Dual-task processing in younger and older adults: similarities and differences revealed by fMRI

fMRI was used to explore age differences in the neural substrate of dual-task processing. Brain activations when there was a 100 ms SOA between tasks, and task overlap was high, were contrasted with activations when there was a 1000 ms SOA, and first task processing was largely complete before the second task began. Younger adults (M=21 yrs) showed activation in dorsolateral prefrontal cortex and in parietal areas as well as in ventral medial frontal cortex and sub-lobar areas. Activations in older adults (M=71 yrs) did not differ significantly from younger adults except for higher activations in occipital and polar prefrontal cortex. The results were well fit by a model with two networks managing dual-task interference, a medial prefrontal network that detects changes in the stimulus situation and maps them to associated changes in the valence of response mappings and a lateral frontal-parietal network that initiates and carries out the shift from one task to the other. The additional activations in older adults as a group and the correlations of individual differences in activation with performance were consistent with recruitment within each of these networks. Alternative explanations such as hemispheric asymmetry reduction and reactive rather than proactive processing in older adults were not supported.     

Space Cannot Be Cut—Why Self-Identity Naturally Includes Neighbourhood

Psychology is not alone in its struggle with conceptualizing the dynamic relationship between space and individual or collective identity. This general epistemological issue haunts biology where it has a specific focus in evolutionary arguments. It arises because of the incompatibility between definitive logical systems of ‘contradiction or unity’, which can only apply to inert material systems, and natural evolutionary processes of cumulative energetic transformation. This incompatibility makes any attempt to apply definitive logic to evolutionary change unrealistic and paradoxical. It is important to recognise, because discrete perceptions of self and group, based on the supposition that any distinguishable identity can be completely cut free, as an ‘independent singleness’, from the space it inescapably includes and is included in, are a profound but unnecessary source of psychological, social and environmental conflict. These perceptions underlie Darwin’s definition of ‘natural selection’ as ‘the preservation of favoured races in the struggle for life’. They result in precedence being given to striving for homogeneous supremacy, through the competitive suppression of others, instead of seeking sustainable, co-creative evolutionary relationship in spatially and temporally heterogeneous communities. Here, I show how ‘natural inclusion’, a new, post-dialectic understanding of evolutionary process, becomes possible through recognising space as a limitless, indivisible, receptive (non-resistive) ‘intangible presence’ vital for movement and communication, not as empty distance between one tangible thing and another. The fluid boundary logic of natural inclusion as the co-creative, fluid dynamic transformation of all through all in receptive spatial context, allows all form to be understood as flow-form, distinctive but dynamically continuous, not singularly discrete. This simple move from regarding space and boundaries as sources of discontinuity and discrete definition to sources of continuity and dynamic distinction correspondingly enables self-identity to be understood as a dynamic inclusion of neighbourhood, through the inclusion of space throughout and beyond all natural figural forms as configurations of energy. Fully to appreciate and communicate the significance of this move, it is necessary to widen the linguistic, mathematical and imaginative remit of conventional scientific argument and explication so as to include more poetic, fluid and artistic forms of expression.     

The perceived ethnic discrimination questionnaire--community version: validation in a multiethnic Asian sample

This study evaluated the validity and reliability of the Perceived Ethnic Discrimination Questionnaire-Community Version (PEDQ-CV) Lifetime Exposure scale in a multiethnic Asian sample (N = 509). The 34-item scale measures perceived interpersonal racial/ethnic discrimination and includes four subscales assessing different types of discrimination: Social Exclusion, Stigmatization, Discrimination at Work/School, and Threat/Aggression. The Lifetime Exposure scale demonstrated excellent reliability across the full group and in all major subgroups. Subscales displayed good reliability across the full group and moderate-to-good reliability in each subgroup. The Lifetime Exposure scale was significantly correlated with the depression and anxiety subscales of the SCL-90-R, providing preliminary evidence of construct validity. The data suggest the Lifetime Exposure scale, previously validated in Black and Latino adults, is also appropriate for use with Asian samples, and can be used to examine both within-group and between-groups differences in discrimination.     

Embodiment of motor skills when observing expert and novice athletes

If people are shown a dynamic movie of an action such as kicking a soccer ball or hitting a tennis ball, they will respond to it faster if it requires the same effector. This standard congruency effect was reported to reverse when participants viewed static images of famous athletes not actually performing an action. It was suggested that the congruent response was inhibited because of a social contrast effect, based on an implied action, whereby responders viewed themselves as comparatively worse than the professional athlete. The present study recorded hand and foot responses when identifying static images of both famous and novice athletes in soccer and tennis. The action was either explicit or implied. In Experiment 1, a standard congruency effect was found for all images. In Experiment 2, when a response was based on the identity of the athlete rather than their expertise, the standard congruency effect was enhanced for images of novice athletes, but was eliminated for experts, suggesting a social contrast effect. Our study is the first to show that embodiment effects can be seen for implied and explicit action images of both novices and experts, and that static images are capable of eliciting priming effects associated with sport-relevant effector pairings.     

Deleterious effects of alcohol intoxication: diminished cognitive control and its behavioral consequences

The authors tested the hypothesis that impaired behavioral performance during intoxication results partly from alcohol's deleterious effects on cognitive control. The impact of alcohol on perseverative behavior was examined with an n-back working memory task that included manipulations of task complexity and prepotency of inclinations to respond or withhold responding. Thirty-two social drinkers (16 men) participated in either an alcohol (.075g/100ml) or a no-alcohol condition. Alcohol increased perseveration of prepotent, task-inappropriate response patterns only under cognitively demanding (heavy memory load) conditions. This effect was evident for both commission errors (response persistence despite contingencies altered to require restraint) and omission errors (failure to respond when contingencies were revised to encourage action). Findings suggested that alcohol-induced perseveration arises from impairments in cognitive control.     

Mass Murder: An Analysis of Extreme Violence

Mass murder involves the slaughter of four or more victims by one or a few assailants within a single event, lasting but a few minutes or as long as several hours. More than just arbitrary, using this minimum body count—as opposed to a two- or three-victim threshold suggested by others (e.g., Ressler et al., 1988, Holmes and Holmes, 2001)—helps to distinguish multiple killing from homicide generally. Moreover, by restricting our attention to acts committed by one or a few offenders, our working definition of multiple homicide also excludes highly organized or institutionalized killings (e.g., war crimes and large-scale acts of political terrorism as well as certain acts of highly organized crime rings). Although state-sponsored killings are important in their own right, they may be better explained through the theories and methods of political science than criminology. Thus, for example, the definition of multiple homicide would include the crimes committed by Charles Manson and his followers, but not those of Hitler's Third Reich, or the 9/11 terrorists, despite some similarities in the operations of authority.     

The role of spatial working memory in inhibition of return: evidence from divided attention tasks

Inhibition of return (IOR) refers to a bias against returning attention to a location that has been recently attended. In the present experiments, we examined the role of working memory in IOR by introducing secondary tasks (in the temporal interval between the cue and the target) that involved a working memory component. When the secondary task was nonspatial in nature (monitoring odd digits or adding digits), IOR was present, although overall reaction times were greater in the presence of the secondary task. When the task involved a spatial working memory load (remembering the directionality of arrows or the orientation of objects), IOR was eliminated. However, when the participants had incentive to process the directionality of an arrow but did not have to use any memory system, IOR persisted at peripheral locations. Overall, the results suggest that IOR is partially mediated by a spatial working memory system.     

Visual spatial perception and paternal deprivation

College men and women who were father deprived for at least 1 year from birth to 18 years of age or non-deprived were compared on the Spatial Relations Test of the Differential Aptitude Tests (DAT), the Identical Blocks Test (IBT) and the Water Level Test (WLT). There was a significant sex difference favoring men—as expected—on the IBT and WLT but not on the DAT. There was no significant effect of father deprivation on the mean performance on any test but there was a correlation between years of deprivation and WLT performance for men (r = 0.48,P < 0.001). No other correlation between deprivation and test performance was significant.     

Impulsive versus premeditated aggression: implications for mens rea decisions

Science can provide more information about the nature of aggressive acts, and therefore the mens rea of criminal offenses, than is commonly assumed. For example, progress has been made in classifying aggression as impulsive or premeditated within the context of the role of conscious experience in controlling behavior. This review of the status of the scientific ability to distinguish conscious from unconscious acts and more specifically impulsive from premeditated aggressive acts is organized around four themes: (i) How is aggression defined and measured in general? (ii) How does the distinction between impulsive and premeditated aggression relate to the legal concept of mens rea? (iii) How do various scientific disciplines contribute to the mind/body discourse? (iv) What risk factors are associated with impulsive and premeditated aggression respectively? The authors conclude that the most promising approach to researching the nature of behavioral intention and motivation is to apply a discipline neutral model that integrates the data from multiple disciplines, collectively designated the cognitive neurosciences.