Cholinergic modulation of visual attention and working memory: dissociable effects of basal forebrain 192-IgG-saporin lesions and intraprefrontal infusions of scopolamine

Two experiments examined the effects of reductions in cortical cholinergic function on performance of a novel task that allowed for the simultaneous assessment of attention to a visual stimulus and memory for that stimulus over a variable delay within the same test session. In the first experiment, infusions of the muscarinic receptor antagonist scopolamine into the medial prefrontal cortex (mPFC) produced many omissions but did not impair rats' ability to correctly detect a brief visual stimulus. However, these animals were highly impaired in remembering the location of that stimulus following a delay period, although in a delay-independent manner. In the second experiment, another group of animals with selective 192IgG-saporin lesions of the nucleus basalis magnocellularis (nBM) were not impaired under conditions of low-attentional demand. However, when the stimulus duration was reduced, a significant memory impairment was observed, but similar to the results of the first experiment, the nBM-lesioned animals were not impaired in attentional accuracy, although aspects of attention were compromised (e.g., omissions). These findings demonstrate that (1) cortical cholinergic depletion produces dissociable deficits in attention and memory, depending on the task demands, (2) delay-independent mnemonic deficits produced by scopolamine are probably due to impairments other than simple inattention, and (3) working memory deficits are not simply dependent on attentional difficulties per se. Together, these findings implicate the nBM cortical cholinergic system in both attentional and mnemonic processing.     

Which factors affect hand selection in children's grasping in hemispace? Combined effects of task demand and motor dominance

Sixty-five right- and left-handed preschool and school children were tested on three reach-to-grasp tasks of different levels of complexity, performed in three space locations. Our goal was to evaluate how the effect of attentional information related to object location interacts with task complexity and degree of handedness on children's hand selection. Results revealed a shift to the non-preferred hand in the contralateral hemispace, which was more or less pronounced according to the level of task complexity. The subject's degree of handedness also influenced this shift, since strongly lateralized children exhibited a greater use of their preferred hand than less lateralized ones for actions in the contralateral hemispace. These findings confirm that hand selection is to some extent adaptable to task demand and environmental context.     

Episodic and semantic remote autobiographical memory in ageing

Many laboratory studies have demonstrated an age effect on episodic memory which is in contrast with the preservation of semantic memory. The aim of this study was the assessment of age effects on autobiographical memory according to the length of the retention interval, taking into account the episodic and semantic components. A total of 52 subjects, aged between 40 and 79, were divided into four age groups. They were tested with a sophisticated autobiographical questionnaire consisting of two tasks, one involving the recall of semantic information and another the recall of episodic events. Results revealed that episodic recall deteriorated more with age and retention interval than semantic recall. These data, gathered using an ecological test, confirm age differences demonstrated by laboratory tests on the episodic-semantic distinction. Furthermore, the profile of results obtained for the recall of specific detailed events, and analysed according to age of encoding, confirms the distribution of episodic memories across the lifespan, as modelled by Rubin, Wetzler, and Nebes (1986) with the cue-word technique.     

More dissociations and interactions within central executive functioning: a comprehensive latent-variable analysis

The present study examined the separability of six executive functions (verbal storage-and-processing coordination, visuospatial storage-and-processing coordination, dual-task coordination, strategic retrieval, selective attention, and shifting) and their relationships, by means of confirmatory factor analysis. A set of tasks thought to primarily assess each target function was administered to 180 participants. The results demonstrated that five of the six functions initially considered were distinguishable albeit related constructs, with one of these functions combining inhibitory and strategic retrieval processes. The analyses failed to reveal a single dual-task coordination ability underlying performance on the dual-tasks. These findings provide further support for the fractionation of the central executive into several functions and also stress the need to approach executive functioning in terms of both dissociations within general functions and specific interactions between some of these functions.     

Cognitive avoidance of intrusive memories and autobiographical memory: specificity, autonoetic consciousness, and self-perspective

Autobiographical memory (AM) specificity is impaired in depression and post-traumatic stress disorder. Previous studies emphasised the role of cognitive avoidance of intrusive memories in this impairment. This study aimed to examine the association of cognitive avoidance of intrusive memories with specificity, autonoetic consciousness, and self-perspective. A total of 38 healthy participants were given the revised Impact of Event Scale (IES-R) and an AM task designed to assess positive and negative memories regarding specificity, autonoetic consciousness (remember/know procedure), and self-perspective (field/observer procedure). Taking into account age, verbal IQ, mood, harm avoidance, and executive resources, the IES-R avoidance subscale was negatively correlated with specificity and remember responses for positive memories, and with remember and field responses for negative memories. These findings suggest that cognitive avoidance of intrusive memories is associated with a decrease of the episodic components of AM retrieval.     

Developmental coordination disorder pertains to a deficit in perceptuo-motor synchronization independent of attentional capacities

We investigated from a dynamic pattern perspective to motor coordination whether the deficiency in motor coordination characterizing Developmental Coordination Disorder children pertains to a general disorder in synchronization leading to a lower stability of the performed coordination pattern, and the extent to which the trouble is linked to attentional capacities. Twenty-four DCD children without ADHD aged eight to thirteen and 60 control children were asked (1) to perform a Continuous Performance Test assessing sustained attention; (2) to flex one finger either in synchrony or in syncopation with a visual periodic signal whose frequency was increased stepwise, assessing synchronization abilities. For the attentional task, percentage of exact responses, number of errors and reaction time were recorded. For the synchronization task, we measured relative phase (i.e., the ratio between the stimulus and the response onset and the time separating two successive stimuli). DCD children were significantly more variable than controls in both conditions and the difficulty in synchronization was unrelated to attentional disorders (ANCOVA). These findings support the idea of a general synchronization disorder in DCD children underlying their poor motor coordination. Moreover, this synchronization disorder does not appear to be strictly dependent on the level of sustained attentional capacities.     

Working memory and error detection in texts: what are the roles of the central executive and the phonological loop?

Subjects performed a text error detection task, either alone or in conjunction with a secondary task aimed at specifically hindering the functioning of either the central executive in working memory or of the phonological loop. We focused on the decline in detection performance as a function of the type of error to be detected (typographical, orthographic, or semantic/syntactic) and the processing span required for detection (one word, several words within the same clause, or several clauses). The results showed that the central executive in working memory is involved in detecting semantic/syntactic errors and in detecting orthographic ones, but not in detecting typographical errors. Moreover, the degree of involvement increases with the processing span. The phonological loop is involved in detection whenever processing above the word level is required. As observed in many studies, these results suggest that the difficulty subjects have detecting semantic errors as compared to other types of errors is due to the heavier working memory load: maintenance of the phonological representation and greater involvement of the central executive. © 1998 John Wiley & Sons, Ltd.     

Between cultural relativism and liberal ethnocentrism: What does Saudi Arabia tell us about cultural variation in moral identity and prejudice?

Cultural conceptions of morality are grounded in diverse moral foundations, but moral identity research often assumes that individualizing concerns are the universal basis for morality. Moral identity scales grounded only in individualizing foundations risk liberal ethnocentrism, to the extent that binding foundations emphasized in collectivist cultures are overlooked. Three hundred and ninety-five Saudi Arabian and UK participants completed prejudice and moral identity measures, which either narrowly measured only individualizing foundations or broadly measured both binding and individualizing foundations. The broader measure had greater power to predict prejudice scores in both countries, particularly in Saudi Arabia. Generally, moral identities grounded in individualizing foundations predicted less prejudice, while moral identities grounded in binding foundations predicted higher prejudice in both countries. Individualizing measures of moral identity may assess ethnocentric concepts, but recognizing morality grounded in binding considerations may taint the category of moral identity with self-concepts that are associated with greater—not less—ethnocentrism.     

A new look at the attribution of moral responsibility: The underestimated relevance of social roles

What are the main features that influence our attribution of moral responsibility? It is widely accepted that there are various factors which strongly influence our moral judgments, such as the agent’s intentions, the consequences of the action, the causal involvement of the agent, and the agent’s freedom and ability to do otherwise. In this paper, we argue that this picture is incomplete: We argue that social roles are an additional key factor that is radically underestimated in the extant literature. We will present an experiment to support this claim.