Eye and hand movements during reconstruction of spatial memory

© 2012 a Pion publicationRecent behavioural and biological evidence indicates common mechanisms serving working memory and attention (e.g., Awh et al, 2006 Neuroscience 139 201-208). This study explored the role of spatial attention and visual search in an adapted Corsi spatial memory task. Eye movements and touch responses were recorded from participants who recalled locations (signalled by colour or shape change) from an array presented either simultaneously or sequentially. The time delay between target presentation and recall (0, 5, or 10 s) and the number of locations to be remembered (2-5) were also manipulated. Analysis of the response phase revealed subjects were less accurate (touch data) and fixated longer (eye data) when responding to sequentially presented targets suggesting higher cognitive effort. Fixation duration on target at recall was also influenced by whether spatial location was initially signalled by colour or shape change. Finally, we found that the sequence tasks encouraged longer fixations on the signalled targets than simultaneous viewing during encoding, but no difference was observed during recall. We conclude that the attentional manipulations (colour/shape) mainly affected the eye movement parameters, whereas the memory manipulation (sequential versus simultaneous, number of items) mainly affected the performance of the hand during recall, and thus the latter is more important for ascertaining if an item is remembered or forgotten. In summary, the nature of the stimuli that is used and how it is presented play key roles in determining subject performance and behaviour during spatial memory tasks

High altitude climbers as ethnomethodologists making sense of cognitive dissonance: ethnographic insights from an attempt to scale Mt Everest

This ethnographic study examined how a group of high altitude climbers (N = 6)drew on ethnomethodological principles (the documentary method of interpretation, reflexivity, indexicality, and membership) to interpret their experiences of cognitive dissonance during an attempt to scale Mt. Everest. Data were collected via participant observation, interviews, and a field diary. Each data source was subjected to a content mode of analysis. Results revealed how cognitive dissonance reduction is accomplished from within the interaction between a pattern of self-justification and self-inconsistencies; how the reflexive nature of cognitive dissonance is experienced; how specific features of the setting are inextricably linked to the cognitive dissonance experience; and how climbers draw upon a shared stock of knowledge in their experiences with cognitive dissonance

Omega Oracle: forecasting estuarine carbonate weather

There are serious concerns about ecological, social, and economic impacts in the Pacific Northwest due to Ocean Acidification (OA). We built a system to predict aragonite saturation state (Ω) of seawater in Netarts Bay, Oregon based on large scale forcing parameters. An artificial neural network – trained against a continuous, multiyear monitoring record of carbonate chemistry – learns a regression estimate of Ω based on seasonality, tides, and wind conditions. This approach is agnostic to the details of the underlying chemical and biological processes offering a distinct modelling perspective. The result is a conceptually simpler and more strictly empirical parameterization and a model that is flexible in application due to dependence on only easily obtainable parameters. Forecast validation by a cross validation method indicates good prediction performance, particularly for the high frequency content of the Ω time series, over periods of stable wind forecasting. Our forecast model demonstrates that the complex temporal dynamics of carbonate chemistry within an estuary can emerge from forcing operating on longer timescales. This further elucidates the management and commercial value of this model; experimental work with calcifiers suggests the details of these high frequency chemical dynamics are critical to the magnitude of stress imposed. Lastly, these forecasts, deployed as a web application, can facilitate OA mitigation strategies by providing aquaculturists with real-time predictions for consideration in operational decisions. Numerous sites, including on the Salish Sea, are poised to soon have viable training data for application of this method. Broader deployment promises to enable comparison between sites and expansion of direct aquaculture and management applications. Expansion to other sites is expected to require altered explanatory variables but this exercise may itself yield insight. Relatedly, we note the potential of this approach to help constrain timescales and sources (natural and anthropogenic) of contributions to physiological OA stress

Thymomas: a cytological and immunohistochemical study, with emphasis on lymphoid and neuroendocrine markers

<p>Abstract</p> <p>Background</p> <p>The current study correlates cytologic morphology with histologic type and describes immunophenotypes with a focus on epithelial, neuroendocrine, and lymphoid characteristics in an institutional series of surgically excised thymomas.</p> <p>Methods</p> <p>Fine needle aspirates (FNAs) and surgical specimens were retrospectively analyzed, and immunohistochemical stains were performed for EMA, cytokeratin 7, cytokeratin 20, CD57 CD5, bcl-2, calretinin, vimentin, CD3, CD20, CD1a, CD99 and Ki67. Tumors were classified by WHO criteria.</p> <p>Results</p> <p>There were eleven male and six female patients with an age range of 41 to 84 years (mean, 61 years) and a male to female ratio of 1.8:1. Four thymomas (4/17, 23.5%) were associated with neuromuscular disease: myasthenia gravis (n = 3) and limbic encephalitis (n = 1). FNA, under CT guidance, was performed in 7 cases. The positive predictive value for thymoma by FNA cytology was 100% and the sensitivity was 71%. Thymomas associated with neuromuscular disorders were WHO types B2 (n = 1) and B3 (n = 3), and showed a strong expression of CD57 in the majority of neoplastic epithelial cells accompanied by large numbers of CD20+ intratumoral B lymphocytes. Two of seventeen (11.7%) thymomas (all sporadic B3 type) contained numerous neoplastic epithelial cells positive for CD5 and bcl-2.</p> <p>Conclusion</p> <p>Our results suggest that thymomas associated with autoimmune disorders contain a significant population of CD20+ intratumoral B lymphocytes. Strong CD57 positivity in thymomas may suggest a concomitant neuromuscular disorder, notably myasthenia gravis. CD5 expression is of limited value in the differential diagnosis of primary thymic epithelial neoplasms since both thymic carcinomas and thymomas may express CD5.</p

Robust Weak-lensing Mass Calibration of Planck Galaxy Clusters

In light of the tension in cosmological constraints reported by the Planck team between their SZ-selected cluster counts and Cosmic Microwave Background (CMB) temperature anisotropies, we compare the Planck cluster mass estimates with robust, weak-lensing mass measurements from the Weighing the Giants (WtG) project. For the 22 clusters in common between the Planck cosmology sample and WtG, we find an overall mass ratio of \left = 0.688 \pm 0.072. Extending the sample to clusters not used in the Planck cosmology analysis yields a consistent value of $\left< M_{Planck}/M_{\rm WtG} \right> = 0.698 \pm 0.062$ from 38 clusters in common. Identifying the weak-lensing masses as proxies for the true cluster mass (on average), these ratios are $\sim 1.6\sigma$ lower than the default mass bias of 0.8 assumed in the Planck cluster analysis. Adopting the WtG weak-lensing-based mass calibration would substantially reduce the tension found between the Planck cluster count cosmology results and those from CMB temperature anisotropies, thereby dispensing of the need for "new physics" such as uncomfortably large neutrino masses (in the context of the measured Planck temperature anisotropies and other data). We also find modest evidence (at 95 per cent confidence) for a mass dependence of the calibration ratio and discuss its potential origin in light of systematic uncertainties in the temperature calibration of the X-ray measurements used to calibrate the Planck cluster masses. Our results exemplify the critical role that robust absolute mass calibration plays in cluster cosmology, and the invaluable role of accurate weak-lensing mass measurements in this regard.Comment: 5 pages, 2 figure