Redundancy of noise elements and signals in visual detection of letters

Abstract

Forced-choice detection was studied in relation to heterogeneity of noise letters and multiple signal letters within tachistoscopic displays. Curves plotting both probability and latency of correct detections vs number of redundant signals at different display sizes exhibit significant interactions with heterogeneity of the noise background, but do not differ as a function of similarity among redundant signals. Application of interactive and independent channels models indicated that noise redundancy operates to a major extent through effects of signal-noise confusability at the decision level, but may also involve perceptual interaction at the level of feature detectors.

The use of a visual mask may seriously confound your experiment

“…Few, if any, models are so explicitly detailed as to distinguish between masked and nonmasked inputs, and the formulations they pose for experimental tests would be the same with either. Illustrative of this latter point is recent research on the interactive channels model as applied to visual search (Estes, 1974). These experiments have been concerned with testing whether the recognition accuracy for target letters in a display is affected by the degree of feature similarity or featural overlap the target shares with noise letters in the display.…”

Good continuation affects visual detection

“…Second, performance declines as the similarity between target and noise (nontarget) items in the array increases (Estes, 1972;Gardner, 1973;McIntyre, Fox, & Neale, 1970). Third, performance improves as similarity among noise items increases (Estes, 1974;McIntyre et al 1970;McLaughlin, Masterson, & Herrmann, 1972). Finally, target detection is inversely related to targetnoise proximity (Banks, Bodinger, & Illige, 1974;Estes, 1972;Eriksen & Eriksen, 1974).…”

“…The present study compares Banks and Prinzmetal's (1976) configurational hypothesis of visual detection to feature analytic approaches, of which the interactive channels theory (Estes, 1972(Estes, , 1974 is the most complete. Both the interactive channels theory and the configurational hypothesis can explain the major findings in visual detection experiments.…”

“…The display size effect results from the increased probability that a confusable noise item will inhibit an input channel for the target when the density of elements in the display is increased. Estes (1974) explains the effect of noise homogeneity in terms of two separate effects of the variability of features in the noise. Increasing variability (i.e., decreasing homogeneity) increases the probability that a noise element will be confused with a target; increasing variability also increases the probability of inhibitory interactions among input channels to feature detectors.…”

“…Increasing variability (i.e., decreasing homogeneity) increases the probability that a noise element will be confused with a target; increasing variability also increases the probability of inhibitory interactions among input channels to feature detectors. Estes (1974) has separate mathematical appendices showing how each of these effects can take place.…”