Memory trace stabilization leads to large-scale changes in the retrieval network: a functional MRI study on associative memory

Spaced learning with time to consolidate leads to more stabile memory traces. However, little is known about the neural correlates of trace stabilization, especially in humans. The present fMRI study contrasted retrieval activity of two well-learned sets of face-location associations, one learned in a massed style and tested on the day of learning (i.e., labile condition) and another learned in a spaced scheme over the course of one week (i.e., stabilized condition). Both sets of associations were retrieved equally well, but the retrieval of stabilized association was faster and accompanied by large-scale changes in the network supporting retrieval. Cued recall of stabilized as compared with labile associations was accompanied by increased activity in the precuneus, the ventromedial prefrontal cortex, the bilateral temporal pole, and left temporo–parietal junction. Conversely, memory representational areas such as the fusiform gyrus for faces and the posterior parietal cortex for locations did not change their activity with stabilization. The changes in activation in the precuneus, which also showed increased connectivity with the fusiform area, are likely to be related to the spatial nature of our task. The activation increase in the ventromedial prefrontal cortex, on the other hand, might reflect a general function in stabilized memory retrieval. This area might succeed the hippocampus in linking distributed neocortical representations.     

How good is good luck? The role of counterfactual thinking in the perception of lucky and unlucky events

Spontaneous references to ‘luck’ (e.g. in the mass media) frequently occur in connection with narrow escapes from accidents. The hypothesis that lucky events are not always positive, to the same degree as unlucky events are negative, was tested by asking Norwegian and Polish students to describe incidents of good and bad luck from their own lives, These stories were subsequently evaluated by the narrators and by a group of judges. Ratings showed unlucky events to be uniformly negative whereas lucky events varied widely in attractiveness. Both were characterized by the idea that the outcome could easily have been a dramatically different one. In a parallel set of studies, pleasant and unpleasant experiences from students' everyday life were collected (without specific reference to luck) and evaluated along the same dimensions. The results confirm that unlucky and unpleasant events have more in common than lucky and pleasant ones. Pleasant and unpleasant events can be imagined to have opposite alternative outcomes, but these are felt with less immediacy than in the case of luck. It is concluded that luck attributions typically occur in situations that could easily have taken a worse turn. How lucky depends upon how easily and how much worse.     

Cognitive processes in the Extrinsic Affective Simon Task: a task-set switching account of EAST effects

Recently, De Houwer (2003) introduced the Extrinsic Affective Simon Task (EAST) as a new procedure for the indirect assessment of attitudes. In the present paper, we propose an explanation of EAST effects based on a task-set switching account. Specifically, we argue that EAST effects result from difficulties in efficiently switching between two different task sets. Results from two experiments support the assumptions of the task-set switching account: While there were strong EAST effects in task-shift trials, no robust effects were found in task-repetition trials. In Experiment 2, the robustness of this task-shift effect on the EAST was demonstrated: Visual similarity between concept and attribute stimuli did not qualify the task-shift effects. Implications for the interpretation of EAST effects are discussed.     

The positivity proportion effect: A list context effect in masked affective priming

In the evaluative decision task, participants decide whether target words denote something positive or negative. Positive and negative prime words are known to engender so-called affective priming effects in this task. Primes were sandwich masked, and the proportion of positive to negative target words was manipulated. In Experiment 1, prime valence and positivity proportion interacted, so that primes of the less frequently presented target valence caused larger priming effects. Experiment 2 rendered an explanation of this interaction in terms of response bias unlikely, Experiment 3 ruled out a peripheral locus of the effect, and Experiment 4 ruled out an account in terms of stimulus repetition. The effect is explained by means of an attentional bias favoring the rare kind of valence.     

Organization of Compensatory Postural Coordination Patterns

The authors investigated whether compensatory postural coordination patterns are organized according to the same dynamical principles as are nonequilibrium phase transitions. Eight participants were asked to maintain upright balance on a moving platform that was sinusoidally translated in the anterior-posterior direction and was systematically increased and decreased 0.19 Hz as a step function every 10 platform cycles through the frequency range 0.19–1.46 Hz. At low platform frequencies, all participants exhibited small joint angular motions with high variability, and the relative phase between the joint motions exhibited drifting patterns and large fluctuations. As platform frequency increased, the amplitude of joint motion increased systematically and joint-specific oscillatory patterns emerged. The findings provided no evidence for a Hopf bifurcation or hysteresis in the transitions of postural coordination modes, however, or, mote generally, a basis for distinguishing the relevance of linear versus nonlinear models of postural control.     

Effects of physical attractiveness on evaluations of a male employee's allegation of sexual harassment by his female employer

College students (N = 324) served as mock jurors in a simulated civil case in which a male plaintiff accused a female defendant of sexual harassment. The authors experimentally manipulated the physical attractiveness of the litigants. The authors asked mock jurors to decide whether the defendant was guilty and to rate their certainty of belief in the defendant's guilt (or lack of guilt). Jurors were more certain of the guilt of the defendant when the plaintiff was attractive than when he was unattractive. Plaintiff attractiveness significantly affected female jurors' individual recommended verdicts when the defendant was unattractive but not when she was attractive. With male jurors, plaintiff attractiveness significantly affected their verdicts when the defendant was attractive but not when she was unattractive. Female jurors were more likely than male jurors to conclude that sexual harassment had taken place but only when the litigants were different in attractiveness.     

Fear and the amygdala: manipulation of awareness generates differential cerebral responses to phobic and fear-relevant (but nonfeared) stimuli

Rapid response to danger holds an evolutionary advantage. In this positron emission tomography study, phobics were exposed to masked visual stimuli with timings that either allowed awareness or not of either phobic, fear-relevant (e.g., spiders to snake phobics), or neutral images. When the timing did not permit awareness, the amygdala responded to both phobic and fear-relevant stimuli. With time for more elaborate processing, phobic stimuli resulted in an addition of an affective processing network to the amygdala activity, whereas no activity was found in response to fear-relevant stimuli. Also, right prefrontal areas appeared deactivated, comparing aware phobic and fear-relevant conditions. Thus, a shift from top-down control to an affectively driven system optimized for speed was observed in phobic relative to fear-relevant aware processing.     

Regional brain electrical activity in posttraumatic stress disorder after motor vehicle accident

This study examined whether patients with posttraumatic stress disorder (PTSD) related to motor vehicle accidents (MVAs) would show an abnormal pattern of electroencephalographic (EEG) alpha asymmetries, which has been proposed for particular types of anxiety. Patients with PTSD (n = 22) or subsyndromal PTSD (n = 21), traumatized controls without PTSD (non-PTSD with MVA; n = 21), and healthy controls without MVA (n = 23) underwent measurement of EEG activity during baseline and exposure to a neutral, a positive, a negative, and an accident-related picture. Differences in brain asymmetry between groups were observed only during exposure to trauma-related material. PTSD and subsyndromal PTSD patients showed a pattern of enhanced right anterior and posterior activation, whereas non-PTSD with MVA participants showed the opposite pattern. Furthermore, posterior asymmetry in nontraumatized healthy controls varied with gender, with female participants showing a pattern of higher right posterior activation. The results support the hypothesis that symptomatic MVA survivors are characterized by a pattern of right hemisphere activation that is associated with anxious arousal and symptoms of PTSD during processing of trauma-specific information.     

Getting even or moving on? Power, procedural justice, and types of offense as predictors of revenge, forgiveness, reconciliation, and avoidance in organizations

A field study and an experimental study examined relationships among organizational variables and various responses of victims to perceived wrongdoing. Both studies showed that procedural justice climate moderates the effect of organizational variables on the victim's revenge, forgiveness, reconciliation, or avoidance behaviors. In Study 1, a field study, absolute hierarchical status enhanced forgiveness and reconciliation, but only when perceptions of procedural justice climate were high; relative hierarchical status increased revenge, but only when perceptions of procedural justice climate were low. In Study 2, a laboratory experiment, victims were less likely to endorse vengeance or avoidance depending on the type of wrongdoing, but only when perceptions of procedural justice climate were high.