Response competition effects insame-different judgments

Subjects judged whether two adjacent letters were identical or different. Different pairs were similar, for example HM, DO, VY, or dissimilar, for example DY, HV,MO. According to the noisyoperator theory, increasing the heterogeneity of difference (external noise) by intermixing similar and dissimilar different pairs ought to produce faster but less accurate responses on different trials. As predicted, the tendency to make more false-different responses (i.e., errors on same pairs) decreased when the similar and dissimilar different pairs were intermixed rather than presented in separate blocks. The fast-same effect did not change, however, seemingly due to criterion misadjustment. Proctor and Rao apparently found no effect of heterogeneity of difference on RT and errors because they used a less sensitive procedure (between-subjects design; different set of letters for more and less heterogeneous conditions). Consistent with the internal-noise principle, but not with the response-competition model of Eriksen, O'Hara, and Eriksen, the enhanced fastsame effect on blocks containing only similar (vs. dissimilar) different pairs was accompanied by an increased preponderance of false-different errors.When people judge whether two letters are identical or not, same judgments typically are faster than different judgments. According to the noisy-operator theory (Krueger, 1978), internal noise more often changes physical matches into spurious perceived mismatches than vice versa. As a result, different judgments are slower, owing to more rechecking of perceived mismatches, and subjects typically make more false-different responses (i.e., errors on same trials) than false-same ones.External noise also must be considered, however. Variability in the perceived difference count is the joint effect of variability within the subject (internal noise) and variability dependent on the investigator (external noise), who controls the number of differing features present (Krueger, 1978(Krueger, , 1979. While internal noise ought to produce faster but less accurate responses on same trials, external noise ought to produce faster but less accurate responses on different trials. When the different pairs vary in the degree of their featural overlap with the same pairs, then the similar different pairs would tend to be confused with same pairs and produce false-same errors, and the rechecking needed to eliminate such errors would slow down the same judgments. In effect, the similar different pairs would undermine the same distribution on the perceived difference count.

Section: Response-competition Principlesupporting

confidence: 77%

“…Their null finding is consistent with the view that letters, for all their differences, are remarkably similar or alike in many or most respects (Eriksen, O'Hara, & Eriksen, 1982). Quite likely, they would have found a definite effect had they used materials permitting greater heterogeneity of difference.…”

supporting

confidence: 79%

Positive effect of heterogeneity of difference on thesame-different disparity in letter matching

Krueger

1986

“…Because the present study did not involve discrimination judgments, it would be inappropriate to speculate at this point about a fast "same" effect for tactually presented stimuli. The results do, however, suggest that, as with visually presented stimuli, there is something special about identity (Eriksen, O'Hara, & Eriksen, 1982;Evans & Smith, 1988;Smith & Evans, 1989). Further empirical research is called for to investigate the locus of this effect with tactile stimuli.…”

Section: Discussionmentioning

confidence: 76%

Perceptual processing of adjacent and nonadjacent tactile nontargets

Evans

Craig

Rinker

1992

Previous research has shown that subjects appear unable to restrict processing to a single finger and ignore a stimulus presented to an adjacent finger. Furthermore, the evidence suggests that, at least for moving stimuli, an adjacent nontarget is fully processed to the level of incipient response activation, The present study replicated and expanded upon these original findings. The results of Experiment 1 showed that an equally large response-competition effect occurred when the nontarget was presented to adjacent and nonadjacent fingers (on the same hand). The results of Experiment 2 showed that the effects observed in Experiment 1 (and in previous studies) were also obtained with stationary stimuli. Although small, there was some indication in the results of Experiment 2 that interference may dissipate more rapidly with distance with stationary stimuli. An additional finding was that interference effects were observed in both experiments with temporal separations between the target and nontarget of up to 100 msec. In Experiment 3, target and nontarget stimuli were presented to opposite hands. Although reduced, interference was still evident with target and nontarget stimuli presented to opposite hands. Varying the physical distance between hands did not produce any change in the amount of interference. The results suggest that the focus of attention on the skin extends nearly undiminished across the fingers of one hand and is not dependent upon the physical distance between sites of stimulation. 571A recent study by Evans and Craig (1991) indicated that subjects have difficulty focusing their attention on one finger and ignoring stimulation at an adjacent site. In this study, subjects were instructed to focus their attention on the left index fmger and to identify the direction of movement of the stimulus presented to that finger. A second stimulus, also moving, was presented to the middle finger, adjacent to the index finger. The stimuli moved in the same direction or in opposite directions. We reasoned that if subjects could restrict their attention to the target location, the presence of the nontarget would produce little, if any, interference. If, however, subjects are unable to restrict their attention to a single finger on one hand, then the direction of movement of the adjacent nontarget might interfere with target performance in a systematic fashion. Specifically, target performance might be interfered with when the direction of movement of the nontarget was opposite to that of the target. The results showed that when the target and nontarget moved in opposite directions, accuracy was reduced and response latencies (correct trials) This research was supported by Grant DC-00095 from the National Institutesof Health and was conducted while the first author was a visiting scholar in the Institute for the Study of Human Capabilities at Indiana University. The authors thank Roger P. Rhodes for his assistance in conducting these experiments. Reprint requests should be addressed to P. M. Evans, Department o...

“…Biasing features of various sorts might indeed affect same-differentjudgments. Thus, responses may beslower on similar than on dissimilar differentpairs owing to response competition induced by matching features (Chignell & Krueger, 1984;Eriksen, O'Hara, & Eriksen, 1982). Chignell and Krueger found that falsesame responses on similar different pairs exceeded those on dissimilar different pairs.…”

Section: Questionmentioning

confidence: 99%

Effect of intermixed foveal and parafoveal presentation onsame-different judgments: Evidence for a criterion-inertia model

Krueger

1985

Subjects judged whether two adjacent letters, which were presented either 0.5 0 (foveal or near condition) or 2.0 0 (parafoveal or far condition) from fixation, were identical or different. The preponderance of false-dijferent responses (i.e., errors on same trials) over false-same ones increased, whereas the fast-same effect was eliminated, on the far pairs, but only when they were intermixed with near pairs rather than presented in separate (pure) blocks of trials. Intermixing the near and far pairs produced the opposite trends on near trials (i.e., smaller preponderance offalse-dijferent errors, larger fast-same effect). Carr et al., who presented trigrams, found a similar criterion misadjustment, which likewise depended on intermixed presentation. They proposed that their easy (familiar or orthographically regular) pairs produced a bias or criterion shift towards "same." No obvious biasing features were present in the near or far pairs, however, so the criterion misadjustment found here was attributed to the combined effect of internal noise and criterion inertia, not to criterion shifting. Increasing the level of internal noise on far trials produced more spurious perceived mismatches, but on mixed blocks of near and far trials, subjects relied on a common, compromise criterion for responding versus rechecking (recheck moderate perceived differences), instead of the separate, more appropriate criteria for near trials (recheck small differences) and far trials (recheck large differences) used on pure blocks.When people judge whether two letters are identical or not, same judgments typically are faster than different judgments. According to the noisy-operator theory (Krueger, 1978), internal noise more often changes physical matches into spurious perceived mismatches than vice versa. As a result, different judgments are slower, owing to more rechecking of perceived mismatches, and there typically is a tendency to make more false-different responses (i.e., errors on same trials) than false-same ones.If internal noise is so important a factor, then the fast-