PIGA mutations and glycosylphosphatidylinositol anchor dysregulation in polyposis-associated duodenal tumorigenesis

The pathogenesis of duodenal tumours in the inherited tumour syndromes Familial Adenomatous Polyposis (FAP) and MUTYH-associated Polyposis (MAP) is poorly understood. This study aimed to identify genes that are significantly mutated in these tumours and to explore the effects of these mutations. Whole exome and whole transcriptome sequencing identified recurrent somatic coding variants of PIGA in 19/70 (27%) FAP and MAP duodenal adenomas, and further confirmed the established driver roles for APC and KRAS. PIGA catalyses the first step in glycosylphosphatidylinositol (GPI) anchor biosynthesis. Flow cytometry of PIGA-mutant adenoma-derived and CRISPR-edited duodenal organoids confirmed loss of GPI anchors in duodenal epithelial cells and transcriptional profiling of duodenal adenomas revealed transcriptional signatures associated with loss of PIGA. Implications: PIGA somatic mutation in duodenal tumours from patients with FAP and MAP and loss of membrane GPI-anchors may present new opportunities for understanding and intervention in duodenal tumorigenesis.

Action does not drive visual biases in peri-tool space

Observers experience visual biases in the area around handheld tools. These biases may occur when active use leads an observer to incorporate a tool into the body schema. However, the visual salience of a handheld tool may instead create an attentional prioritization that is not reliant on body-based representations. We investigated these competing explanations of near-tool visual biases in two experiments during which participants performed a target detection task. Targets could appear near or far from a tool positioned next to a display. In Experiment 1, participants showed facilitation in detecting targets that appeared near a simple handheld rake tool regardless of whether they first used the rake to retrieve objects, but participants who only viewed the tool without holding it were no faster to detect targets appearing near the rake than targets that appeared on the opposite side of the display. In a second experiment, participants who held a novel magnetic tool again showed a near-tool bias even when they refrained from using the tool. Taken together, these results suggest active use is unnecessary, but visual salience is not sufficient, to introduce visual biases in peri-tool space.

Dominantly inherited micro-satellite instable cancer - the four Lynch syndromes - an EHTG, PLSD position statement

The recognition of dominantly inherited micro-satellite instable (MSI) cancers caused by pathogenic variants in one of the four mismatch repair (MMR) genes MSH2, MLH1, MSH6 and PMS2 has modified our understanding of carcinogenesis. Inherited loss of function variants in each of these MMR genes cause four dominantly inherited cancer syndromes with different penetrance and expressivities: the four Lynch syndromes. No person has an "average sex "or a pathogenic variant in an "average Lynch syndrome gene" and results that are not stratified by gene and sex will be valid for no one. Carcinogenesis may be a linear process from increased cellular division to localized cancer to metastasis. In addition, in the Lynch syndromes (LS) we now recognize a dynamic balance between two stochastic processes: MSI producing abnormal cells, and the host's adaptive immune system's ability to remove them. The latter may explain why colonoscopy surveillance does not reduce the incidence of colorectal cancer in LS, while it may improve the prognosis. Most early onset colon, endometrial and ovarian cancers in LS are now cured and most cancer related deaths are after subsequent cancers in other organs. Aspirin reduces the incidence of colorectal and other cancers in LS. Immunotherapy increases the host immune system's capability to destroy MSI cancers. Colonoscopy surveillance, aspirin prevention and immunotherapy represent major steps forward in personalized precision medicine to prevent and cure inherited MSI cancer.

Inherited MUTYH mutations cause elevated somatic mutation rates and distinctive mutational signatures in normal human cells

Cellular DNA damage caused by reactive oxygen species is repaired by the base excision repair (BER) pathway which includes the DNA glycosylase MUTYH. Inherited biallelic MUTYH mutations cause predisposition to colorectal adenomas and carcinoma. However, the mechanistic progression from germline MUTYH mutations to MUTYH-Associated Polyposis (MAP) is incompletely understood. Here, we sequence normal tissue DNAs from 10 individuals with MAP. Somatic base substitution mutation rates in intestinal epithelial cells were elevated 2 to 4-fold in all individuals, except for one showing a 31-fold increase, and were also increased in other tissues. The increased mutation burdens were of multiple mutational signatures characterised by C > A changes. Different mutation rates and signatures between individuals are likely due to different MUTYH mutations or additional inherited mutations in other BER pathway genes. The elevated base substitution rate in normal cells likely accounts for the predisposition to neoplasia in MAP. Despite ubiquitously elevated mutation rates, individuals with MAP do not display overt evidence of premature ageing. Thus, accumulation of somatic mutations may not be sufficient to cause the global organismal functional decline of ageing.

Germline MBD4 deficiency causes a multi-tumor predisposition syndrome

We report an autosomal recessive, multi-organ tumor predisposition syndrome, caused by bi-allelic loss-of-function germline variants in the base excision repair (BER) gene MBD4. We identified five individuals with bi-allelic MBD4 variants within four families and these individuals had a personal and/or family history of adenomatous colorectal polyposis, acute myeloid leukemia, and uveal melanoma. MBD4 encodes a glycosylase involved in repair of G:T mismatches resulting from deamination of 5'-methylcytosine. The colorectal adenomas from MBD4-deficient individuals showed a mutator phenotype attributable to mutational signature SBS1, consistent with the function of MBD4. MBD4-deficient polyps harbored somatic mutations in similar driver genes to sporadic colorectal tumors, although AMER1 mutations were more common and KRAS mutations less frequent. Our findings expand the role of BER deficiencies in tumor predisposition. Inclusion of MBD4 in genetic testing for polyposis and multi-tumor phenotypes is warranted to improve disease management.

Aging and Inhibition of Return to Locations and Objects

Inhibition of return (IOR) is thought to reflect a cognitive mechanism that biases attention from returning to previously engaged items. While models of cognitive aging have proposed deficits within select inhibitory domains, older adults have demonstrated preserved IOR functioning in previous studies. The present study investigated whether inhibition associated with objects shows the same age patterns as inhibition associated with locations. Young adults (18-22 years) and older adults (60-86 years) were tested in two experiments measuring location- and object-based IOR. Using a dynamic paradigm (Experiment 1), both age groups produced significant location-based IOR, but only young adults produced significant object-based IOR, consistent with previous findings. However, with a static paradigm (Experiment 2), young adults and older adults produced both location- and object-based IOR, indicating that object-based IOR is preserved in older adults under some conditions. The findings provide partial support for unique age-related inhibitory patterns associated with attention to objects and locations.

G3BPs tether the TSC complex to lysosomes and suppress mTORC1 signaling

Ras GTPase-activating protein-binding proteins 1 and 2 (G3BP1 and G3BP2, respectively) are widely recognized as core components of stress granules (SGs). We report that G3BPs reside at the cytoplasmic surface of lysosomes. They act in a non-redundant manner to anchor the tuberous sclerosis complex (TSC) protein complex to lysosomes and suppress activation of the metabolic master regulator mechanistic target of rapamycin complex 1 (mTORC1) by amino acids and insulin. Like the TSC complex, G3BP1 deficiency elicits phenotypes related to mTORC1 hyperactivity. In the context of tumors, low G3BP1 levels enhance mTORC1-driven breast cancer cell motility and correlate with adverse outcomes in patients. Furthermore, G3bp1 inhibition in zebrafish disturbs neuronal development and function, leading to white matter heterotopia and neuronal hyperactivity. Thus, G3BPs are not only core components of SGs but also a key element of lysosomal TSC-mTORC1 signaling.

Secular changes in severity of intellectual disability in tuberous sclerosis complex: A reflection of improved identification and treatment of epileptic spasms?

Tuberous sclerosis complex (TSC) is a multisystem genetic disorder caused by mutations in TSC1 or TSC2. Epilepsy occurs in 80%-90% of affected individuals during their lifetime, and up to one-third of children with TSC will develop epileptic (infantile) spasms, for which vigabatrin has been shown to be particularly effective. Epilepsy severity and epileptic spasms are consistent markers of risk for the development of intellectual impairment in TSC. Although previous studies demonstrate a bimodal distribution of intellectual ability in TSC, recent findings suggest a unimodal distribution, which may reflect a change in IQ distribution over time. We compared 3 large historical UK cohorts of TSC (n = 331) that show varied distributions of intellectual ability, first ruling out differences in study methodology. Later-born individuals had a higher frequency of reported spasms and higher likelihood of vigabatrin administration, but were less likely to have profound intellectual impairment, compared to the earlier-born individuals. Our findings suggest that epileptic spasms went undetected in the older patients and therefore were not treated, leading to a higher occurrence of profound impairment, whereas the later born cohort had better access to treatment. These findings support the importance of early identification and treatment of seizures in TSC.

Burden and Profile of Somatic Mutation in Duodenal Adenomas from Patients with Familial Adenomatous- and MUTYH-associated Polyposis

Purpose: Duodenal polyposis and cancer are important causes of morbidity and mortality in familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP). This study aimed to comprehensively characterize somatic genetic changes in FAP and MAP duodenal adenomas to better understand duodenal tumorigenesis in these disorders.Experimental Design: Sixty-nine adenomas were biopsied during endoscopy in 16 FAP and 10 MAP patients with duodenal polyposis. Ten FAP and 10 MAP adenomas and matched blood DNA samples were exome sequenced, 42 further adenomas underwent targeted sequencing, and 47 were studied by array comparative genomic hybridization. Findings in FAP and MAP duodenal adenomas were compared with each other and to the reported mutational landscape in FAP and MAP colorectal adenomas.Results: MAP duodenal adenomas had significantly more protein-changing somatic mutations (P = 0.018), truncating mutations (P = 0.006), and copy number variants (P = 0.005) than FAP duodenal adenomas, even though MAP patients had lower Spigelman stage duodenal polyposis. Fifteen genes were significantly recurrently mutated. Targeted sequencing of APC, KRAS, PTCHD2, and PLCL1 identified further mutations in each of these genes in additional duodenal adenomas. In contrast to MAP and FAP colorectal adenomas, neither exome nor targeted sequencing identified WTX mutations (P = 0.0017).Conclusions: The mutational landscapes in FAP and MAP duodenal adenomas overlapped with, but had significant differences to those reported in colorectal adenomas. The significantly higher burden of somatic mutations in MAP than FAP duodenal adenomas despite lower Spigelman stage disease could increase cancer risk in the context of apparently less severe benign disease. Clin Cancer Res; 23(21); 6721-32. ©2017 AACR.

Action Experience Drives Visual-Processing Biases Near the Hands

Observers experience affordance-specific biases in visual processing for objects within the hands' grasping space, but the mechanism that tunes visual cognition to facilitate action remains unknown. I investigated the hypothesis that altered vision near the hands is a result of experience-driven plasticity. Participants performed motion-detection and form-perception tasks-while their hands were either near the display, in atypical grasping postures, or positioned in their laps-both before and after learning novel grasp affordances. Participants showed enhanced temporal sensitivity for stimuli viewed near the backs of the hands after training to execute a power grasp using the backs of their hands (Experiment 1), but showed enhanced spatial sensitivity for stimuli viewed near the tips of their little fingers after training to use their little fingers to execute a precision grasp (Experiment 2). These results show that visual biases near the hands are plastic, facilitating processing of information relevant to learned grasp affordances.

Inherited predisposition to colorectal cancer: towards a more complete picture

Colorectal carcinoma (CRC) is the third most common cancer worldwide. Hereditary factors are important in 15%-35% of affected patients. This review provides an update on the genetic basis of inherited predisposition to CRC. Currently known genetic factors include a group of highly penetrant mutant genes associated with rare mendelian cancer syndromes and a group of common low-penetrance alleles that have been identified through genetic association studies. Additional mechanisms, which may underlie a predisposition to CRC, will be outlined, for example, variants in intermediate penetrance alleles. Recent findings, including mutations in POLE, POLD1 and NTHL1, will be highlighted, and we identify gaps in present knowledge and consider how these may be addressed through current and emerging genomic approaches. It is expected that identification of the missing heritable component of CRC will be resolved through evermore comprehensive cataloguing and phenotypic annotation of CRC-associated variants identified through sequencing approaches. This will have important clinical implications, particularly in areas such as risk stratification, public health and CRC prevention.

Competition makes observers remember faces as more aggressive

People use facial appearance to predict social behavior, but can social context also influence face perception? Leveraging a link between competition and aggression, we investigated the effects of competitive interactions with confederates on participants' performance in a face reconstruction task. Participants played a game either in competition or cooperation with confederates and were then asked to create facial portraits of these confederates by arranging their component features into their best estimate of an accurate configuration. Across 2 experiments, participants who played in a competitive context reconstructed faces in a more aggressive configuration-with higher width-to-height ratios-than did participants who played cooperatively or alone. This result demonstrates that the social perception of faces is not merely a feed-forward process, but instead that the social contexts in which people interact can shape memory for faces.

Grasp posture alters visual processing biases near the hands

Observers experience biases in visual processing for objects within easy reach of their hands; these biases may assist them in evaluating items that are candidates for action. I investigated the hypothesis that hand postures that afford different types of actions differentially bias vision. Across three experiments, participants performed global-motion-detection and global-form-perception tasks while their hands were positioned (a) near the display in a posture affording a power grasp, (b) near the display in a posture affording a precision grasp, or (c) in their laps. Although the power-grasp posture facilitated performance on the motion-detection task, the precision-grasp posture instead facilitated performance on the form-perception task. These results suggest that the visual system weights processing on the basis of an observer's current affordances for specific actions: Fast and forceful power grasps enhance temporal sensitivity, whereas detail-oriented precision grasps enhance spatial sensitivity.

What you see is what you get: webcam placement influences perception and social coordination

Building on a well-established link between elevation and social power, we demonstrate that—when perceptual information is limited—subtle visual cues can shape people’s representations of others and, in turn, alter strategic social behavior. A cue to elevation (unrelated to physical size) provided by the placement of web cameras in a video chat biased individuals’ perceptions of a partner’s height (Experiment 1) and shaped the extent to which they made decisions in their own self-interest: participants tended to coordinate their behavior in a manner that benefitted the preferences of a partner pictured from a low camera angle during a game of asymmetric coordination (Experiment 2). Our results suggest that people are vulnerable to the influence of a limited viewpoint when forming representations of others in a manner that shapes their strategic choices.

Evaluation of copy number variation and gene expression in neurofibromatosis type-1-associated malignant peripheral nerve sheath tumours

BACKGROUND

Neurofibromatosis type-1 (NF1) is a complex neurogenetic disorder characterised by the development of benign and malignant tumours of the peripheral nerve sheath (MPNSTs). Whilst biallelic NF1 gene inactivation contributes to benign tumour formation, additional cellular changes in gene structure and/or expression are required to induce malignant transformation. Although few molecular profiling studies have been performed on the process of progression of pre-existing plexiform neurofibromas to MPNSTs, the integrated analysis of copy number alterations (CNAs) and gene expression is likely to be key to understanding the molecular mechanisms underlying NF1-MPNST tumorigenesis. In a pilot study, we employed this approach to identify genes differentially expressed between benign and malignant NF1 tumours.

RESULTS

SPP1 (osteopontin) was the most differentially expressed gene (85-fold increase in expression), compared to benign plexiform neurofibromas. Short hairpin RNA (shRNA) knockdown of SPP1 in NF1-MPNST cells reduced tumour spheroid size, wound healing and invasion in four different MPNST cell lines. Seventy-six genes were found to exhibit concordance between CNA and gene expression level.

CONCLUSIONS

Pathway analysis of these genes suggested that glutathione metabolism and Wnt signalling may be specifically involved in NF1-MPNST development. SPP1 is associated with malignant transformation in NF1-associated MPNSTs and could prove to be an important target for therapeutic intervention.

Change in levels of physical activity after diagnosis of type 2 diabetes: an observational analysis from the NAVIGATOR study

Increased physical activity is known to be beneficial in people with type 2 diabetes mellitus (T2DM), but it is not known whether individuals change their activity levels after T2DM diagnosis. The present Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial, conducted in participants with impaired glucose tolerance at high cardiovascular risk, assessed ambulatory activity annually using research-grade pedometers. Oral glucose tolerance tests were performed annually and repeated to confirm T2DM diagnosis. This observational analysis used general linear models to compare step counts before and after T2DM diagnosis in the 2816 participants with the requisite data. Participants were relatively inactive at baseline, taking a median (interquartile range) of 5488 (3258-8361) steps/day, which decreased after T2DM diagnosis by a mean (s.e.) of 258 (64) steps/day (p < 0.0001); however, after adjusting for background trend for activity, step count after T2DM diagnosis was unchanged [mean (s.e.) of 103 (87) fewer steps/day; p = 0.23]. Awareness of T2DM diagnosis had no impact on the trajectory of activity established before the diagnosis.

Competitive interaction leads to perceptual distancing between actors

People physically distance themselves from competitors and the disliked, and cooperate less with those who are further away. We examine whether social interaction can also impact the space people perceive between themselves and others by measuring the influence of competitive dynamics on visual perception. In 2 experiments, participants played a ball toss game until they reached a target score. In Experiment 1, a confederate stood across the room from the participant and either (a) played the same game competitively, (b) played the same game cooperatively, or (c) observed the participant without playing, while in Experiment 2, 2 participants played the same versions of the game with each other. After the game, participants provided an estimate of the distance between themselves and the other player. Participants in Experiment 1 who competed with the confederate consistently judged her to be more distant than participants who cooperated with the confederate or played alone. In Experiment 2, players who lost the competition perceived more distance between themselves and their opponents than did players who won, suggesting that the experience of losing a competition drives this perceptual distancing. These findings demonstrate the power of a socially distancing interaction to create perceptual distance between people.

Biased attention near another's hand following joint action

Previous research has shown that attention is prioritized for the space near the hand, leading to faster detection of visual targets appearing close to one's own hand. In the present study, we examined whether observers are also facilitated in detecting targets presented near another's hand by having participants perform a Posner cueing task while sitting next to a friend. Across blocks, either the participant or the friend placed a hand next to one of the target locations. Our results robustly showed that participants detected targets appearing near their own hands more quickly than targets appearing away from their hands, replicating previous work demonstrating that spatial attention is prioritized near one's own hand (Experiments 1-4). No such attentional bias effects were found for targets appearing near the friend's hand, suggesting that spatial attention is not automatically prioritized near another's hand (Experiments 1 and 2). However, participants were faster to detect targets near the friend's hand following a joint action task, suggesting a shared body representation plays an influential role in biasing attention to the space near another's hand (Experiment 4).

Grasp posture modulates attentional prioritization of space near the hands

Changes in visual processing near the hands may assist observers in evaluating items that are candidates for actions. If altered vision near the hands reflects adaptations linked to effective action production, then positioning the hands for different types of actions could lead to different visual biases. I examined the influence of hand posture on attentional prioritization to test this hypothesis. Participants placed one of their hands on a visual display and detected targets appearing either near or far from the hand. Replicating previous findings, detection near the hand was facilitated when participants positioned their hand on the display in a standard open palm posture affording a power grasp (Experiments 1 and 3). However, when participants instead positioned their hand in a pincer grasp posture with the thumb and forefinger resting on the display, they were no faster to detect targets appearing near their hand than targets appearing away from their hand (Experiments 2 and 3). These results demonstrate that changes in visual processing near the hands rely on the hands' posture. Although hands positioned to afford power grasps facilitate rapid onset detection, a pincer grasp posture that affords more precise action does not.

Spatial working memory is necessary for actions to guide thought

Directed actions can play a causal role in cognition, shaping thought processes. What drives this cross-talk between action and thought? I investigated the hypothesis that representations in spatial working memory mediate interactions between directed actions and problem solving. Participants attempted to solve an insight problem while occasionally either moving their eyes in a pattern embodying the problem's solution or maintaining fixation. They simultaneously held either a spatial or verbal stimulus in working memory. Participants who moved their eyes in a pattern that embodied the solution were more likely to solve the problem, but only while also performing a verbal working memory task. Embodied guidance of insight was eliminated when participants were instead engaged in a spatial working memory task while moving their eyes, implying that loading spatial working memory prevented movement representations from influencing problem solving. These results point to spatial working memory as a mechanism driving embodied guidance of insight, suggesting that actions do not automatically influence problem solving. Instead, cross-talk between action and higher order cognition requires representations in spatial working memory.

Role of TNF in sickness behavior and allodynia during the acute phase of Chagas' disease

Chagas disease, caused by the intracellular protozoan Trypanosoma cruzi, is associated with inflammation, discomfort and pain during the acute phase. The influence of TNF-α (tumor necrosis factor) in this disease outcome is controversial. In this way, the aim of this work was to determine the role of the TNF-α blocker etanercept in the pain, discomfort, and survival during the Chagas' acute phase of mice experimentally infected with a wild virulent strain of T. cruzi. The infection with this wild strain was responsible for a severe visceral inflammation and said parasite showed a tropism in peritoneal fluid cells. Etanercept was able to restore spontaneous vertical and horizontal activities during the second week after infection and to abolish mechanical allodynia during the first week after infection. Finally, etanercept delayed the mortality without any effect on the parasitemia rates. This is the first report that correlates sickness behavior and allodynia with TNF-α and suggests that this cytokine may play an important role in the physiopathology of the acute phase.

How Many Objects are You Worth? Quantification of the Self-Motion Load on Multiple Object Tracking

Perhaps walking and chewing gum is effortless, but walking and tracking moving objects is not. Multiple object tracking is impaired by walking from one location to another, suggesting that updating location of the self puts demands on object tracking processes. Here, we quantified the cost of self-motion in terms of the tracking load. Participants in a virtual environment tracked a variable number of targets (1-5) among distractors while either staying in one place or moving along a path that was similar to the objects' motion. At the end of each trial, participants decided whether a probed dot was a target or distractor. As in our previous work, self-motion significantly impaired performance in tracking multiple targets. Quantifying tracking capacity for each individual under move versus stay conditions further revealed that self-motion during tracking produced a cost to capacity of about 0.8 (±0.2) objects. Tracking your own motion is worth about one object, suggesting that updating the location of the self is similar, but perhaps slightly easier, than updating locations of objects.

Explicit Plancherel theorem for ground state representation of the Heisenberg chain

In its ground state representation, the infinite spin 1/2 Heisenberg chain provides a model for spin wave scattering that entails many features of the quantum mechanical N-body problem. Here, we give a complete eigenfunction expansion for the Hamiltonian of the chain in this representation, for all numbers of spin waves. Our results resolve the questions of completeness and orthogonality of the eigenfunctions given by Bethe for finite chains, in the infinite volume limit.

Covert shifts of attention function as an implicit aid to insight

Previous research shows that directed actions can unconsciously influence higher-order cognitive processing, helping learners to retain knowledge and guiding problem solvers to useful insights (e.g. Cook, S. W., Mitchell, Z., & Goldin-Meadow, S. (2008). Gesturing makes learning last. Cognition, 106, 1047-1058; Thomas, L. E., & Lleras, A. (2007). Moving eyes and moving thought: on the spatial compatibility between eye movements and cognition. Psychonomic Bulletin and Review, 14, 663-668). We examined whether overt physical movement is necessary for these embodied effects on cognition, or whether covert shifts of attention are sufficient to influence cognition. We asked participants to try to solve Duncker's radiation problem while occasionally directing them, via an unrelated digit-tracking task, to shift their attention (while keeping their eyes fixed) in a pattern related to the problem's solution, to move their eyes in this pattern, or to keep their eyes and their attention fixed in the center of the display. Although they reported being unaware of any relationship between the digit-tracking task and the radiation problem, participants in both the eye-movement and attention-shift groups were more likely to solve the problem than were participants who maintained fixation. Our results show that by shifting attention in a pattern compatible with a problem's solution, we can aid participants' insight even in the absence of overt physical movements.

Fruitful visual search: inhibition of return in a virtual foraging task

Inhibition of return (IOR) has long been viewed as a foraging facilitator in visual search. We investigated the contribution of IOR in a task that approximates natural foraging more closely than typical visual search tasks. Participants in a fully immersive virtual reality environment manually searched an array of leaves for a hidden piece of fruit, using a wand to select and examine each leaf location. Search was slower than in typical IOR paradigms, taking seconds instead of a few hundred milliseconds. Participants also made a speeded response when they detected a flashing leaf that either was or was not in a previously searched location. Responses were slower when the flashing leaf was in a previously searched location than when it was in an unvisited location. These results generalize IOR to an approximation of a naturalistic visual search setting and support the hypothesis that IOR can facilitate foraging. The experiment also constitutes the first use of a fully immersive virtual reality display in the study of IOR.

The effect of saccades on number processing

Recent research has shown that saccadic eye movements interfere with dorsal-stream tasks such as judgments of object orientation, but not with ventral-stream tasks such as object recognition. Because saccade programming and execution also rely on the dorsal stream, it has been hypothesized that cognitive saccadic suppression occurs as a result of dual-task interference within the dorsal stream. Judging whether one number is larger or smaller than another (magnitude comparison) is a dorsal-stream task that relies especially on the right parietal cortex. In contrast, judging whether a number is odd or even (parity judgment) does not involve the dorsal stream. In the present study, one group of subjects judged whether two-digit numbers were greater than or less than 65, whereas another group judged whether two-digit numbers were odd or even. Subjects in both groups made these judgments while making no, short, or long saccades. Saccade distance had no effect on parity judgments, but reaction times to make magnitude comparison judgments increased with saccade distance when the eyes moved from right to left. Because the right parietal cortex is instrumental in generating leftward saccades, these results provide further evidence for the hypothesis that cognitive suppression during saccades occurs as a result of dual-task interference within the dorsal stream.

Spatial updating relies on an egocentric representation of space: effects of the number of objects

Models of spatial updating attempt to explain how representations of spatial relationships between the actor and objects in the environment change as the actor moves. In allocentric models, object locations are encoded in an external reference frame, and only the actor's position and orientation in that reference frame need to be updated. Thus, spatial updating should be independent of the number of objects in the environment (set size). In egocentric updating models, object locations are encoded relative to the actor, so the location of each object relative to the actor must be updated as the actor moves. Thus, spatial updating efficiency should depend on set size. We examined which model better accounts for human spatial updating by having people reconstruct the locations of varying numbers of virtual objects either from the original study position or from a changed viewing position. In consistency with the egocentric updating model, object localization following a viewpoint change was affected by the number of objects in the environment.

Voluntary eyeblinks disrupt iconic memory

In the present research, we investigated whether eyeblinks interfere with cognitive processing. In Experiment 1, the participants performed a partial-report iconic memory task in which a letter array was presented for 106 msec, followed 50, 150, or 750 msec later by a tone that cued recall of onerow of the array. At a cue delay of 50 msec between array offset and cue onset, letter report accuracy was lower when the participants blinked following array presentation than under no-blink conditions; the participants made more mislocation errors under blink conditions. This result suggests that blinking interferes with the binding of object identity and object position in iconic memory. Experiment 2 demonstrated that interference due to blinks was not due merely to changes in light intensity. Experiments 3 and 4 demonstrated that other motor responses did not interfere with iconic memory. We propose a new phenomenon, cognitive blink suppression, in which blinking inhibits cognitive processing. This phenomenon may be due to neural interference. Blinks reduce activation in area V1, which may interfere with the representation of information in iconic memory.

Acquired pulmonary stenosis: ultrasonographic diagnosis

A 15-year-old boy presented with chest pain and a new heart murmur. The clinical diagnosis of pulmonary stenosis was confirmed by two-dimensional and Doppler echocardiographic examinations. A large, encapsulated, partly solid and partly cystic tumor in the anterior mediastinum, visualized by ultrasonography, was compressing the main pulmonary artery and producing the right ventricular outflow tract obstruction. The tumor was removed surgically and was found to be a benign teratoma. Postoperative ultrasound examination of the right ventricular outflow tract showed no evidence of obstruction. We conclude that: (1) there are subtle clinical diagnostic differences between intrinsic and extrinsic pulmonary stenosis; (2) ultrasound examination can make cardiac catheterization unnecessary; and (3) relief of the extrinsic cause of pulmonary stenosis should be curative.

Identity, ideology and medicine: health attitudes and behavior among Hindu religious renunciates

In-depth interviews and participant observation was conducted with 14 Hindu religious renunciates, 70 years or older. Despite having taken vows renouncing concern for physical pain or comfort, respondents differed markedly in their attitudes toward pain and their rationale for utilizing medical treatment. They differed still further in their use of Ayurvedic and allopathic medicine, with the most culturally conservative accepting only Ayurvedic medicine. Rejection of allopathic medicine tended to be associated with a highly systematized religious world-view. The results are discussed in terms of both the ideological conflict between religious world-view and medical usage, and the need for sophisticated distinction of religious world-view if research on the religious factor of health care utilization is to prove fruitful.

Correlates of sexual interest among elderly men

Interview data were collected from 46 English elderly men (age 70 to 94 years) relating to attitudes, psychological traits, and life satisfaction. Sexual interest was not related to life satisfaction or marital status but was significantly correlated with measures of emotional expressivity, personal identity, as well as regrets about the past. Findings are discussed in terms of Erikson's later stages of ego development.

Dialogues with three religious renunciates and reflections on wisdom and maturity

In-depth interviews and participation observation were conducted with Hindu religious renunciates living in Varanasi and Pondicherry, India. The respondents selected were designated by their acquaintances as being spiritually mature. Analysis of excerpts from three representative interviews indicate that these men rate as highly mature by Western developmental models, but Western correlates of life satisfaction were not found to hold for these men. The implications for Western aging are considered, particularly the importance of contemplation and acceptance of death.

Phenomenology of life satisfaction among elderly men: quantitative and qualitative views

Standardized measures of subjective well-being were compared with qualitative analysis of life satisfaction from 100 elderly men (70 years and older) from New Delhi, India, and London, England. 3 structured measures were used, Life Satisfaction Index (A), Cantril Self-Anchoring Ladder, and a one-item happiness question. Qualitative data were obtained from semistructured interviews covering past and present experiences. Meaning units were extracted from interview protocols, emerging themes were identified for each respondent, and overall summaries were written for English and Indian samples. Groups did not differ significantly on any of the structured measures, but showed marked differences in the qualitative analysis. Limitations of structured measures of subjective well-being are discussed in terms of "context-stripping," both in data collection and data analysis.

Phenomenology of life satisfaction among elderly men: Quantitative and qualitative views

Standardized measures of subjective well-being were compared with qualitative analysis of life satisfaction from 100 elderly men (70 years and older) from New Delhi, India, and London, England. 3 structured measures were used, Life Satisfaction Index (A), Cantril Self-Anchoring Ladder, and a one-item happiness question. Qualitative data were obtained from semistructured interviews covering past and present experiences. Meaning units were extracted from interview protocols, emerging themes were identified for each respondent, and overall summaries were written for English and Indian samples. Groups did not differ significantly on any of the structured measures, but showed marked differences in the qualitative analysis. Limitations of structured measures of subjective well-being are discussed in terms of "context-stripping," both in data collection and data analysis.

Identity loss and psychological crisis in widowhood: a re-evaluation

This study seeks to clarify the effect of widowhood on ego identity and psychological functioning. The sample consisted of eighty-three widows, ranging in age from twenty-two to seventy-four, who had been widowed an average of 4.9 years. A majority were found to be Identity Achievers on the Marcia instrument, and the group scored significantly higher on a structured measure of self-esteem (TSCS) in comparison to national norms. A quarter of the sample reported positive change after widowhood, 39 percent reported mixed effects, and only 30 percent reported only negative change. The results are discussed in terms of Erikson's developmental theory, suggesting that intimacy may be a more central issue of widowhood than ego identity. Further, little support is given the pathological sheen often attributed to widowhood. Rather, the data better fit a developmental or growth model of crisis resolution.

Survival of herpes simplex virus and other selected microorganisms on patient charts: potential source of infection

This study indicated that when inoculated onto dental charts, both viruses and bacteria were capable of survival allowing the potential for transmission of infection within the dental office. The conscientious dental practitioner can take steps to reduce this possible mode of infection by removing contaminated surgical gloves or washing hands before handling the chart. An additional method of reducing this potential would be to wipe the chart with an antiseptic solution. Although this study has shown that there is a potential for the spread of infection with the organisms tested, the actual extent of dental chart contamination and resultant illnesses contracted are the basis for further study. Additional studies are needed to follow the pattern of chart distribution from person to person within the dental office, determine the types and quantities of pathogens present in the mouth that would contaminate the charts, and sample the charts under actual clinical conditions to determine the types and viability of the organisms present.

Detection of arrhythmia: limited usefulness of patient activated recording devices

The findings of 24 hour ambulatory electrocardiography and monitoring with the Cardiomemo, a device recording 32 seconds of electrocardiogram during symptoms, were compared in 20 patients with symptoms suggestive of arrhythmia. Ambulatory electrocardiography showed arrhythmia in seven patients, extrasystoles in six, and normal findings in seven. Nine patients failed to transmit any Cardiomemo recordings, and the Cardiomemo failed to show ventricular and supraventricular tachycardia. It did not show any appreciable arrhythmia in the seven patients with normal 24 hour electrocardiograms. The Cardiomemo does not offer any important advantages over ambulatory electrocardiography, and its relative cheapness is outweighed by the limited number of patients who can use the device in one year. It can, however, reassure anxious patients of the absence of arrhythmia during symptoms.

Head and neck manifestations of gastroesophageal reflux

Gastroesophageal reflux (GER) is a common condition with many manifestations which are of interest to the otolaryngologist. Factors predisposing to GER include anatomic abnormalities of the esophagus and pharynx, neurogenic disease and diet induced decreased lower esophageal sphincter pressure. Three interesting cases are reported, including subglottic stenosis which has not previously been thought to be a complication of GER. A literature review of otolaryngologic symptoms, the problems of diagnosis, and a suggested treatment plan are presented.

Subjective time experience in an intergenerational sample

The roles chronological age and gender play in subjective time experience were explored in a sample of 294 adult men and women. Subjective time experience (STE: the difference between subjective age and chronological age) was found to vary widely among individuals, with some being "accurate" (SA = CA), and others either "retarded" (SA less than CA) or "advanced" (SA greater than CA). Males were more retarded in STE than females at every point in the lifespan, and patterns of age differences in adulthood differed for the two sexes as well. The results suggest that chronological age may play a key role in transitions in STE, and that chronological age is more significant in the STE of women than in the STE of men.

Age norms for Templer's Death Anxiety Scale

Templer's Death Anxiety Scale was administered to 295 adults ranging in age from 16 to 83 yr. Results indicated that older adults (60—83 yr.) had significantly lower scores than younger adults. Users of the scale are cautioned that the age of the individual may be important in interpreting scores, and preliminary age norms are presented.

Adolescent drug use: an analysis

In a survey of self-reports to a 60-item questionnaire from 3,348 students in Grades 8 to 12, an increase with age was found in the use of alcohol, tobacco, marijuana, and the hallucinogens. Interestingly, the female Ss reported greater use of tobacco from Grades 8 to 11 than males. Alcohol still headed the list of favorite drugs, with 73% of the seniors reporting its use. Adequacy of family communication was negatively associated with drug usage, with peer advice and help being sought more frequently when youth were involved with drugs. Fear of harmful physiological effects was an important deterrent to the use of these substances; fear of arrest was not. Of the different hypotheses for drug use, strongest support was shown for differential association. Peer use of illegal drugs was an important correlate of the adolescents' use of these substances