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The complete design in the composite face paradigm: role of response bias, target certainty, and feedback.

Meinhardt G, Meinhardt-Injac B, Persike M - Front Hum Neurosci (2014)

Bottom Line: Some years ago an improved design (the "complete design") was proposed to assess the composite face effect in terms of a congruency effect, defined as the performance difference for congruent and incongruent target to no-target relationships (Cheung et al., 2008).In a recent paper Rossion (2013) questioned whether the congruency effect was a valid hallmark of perceptual integration, because it may contain confounds with face-unspecific interference effects.We conclude that the congruency effect, when complemented by an evaluation of response bias, is a valid hallmark of feature integration that allows one to separate faces from non-face objects.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Johannes Gutenberg University Mainz Mainz, Germany.

ABSTRACT
Some years ago an improved design (the "complete design") was proposed to assess the composite face effect in terms of a congruency effect, defined as the performance difference for congruent and incongruent target to no-target relationships (Cheung et al., 2008). In a recent paper Rossion (2013) questioned whether the congruency effect was a valid hallmark of perceptual integration, because it may contain confounds with face-unspecific interference effects. Here we argue that the complete design is well-balanced and allows one to separate face-specific from face-unspecific effects. We used the complete design for a same/different composite stimulus matching task with face and non-face objects (watches). Subjects performed the task with and without trial-by-trial feedback, and with low and high certainty about the target half. Results showed large congruency effects for faces, particularly when subjects were informed late in the trial about which face halves had to be matched. Analysis of response bias revealed that subjects preferred the "different" response in incongruent trials, which is expected when upper and lower face halves are integrated perceptually at the encoding stage. The results pattern was observed in the absence of feedback, while providing feedback generally attenuated the congruency effect, and led to an avoidance of response bias. For watches no or marginal congruency effects and a moderate global "same" bias were observed. We conclude that the congruency effect, when complemented by an evaluation of response bias, is a valid hallmark of feature integration that allows one to separate faces from non-face objects.

No MeSH data available.


Related in: MedlinePlus

Box-Whisker plots of the decision criterion c used to assess response bias for faces (A) and watches (B).
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Figure 7: Box-Whisker plots of the decision criterion c used to assess response bias for faces (A) and watches (B).

Mentions: Figure 7 shows the response criterion c for faces (upper panels, A) and watches (lower panels, B) as Box-Whisker plots. Tables 3, 4 show detailed results, including both the c and the q measure, miss and false alarm rates, overall error rate pe, and odds ratio of misses and false alarms. To judge response bias statistically it has to be verified whether the mean c value is significantly above (“different” bias), or below (“same” bias) the expected value 0, as indicated by the Whiskers3. For faces, there was only one significant bias in the feedback condition (see left upper panel of Figure 7), where a tendency toward “same” responses existed for congruent trials when the cue came at the second position [c = −0.14, t(26) = −5.03, p = 3.1 · 10−5]. There was no response bias in the absence of feedback in congruent contexts; however, a pronounced tendency toward “different” responses existed in incongruent trials [cue1st: c = 0.27, t(23) = 5.19, p = 2.9 · 10−5; cue2nd: c = 0.24, t(23) = 4.80, p = 7.6 · 10−5]. To judge bias it is also important how many errors occurred in a given condition because response bias is of practical relevance only if a substantial number of errors are made. This was the case for incongruent trials in the absence of feedback. Here, 14% misses stood against 5.3% false alarms when the cue came first (pe = 9.7%), and 29.8% misses compared to 15.5% false alarms when the cue came at the second position (pe = 22.6%). Response bias did not occur in the feedback condition in incongruent trials when the cue came at the second position, although the error rates were rather high (pe = 18.8%, see last line of Table 3). Instead, there was “same” bias in congruent trials, but there, the error rate was moderate, with 9.3% false alarms compared to 5.5% misses (pe = 7.4%, see 2nd last line of Table 3). This indicates that trial-by-trial feedback influenced the subjects' response strategies. Comparing the likelihood of both kind of errors with the odds-ratio statistics confirmed this result. In the absence of feedback and in incongruent trials the chance for wrong “different” responses was more than double the chance for wrong “same” responses when the cue came at the second position, and nearly threefold when the cue came at the first position. With feedback and in congruent trials the chance for wrong “different” responses was nearly halved when the cue came at the second position. All other odds-ratios are about 1, which indicates balanced chances for errors of both kinds.


The complete design in the composite face paradigm: role of response bias, target certainty, and feedback.

Meinhardt G, Meinhardt-Injac B, Persike M - Front Hum Neurosci (2014)

Box-Whisker plots of the decision criterion c used to assess response bias for faces (A) and watches (B).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4215786&req=5

Figure 7: Box-Whisker plots of the decision criterion c used to assess response bias for faces (A) and watches (B).
Mentions: Figure 7 shows the response criterion c for faces (upper panels, A) and watches (lower panels, B) as Box-Whisker plots. Tables 3, 4 show detailed results, including both the c and the q measure, miss and false alarm rates, overall error rate pe, and odds ratio of misses and false alarms. To judge response bias statistically it has to be verified whether the mean c value is significantly above (“different” bias), or below (“same” bias) the expected value 0, as indicated by the Whiskers3. For faces, there was only one significant bias in the feedback condition (see left upper panel of Figure 7), where a tendency toward “same” responses existed for congruent trials when the cue came at the second position [c = −0.14, t(26) = −5.03, p = 3.1 · 10−5]. There was no response bias in the absence of feedback in congruent contexts; however, a pronounced tendency toward “different” responses existed in incongruent trials [cue1st: c = 0.27, t(23) = 5.19, p = 2.9 · 10−5; cue2nd: c = 0.24, t(23) = 4.80, p = 7.6 · 10−5]. To judge bias it is also important how many errors occurred in a given condition because response bias is of practical relevance only if a substantial number of errors are made. This was the case for incongruent trials in the absence of feedback. Here, 14% misses stood against 5.3% false alarms when the cue came first (pe = 9.7%), and 29.8% misses compared to 15.5% false alarms when the cue came at the second position (pe = 22.6%). Response bias did not occur in the feedback condition in incongruent trials when the cue came at the second position, although the error rates were rather high (pe = 18.8%, see last line of Table 3). Instead, there was “same” bias in congruent trials, but there, the error rate was moderate, with 9.3% false alarms compared to 5.5% misses (pe = 7.4%, see 2nd last line of Table 3). This indicates that trial-by-trial feedback influenced the subjects' response strategies. Comparing the likelihood of both kind of errors with the odds-ratio statistics confirmed this result. In the absence of feedback and in incongruent trials the chance for wrong “different” responses was more than double the chance for wrong “same” responses when the cue came at the second position, and nearly threefold when the cue came at the first position. With feedback and in congruent trials the chance for wrong “different” responses was nearly halved when the cue came at the second position. All other odds-ratios are about 1, which indicates balanced chances for errors of both kinds.

Bottom Line: Some years ago an improved design (the "complete design") was proposed to assess the composite face effect in terms of a congruency effect, defined as the performance difference for congruent and incongruent target to no-target relationships (Cheung et al., 2008).In a recent paper Rossion (2013) questioned whether the congruency effect was a valid hallmark of perceptual integration, because it may contain confounds with face-unspecific interference effects.We conclude that the congruency effect, when complemented by an evaluation of response bias, is a valid hallmark of feature integration that allows one to separate faces from non-face objects.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Johannes Gutenberg University Mainz Mainz, Germany.

ABSTRACT
Some years ago an improved design (the "complete design") was proposed to assess the composite face effect in terms of a congruency effect, defined as the performance difference for congruent and incongruent target to no-target relationships (Cheung et al., 2008). In a recent paper Rossion (2013) questioned whether the congruency effect was a valid hallmark of perceptual integration, because it may contain confounds with face-unspecific interference effects. Here we argue that the complete design is well-balanced and allows one to separate face-specific from face-unspecific effects. We used the complete design for a same/different composite stimulus matching task with face and non-face objects (watches). Subjects performed the task with and without trial-by-trial feedback, and with low and high certainty about the target half. Results showed large congruency effects for faces, particularly when subjects were informed late in the trial about which face halves had to be matched. Analysis of response bias revealed that subjects preferred the "different" response in incongruent trials, which is expected when upper and lower face halves are integrated perceptually at the encoding stage. The results pattern was observed in the absence of feedback, while providing feedback generally attenuated the congruency effect, and led to an avoidance of response bias. For watches no or marginal congruency effects and a moderate global "same" bias were observed. We conclude that the congruency effect, when complemented by an evaluation of response bias, is a valid hallmark of feature integration that allows one to separate faces from non-face objects.

No MeSH data available.


Related in: MedlinePlus