Shuffling your way out of change blindness

Change detection is typically discussed in the literature as a 2-state phenomenon. Small differences between otherwise identical images are easy to detect when the images are superimposed in space and alternated in time (“shuffled”). However, change blindness results from any disruption that prevents the critical change from generating the sole salient transient. Here we show that different presentation strategies produce different degrees of change blindness for the same change. Specifically, shuffling the images supports faster change detection than viewing the same 2 images side by side, even when the images contain a number of distracting differences. In Experiment 1, pairs of photographs having a 50 % chance of containing a difference were viewed either in alternation, in a “Shuffle” condition, or simultaneously, in a “Side-by-Side” condition. Change detection was about 6 seconds faster when the images were viewed in the “Shuffle” mode. In Experiment 2, we presented two images that were slightly laterally shifted relative to each other (0–48 pixels). The RT benefit for the Shuffle viewing mode was very strong when the relative shift was small, to insignificant when there was a large difference between the two images. However, at large shifts, Shuffle maintained an accuracy advantage. It seems that changes are easier to detect when comparing images in a Shuffle condition rather than Side-by-Side. This has important implications for real world tasks like radiology where detection of change is critical.     

Lifting the curtain on the Wizard of Oz: biased voice-based impressions of speaker size

The consistent, but often wrong, impressions people form of the size of unseen speakers are not random but rather point to a consistent misattribution bias, one that the advertising, broadcasting, and entertainment industries also routinely exploit. The authors report 3 experiments examining the perceptual basis of this bias. The results indicate that, under controlled experimental conditions, listeners can make relative size distinctions between male speakers using reliable cues carried in voice formant frequencies (resonant frequencies, or timbre) but that this ability can be perturbed by discordant voice fundamental frequency (F-sub-0, or pitch) differences between speakers. The authors introduce 3 accounts for the perceptual pull that voice F-sub-0 can exert on our routine (mis)attributions of speaker size and consider the role that voice F-sub-0 plays in additional voice-based attributions that may or may not be reliable but that have clear size connotations.     

Group membership,group norms,empathy, and young children's intentions to aggress

This study assessed the effect of ingroup norms and empathy on 6 and 9‐year‐old children's (N=161) attitudes and aggressive intentions toward outgroup members. Prior to an intergroup drawing competition against an outgroup, participants' empathy was measured, and they were randomly assigned to a simulated group with a norm of direct or indirect aggression, or no aggression norm. Results indicated participants' attitudes were less positive toward the outgroup vs. the ingroup, and that both direct and indirect aggressive intentions were displayed toward the outgroup. Most importantly, the ingroup was liked less when it had an aggression norm, and the participants' aggressive intentions were not enhanced by the group aggression norm. Empathy was a significant negative predictor of direct but not indirect aggression intentions. Implications for understanding the instigation and inhibition of children's aggression intentions are discussed. Aggr. Behav. 35:244–258, 2009. © 2009 Wiley‐Liss, Inc.     

Deception in psychotherapy: Frequency,typology and relationship

Deception in therapy has been documented anecdotally through various narratives of therapists. The investigation of its occurrence within therapy has largely been overlooked. We explored the reported frequency of deception within psychotherapy, the types of deception used within therapy, the likelihood of people lying to a therapist compared to other groups of people, and client perceptions of the types of deception that therapists use. Ninety‐one participants were provided with a series of deception examples, asked questions about the use of these types of deception within therapy, and asked generally about their use of deception in therapy. We found that a majority of the participants had been deceptive in therapy, and a majority were willing to be deceptive in future therapeutic contexts. Participants were more likely to use white lies than other forms of deception in therapy. Lastly, participants were less likely to lie to therapists compared to strangers and acquaintances. Implications for research and practice are discussed.     

Effects of information about group members on young children's attitudes towards the in‐group and out‐group

Research shows that being a member of a group is sufficient to instigate more positive attitudes towards the in‐group than an out‐group in young children. The present study assessed whether children's intergroup attitudes during the middle childhood years are moderated by additional information about in‐group and out‐group members, as proposed by Aboud's (1988) socio‐cognitive theory (ST). To a minimal group 6‐, 8‐, and 10‐year‐old children (N=159) were assigned, and received information, or no information, about the interests and activities of the in‐group and out‐group members. Results indicated that the in‐group was always rated more positively than the out‐group, and that the in‐group's ratings were unaffected by either the in‐group or out‐group information. In contrast, out‐group ratings were affected by out‐group information, but only when there was no information available about the in‐group. The implications of the findings for ST, and for social identity development theory, are discussed.     

Judging the Importance of Constant and Variable Candidate Causes: A Test of the Power PC Theory

In two causal induction experiments subjects rated the importance of pairs of candidate causes in the production of a target effect; one candidate was present on every trial (constant cause), whereas the other was present on only some trials (variable cause). The design of both experiments consisted of a factorial combination of two values of the variable cause's covariation with the effect and three levels of the base rate of the effect. Judgements of the constant cause were inversely proportional to the level of covariation of the variable cause but were proportional to the base rate of the effect. The judgements were consistent with the predictions derived from the Rescorla-Wagner (1972) model of associative learning and with the predictions of the causal power theory of the probabilistic contrast model (Cheng, 1997) or 'power PC theory'. However, judgements of the importance of the variable candidate cause were proportional to the base rate of the effect, a phenomenon that is in some cases anticipated by the power PC theory. An alternative associative model, Pearce's (1987) similaritybased generalization model, predicts the influence of the base rate of the effect on the estimates of both the constant and the variable cause.     

Competence with fractions predicts gains in mathematics achievement

Competence with fractions predicts later mathematics achievement, but the codevelopmental pattern between fractions knowledge and mathematics achievement is not well understood. We assessed this codevelopment through examination of the cross-lagged relation between a measure of conceptual knowledge of fractions and mathematics achievement in sixth and seventh grades (N = 212). The cross-lagged effects indicated that performance on the sixth grade fractions concepts measure predicted 1-year gains in mathematics achievement (ß = .14, p < .01), controlling for the central executive component of working memory and intelligence, but sixth grade mathematics achievement did not predict gains on the fractions concepts measure (ß = .03, p > .50). In a follow-up assessment, we demonstrated that measures of fluency with computational fractions significantly predicted seventh grade mathematics achievement above and beyond the influence of fluency in computational whole number arithmetic, performance on number fluency and number line tasks, central executive span, and intelligence. Results provide empirical support for the hypothesis that competence with fractions underlies, in part, subsequent gains in mathematics achievement.