Development and Evaluation of a Novel Point-of-Use Quality Assurance Tool for Digital Pathology

Context.— Flexible working at diverse or remote sites is a major advantage when reporting using digital pathology, but currently there is no method to validate the clinical diagnostic setting within digital microscopy. Objective.— To develop a preliminary Point-of-Use Quality Assurance (POUQA) tool designed specifically to validate the diagnostic setting for digital microscopy. Design.— We based the POUQA tool on the red, green, and blue (RGB) values of hematoxylin-eosin. The tool used 144 hematoxylin-eosin–colored, 5×5-cm patches with a superimposed random letter with subtly lighter RGB values from the background color, with differing levels of difficulty. We performed an initial evaluation across 3 phases within 2 pathology departments: 1 in the United Kingdom and 1 in Sweden. Results.— In total, 53 experiments were conducted across all phases resulting in 7632 test images viewed in all. Results indicated that the display, the user's visual system, and the environment each independently impacted performance. Performance was improved with reduction in natural light and through use of medical-grade displays. Conclusions.— The use of a POUQA tool for digital microscopy is essential to afford flexible working while ensuring patient safety. The color-contrast test provides a standardized method of comparing diagnostic settings for digital microscopy. With further planned development, the color-contrast test may be used to create a “Verified Login” for diagnostic setting validation.

Can People Judge the Veracity of Their Intuitions?

People differ in the belief that their intuitions produce good decision outcomes. In the present research, we sought to test the validity of these beliefs by comparing individuals’ self-reports with measures of actual intuition performance in a standard implicit learning task, exposing participants to seemingly random letter strings (Studies 1a–b) and social media profile pictures (Study 2) that conformed to an underlying rule or grammar. A meta-analysis synthesizing the present data ( N = 400) and secondary data by Pretz, Totz, and Kaufman found that people’s enduring beliefs in their intuitions were not reflective of actual performance in the implicit learning task. Meanwhile, task-specific confidence in intuition bore no sizable relation with implicit learning performance, but the observed data favoured neither the null hypothesis nor the alternative hypothesis. Together, the present findings suggest that people’s ability to judge the veracity of their intuitions may be limited.

Auditory Distraction Compromises Random Generation

Auditory distraction of random generation – a quintessentially executive control task – was explored in three experiments. Random number generation was impaired by the mere presence of irrelevant auditory sequences that comprise digits, but not letters, and then only if the digits were heard in a canonical order (1, 2, 3 … or 3, 2, 1 …), not in random order (Experiments 1 and 2). Random letter generation was impaired by irrelevant letters heard in alphabetical order (a, b, c …) and reversed alphabetical order (i, h, g …), but not by numbers in canonical order or letters in random order (Experiment 3). Attempting to ignore canonical sequences – with items that are members of the same category as the to-be-generated items – reduced the randomness of the generated sequence, by decreasing the tendency to change the direction of the produced sequence for random number generation, and by increasing resampling of responses for random letter generation. Like other selective attention tasks, the cost of distraction to random generation appears to stem from preventing habitual responses assuming the control of action.

Brain Structures Involved in Visual Search in the Presence and Absence of Color Singletons

It is still debated to what degree top–down and bottom–up driven attentional control processes are subserved by shared or by separate mechanisms. Interactions between these attentional control forms were investigated using a rapid event-related fMRI design, using an attentional search task. Following a prestimulus mask, target stimuli (consisting of a letter C or a mirror image of the C, enclosed in a diamond outline) were presented either at one unique location among three nontarget items (consisting of a random letter, enclosed in a circle outline; 50% probability), or at all four possible target locations (also 50% probability). On half the trials, irrelevant color singletons were presented, consisting of a color change of one of the four prestimulus masks, just prior to target appearance. Participants were required to search for a target letter inside the diamond and report its orientation. Results indicate that, in addition to a common network of parietal areas, medial frontal cortex is uniquely involved in top–down orienting, whereas bottom–up control is mainly subserved by a network of occipital and parietal areas. Additionally, we found that participants who were better able to suppress orienting to the color singleton showed middle frontal gyrus activation, and that the degree of top–down control correlated with insular activity. We conclude that, in addition to a common set of parietal areas, separate brain areas are involved in top–down and bottom–up driven attentional control, and that frontal areas play a role in the suppression of attentional capture by an irrelevant color singleton.

Increases in Alpha Oscillatory Power Reflect an Active Retinotopic Mechanism for Distracter Suppression During Sustained Visuospatial Attention

Human electrophysiological (EEG) studies have demonstrated the involvement of alpha band (8- to 14-Hz) oscillations in the anticipatory biasing of attention. In the context of visual spatial attention within bilateral stimulus arrays, alpha has exhibited greater amplitude over parietooccipital cortex contralateral to the hemifield required to be ignored, relative to that measured when the same hemifield is to be attended. Whether this differential effect arises solely from alpha desynchronization (decreases) over the “attending” hemisphere, from synchronization (increases) over the “ignoring” hemisphere, or both, has not been fully resolved. This is because of the confounding effect of externally evoked desynchronization that occurs involuntarily in response to visual cues. Here, bilateral flickering stimuli were presented simultaneously and continuously over entire trial blocks, such that externally evoked alpha desynchronization is equated in precue baseline and postcue intervals. Equivalent random letter sequences were superimposed on the left and right flicker stimuli. Subjects were required to count the presentations of the target letter “X” at the cued hemifield over an 8-s period and ignore the sequence in the opposite hemifield. The data showed significant increases in alpha power over the ignoring hemisphere relative to the precue baseline, observable for both cue directions. A strong attentional bias necessitated by the subjective difficulty in gating the distracting letter sequence is reflected in a large effect size of 2.1 (η2 = 0.82), measured from the attention × hemisphere interaction. This strongly suggests that alpha synchronization reflects an active attentional suppression mechanism, rather than a passive one reflecting “idling” circuits.

Finnish Kindergartners' Literacy Development in Contextualized Literacy Episodes: A Focus on Spelling

This study focused on children's spelling development in a Finnish kindergarten. We examined how and when spelling begins when children are provided guided and meaningful literacy opportunities. Field notes, children's writing samples, and four dictations, as well as pre- and postinstruction assessment of literacy-related tasks were analyzed to describe children's progress and strategies. At the start of the study, some children did not know any letters, while others who knew some letters did not necessarily use them in the first dictation, drawing instead. Classroom activities offered children opportunities to increase letter knowledge and demonstrated how to apply that knowledge. The assessment at the end of the study in Phase 1 demonstrated a substantial growth in children's spelling: some children spelled almost all the dictated words correctly, most of the children used invented spelling, and only one child used random letter strings for a few words. In addition, children's reading developedso that several children were alphabetic-phase readers. In Phase 2, all the children used alphabetic strategies.

Quantitative analysis of hemispatial neglect in the intracarotid sodium amobarbital (ISA) test

There are dramatic changes in the electroencephalogram of the inactivated hemisphere in the intracarotid sodium amobarbital test. One of the more profound behavioral changes during this procedure is left hemispatial neglect accompanying right hemisphere inactivation. The present study was designed to ascertain whether there was a clear relationship between the degree of hemispheric inactivation (as measured by the electroencephalogram) and the degree of left hemispatial neglect during this procedure. Sixty-nine participants undergoing right hemisphere intracarotid sodium amobarbital testing were presented with a random letter cancellation test at various points during the procedure. Neglect was quantified as significant, moderate, minimal, or none, based on how many target letters the patients missed. The simultaneous electroencephalogram from each of these testing points was spectrally analyzed and topographic maps were generated. The degree of neglect was then compared with the comparable topographic map. It was found that as the amobarbital-induced right hemispheric dysfunction regressed, the degree of neglect lessened in a systematic fashion, as did the profound electroencephalographic changes induced by the drug. Thus, there is a clear relation between the degree of hemispheric inactivation induced by the amobarbital and the degree of left hemispatial neglect. This relationship held regardless of side of hemispheric language dominance or epileptic focus. These results replicate previous findings that right hemisphere inactivation during the intracarotid sodium amobarbital test results in left hemispatial neglect. They extend these findings by clearly showing that neglect changes in a quantitative fashion (rather than being an all-or-none phenomenon) and further, show that there is a clear relationship between the severity of neglect and the degree of hemispheric dysfunction. (JINS, 1998, 4, 99–105.)