Intellectual disability and the myth of the changeling myth

This article investigates the historical sources for the idea of the "changeling" or substitute child as an explanation for congenital intellectual disability. Pre-modern sources for this idea are elite and theological as much as popular and folkloric, nor do they refer to intellectual disability in any sense recognizable to us. Rather, both the concept of intellectual disability and the notion of a transhistorical changeling myth emerge from the historical core of modern psychology.     

A longitudinal study of personality change in young adulthood

The present research examined personality continuity and change in a sample of young men and women assessed at the beginning and end of college. Two-hundred seventy students completed measures of the Big Five personality traits when they first entered college and then 4 years later. Analyses indicate small- to medium-sized normative (i.e., mean-level) changes, large rank-order stability correlations, high levels of stability in personality structure, and moderate levels of ipsative (i.e. profile) stability. Overall, the findings are consistent with the perspective that personality traits exhibit considerable continuity over time, yet can change in systematic ways.     

Identification of visual stimuli is improved by accompanying auditory stimuli: the role of eye movements and sound location

Can auditory signals influence the processing of visual information? The present study examined the effects of simple auditory signals (clicks and noise bursts) whose onset was simultaneous with that of the visual target, but which provided no information about the target. It was found that such a signal enhances performance in the visual task: the accessory sound reduced response times for target identification with no cost to accuracy. The spatial location of the sound (whether central to the display or at the target location) did not modify this facilitation. Furthermore, the same pattern of facilitation was evident whether the observer fixated centrally or moved their eyes to the target. The results were not altered by changes in the contrast (and therefore visibility) of the visual stimulus or by the perceived utility of the spatial location of the sound. We speculate that the auditory signal may promote attentional 'disengagement' and that, as a result, observers are able to process the visual target sooner when sound accompanies the display relative to when visual information is presented alone.     

Exploring the role of individual differences in the prediction of workplace aggression

This study investigates the relationship between individual differences and the incidence of workplace aggression in a sample of employees from a transportation company and a public school system. Hierarchical multiple regression analysis indicated that measures of trait anger, attribution style, negative affectivity, attitudes toward revenge, self-control, and previous exposure to aggressive cultures accounted for 62% of the variance in the participants' self-reported incidence of workplace aggression. Further research on workplace aggression is advocated, focusing on the role of individual differences and their interactions with organizational and group-level variables.     

Cognitive performances and locomotor activity following dentate granule cell damage in rats: role of lesion extent and type of memory tested

Intradentate injection of colchicine is one of the techniques used to destroy granule cells. This study compared the behavioral effects of various amounts of colchicine (1.0, 3.0, and 6.0 microg; Col 1, Col 3, and Col 6, respectively) injected into the dentate gyrus of adult Long-Evans male rats. Starting 10 days after lesion surgery, behavioral testing assessed home-cage and open-field locomotion, alternation in a T-maze, water-maze, and radial-maze learning according to protocols placing emphasis on reference, and working memory. All of these tasks are sensitive to hippocampal disruption. Histological verifications showed that the extent of the lesions depends on the dose of colchicine (index of dentate gyrus shrinkage: -33% in Col 1, -54% in Col 3, and -67% in Col 6 rats). Colchicine dose-dependently increased nocturnal home cage activity (an effect found 10 days but not 5 months after surgery), but had no significant effect on open-field locomotion or T-maze alternation. A dose-dependent reference memory impairment was found during the acquisition of spatial navigation in the water maze; Col 3 and Col 6 rats were more impaired than Col 1 rats. During the probe trial (platform removed), control rats spent a longer distance swimming over the platform area than all rats with colchicine lesions. In the working memory version of the test, all rats with colchicine lesions showed significant deficits. The deficits were larger in Col 3 and Col 6 rats compared to Col 1 rats. The lesions had no effect on swimming speed. In the radial-maze test, there was also a dose-dependent working memory impairment. However, reference memory was disrupted in a manner that did not differ among the three groups of lesioned rats. Our data are in line with the view that the dentate gyrus plays an important role in the acquisition of new information and is an integral neural substrate for spatial reference and spatial working memory. They also suggest that damage to granule cells might have more pronounced effects on reference than on working memory in the radial maze. Finally, they demonstrate that part of the variability in the conclusions from previous experiments concerning the role of granule cells in cognitive processes, particularly in spatial learning and memory, may be due to the type of tests used and/or the extent of the damage produced.     

Imagined and actual limb selection: a test of preference

Imagined and actual motor performance were compared to determine what factor(s) drive limb selection for programming movements in contralateral hemispace. Forty right-handed blindfolded subjects were asked to 'reach' via auditory stimulus for a small object placed at multiple locations in hemispace. Two conditions were included: arms uncrossed and arms crossed. With the uncrossed condition, responses were similar. With arms crossed, subjects had the choice of keeping the limbs crossed, reacting to proximity, or uncrossing the arms to reach ipsilaterally. In this condition subjects 'imagined' that they would maintain the crossedposition and reach with the hand closest to the stimulus in both right and left hemispace. However, during 'actual' reaching, responses differed. For left-field stimuli, participants kept the arms crossed, but in response to right-field stimuli, subjects preferred to uncross the limbs in order to reach with the dominant hand. These findings suggest that while motor dominance is the primary factor in limb choice for action in ipsilateral hemispace, it appears that object proximity drives limb selection for reaching in contralateral hemispace.     

Global cognitive decline in schizophrenia with remission of symptoms?

The relation of symptoms to cognitive dysfunction in schizophrenia is still controversial. This study was aimed (i) at verifying if a homogeneous sample of 10 young treated outpatients in remission from psychotic symptoms displays a characteristic pattern of cognitive dysfunction and (ii) at testing the issue of a general cognitive impairment. The neuropsychological performance of the patients was confronted with a large control group by means of Equivalent Scores, a normative method widely used in Italy, which allows direct, reliable comparison between tests and between patients. We found that our patients, as a group, were affected by a basic activation deficit in attention and by a semantic impairment. These deficits in symptom-free patients could indicate that their brains are in some ways working differently from those of normal controls and that this pattern is not necessarily linked to psychotic symptoms: their neuropsychological impairment might reflect a basic difference in the way of processing information that is always present and is independent of general intellectual decay.     

Developmental regulation before and after a developmental deadline: the sample case of "biological clock" for childbearing

This quasi-experimental research investigates developmental regulation around a critical life-span transition, the "biological clock" for childbearing. The action-phase model of developmental regulation proposes contrasting control orientations in individuals approaching versus those having passed a developmental deadline. Individuals in an urgency phase close to the deadline should be invested in goal pursuit, whereas those who have passed the deadline without attaining the goal should focus on goal disengagement and self-protection. In 2 studies, women at different ages and with or without children were compared with regard to various indicators of primary and secondary control striving for goal attainment versus goal disengagement and self-protection. Findings support the action-phase model of developmental regulation. Patterns of control striving congruent with the participants' status as pre- versus postdeadline were associated with superior psychological well-being.