Perceptualand Motor Skills, 1990, 71, 919-922.
O Perceptual and Motor Skills 1990
EFFECTS O F SIZE CHANGES O N MEMORY FOR WORDS AND PICTURES ' KATHERINE M. ROBINSON AND LIONEL STANDING Bishop's Uniuersity Summary.-The effects of changing the size of stimuli between learning and recognition sessions were examined for word and picture materials. Size changes did not affect correct recognition of items as new or old, for either words or pictures. However, size alteration impaired recognition memory for the size of word stimuli. With pictures, impaired size recognition was noted with changes only from large to small.
There is very little literature on size shifts in learning. Kolers, Duchnicky, and Sundstroem (1985) performed a recognition study which required subjects to identify the stimuli with or without changes in size between learning and test sessions. They found that increases or decreases in size did not affect word recognition, but impaired picture recognition (where performance was especially poor for the small-to-large condition). An anomalous result was that pictures produced poorer recognition than words. In the present study, size recognition as well as item recognition was examined, to extend the range of learning measures employed. Both pictures and words were used as stimuli, as with Kolers, et al. (1985). However, this study used the Snodgrass and Vanderwart (1980) line drawings rather than the faces employed by Kolers, et al. (1985). Another difference between the two studies is that the learning stimuli were shown at a rate of 1 sec. per slide while the test stimuli were shown at a rate of 3 sec. per slide (cf. 2 sec. and 2 sec.).
Subjects The subjects were 40 psychology students from Bishop's University, 11 men and 29 women. Apparatus and Materials The stimuli comprised 240 slides each for words and pjrtures, randomly drawn from the picture-word sets of Snodgrass and Vanderwort (1980). Of these, 160 slides were used as learning items, the remainder as buffers for the recognition test. All stimuli were shown by means of a Carousel slide 'The authors thank Dale Stout for his advice and encouragement as well as the anonymous referees for their theoretical suggestions and comments. Reprints ma be obtained from L. Standing, Deparrment of Psychology, Bishop's University, ~ e n n o x v J e , Quebec JIM 127, Canada.
920
K. M. ROBINSON & L. STANDING
projector. The large stimuli took up approximately 22O of visual angle while the small stimuli were approximately l I O .
Design and Procedure A 2 x 2 x 2 design was used. The first factor (between subjects) was the order of stimuli types with two counterbalanced orders, word-picture or picture-word. The second factor (between subjects) was the size of the stimuli with two counterbalanced orders, small-large or large-small. The third factor (within subjects) was the type of stimuli of which there were two, words and pictures. Each subject was randomly assigned to one of the two stimulus orders (WP or PW) and to one of the two size orders (SL or LS). There were 10 subjects per cell. The subjects were shown 80 pictures and 80 words at a rate of 1 sec. per slide. The pictures were shown in blocks of 40 large and 40 small, or 40 small then 40 large. The slides were then mixed in random order with 80 buffer items (again in blocks of 40 large and 40 small) for the item- and size-recognition tasks. Of the 80 learned slides, 40 were shown in the same size and the remaining 40 were shown as a different size. The same procedure was used for the word stimuli. Subjects were asked to record on an answer sheet whether they had seen the stimulus before (Yes/No) and if Yes, to indicate whether it was the same size on both presentations or not (YesINo.). The subjects were given one point for each item they correctly recognized, for a ~ o s s i b l e 20 points for each of the four learning and test size-combinations (small-small, small-large, large-small, large-large). The same was done for the size-recognition task. The mean numbers of words and of pictures correctly recognized under each combination of learning sizeltest size is shown in Table 1. The mean numbers of correct size-recognition judgments for words and for pictures are also shown in Table 1. TABLE 1 COKHECT RESPONSES FORITEMA N D FOR SIZERECOGNITION WITH WORDSAND WITH PICTURES(N = 40) Learn
Small Large
M SD M SD
Item Recognition Test: Pictures Test: Words Small Large Small Large
Size Recognition Test: Pictures Test: Words SmaU Large Small Large
11.43 11.78 3.47 3.45 11.30 11.90 3.70 3.55
7.03 2.53 4.35 2.46
14.03 15.10 3.58 3.61 14.65 15.53 3.29 2.87
5.33 3.01 6.75 3.56
9.53 3.78 6.08 3.41
9.43 3.30 8.03 3.81
SIZE CHANGES AND MEMORY
92 1
For the item-recognition task, there was no effect of size ratio for pictures or words; however, pictures were better recognized than were words (F,,,, = 4 3 . 2 2 , p < .01). For the size-recognition task, there was a size ratio effect for words such that, when the size was altered in either direction (small-to-large or largeto-small), performance decreased (F,,,, = 32.47, p < .01). However, for pictures, Newman-Keuls tests (a= .05) indicated that there was reduced performance on the large-to-small condition but the other three conditions were equally well performed. Over-all, size-recognition was better for pictures than for words (F,,,, = 55.78, p < .01).
Kolers, Duchnicky, and Sundstroem (1985) concluded that size plays a basic role in perception. The present results are similar to theirs in that for words there is no effect of size ratio on item recognition, but dissimilar in that pictures do not show the inverted-U function for item-recognition as a function of size ratio. Blakemore and Campbell (1969) hypothesized that the absolute size of an object is redundant for the purpose of image recognition. This principle is supported in the present experiment: there was no significant difference in item-recognition as a result of changing the size of pictures, or of words, between learning and testing. The usual superiority of pictures over words is seen i n the present data for item-recognition (Shepard, 1967). For the size-recognition task, recognition performance over-all was better for pictures than for words. With words, a size-ratio effect was observed such that, when size either increased or decreased between learning and testing, performance declined. This effect is unexpected, and in effect means that 'same' judgments are easier than 'different' judgments for size. Contrary to 'conventional wisdom,' similarity and difference judgments are not necessarily inverses of one another (Medin, Goldstone, & Gentner, 1990). (However, for unknown reasons, the commonsense prediction is fulfilled for pictures.) For the size-recognition task with pictures, the results were asymmetrical, since there was decreased performance for the large-to-sm'd group yet the other three size-combination groups performed equally well Pictures thus display an asymmetrical effect of size changes whereas words show a symmetrical effect. The differential effects of size changes observed here with words and with pictures suggest that words and pictures are encoded in different ways. Conceivably, pictures are encoded as complete images which are reduced in size to occupy less storage space. The decrease in performance from large to small parallels findings by Kosslyn and Alper (1977), who found that, when
922
K. M. ROBINSON & L. STANDING
one of a pair of objects had been imaged at a diminished size, performance dropped. REFERENCES BLAKEMORE, C., & CAMPBELL,F. W. (1969) O n the existence of neurones in the human visual system selectively sensitive to the criteria and size of retinal images. Journal of Physiology, 203, 237-260. KOLERS,P. A,, DUCFINICKY, R. L., & SUNDSTROEM, G . (1985) Size in the visual processing of faces and words. Jozrrnal of Experimental Psychology: Htiman Perception and Performance, 11. 726-751. KOSSLYN, S. M., & ALPER,S. N. (1977) O n the pictorial properties of visual images: effects of image size on memory for words. Canadian Jozrrnal of Psychology, 31, 32-40. MEDIN, D . L., GOLDSTONE, R . L., & GENTNER, D. (1990) Similarity involving attributes and relations: judgments of similarity and difference are not inverses. Psychological Science, 1, 64-69. SHEPARD,R. N. (1967) Reco nition memory for words, sentences, and pictures. Journal of l 6, 156-163. Verbal Learning and ~ e r f oBehavior, SNODGRASS, J. G., & VANDERWART, M. (1980) A standardized set of 260 pictures: norms for name agreement, image agreement, familiarity and visual complexity. Journal of Experimental Psychology: Human Learning and Memory, 6, 174-215.
Accepted October 19, 1990.
O Perceptual and Motor Skills 1990
EFFECTS O F SIZE CHANGES O N MEMORY FOR WORDS AND PICTURES ' KATHERINE M. ROBINSON AND LIONEL STANDING Bishop's Uniuersity Summary.-The effects of changing the size of stimuli between learning and recognition sessions were examined for word and picture materials. Size changes did not affect correct recognition of items as new or old, for either words or pictures. However, size alteration impaired recognition memory for the size of word stimuli. With pictures, impaired size recognition was noted with changes only from large to small.
There is very little literature on size shifts in learning. Kolers, Duchnicky, and Sundstroem (1985) performed a recognition study which required subjects to identify the stimuli with or without changes in size between learning and test sessions. They found that increases or decreases in size did not affect word recognition, but impaired picture recognition (where performance was especially poor for the small-to-large condition). An anomalous result was that pictures produced poorer recognition than words. In the present study, size recognition as well as item recognition was examined, to extend the range of learning measures employed. Both pictures and words were used as stimuli, as with Kolers, et al. (1985). However, this study used the Snodgrass and Vanderwart (1980) line drawings rather than the faces employed by Kolers, et al. (1985). Another difference between the two studies is that the learning stimuli were shown at a rate of 1 sec. per slide while the test stimuli were shown at a rate of 3 sec. per slide (cf. 2 sec. and 2 sec.).
Subjects The subjects were 40 psychology students from Bishop's University, 11 men and 29 women. Apparatus and Materials The stimuli comprised 240 slides each for words and pjrtures, randomly drawn from the picture-word sets of Snodgrass and Vanderwort (1980). Of these, 160 slides were used as learning items, the remainder as buffers for the recognition test. All stimuli were shown by means of a Carousel slide 'The authors thank Dale Stout for his advice and encouragement as well as the anonymous referees for their theoretical suggestions and comments. Reprints ma be obtained from L. Standing, Deparrment of Psychology, Bishop's University, ~ e n n o x v J e , Quebec JIM 127, Canada.
920
K. M. ROBINSON & L. STANDING
projector. The large stimuli took up approximately 22O of visual angle while the small stimuli were approximately l I O .
Design and Procedure A 2 x 2 x 2 design was used. The first factor (between subjects) was the order of stimuli types with two counterbalanced orders, word-picture or picture-word. The second factor (between subjects) was the size of the stimuli with two counterbalanced orders, small-large or large-small. The third factor (within subjects) was the type of stimuli of which there were two, words and pictures. Each subject was randomly assigned to one of the two stimulus orders (WP or PW) and to one of the two size orders (SL or LS). There were 10 subjects per cell. The subjects were shown 80 pictures and 80 words at a rate of 1 sec. per slide. The pictures were shown in blocks of 40 large and 40 small, or 40 small then 40 large. The slides were then mixed in random order with 80 buffer items (again in blocks of 40 large and 40 small) for the item- and size-recognition tasks. Of the 80 learned slides, 40 were shown in the same size and the remaining 40 were shown as a different size. The same procedure was used for the word stimuli. Subjects were asked to record on an answer sheet whether they had seen the stimulus before (Yes/No) and if Yes, to indicate whether it was the same size on both presentations or not (YesINo.). The subjects were given one point for each item they correctly recognized, for a ~ o s s i b l e 20 points for each of the four learning and test size-combinations (small-small, small-large, large-small, large-large). The same was done for the size-recognition task. The mean numbers of words and of pictures correctly recognized under each combination of learning sizeltest size is shown in Table 1. The mean numbers of correct size-recognition judgments for words and for pictures are also shown in Table 1. TABLE 1 COKHECT RESPONSES FORITEMA N D FOR SIZERECOGNITION WITH WORDSAND WITH PICTURES(N = 40) Learn
Small Large
M SD M SD
Item Recognition Test: Pictures Test: Words Small Large Small Large
Size Recognition Test: Pictures Test: Words SmaU Large Small Large
11.43 11.78 3.47 3.45 11.30 11.90 3.70 3.55
7.03 2.53 4.35 2.46
14.03 15.10 3.58 3.61 14.65 15.53 3.29 2.87
5.33 3.01 6.75 3.56
9.53 3.78 6.08 3.41
9.43 3.30 8.03 3.81
SIZE CHANGES AND MEMORY
92 1
For the item-recognition task, there was no effect of size ratio for pictures or words; however, pictures were better recognized than were words (F,,,, = 4 3 . 2 2 , p < .01). For the size-recognition task, there was a size ratio effect for words such that, when the size was altered in either direction (small-to-large or largeto-small), performance decreased (F,,,, = 32.47, p < .01). However, for pictures, Newman-Keuls tests (a= .05) indicated that there was reduced performance on the large-to-small condition but the other three conditions were equally well performed. Over-all, size-recognition was better for pictures than for words (F,,,, = 55.78, p < .01).
Kolers, Duchnicky, and Sundstroem (1985) concluded that size plays a basic role in perception. The present results are similar to theirs in that for words there is no effect of size ratio on item recognition, but dissimilar in that pictures do not show the inverted-U function for item-recognition as a function of size ratio. Blakemore and Campbell (1969) hypothesized that the absolute size of an object is redundant for the purpose of image recognition. This principle is supported in the present experiment: there was no significant difference in item-recognition as a result of changing the size of pictures, or of words, between learning and testing. The usual superiority of pictures over words is seen i n the present data for item-recognition (Shepard, 1967). For the size-recognition task, recognition performance over-all was better for pictures than for words. With words, a size-ratio effect was observed such that, when size either increased or decreased between learning and testing, performance declined. This effect is unexpected, and in effect means that 'same' judgments are easier than 'different' judgments for size. Contrary to 'conventional wisdom,' similarity and difference judgments are not necessarily inverses of one another (Medin, Goldstone, & Gentner, 1990). (However, for unknown reasons, the commonsense prediction is fulfilled for pictures.) For the size-recognition task with pictures, the results were asymmetrical, since there was decreased performance for the large-to-sm'd group yet the other three size-combination groups performed equally well Pictures thus display an asymmetrical effect of size changes whereas words show a symmetrical effect. The differential effects of size changes observed here with words and with pictures suggest that words and pictures are encoded in different ways. Conceivably, pictures are encoded as complete images which are reduced in size to occupy less storage space. The decrease in performance from large to small parallels findings by Kosslyn and Alper (1977), who found that, when
922
K. M. ROBINSON & L. STANDING
one of a pair of objects had been imaged at a diminished size, performance dropped. REFERENCES BLAKEMORE, C., & CAMPBELL,F. W. (1969) O n the existence of neurones in the human visual system selectively sensitive to the criteria and size of retinal images. Journal of Physiology, 203, 237-260. KOLERS,P. A,, DUCFINICKY, R. L., & SUNDSTROEM, G . (1985) Size in the visual processing of faces and words. Jozrrnal of Experimental Psychology: Htiman Perception and Performance, 11. 726-751. KOSSLYN, S. M., & ALPER,S. N. (1977) O n the pictorial properties of visual images: effects of image size on memory for words. Canadian Jozrrnal of Psychology, 31, 32-40. MEDIN, D . L., GOLDSTONE, R . L., & GENTNER, D. (1990) Similarity involving attributes and relations: judgments of similarity and difference are not inverses. Psychological Science, 1, 64-69. SHEPARD,R. N. (1967) Reco nition memory for words, sentences, and pictures. Journal of l 6, 156-163. Verbal Learning and ~ e r f oBehavior, SNODGRASS, J. G., & VANDERWART, M. (1980) A standardized set of 260 pictures: norms for name agreement, image agreement, familiarity and visual complexity. Journal of Experimental Psychology: Human Learning and Memory, 6, 174-215.
Accepted October 19, 1990.
