After a 30 sec retention interval, stimuli from a set of 11 spatial frequencies were presented in random order for 200 msecs each. On each trial Ss judged whether the test grating was higher or lower in spatial frequency than the reference stimulus. Three sets of test gratings were generated each ranging from -0.5 to +0.25 octave around the midpoint. The midpoints were 2.25, 2.5 and 2.75 cpd in one condition and 4.5, 5.0 and 5.5 cpd in the other. Ss received the different sets of test stimuli in three sessions on consecutive days. Results. Psychometric functions (Weibull) were fitted to the individual data and analyses of variance were performed on the parameters of these functions. Thresholds shifted to the midpoints of the test sets without change in the shapes of the functions, with one exception. Conclusions. The results suggest that long-term storage and retrieval of spatial frequency information is not necessary to perform this task. An explanation can be offered in terms of criterion setting theory (Treisman & Williams, 1984) in which the information provided by the test stimuli determines the location of the midpoint. These findings are supported by a second experiment involving gratings with different orientations.

• Item Type: Articles
• Additional Information: Association for Research in Vision and Ophthalmology 1996 annual meeting. Fort Lauderdale, Florida, April 21-26, 1996
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Lages, Dr Martin
• Authors: Lages, M., and Treisman, M.
• College/School: College of Science and Engineering > School of Psychology
• Journal Name: Investigative Ophthalmology and Visual Science
• Publisher: Association for Research in Vision and Ophthalmology
• ISSN: 0146-0404
• ISSN (Online): 1552-5783