Knowledge that Transforms

The affective-valence hypothesis is among the most successful theories in the science of emotion. It proposes a frontal asymmetry, with the left prefrontal cortex (PFC) subserving approachrelated positive affect, and the right PFC subserving withdrawalrelated negative affect (Davidson, 1984). However, even in the early years of the theory, occasional anomalies in experimental findings suggested that the left PFC processed the negative emotion anger. Although such findings fit the approach-withdrawal dimension of the affective-valence model, because anger prepares the organism for the prototypical approach response of aggression (Fox, 1991), they are irreconcilable with the positivenegative dimension. In recent years, evidence that anger is processed by the left PFC has been accumulating (HarmonJones, 2004). Consequently, Harmon-Jones (2004) parsimoniously removed the positive-negative distinction from the affective-valence model and built his motivational-direction model on the remaining dimensions of approach and withdrawal. Thus, in this model, the dimensions of approach and withdrawal exclusively define the frontal asymmetry of emotion. Recently, Harmon-Jones and his coworkers (Harmon-Jones, Lueck, Fearn, & Harmon-Jones, 2006) reported further evidence supporting his model. Left PFC activation in response to personally relevant anger-provoking stimuli was demonstrated during approach-related action expectation. In this case, as in most of Harmon-Jones's research, evidence was gathered by experimentally manipulating mood or emotion. In contrast, the evidence that favors the affective-valence model is weaker correlational evidence relating positive emotion to the left PFC. To reconcile the affective-valence model with the findings regarding anger, Davidson (2004) recently suggested that some kinds of anger might be processed alongside positive emotions, such as happiness, within the left PFC. However, this notion is contrary to the idea that the frontal asymmetry of emotion evolved to preclude conflicts among action tendencies (Davidson, 2004), because happiness works antagonistically to both anger and anxiety (Wegner & Pennebaker, 1993). Given their inherent approachand withdrawal-related properties, anger and anxiety seem the best candidates for asymmetric frontal processing, but there seems to be no direct reason for happiness to be processed asymmetrically in the PFC (Harmon-Jones, 2004). Happiness more likely is a state of psychobiological wellbeing that requires a balance between affective approach and withdrawal (Schulkin, 2003; Van Honk & Schutter, 2006). A technique that can provide definitive answers in controversies regarding the frontal asymmetry of emotion is repetitive transcranial magnetic stimulation (rTMS). Indeed, a recent rTMS study supported the motivational-direction model in demonstrating greater processing of anger when left-sided dominance was induced in the PFC than when right-sided dominance was induced in the PFC (d'Alfonso, van Honk, Hermans, Postma, & De Haan, 2000). This study, however, lacked the sham rTMS control necessary to directly pinpoint anger to the left PFC. In the present study, brain activity in the left and the right PFC of healthy subjects was locally decreased by applying low-intensity/low-frequency rTMS; in the control conditions, sham rTMS over the left and right PFC was used instead. Next, subjects performed an emotional memory task that taps into the attention and working memory abilities of the PFC and indexes the processing of anger and happiness (Van Honk et al., 2003). According to the motivational-direction model, deactivation of the left PFC by rTMS should decrease the processing of anger but not necessarily happiness, relative to sham rTMS or deactivation of the right PFC by rTMS. The affective-valence model predicts the opposite pattern, with deactivation of the left PFC causing decreased processing of happiness but, in general, not anger.

A theoretical analysis shows that sample correlations between two binary variables will be inflated when the frequency distributions of the two variables are flatter (i.e., closer to equal frequencies for the two values) in the sample than in the population. A correlation-assessment study in which participants were free to choose their own sample revealed an overwhelming preference for samples that included roughly the same number of observations for the two values of dichotomous variables, irrespective of their actual distribution in the population. Subjective estimates of observed correlations followed the sample correlations--which were inflated, as predicted--more closely than the true correlations. People's sampling behavior thus resembles that of a research designer who maximizes the chance of detecting a relationship, at the cost of diminished accuracy in estimating its strength.

When asked to mark the center of a horizontal line, neurologically intact right-handers show a slight yet reliable tendency to bisect about 2% to the left of the true center (Hausmann, Ergun, Yazgan, & Gu¨ ntu¨ rku¨ n, 2002). This systematic error has been termed right pseudoneglect (Bowers & Heilman, 1980), implying a mild, natural neglect of right hemispace, and has been attributed to dominance of the right hemisphere for visuospatial attention (Oliveri et al., 2004). Supporting this interpretation, a recent brain-imaging study reported activation of the right parietal regions when participants performed the landmark task, which is similar to the line-bisection task (Finket al., 2000).

Two studies were conducted to examine whether facial feedback can modulate implicit racial bias as assessed by the Implicit Association Test (IAT). Participants were surreptitiously induced to smile through holding a pencil in their mouth while viewing photographs of unfamiliar Black or White males or performed no somatic configuration while viewing the photographs (Study 1 only). All participants then completed the IAT with no facial manipulation. Results revealed a spreading attitude effect, with significantly less racial bias against Blacks among participants surreptitiously induced to smile during prior viewing of Black faces than among participants surreptitiously induced to smile during prior viewing of White faces.

The human visual system possesses a remarkable ability to reconstruct the shape of an object that is partly occluded by an interposed surface. Behavioral results suggest that, under some circumstances, this perceptual process (termed amodal completion) progresses from an initial representation of local image features to a completed representation of a shape that may include features that are not explicitly present in the retinal image. Recent functional magnetic resonance imaging (fMRI) studies have shown that the completed surface is represented in early visual cortical areas. We used fMRI adaptation, combined with brief, masked exposures, to track the amodal completion process as it unfolds in early visual cortical regions. We report evidence for an evolution of the neural representation from the image-based feature representation to the completed representation. Our method offers the possibility of measuring changes in cortical activity using fMRI over a time scale of a few hundred milliseconds.

Do people believe mental disorders are real and possess underlying essences? The current study found that both novices and practicing clinicians held weaker essentialist beliefs about mental disorders than about medical disorders. They were also unwilling to endorse the idea that mental disorders are real and natural. Furthermore, compared with novices, mental health clinicians were less likely to endorse the view that there is a shared cause underlying a mental disorder and that one needs to remove the cause to get rid of the mental disorder. Clinicians were polarized on their views about whether mental disorders are categorical or dimensional. These findings reflect current controversies about mental disorders in the field at large.

Individuals who saw pictures for 1 to 3 s in the laboratory were tested 17 years later by mail. Identification rates were significantly higher for fragments from these previously exposed targets than for novel fragments, whereas the same stimuli evoked no differences in control groups that had not been previously exposed to the pictures. Priming--the memorial advantage conferred by prior perceptual experience--was stable over the years (r= .51). Priming was dissociated from episodic memory, in that it was present even in subjects who reported no conscious recollection of their participation in the original laboratory session. These findings suggest that the perceptual representation system is an invulnerable memory system functioning below conscious awareness.

Speakers' descriptions sometimes inappropriately refer to information known only to them, thereby "leaking" knowledge of that private information. We evaluated whether speakers can explicitly control such leakage in light of its communicative consequences. Speakers described mutually known objects (e.g., a triangle) that had size-contrasting matches that were privileged to the speakers (e.g., a larger triangle visible to the speakers only), so that use of a contrasting adjective (e.g., small) involved referring to the privileged information. Half the time, speakers were instructed to conceal the identity of the privileged object. If speakers can control their leaked references to privileged information, this conceal instruction should make such references less likely. Surprisingly, the conceal instruction caused speakers to refer to privileged objects more than they did in the baseline condition. Thus, not only do speakers have difficulty not leaking privileged information, but attempts to avoid such leakage only make it more likely.

It is often asserted that Black Americans have made no IQ gains on White Americans. Until recently, there have been no adequate data to measure trends in Black IQ. We analyzed data from nine standardization samples for four major tests of cognitive ability. These data suggest that Blacks gained 4 to 7 IQ points on non-Hispanic Whites between 1972 and 2002. Gains have been fairly uniform across the entire range of Black cognitive ability.