Perceptual and Motor Skills, 1976, 42, 295-297.
@ Perceptual and hiotor Skills 1976
FIELD DEPENDENCE AND DISTRACTION REVISITED GEOFFREY H. BLOWERS',' University of Hong Kong Summary.-An attempt is made to replicate a former study of the relationship of field dependence as measured by rod-and-frame errors to distraction in an R T paradigm. For two groups of Ss ( n = 14) who differed specifically in their dependence upon the tilted frame and were classified as frame-dependent and frame-independent, no relationship of frame (or field) dependence to susceptibility to distraction was found.
In spite of the assumption that rod-and-frame errors reflect differential abilities in selective attention, Blowers (1974) was unable to confirm his hypothesis that field-independent Ss would obtain lower RTs during distraction than field-dependent Ss (as determined specifically by their rod-and-frame test scores) because they would be better able to suppress such distracting stimuli. Consideration was given, however, to the fact that greater differences in field-dependence scores might have been required to detect differences in susceptibility to distraction, and it was conceded that a practice effect for one of the two subject groups might have confounded the results. The present study, therefore, was a replication of the previous one using well practiced Ss. It is acknowledged that many factors can contribute to Ss incurring large rodand-frame errors (e.g., Lester, 1968); these may not necessarily reflect 'selective attentional ability.' A more precise estimate of such ability lies in S s dependence upon the tilt of the frame. Nyborg (1974), and Nyborg and Isaksen (1974) have devised a statistical method for estimating such frame effects and have demonstrated their relationship to mean rod-and-frame errors. The present study employs Nyborg's method to differentiate Ss into two groups, frame-dependent and frame-independent. The modified hypothesis to be tested here is that frame-dependent Ss would be more susceptible to distraction than frame-independent Ss. Fourteen frame-dependent and 14 frame-independent Ss as estimated by Nyborg's method were selected from a larger group of 62 Ss in a psychology class. All had previously been administered a portable rod-and-frame test. They were then given an RT task using a consrant foreperiod and identical to that described elsewhere (Blowers, 1974) except that of the five conditions administered only 'Address for reprints: Geoffrey H. Blowers, Department of Psychology, Universiry of Hong Kong, Hong Kong. 'I should like to express my sincere thanks to Mr. E. Kvan for his supervision and Mr. R. K C. Li for his statistical help in the drafting of both this and the former paper (B!owers, 1974 ).
296
G.H. BLOWERS
one distraction condition (random noise) was employed (Condition 3 ) , the other distraction (continuous music) being dropped as music was shown to be ineffective as a distractor. Conditions 1, 2, 4, and 5 were 'baseline' and Condition 3 was a 'treatment' condition of distraction. As in the previous scudy 10 S1-S2-R trials in each condition were given and all conditions were run in the same order for all s u b j e ~ t s . ~The experiment was performed twice on separate days so that each S was well practiced. The results for only the second session are reported here.
RESULTSA N D DISCUSSION The mean log R T scores over five conditions for each group of Ss are shown in Table 1 together with their mean rod-and-frame scores. The two groups differed significantly on their mean rod-and-frame scores as shown by a Mann-Whitney U test.
TABLE
1
MEAN LOG RTs (MSEC.)FOR EACH GROUPOVER FIVE CONDITIONS TOGETHER WITH MEAN ROD-AND-FRAME ERRORS (DEGREES) AND STANDARDDEV~ATIONS Group Frame-independent
M
Frame-dependent
SD M SD
RFT
1
2
Conditions 3
4
5
2.29 0.10 2.24 0.09
2.27 0.11 2.23 0.13
2.42 0.14 2.35 0.13
2.29 0.08 2.20 0.12
2.27 0.09 2.23 0.11
1.37 0.83 2.15 0.85
The statistical model for che log R T data was a 3-factorial fixed-effects model (subject group X condicions X trials within conditions) with repeated measures on the last two factors (Winer, 1971, p. 539). The analysis of variance yielded significant F ratios for condicions and for condicions X trials within conditions. All other terms were non-significant (see Table 2 ) . Using the method of orthogonal contrasts (Guilford, 1973, p. 240) on the mean log RTs for each of the five conditions combined for the two groups of Ss, the four 'baseline' conditions (1, 2, 4 and 5 ) did not differ significantly from one anocher bur did differ significantly ( p < 0.01) from Condition 3 (distraction). A 'distraction score' calculated as the difference between the score for the distraction condition and the mean of the scores for the four baseline conditions for each S was calculated. This score was paired with each S's field-dependence score and a Spearman rho calculared for the 28 Ss. The correlation (0.05) did not reach significance. Tlacing a 'treatment' condition in the middle of a series of 'baseline' conditions enables a change in baseline to be determined (treatment effect). Removal of such an effect by reintroducing the baseline condition and establishing a level of responding similar to pre-treatment conditions prevents post-treatment conditions from being confounded with treatment carry-over effects (Johnson 81 Lubin, 1972).
FIELD DEPENDENCE AND DISTRACTION TABLE 2 ANALYSISOF VARIANCEFOR ALL MODELTERMS
Source
df
MS
F
P
Groups Ss wirhin Groups Conditions Groups x Conditions Conditions x Ss within Groups Trials within Conditions Groups x Trials within Conditions Trials wirhin Conditions x Ss within Groups Conditions x Trials within Conditions Groups X Conditions X Trials within Conditions Conditions x Trials within Conditions x Ss within Groups Nore.--Different denominator terms were used in the calcular~onof each F ratio (after Winer, 1971, p. 540).
With practice effects controlled and Ss differentiated specifically according to their dependence or otherwise upon the tilt of the frame in the rod-andframe test, no significant differences in suscep;ibility to distraction were detected in the two groups. The result tends to confirm previous findings un(Schimek & Wachtel, 1969; Blowers, 1974), and distractibility. appears -related not only to field dependence but more specifically to frame-dependence. If frame-dependence is a measure of selective attention, then individual differences in such measures are not reflected in RT under distraction created b jr random noise on chis psychomotor task. REFERENCES
BLOWERS, G. H. Field dependence and distraction in a simple psychomotor task with a constant foreperiod.
Perceptual and Motor Skills, 1974, 31, 1239-1244.
GUILFORD, J. P. Fundamental staris!ics in psychology and education. New York: McGraw-Hill, 1973. 8: LUBIN, A. On planning psychophysiological experiments: design, measurement and analysis. In N. S. Greenfie!d & R. A. Sternbach (Eds.), Handbook of psychophysiology. New York: Holt, Rinehart 8: Winston, 1972. Pp. 125-158. LESTER,G. The rod-and-frame test: some comments on methodology. Perceptual and Moror Skills, 1968, 26, 1307-13 14. NYBORG, H. A method of analysing performance in the rod-and-frame test: I. Scandinavian Journal of Psychology, 1974, 15, 119-123. NYBORG, H., & ISAKSEN, B. A method of analysing performance in the rod-and-frame test: 11. Scandinavian Journal of Psychology, 1974, 15, 124-126. SCHIMEK, J. G., & WACHTEL, P. L. Exploration of the effects of distraction, competing tasks and cognitive style on artentional deployment. Perceptual and Moior Skills, 1969, 28, 567-574. WINER,B. J. Statistical principles in experimental design. New York: McGraw-Hill,
JOHNSON, L. C.,
1971.
Accepted November 17, 197s.
@ Perceptual and hiotor Skills 1976
FIELD DEPENDENCE AND DISTRACTION REVISITED GEOFFREY H. BLOWERS',' University of Hong Kong Summary.-An attempt is made to replicate a former study of the relationship of field dependence as measured by rod-and-frame errors to distraction in an R T paradigm. For two groups of Ss ( n = 14) who differed specifically in their dependence upon the tilted frame and were classified as frame-dependent and frame-independent, no relationship of frame (or field) dependence to susceptibility to distraction was found.
In spite of the assumption that rod-and-frame errors reflect differential abilities in selective attention, Blowers (1974) was unable to confirm his hypothesis that field-independent Ss would obtain lower RTs during distraction than field-dependent Ss (as determined specifically by their rod-and-frame test scores) because they would be better able to suppress such distracting stimuli. Consideration was given, however, to the fact that greater differences in field-dependence scores might have been required to detect differences in susceptibility to distraction, and it was conceded that a practice effect for one of the two subject groups might have confounded the results. The present study, therefore, was a replication of the previous one using well practiced Ss. It is acknowledged that many factors can contribute to Ss incurring large rodand-frame errors (e.g., Lester, 1968); these may not necessarily reflect 'selective attentional ability.' A more precise estimate of such ability lies in S s dependence upon the tilt of the frame. Nyborg (1974), and Nyborg and Isaksen (1974) have devised a statistical method for estimating such frame effects and have demonstrated their relationship to mean rod-and-frame errors. The present study employs Nyborg's method to differentiate Ss into two groups, frame-dependent and frame-independent. The modified hypothesis to be tested here is that frame-dependent Ss would be more susceptible to distraction than frame-independent Ss. Fourteen frame-dependent and 14 frame-independent Ss as estimated by Nyborg's method were selected from a larger group of 62 Ss in a psychology class. All had previously been administered a portable rod-and-frame test. They were then given an RT task using a consrant foreperiod and identical to that described elsewhere (Blowers, 1974) except that of the five conditions administered only 'Address for reprints: Geoffrey H. Blowers, Department of Psychology, Universiry of Hong Kong, Hong Kong. 'I should like to express my sincere thanks to Mr. E. Kvan for his supervision and Mr. R. K C. Li for his statistical help in the drafting of both this and the former paper (B!owers, 1974 ).
296
G.H. BLOWERS
one distraction condition (random noise) was employed (Condition 3 ) , the other distraction (continuous music) being dropped as music was shown to be ineffective as a distractor. Conditions 1, 2, 4, and 5 were 'baseline' and Condition 3 was a 'treatment' condition of distraction. As in the previous scudy 10 S1-S2-R trials in each condition were given and all conditions were run in the same order for all s u b j e ~ t s . ~The experiment was performed twice on separate days so that each S was well practiced. The results for only the second session are reported here.
RESULTSA N D DISCUSSION The mean log R T scores over five conditions for each group of Ss are shown in Table 1 together with their mean rod-and-frame scores. The two groups differed significantly on their mean rod-and-frame scores as shown by a Mann-Whitney U test.
TABLE
1
MEAN LOG RTs (MSEC.)FOR EACH GROUPOVER FIVE CONDITIONS TOGETHER WITH MEAN ROD-AND-FRAME ERRORS (DEGREES) AND STANDARDDEV~ATIONS Group Frame-independent
M
Frame-dependent
SD M SD
RFT
1
2
Conditions 3
4
5
2.29 0.10 2.24 0.09
2.27 0.11 2.23 0.13
2.42 0.14 2.35 0.13
2.29 0.08 2.20 0.12
2.27 0.09 2.23 0.11
1.37 0.83 2.15 0.85
The statistical model for che log R T data was a 3-factorial fixed-effects model (subject group X condicions X trials within conditions) with repeated measures on the last two factors (Winer, 1971, p. 539). The analysis of variance yielded significant F ratios for condicions and for condicions X trials within conditions. All other terms were non-significant (see Table 2 ) . Using the method of orthogonal contrasts (Guilford, 1973, p. 240) on the mean log RTs for each of the five conditions combined for the two groups of Ss, the four 'baseline' conditions (1, 2, 4 and 5 ) did not differ significantly from one anocher bur did differ significantly ( p < 0.01) from Condition 3 (distraction). A 'distraction score' calculated as the difference between the score for the distraction condition and the mean of the scores for the four baseline conditions for each S was calculated. This score was paired with each S's field-dependence score and a Spearman rho calculared for the 28 Ss. The correlation (0.05) did not reach significance. Tlacing a 'treatment' condition in the middle of a series of 'baseline' conditions enables a change in baseline to be determined (treatment effect). Removal of such an effect by reintroducing the baseline condition and establishing a level of responding similar to pre-treatment conditions prevents post-treatment conditions from being confounded with treatment carry-over effects (Johnson 81 Lubin, 1972).
FIELD DEPENDENCE AND DISTRACTION TABLE 2 ANALYSISOF VARIANCEFOR ALL MODELTERMS
Source
df
MS
F
P
Groups Ss wirhin Groups Conditions Groups x Conditions Conditions x Ss within Groups Trials within Conditions Groups x Trials within Conditions Trials wirhin Conditions x Ss within Groups Conditions x Trials within Conditions Groups X Conditions X Trials within Conditions Conditions x Trials within Conditions x Ss within Groups Nore.--Different denominator terms were used in the calcular~onof each F ratio (after Winer, 1971, p. 540).
With practice effects controlled and Ss differentiated specifically according to their dependence or otherwise upon the tilt of the frame in the rod-andframe test, no significant differences in suscep;ibility to distraction were detected in the two groups. The result tends to confirm previous findings un(Schimek & Wachtel, 1969; Blowers, 1974), and distractibility. appears -related not only to field dependence but more specifically to frame-dependence. If frame-dependence is a measure of selective attention, then individual differences in such measures are not reflected in RT under distraction created b jr random noise on chis psychomotor task. REFERENCES
BLOWERS, G. H. Field dependence and distraction in a simple psychomotor task with a constant foreperiod.
Perceptual and Motor Skills, 1974, 31, 1239-1244.
GUILFORD, J. P. Fundamental staris!ics in psychology and education. New York: McGraw-Hill, 1973. 8: LUBIN, A. On planning psychophysiological experiments: design, measurement and analysis. In N. S. Greenfie!d & R. A. Sternbach (Eds.), Handbook of psychophysiology. New York: Holt, Rinehart 8: Winston, 1972. Pp. 125-158. LESTER,G. The rod-and-frame test: some comments on methodology. Perceptual and Moror Skills, 1968, 26, 1307-13 14. NYBORG, H. A method of analysing performance in the rod-and-frame test: I. Scandinavian Journal of Psychology, 1974, 15, 119-123. NYBORG, H., & ISAKSEN, B. A method of analysing performance in the rod-and-frame test: 11. Scandinavian Journal of Psychology, 1974, 15, 124-126. SCHIMEK, J. G., & WACHTEL, P. L. Exploration of the effects of distraction, competing tasks and cognitive style on artentional deployment. Perceptual and Moior Skills, 1969, 28, 567-574. WINER,B. J. Statistical principles in experimental design. New York: McGraw-Hill,
JOHNSON, L. C.,
1971.
Accepted November 17, 197s.
