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Hand-held ultrasound devices are emerging as a promising intervention to aid in diagnosing deadly early childhood pneumonia in the developing world. Lung ultrasound (LUS) data, however, can be difficult to read and interpret accurately, and thus require trained professionals. A variety of deep learning (DL) models have been developed to aid professionals in this task, but the difficulty curating quality training datasets limits the generalization capabilities of these models. To combat this data scarcity, we utilized a variety of DL models trained on LUS data collected from adult COVID-19 patients in Italy and were able to apply transfer learning to increase pneumonia related imaging pattern classification in LUS data from children and infants in rural Zambia. In this regard, we found that transfer learning significantly increased frame classification F1 performance as compared to training models from scratch. These findings indicate the promising potential for developing generalizable AI for LUS classification in diverse contexts given limited data. This analysis demonstrates that DL models effectively transfer their capabilities when fine tuned on a new population demographics, allowing the possibility to clinically deploy these models without the need to acquire large amounts of new data.

Aim Magnesium (Mg) deficiency (known as grass tetany) is a serious metabolic disorder that affects grazing ruminants. We tested whether Mg-fertiliser can increase Mg concentration of Italian ryegrasses (Lolium multiflorum L.) including a cultivar (cv. Bb2067; ‘Magnet’), bred to accumulate larger concentrations of Mg. Methods Under controlled environment (CE) conditions, three cultivars (cv. Bb2067, cv. Bb2068, cv. RvP) were grown in low-nutrient compost at six fertiliser rates (0–1500 μM MgCl2.6H2O). Under field conditions, the three cultivars in the CE condition and cv. Alamo were grown at two sites, and four rates of MgSO4 fertiliser application rates (0–200 kg ha−1 MgO). Multiple grass cuts were taken over two-years. Results Grass Mg concentration increased with increasing Mg-fertiliser application rates in all cultivars and conditions. Under field conditions, cv. Bb2067 had 11–73% greater grass Mg concentration and smaller forage tetany index (FTI) than other cultivars across the Mg-fertiliser application rates, sites and cuts. Grass dry matter (DM) yield of cv. Bb2067 was significantly (p p ≥ 0.05). Conclusions Biofortification of grass with Mg through breeding and agronomy can improve the forage Mg concentration for grazing ruminants, even in high-growth spring grass conditions when hypomagnesaemia is most prevalent. Response to agronomic biofortification varied with cultivar, Mg-fertiliser rate, site and weather. The cost:benefit of these approaches and farmer acceptability, and the impact on cattle and sheep grazing on grasses biofortified with Mg requires further investigation.

This narrative review addresses scabies, a highly contagious, pruritic infestation of the skin caused by the mite Sarcoptes scabiei var hominis. Scabies is a common disorder that has a prevalence worldwide estimated to be between 200 and 300 million cases per year. Infestation is of greatest concern in children, the elderly, immunocompromised people and resource-poor endemic populations at risk of chronic complications. A diagnosis of scabies involves a clinical suspicion, a detailed targeted history, clinical examination and contact tracing. Dermoscopy and microscopy, where available, is confirmatory. Due to its infectivity and transmissibility, the management for scabies requires a multimodal approach: topical antiscabetic agents are the first line for most cases of childhood classic scabies and their contacts, which must also be identified and treated to prevent treatment failure and reacquisition. Environmental strategies to control fomite-related reinfestation are also recommended. Oral ivermectin, where available, is reserved for use in high-risk cases in children or in mass drug administration programmes in endemic communities. The prevention of downstream complications of scabies includes surveillance, early identification and prompt treatment for secondary bacterial infections, often superficial but can be serious and invasive with associated chronic morbidity and mortality. Post-scabetic itch and psychosocial stigma are typical sequelae of the scabies mite infestation. The early identification of patients with scabies and treatment of their contacts reduces community transmission. Although time consuming and labour intensive for caregivers, the implementation of appropriate treatment strategies usually results in prompt cure for the child and their contacts. Here, we provide a summary of treatments and recommendations for the management of paediatric scabies.

Drugs used for sedation/analgesia during gastrointestinal (GI) endoscopy, including midazolam, fentanyl, and propofol, result in short-term, reversible decline in cognitive function. This prospective cohort trial aimed to identify the sedative/analgesic regimen associated with the least impairment of cognition at the time of discharge.Patients undergoing elective GI endoscopy were included. Patients investigated at the Prince of Wales Hospital, Sydney, received midazolam/fentanyl (M/F), whereas patients investigated at the Prince of Wales Private Hospital, Sydney, received midazolam/fentanyl/propofol (M/F/P) or midazolam/propofol (M/P). Patients underwent a computerized neurocognitive test, the CogState Brief Battery, before sedation and at discharge.Patients in the M/F group who received gastroscopy (n=22) were administered midazolam 3.36 mg (±0.79 mg) and fentanyl 61.36 μg (±16.77 μg), those who received colonoscopy (n=50) were administered midazolam 3.98 mg (±1.06 mg) and fentanyl 74.50 μg (±24.48 μg), and those who received gastroscopy/colonoscopy (n=28) were administered midazolam 4.82 mg (±1.41 mg) and fentanyl 94.64 μg (±24.35 μg). Patients in the M/F/P group who received colonoscopy (n=45) were administered midazolam 2.77 mg (±0.55 mg), fentanyl 45.11 μg (±25.78 μg), and propofol 148.64 mg (±57.65 mg), and those who received gastroscopy/colonoscopy (n=36) were administered midazolam 2.64 mg (±0.472 mg), fentanyl 35.28 μg (±19.16 μg), and propofol 168.06 mg (±60.75 mg). Nineteen patients in the M/P group who received gastroscopy (n=19) were administered midazolam 2.37 mg (±0.04 mg) and propofol 13.68 mg (±37.74 mg). Neurocognitive scores were significantly lower in the postprocedure test compared with baseline scores for detection, identification, and one card learning (P0.001). Postprocedure detection test scores were significantly impaired in the M/F group compared with the M/F/P and M/P groups. Predictors of poorer neurocognitive function were midazolam dosage3 mg (P0.006) and fentanyl dosage50 μg (P0.009).The use of propofol in GI endoscopy allows for less exposure to midazolam and fentanyl and is associated with improved cognition at the time of discharge.

In goal neglect, a person ignores some task requirement though being able to describe it. Goal neglect is closely related to general intelligence or C. Spearman's (1904) g (J. Duncan, H. Emslie, P. Williams, R. Johnson, and C. Freer, 1996). The authors tested the role of task complexity in neglect and the hypothesis that different task components in some sense compete for attention. In contrast to many kinds of attentional limits, increasing the real-time demands of one task component does not promote neglect of another. Neither does neglect depend on preparation for different possible events in a block of trials. Instead, the key factor is complexity in the whole body of knowledge specified in task instructions. The authors suggest that as novel activity is constructed, relevant facts, rules, and requirements must be organized into a "task model." As this model increases in complexity, different task components compete for representation, and vulnerable components may be lost. Construction of effective task models is closely linked to g.

Many tests of specific 'executive functions' show deficits after frontal lobe lesions. These deficits appear on a background of reduced fluid intelligence, best measured with tests of novel problem solving. For a range of specific executive tests, we ask how far frontal deficits can be explained by a general fluid intelligence loss. For some widely used tests, e.g. Wisconsin Card Sorting, we find that fluid intelligence entirely explains frontal deficits. When patients and controls are matched on fluid intelligence, no further frontal deficit remains. For these tasks too, deficits are unrelated to lesion location within the frontal lobe. A second group of tasks, including tests of both cognitive (e.g. Hotel, Proverbs) and social (Faux Pas) function, shows a different pattern. Deficits are not fully explained by fluid intelligence and the data suggest association with lesions in the right anterior frontal cortex. Understanding of frontal lobe deficits may be clarified by separating reduced fluid intelligence, important in most or all tasks, from other more specific impairments and their associated regions of damage.

Frontoparietal cortex is thought to be essential for flexible behavior, but the mechanism for control remains elusive. Here, we demonstrate a potentially critical property of this cortex: its dynamic configuration for coding of task-critical information. Using multivoxel pattern analysis of human functional imaging data, we demonstrate an adaptive change in the patterns of activation coding task-relevant stimulus distinctions. When task demands made perceptual information more difficult to discriminate, frontoparietal regions showed increased coding of this information. Visual cortices showed the opposite result: a weaker representation of perceptual information in line with the physical change in the stimulus. On a longer timescale, a rebalancing of coding was also seen after practice, with a diminished representation of task rules as they became familiar. The results suggest a flexible neural system, exerting cognitive control in a wide range of tasks by adaptively representing the task features most challenging for successful goal-directed behavior.

A role for rostral prefrontal cortex (BA10) has been proposed in multitasking, in particular, the selection and maintenance of higher order internal goals while other sub-goals are being performed. BA10 has also been implicated in the ability to infer someone else's feelings and thoughts, often referred to as theory of mind. While most of the data to support these views come from functional neuroimaging studies, lesion studies are scant. In the present study, we compared the performance of a group of frontal patients whose lesions involved BA10, a group of frontal patients whose lesions did not affect this area (nonBA10), and a group of healthy controls on tests requiring multitasking and complex theory of mind judgments. Only the group with lesions involving BA10 showed deficits on multitasking and theory of mind tasks when compared with control subjects. NonBA10 patients performed more poorly than controls on an executive function screening tool, particularly on measures of response inhibition and abstract reasoning, suggesting that theory of mind and multitasking deficits following lesions to BA10 cannot be explained by a general worsening of executive function. In addition, we searched for correlations between performance and volume of damage within different subregions of BA10. Significant correlations were found between multitasking performance and volume of damage in right lateral BA10, and between theory of mind and total BA10 lesion volume. These findings stress the potential pivotal role of BA10 in higher order cognitive functions.

In the human brain, a network of frontal and parietal regions is commonly recruited during tasks that demand the deliberate, focused control of thought and action. Previously, using a simple target detection task, we reported striking differences in the selectivity of the BOLD response in anatomically distinct subregions of this network. In particular, it was observed that the right inferior frontal gyrus (IFG) followed a tightly tuned function, selectively responding only to the current target object. Here, we examine this functional specialization further, using adapted versions of our original task. Our results demonstrate that the response of the right IFG to targets is a strong and replicable phenomenon. It occurs under increased attentional load, when targets and distractors are equally frequent, and when controlling for inhibitory processes. These findings support the hypothesis that the right IFG responds selectively to those items that are of the most relevance to the currently intended task schema.

Tests of fluid intelligence predict success in a wide range of cognitive activities. Much uncertainty has surrounded brain lesions producing deficits in these tests, with standard group comparisons delivering no clear result. Based on findings from functional imaging, we propose that the uncertainty of lesion data may arise from the specificity and complexity of the relevant neural circuit. Fluid intelligence tests give a characteristic pattern of activity in posterolateral frontal, dorsomedial frontal, and midparietal cortex. To test the causal role of these regions, we examined fluid intelligence in 80 patients with focal cortical lesions. Damage to each of the proposed regions predicted fluid intelligence loss, whereas damage outside these regions was not predictive. The results suggest that coarse group comparisons (e.g., frontal vs. posterior) cannot show the neural underpinnings of fluid intelligence tests. Instead, deficits reflect the extent of damage to a restricted but complex brain circuit comprising specific regions within both frontal and posterior cortex.

Multivariate pattern analysis is often assumed to rely on signals that directly reflect differences in the distribution of particular neural populations. The source of the signal used in these analyses remains unclear however, and an alternative model suggests that signal from larger draining veins may play a significant role. The current study was designed to investigate the vascular contribution to pattern analyses at 3T by comparing the results obtained from gradient and spin echo data. Classification analyses were carried out comparing line orientations in V1, tone frequencies in A1, and responses from different fingers in M1. In all cases, classification accuracy in the spin echo data was not significantly different from chance. In contrast, classification accuracies in the gradient echo data were significantly above chance, and significantly higher than the accuracies observed for the spin echo data. These results suggest that at the field strength and spatial resolution used for the majority of fMRI studies, a considerable proportion of the signal used by pattern analysis originates in the vasculature.

Evidence from primates suggests that prefrontal and parietal regions selectively represent information that is relevant for current behavior. In humans, whilst functional imaging has shown that fronto-parietal areas are activated by a range of different cognitive demands, the actual content of representation remains unclear. The current report describes two studies designed to address this issue using fMRI adaptation. In both studies, participants completed a delayed matching task where they attended to either the color or the shape of a series of sample stimuli and indicated whether occasional test stimuli matched the preceding sample on the attended dimension. Whole brain contrasts showed that changes to the value of the currently attended dimension produced significantly greater responses in frontal and parietal areas than events where the value was repeated. In addition, prefrontal and parietal regions of interest showed strong interactions between the currently attended dimension and the type of stimulus change, reflecting an attentional modulation of responses to stimulus change. Further comparisons suggested that the differences between attended changes and stimulus repetitions carried information about specific stimulus values, and did not simply reflect a generic response to attended changes.

The Prader-Willi/Angelman Critical Region (PWACR; Chromosome 15q11-13) is of interest as a potential locus for genes conferring susceptibility to autism spectrum disorders (ASD). This report describes a female proband referred for evaluation of a possible ASD. Genetic analyses indicated that the proband, her father and one of her sisters, carried a paternally derived interstitial duplication involving 15q11-13. The proband showed evidence of ASD (PDD-NOS), borderline mental retardation, mild hypotonia and joint laxity. Her father and her sister were of normal intelligence and neither was thought to have an ASD, although speech/language difficulties and some autistic type behaviours were reported to have been present early in the development of the sister. This is one of the first reports of a child with a paternal duplication and an autism spectrum disorder. More research is required to determine whether paternally derived duplications that involve 15q11-13 are associated with developmental impairments.

Objectives: The frequency of abnormalities of 15q11-q13 and other possibly causal medical disorders including karyotypic abnormalities was investigated in an unselected series of children who were referred to one of two autism assessment centres. Methods: Two hundred and twenty-one cases were assessed using the Autism Diagnostic Interview and Observation Schedule and, where appropriate, standardized tests of intelligence and language abilities. Medical histories and notes were reviewed, and molecular and cytogenetic investigations used to detect chromosomal abnormalities. Results: One hundred and eighty-one cases were diagnosed according to International Classification of Diseases - version 10 criteria as having an autism spectrum disorder (autistic-like Pervasive Developmental Disorder) and 40 cases as having other disorders. Twenty-one (11.6%) of the children with autism spectrum disorders had a possibly causal condition compared with six (15%) of the children with other diagnoses. One child with an autism spectrum disorder had a paternally inherited familial duplication of 15q11-13. The pattern of genotype-phenotype correlation within the family indicated that this form of abnormality might carry a risk for developmental difficulties, although the risk did not appear to be specific for autism spectrum disorders. Conclusion: The overall rate of possibly causal medical and cytogenetic conditions in children with autism spectrum disorders was low and no different from the rate of disorder in children with other developmental/neuropsychiatric disorders that attended the same clinics. Further research is required to determine whether paternal duplication of 15q11-13 gives rise to adverse developmental outcomes.

The case of a 15-year-old male with Angelman syndrome, paternal uniparental disomy of chromosome 15, and a small supernumerary marker chromosome is discussed. Assessment of cognitive functioning revealed an uneven profile of ability across different domains; in particular, receptive language ability was found to be superior to expressive language ability, whilst both gross and fine motor skills were found to be relatively well developed. Assessment using the Autism Diagnostic Observation Schedule showed very little evidence of autistic symptomatology. The patient showed an interest in social interaction and used a variety of methods to communicate, including some gestures and several single words. A clinical history revealed febrile convulsions during childhood but an absence of seizures in the previous 5 years. The patient was not hypopigmented, and height, weight, and head circumference were within the normal range for his age. The implications of these features are discussed in the context of previous work describing a milder phenotype in nondeletion cases of Angelman syndrome and work that has examined the prevalence of autism spectrum disorders amongst individuals with Angelman syndrome.

This study investigated the phenotypic manifestations of interstitial duplications of chromosome 15 that involve the Prader-Willi/Angelman syndrome critical region (PWACR). Twenty-one affected individuals from six families were evaluated in detail, using standardized and semi-standardized measures of intelligence, psychopathology, and physical anomalies. Special attention was placed on determining the prevalence of autism spectrum disorders as well as the relationship between the parental origin of the duplication and the phenotypic effects. Assessments of the affected individuals were compared with evaluations of the unaffected relatives from the same families. Results indicated that duplications in the region were associated with variable degrees of intellectual impairments and motor coordination problems. Four of the subjects received a diagnosis of pervasive developmental disorder. Three of these cases were probands and only one met criteria for classic autism. There was very little evidence of the duplication cosegregating with autism spectrum disorder diagnosis. Paternally inherited duplications were significantly less likely to give rise to phenotypic effects. The findings indicate that duplications in the PWACR give rise to developmental delay but not necessarily autism spectrum disorders. They also suggest that phenotypic expression is dependent on the parental origin of the duplication and implicate maternally active genes in the pathogenesis of the developmental impairments. Further research will be required to clarify the range and basis of the phenotypic manifestations.

The olfactory ensheathing cell (OEC) is a unique glial cell able to support neurite outgrowth in the CNS throughout life. The OEC has been described as having both Schwann cell-like and astrocyte-like characteristics. The purpose of this study was to compare gap junctional communication and connexin (Cx) expression in cultured olfactory ensheathing cells with both astrocytes and Schwann cells to establish which of these two cells types they most closely resemble. We examined the Cx mRNA profile of OECs, astrocytes, and Schwann cells using primers to Cx26, Cx32, Cx37, Cx43, Cx46, and Cx50. All connexins tested except Cx50 were expressed by all three cell types when initially cultured. However, we observed differences in the levels of expression of Cx32 and Cx26 between astrocytes, Schwann cells, and OECs that became pronounced with time. All three cell types show limited and variable gap junctional communication in culture as assessed by the transfer of microinjected Lucifer yellow. OECs had limited coupling compared with Schwann cells and astrocytes, although the extent of the dye spread through OECs was more comparable to that seen with Schwann cells than astrocytes. Thus, OECs display a profile of Cx expression that more closely resembles the Cx expression of Schwann cells rather than astrocytes. J. Neurosci. Res. 65:520–528, 2001. © 2001 Wiley-Liss, Inc.

Recently we demonstrated that a member of the neuregulin-1 (NRG-1) family of growth factors is a mitogen and survival factor for olfactory ensheathing cells (OECs). OECs are specialized glial cells within the olfactory system that are believed to play a role in the continual nerve re-growth of this tissue. OECs share properties with both astrocytes and Schwann cells but are likely to be a distinct glial cell type. NRG-1s have been found to be important regulators of Schwann cells in vivo, but the role of NRG-1 for OECs is less clear. The nrg-1 gene produces at least 12 different isoforms, that are likely to have different functions, due to alternative splicing of its mRNA. In this study, the expression of NRG-1 mRNAs in OECs was compared with other glial cells and their corresponding tissue sources. Cultured glial cells, unlike their tissue sources, expressed NRG-1 mRNAs containing the α EGF-like domain and expressed only the type 1β isoform that lacks the glycosylated spacer domain. This correlated with expression of these isoforms during olfactory nerve degeneration in vivo. Although OECs expressed mRNA for all NRG-1 isoforms, the protein could not be detected in concentrated supernatant, or on the cell surface by immunofluorescence, but was detected in the nucleus or cytoplasm (depending on the isoform). These data support the hypothesis that NRG-1s play a functional role in OEC biology. J. Neurosci. Res. 61:172–185, 2000. © 2000 Wiley-Liss, Inc.

Objective To determine the prevalence of allergy to natural rubber latex and potential crossreacting foods in operating room nurses. Method Two hundred forty-seven operating room nurses completed a latex allergy questionnaire. They were questioned about symptoms of latex reactivity and about other allergies particularly to foods that may crossreact with latex. Informed consent was obtained and skin prick testing was performed with natural rubber latex and five latex extracts representing low (0.08 to 0.25 micrograms/mL) and high (18 to 106 micrograms/mL) natural rubber latex protein gloves. Skin prick tests were done with four potentially crossreacting foods (banana, avocado, kiwi, and potato), saline, and histamine controls. Results One hundred thirty-five (54.7%) nurses described allergic symptoms they attributed to latex exposure. Of these 12 (4.9%) tested positive to latex extracts alone, 12 (4.9%) tested positive to food extracts alone, and 5 (2.0%) tested positive to both latex and crossreactive foods. Three of the 17 (17.6%) nurses testing positive to latex gave no history of reactivity to latex. Indirect ELISA was done on the serum of skin test-positive patients with a 70.6% sensitivity. Conclusion Of the nurses tested, 6.9% had positive skin prick tests to latex extracts; 17.6% of these were asymptomatic and 29.4% had associated food positive skin prick tests.

Recently (Roca et al. (2010), we used the relationship with general intelligence (Spearman’s g) to define two sets of frontal lobe or “executive” tests. For one group, including Wisconsin card sorting and verbal fluency, reduction in g entirely explained the deficits found in frontal patients. For another group, including tests of social cognition and multitasking, frontal deficits remained even after correction for g. Preliminary evidence suggested a link of the latter tasks to more anterior frontal regions. Here we develop this distinction in the context of behavioural-variant frontotemporal dementia (bvFTD), a disorder which progressively affects frontal lobe cortices. In bvFTD, some executive tests, including tests of social cognition and multitasking, decline from the early stage of the disease, while others, including classical executive tests such as Wisconsin card sorting, verbal fluency or Trail Making Test part B, show deficits only later on. Here we show that, while deficits in the classical executive tests are entirely explained by g, deficits in the social cognition and multitasking tests are not. The results suggest a relatively selective cognitive deficit at mild stages of the disease, followed by more widespread cognitive decline well predicted by g., Highlights ► A progressive loss of general intelligence (g) can be found in patients with FTD. ► Advanced FTD classical executive deficits can be entirely explained by loss of g. ► Early social cognition and multitasking deficits exceed the ones predicted from g. ► Assessment in FTD should encompass g, multitasking and social cognition.

Many varieties of working memory have been linked to fluid intelligence. In Duncan et al. (Journal of Experimental Psychology:General 137:131-148, 2008), we described limited working memory for new task rules: When rules are complex, some may fail in their control of behavior, though they are often still available for explicit recall. Unlike other kinds of working memory, load is determined in this case not by real-time performance demands, but by the total complexity of the task instructions. Here, we show that the correlation with fluid intelligence is stronger for this aspect of working memory than for several other, more traditional varieties-including simple and complex spans and a test of visual short-term memory. Any task, we propose, requires construction of a mental control program that aids in segregating and assembling multiple task parts and their controlling rules. Fluid intelligence is linked closely to the efficiency of constructing such programs, especially when behavior is complex and novel.

Classic social psychology studies demonstrate that people can behave in ways that contradict their intentions--especially within the moral domain. We measured brain activity while subjects decided between financial self-benefit (earning money) and preventing physical harm (applying an electric shock) to a confederate under both real and hypothetical conditions. We found a shared neural network associated with empathic concern for both types of decisions. However, hypothetical and real moral decisions also recruited distinct neural circuitry: hypothetical moral decisions mapped closely onto the imagination network, while real moral decisions elicited activity in the bilateral amygdala and anterior cingulate--areas essential for social and affective processes. Moreover, during real moral decision-making, distinct regions of the prefrontal cortex (PFC) determined whether subjects make selfish or pro-social moral choices. Together, these results reveal not only differential neural mechanisms for real and hypothetical moral decisions but also that the nature of real moral decisions can be predicted by dissociable networks within the PFC.

In this study, we explored the neural correlates of perceptual awareness during a masked face detection task. To assess awareness more precisely than in previous studies, participants employed a 4-point scale to rate subjective visibility. An event-related fMRI and a high-density ERP study were carried out. Imaging data showed that conscious face detection was linked to activation of fusiform and occipital face areas. Frontal and parietal regions, including the pre-SMA, inferior frontal sulcus, anterior insula/frontal operculum, and intraparietal sulcus, also responded strongly when faces were consciously perceived. In contrast, no brain area showed face-selective activity when participants reported no impression of a face. ERP results showed that conscious face detection was associated with enhanced N170 and also with the presence of a second negativity around 300 msec and a slow positivity around 415 msec. Again, face-related activity was absent when faces were not consciously perceived. We suggest that, under conditions of backward masking, ventral stream and fronto-parietal regions show similar, strong links of face-related activity to conscious perception and stress the importance of a detailed assessment of awareness to examine activity related to unseen stimulus events.

Humans and other primates are adept at using the direction of another's gaze or head turn to infer where that individual is attending. Research in macaque neurophysiology suggests that anterior superior temporal sulcus (STS) contains a direction-sensitive code for such social attention cues. By contrast, most human functional Magnetic resonance imaging (fMRI) studies report that posterior STS is responsive to social attention cues. It is unclear whether this functional discrepancy is caused by a species difference or by experimental design differences. Furthermore, social attention cues are dynamic in naturalistic social interaction, but most studies to date have been restricted to static displays. In order to address these issues, we used multivariate pattern analysis of fMRI data to test whether response patterns in human right STS distinguish between leftward and rightward dynamic head turns. Such head turn discrimination was observed in right anterior STS/superior temporal gyrus (STG). Response patterns in this region were also significantly more discriminable for head turn direction than for rotation direction in physically matched ellipsoid control stimuli. Our findings suggest a role for right anterior STS/STG in coding the direction of motion in dynamic social attention cues.

article i nfo Article history: In human functional magnetic resonance imaging (fMRI), a characteristic pattern of frontal and parietal activity is produced by many different cognitive demands. Although frontoparietal cortex has been shown to represent a variety of task features in different contexts, little is known about detailed representation of different task features within and across different regions. We used multi-voxel pattern analysis (MVPA) of human fMRI data to assess the representational content of frontoparietal cortex in a simple stimulus- response task. Stimulus-response mapping rule was the most strongly represented task feature, significantly coded in a lateral frontal region surrounding the inferior frontal sulcus, a more ventral region including the anterior insula/frontal operculum, and the intraparietal sulcus. Next strongest was coding of the instruction cue (screen color) indicating which rule should be applied. Coding of individual stimuli and responses was weaker, approaching significance in a subset of regions. In line with recent single unit data, the results show a broad representation of task-relevant information across human frontoparietal cortex, with strong representation of a general rule or cognitive context, and weaker coding of individual stimulus/response instances.

Severe capacity limits, closely associated with fluid intelligence, arise in learning and use of new task rules. We used fMRI to investigate these limits in a series of multirule tasks involving different stimuli, rules, and response keys. Data were analyzed both during presentation of instructions and during later task execution. Between tasks, we manipulated the number of rules specified in task instructions, and within tasks, we manipulated the number of rules operative in each trial block. Replicating previous results, rule failures were strongly predicted by fluid intelligence and increased with the number of operative rules. In fMRI data, analyses of the instruction period showed that the bilateral inferior frontal sulcus, intraparietal sulcus, and presupplementary motor area were phasically active with presentation of each new rule. In a broader range of frontal and parietal regions, baseline activity gradually increased as successive rules were instructed. During task performance, we observed contrasting fronto-parietal patterns of sustained (block-related) and transient (trial-related) activity. Block, but not trial, activity showed effects of task complexity. We suggest that, as a new task is learned, a fronto-parietal representation of relevant rules and facts is assembled for future control of behavior. Capacity limits in learning and executing new rules, and their association with fluid intelligence, may be mediated by this load-sensitive fronto-parietal network.

To cite this article: Bakolis I, Hooper R, Thompson RL, Shaheen SO. Dietary patterns and adult asthma: population-based case–control study. Allergy 2010; 65: 606–615. Abstract Background: Epidemiological studies of diet and asthma have focused on relations with intakes of individual nutrients and foods and evidence has been conflicting. Few studies have examined associations with dietary patterns. Methods: We carried out a population-based case–control study of asthma in adults aged between 16 and 50 in South London, UK. Information about usual diet was obtained by food frequency questionnaire and we used principal components analysis to define five dietary patterns in controls. We used logistic and linear regression, controlling for confounders, to relate these patterns to asthma, asthma severity, rhinitis and chronic bronchitis in 599 cases and 854 controls. Results: Overall, there was weak evidence that a ‘vegetarian’ dietary pattern was positively associated with asthma [adjusted odds ratio comparing top vs bottom quintile of pattern score 1.43 (95% CI: 0.93–2.20), P trend 0.075], and a ‘traditional’ pattern (meat and vegetables) was negatively associated [OR 0.68 (0.45–1.03), P trend 0.071]. These associations were stronger amongst nonsupplement users (P trend 0.030 and 0.001, respectively), and the association with the ‘vegetarian’ pattern was stronger amongst whites (P trend 0.008). No associations were observed with asthma severity. A ‘prudent’ dietary pattern (wholemeal bread, fish and vegetables) was positively associated with chronic bronchitis [OR 2.61 (1.13–6.05), P trend 0.025], especially amongst nonsupplement users (P trend 0.002). Conclusions: Overall there were no clear relations between dietary patterns and adult asthma; associations in nonsupplement users and whites require confirmation. The finding for chronic bronchitis was unexpected and also requires replication.

In a variety of attention and search tasks, single-cell recordings of the primate brain have frequently shown an enhancement of responses in early visual areas to selected target stimuli. This enhancement is observed only at longer latencies, suggesting the possibility that it reflects the action of feedback or return signals from upstream processing areas. However, in typical studies, targets are specified on the basis of elementary visual features; as these are coded at multiple levels of the visual system, it is impossible to determine where enhanced target processing begins. Using human functional magnetic resonance imaging (fMRI), we demonstrate enhancement of activity in early visual areas even when low-level visual information is insufficient for target detection to occur. We found enhanced activity in early visual areas to targets defined purely by semantic category, suggesting that feedback signals returning from at least as far forward as temporal lobe semantic processing can influence visual responses. These findings also suggest feedback signaling as a mechanism by which early and late brain systems coding for different properties of a target object can integrate their activity, allowing for the target object to dominate overall processing.

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.