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Recent studies have shown that selective attention is of considerable importance for encoding task-relevant items into visual short-term memory (VSTM) according to our behavioral goals. However, it is not known whether top–down attentional biases can continue to operate during the maintenance period of VSTM. We used ERPs to investigate this question across two experiments. Specifically, we tested whether orienting attention to a given spatial location within a VSTM representation resulted in modulation of the contralateral delay activity (CDA), a lateralized ERP marker of VSTM maintenance generated when participants selectively encode memory items from one hemifield. In both experiments, retrospective cues during the maintenance period could predict a specific item (spatial retrocue) or multiple items (neutral retrocue) that would be probed at the end of the memory delay. Our results revealed that VSTM performance is significantly improved by orienting attention to the location of a task-relevant item. The behavioral benefit was accompanied by modulation of neural activity involved in VSTM maintenance. Spatial retrocues reduced the magnitude of the CDA, consistent with a reduction in memory load. Our results provide direct evidence that top–down control modulates neural activity associated with maintenance in VSTM, biasing competition in favor of the task-relevant information.

The contralateral transfer of strength following unilateral strength training (ULS) is thought to be due to changes within the nervous system. Using transcranial magnetic stimulation (TMS) we compared corticospinal responses following ULS of the right biceps brachii (BB) projecting to the untrained left BB. Motor evoked potentials (MEPs) were recorded from both BB of 23 individuals pre and post 4 weeks heavy load (80% of 1RM) ULS of right BB. TMS was delivered at intensities below active motor threshold (AMT) to saturation of the MEP (MEPmax). ULS resulted in a 28% increase in 1RM right BB strength, resulting in a 19.2% increase in contralateral strength of the left BB (p = .0001). There was a significant increase in MEP amplitude of 30.3% (p = .03), 33% (p = .05), and 26.5% (p = .01) at AMT, 20% above AMT and MEPmax respectively. No significant differences in silent period were seen at AMT, 20% above AMT or MEPmax. This study has demonstrated increased corticospinal excitability projecting to the untrained arm following heavy load ULS.

Research highlights ► Preparatory attention increases the probability that cued items enter VSTM. ► Markers of anticipatory attention were evident prior to VSTM encoding. ► ERP markers of anticipatory attention predicted attention-related increases in recall probability. ► There was no evidence that preparatory attention modulates the precision of VSTM encoding., Visual short-term memory (VSTM) is limited in capacity. Therefore, it is important to encode only visual information that is most likely to be relevant to behaviour. Here we asked which aspects of selective biasing of VSTM encoding predict subsequent memory-based performance. We measured EEG during a selective VSTM encoding task, in which we varied parametrically the memory load and the precision of recall required to compare a remembered item to a subsequent probe item. On half the trials, a spatial cue indicated that participants only needed to encode items from one hemifield. We observed a typical sequence of markers of anticipatory spatial attention: early attention directing negativity (EDAN), anterior attention directing negativity (ADAN), late directing attention positivity (LDAP); as well as of VSTM maintenance: contralateral delay activity (CDA). We found that individual differences in preparatory brain activity (EDAN/ADAN) predicted cue-related changes in recall accuracy, indexed by memory-probe discrimination sensitivity (d′). Importantly, our parametric manipulation of memory-probe similarity also allowed us to model the behavioural data for each participant, providing estimates for the quality of the memory representation and the probability that an item could be retrieved. We found that selective encoding primarily increased the probability of accurate memory recall; that ERP markers of preparatory attention predicted the cue-related changes in recall probability.

A neurological substrate for subjective well-being (SWB) has received little research attention. This study was designed to conduct exploratory investigation into the neuroanatomical correlates of SWB, by monitoring the SWB of a head-injured population over a six-month period. Seventy people with head injury (HI), aged 10–65, were studied. The SWB of each participant was measured, and computed tomography (CT) scans were analysed to obtain regional brain injury location (BIL). SWB was associated with BIL. However, the hypothesis that individuals with left frontal injury would report lower SWB was not supported. Instead, it was observed that participants with injury to their right frontal lobe reported higher SWB than individuals with injury to other regions of the brain. This study provides initial exploration into the neuroanatomical correlates of SWB.

Autism spectrum disorders (ASDs) are developmental conditions characterized by deficits in social interaction, verbal and nonverbal communication and obsessive/stereotyped patterns of behaviour. Although there is no reliable neurophysiological marker associated with ASDs, dysfunction of the parieto-frontal mirror neuron system has been suggested as a disturbance linked to the disorder. Mirror neurons (MNs) are visuomotor neurons which discharge both when performing and observing a goal directed action. Research suggests MNs may have a role in imitation, empathy, theory of mind and language. Although the research base is small, evidence from functional MRI, transcranial magnetic stimulation, and an electroencephalographic component called the mu rhythm suggests MNs are dysfunctional in subjects with ASD. These deficits are more pronounced when ASD subjects complete tasks with social relevance, or that are emotional in nature. Promising research has identified that interventions targeting MN related functions such as imitation can improve social functioning in ASDs. Boosting the function of MNs may improve the prognosis of ASDs, and contribute to diagnostic clarity.

Previous research has found that Contralateral Delay Activity (CDA) is correlated with the number of items maintained in Visual Short Term Memory from one visual field (VF) (Vogel & Machizawa, 2004). CDA is usually elicited by a to-be-remembered array after a prospective cue (pro-cue) signalling the relevant side of the visual display, and is interpreted as a putative electrophysiological signature of WM maintenance. Attention can also be directed to the contents of VSTM, after the presentation of a visual array, using a retroactive cue (retro-cue) (Nobre, Griffin, & Rao, 2008). Because retro-cueing directs attention within a memory trace, potentially reducing the load of items to be maintained, we hypothesised that this would significantly attenuate the CDA. Participants were initially presented with a spatial pro-cue which reduced the number of to-be-remembered items to one side. After a delay, a memory array of either four (low load) or eight (high load) items was displayed. A retro-cue then cued participants to one location within the relevant VF, further reducing the load of to-be-remembered items; or provided no information, requiring participants to hold all items in the relevant VF. At the end of the trial, participants performed a same/different judgement on a test stimulus. Retro-cues significantly improved VSTM performance. Unexpectedly, the CDA was found to be abolished by the presentation of both spatially predictive and neutral cues, independently of the VSTM load participants had to maintain.

The control mechanisms that guide selective attention are typically examined in response to explicit attentional cues. In everyday life, however, the focus of attention is more typically guided according to past experiences than direct instruction. We therefore developed a novel behavioural paradigm to examine the neural substrate of memory-guided attentional orienting. Participants first learn the location of target stimuli hidden within naturalistic scenes. After the target locations have been learned, participants then perform an attention-orienting task. Each experimental trial begins with a cue stimulus, consisting of the memory scene presented without the target stimulus. A test scene is then presented, with a 50% probability of a target stimulus being present at the remembered location. Participants are instructed to use their memories to guide the focus of attention. In a previous fMRI study (Summerfield et al., 2006, Neuron), trials involving memory-guided attention were shown to engage activity in the same dorsal frontoparietal network that is typically associated with explicitly cued shifts of spatial attention, and in the hippocampus. However, it was not possible to isolate target-related processes from cue-related processes. In the present study, we tested and verified the roles of dorsal frontoparietal cortex and hippocampus activity in the neural control of memory-guided attention, by dissociating mnemonic cue-related activity from target-related activity. These results provide additional insights into the functional neural architecture of memory-guided attention, broadening the neuroscientific foundations for a more generalised account of attentional control during real-world behaviour.

Visual imagery is mediated via top-down activation of visual cortex. Similar to stimulus-driven perception, the neural configurations associated with visual imagery are differentiated according to content. For example, imagining faces or places differentially activates visual areas associated with perception of actual face or place stimuli. However, while top-down activation of topographically specific visual areas during visual imagery is well established, the extent to which internally generated visual activity resembles the fine-scale population coding responsible for stimulus-driven perception remains unknown. Here, we sought to determine whether top-down mechanisms can selectively activate perceptual representations coded across spatially overlapping neural populations. We explored the precision of top-down activation of perceptual representations using neural pattern classification to identify activation patterns associated with imagery of distinct letter stimuli. Pattern analysis of the neural population observed within high-level visual cortex, including lateral occipital complex, revealed that imagery activates the same neural representations that are activated by corresponding visual stimulation. We conclude that visual imagery is mediated via top-down activation of functionally distinct, yet spatially overlapping population codes for high-level visual representations.

The mechanisms of attention prioritize sensory input for efficient perceptual processing. Influential theories suggest that attentional biases are mediated via preparatory activation of task-relevant perceptual representations in visual cortex, but the neural evidence for a preparatory coding model of attention remains incomplete. In this experiment, we tested core assumptions underlying a preparatory coding model for attentional bias. Exploiting multivoxel pattern analysis of functional neuroimaging data obtained during a non-spatial attention task, we examined the locus, time-course, and functional significance of shape-specific preparatory attention in the human brain. Following an attentional cue, yet before the onset of a visual target, we observed selective activation of target-specific neural subpopulations within shape-processing visual cortex (lateral occipital complex). Target-specific modulation of baseline activity was sustained throughout the duration of the attention trial and the degree of target specificity that characterized preparatory activation patterns correlated with perceptual performance. We conclude that top-down attention selectively activates target-specific neural codes, providing a competitive bias favoring task-relevant representations over competing representations distributed within the same subregion of visual cortex.

This paper describes changes in the wellbeing of Australians as measured through the Australian Unity Wellbeing Index. This project has been in progress for six years, from 2001 to 2007. Each of 17 surveys has collected geographically representative data from 2,000 new respondents on both the Personal Wellbeing Index and the National Wellbeing Index. In addition, over the last nine surveys, people have been asked about their perceived likelihood of a terrorist attack in Australia. The variations in wellbeing over the 17 surveys are interpreted in term of data norms, Homeostatic Theory and possible causal agents. It will be shown that some of the wellbeing measures show no systematic variation over time, while others change quite markedly. However, with a few exceptions, it is usually not clear what might be causing such variation. It is concluded that the results generally conform to the predictions of homeostasis but much work remains to be done in order to understand the kinds of factors that influence such changes in population wellbeing.

Gender differences in perceptions of sexual intent and commitment have been the subject of formal and informal inquiry for considerable time. One evolutionary theory, Error Management Theory (EMT), predicts that opposite-sex perceptions of female sexual intent and male commitment intent reflect intrinsic biases that minimize gender-specific evolutionary costs. The results supporting these hypotheses were obtained from subjects regardless of mood. We hypothesized that mood would influence ratings of sexual and commitment intent. Sixty participants (30 males, 30 females) were recruited and exposed to a positive and negative mood condition in counterbalanced groups using video stimuli. Preliminary analyses found an unexpected effect of order of mood induction, necessitating separate analyses of the Positive-Negative (PN) and Negative-Positive (NP) groups. Contrary to the original study, there were no gender effects. Positive moods led to increased ratings of both sexual and commitment intent across genders. Further, negative to positive mood-change was associated with significantly increased ratings. Both males and females attributed significantly higher sexual intent to same-sex rivals than themselves, but only males assessed themselves as having significantly higher commitment intent than same-sex rivals. The EMT model may require adaptation to acknowledge effects of variables such as mood on its predictions of gender-specific biases.

This exploratory study contrasted and tested the predictive value of the reverse buffering hypothesis of social support and the information processing model of posttraumatic stress disorder (PTSD) in an investigation of trauma-related symptomatology (TRS) in a single sample of 42 student paramedics. Participants completed several anonymous self-report measures of PTSD symptomatology, peer social support, and attitude toward emotional expression. Regression-based path analyses did not support either theory of PTSD in this population. A path model of PTSD in student paramedics was subsequently developed, indicating that a direct relationship exists between duty-related trauma exposure, dysfunctional peer social support, and students' negative attitudes toward emotional expression. This new model accounted for 30% of the variance in student paramedics' TRS.

Transcranial magnetic stimulation (TMS) is a unique method in neuroscience used to stimulate focal regions of the human brain. As TMS gains popularity in experimental and clinical domains, techniques for controlling the extent of brain stimulation are becoming increasingly important. At present, TMS intensity is typically calibrated to the excitability of the human motor cortex, a measure referred to as motor threshold (MT). Although TMS is commonly applied to nonmotor regions, most applications do not consider the effect of changes in distance between the stimulating device and underlying neural tissue. Here we show that for every millimeter from the stimulating coil, an additional 3% of TMS output is required to induce an equivalent level of brain stimulation at the motor cortex. This abrupt spatial gradient will have crucial consequences when TMS is applied to nonmotor regions because of substantial variance in scalp-cortex distances over different regions of the head. Stimulation protocols that do not account for cortical distance therefore risk substantial under- or overstimulation. We describe a simple method for adjusting MT to account for variations in cortical distance, thus providing a more accurate calibration than unadjusted MT for the safe and effective application of TMS in clinical and experimental neuroscience.

Workplace injuries are common and destructive to persons, organisations, and society. Various instruments presently exist that are designed to assess the factors underlying workplace injury. The study reports on the construct and predictive validity of a 46-item instrument, the safety perception survey (SPS), currently used to assess safety climate in industrial organisations throughout Australia. Initially, factor analysis was conducted on the data from a sample of 1238 employees from nine organisations, which indicated a one-factor solution, was the best fit. A structural equation model (SEM) linking injury rates to the safety climate measure for 16 sub-groups of six industrial organisations indicated that the measure contributed just 23% of the variance in injury rates. Interestingly, the results indicated that the number of employees was a better and more significant predictor of injury (R(2)=0.48). It is proposed that the SPS as is would need to be modified significantly from its current form to produce improvements in validity, as in its current form the survey is no more predictive of injury than organisational size. Future research into safety climate measures should incorporate predictive validity analysis on injury rates, as for many organisations; this is a performance outcome measure.

Selective attention is critical for guiding human behavior. Recent theories have described the process of attention as a biased competition between sensory inputs, but questions remain concerning the anatomical basis of these competitive mechanisms. Using transcranial magnetic stimulation, we found that disruption of the right parietal cortex improved the perception of relevant stimuli in competitive visual displays. This enhancement of selective attention is consistent with previous observations and suggests a crucial role of the superior parietal lobule and supramarginal gyrus in mediating competition between visual inputs.

We examine the nature and predictors of social and romantic functioning in adolescents and adults with ASD. Parental reports were obtained for 25 ASD adolescents and adults (13–36 years), and 38 typical adolescents and adults (13–30 years). The ASD group relied less upon peers and friends for social (OR = 52.16, p

Among the many valuable uses of injury surveillance is the potential to alert health authorities and societies in general to emerging injury trends, facilitating earlier development of prevention measures. Other than road safety, to date, few attempts to forecast injury data have been made, although forecasts have been made of other public health issues. This may in part be due to the complex pattern of variance displayed by injury data. The profile of many injury types displays seasonality and diurnal variance, as well as stochastic variance. The authors undertook development of a simple model to forecast injury into the near term. In recognition of the large numbers of possible predictions, the variable nature of injury profiles and the diversity of dependent variables, it became apparent that manual forecasting was impractical. Therefore, it was decided to evaluate a commercially available forecasting software package for prediction accuracy against actual data for a set of predictions. Injury data for a 4-year period (1996 to 1999) were extracted from the Victorian Emergency Minimum Dataset and were used to develop forecasts for the year 2000, for which data was also held. The forecasts for 2000 were compared to the actual data for 2000 by independent t-tests, and the standard errors of the predictions were modelled by stepwise hierarchical multiple regression using the independent variables of the standard deviation, seasonality, mean monthly frequency and slope of the base data (R = 0.93, R(2) = 0.86, F(3, 27) = 55.2, p < 0.0001). Significant contributions to the model included the SD (beta = 1.60, p < 0.001), mean monthly frequency (beta = -0.72, p < 0.002), and the seasonality of the data (beta = 0.16, p < 0.02). It was concluded that injury data could be reliably forecast and that commercial software was adequate for the task. Variance in the data was found to be the most important determinant of prediction accuracy. Importantly, automated forecasting may provide a vehicle for identifying emerging trends.

Mechanisms of selective attention are vital for guiding human behavior. The parietal cortex has long been recognized as a neural substrate of spatial attention, but the unique role of distinct parietal subregions has remained unclear. Using single-pulse transcranial magnetic stimulation, we found that the angular gyrus of the right parietal cortex mediates spatial orienting during two distinct time periods after the onset of a behaviorally relevant event. The biphasic involvement of the angular gyrus suggests that both fast and slow visual pathways are necessary for orienting spatial attention.

(2003). Feasibility of routine collection of injured worker occupational information in hospital emergency departments. Injury Control and Safety Promotion: Vol. 10, No. 4, pp. 261-262.

The use of inflatable jumping castles has directly led to the death and injury of children. In 2007 a child was killed in Budapest, with five others seriously injured when the toy inflatable jumping castle was blown more than 27 m in the air. In response to the death of a young girl in South Australia in 2001, a new standard was introduced in Australia in 2005, governing the manufacture of commercial inflatable jumping castles. However, this did not regulate all jumping castles classified as toys, nor regulate who classified jumping castles as toys. This facilitated some manufacturers to evade the standard, and sell unsafe devices to consumers. Collective data suggests as many as 2200 children across Australia were injured in the period 1996–2006. These injuries led to strong concern that domestic toy jumping castles may be more dangerous and be associated with increased injury risk to children. To address this Kidsafe Victoria developed and conducted an intensive awareness campaign during the period of July to October 2007. This involved direct lobbying of all relevant regulatory agencies and national media promotion to raise community awareness. Substantial media attention triggered action from the various National and regional consumer regulatory bodies (ACCC, CAV and Standards Australia), who all commenced internal investigations and intervened with public warning notices and advised that a dedicated standard would be written. This presentation will discuss the issue and the methodology behind the campaign and future implications for advocacy in child safety.

Editor,— Recent injury data collected by the Victorian Injury Surveillance and Applied Research System (VISS), suggests the current resurgence in scooter use by children is associated with increases in the numbers of children injured, some extremely seriously. Scooter injuries to children have increased from an average of 9.5 annually (1996 to 1999) to 153 cases predicted for 2000 if there is no further increase in scooter exposure. This figure is based upon 128 cases of injury for January to September 2000. However, considering the observed monthly rate of growth in scooter exposure, we project as many as 320 scooter related injuries in Victoria alone for 2000 (R2=0.97, y =0.20 x 3−0.27 x 2−2.48 x +47.67). Nationally, between 750 and 1500 Australian children may suffer injury as a result of riding a scooter by the end of 2000. Data for the first …