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Objectives: The sexually transmitted infections, Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV), and Mycoplasma genitalium (MG), have similar risk factors and symptoms, supporting use of a quadruplex test as an efficient diagnostic modality.We assessed the clinical and analytical performance of the Abbott Alinity m STI assay to detect these pathogens. Design and methods: Urine and genital swabs from 142 patient samples were tested from an adult outpatient population in the Northeast United States. The positive and negative percent agreement for CT, NG, and TV were determined by comparison with the Hologic Panther Aptima assay. The analytical sensitivity was determined through serial dilution of standards for CT, NG, TV, and MG in negative urine and swab matrix. Results: The positive and negative percent agreement of the Alinity m assay in comparison with the Hologic Panther Aptima assay were, respectively: CT [100.0% (90.6–100.0%) and 99.1% (94.8–100.0%)], NG [100.0% (89.6–100.0%) and 99.1% (94.9–100.0%)]; and TV [96.3% (81.7–99.8%) and 99.1% (95.2–100.0%)]. The limits of detection in urine and swab matrix were, respectively: CT ≤ 5, ≤1; NG ≤ 5, ≤5; TV ≤ 0.5, ≤0.5; and MG ≤ 500, ≤250 genome copies/mL. Conclusions: The Alinity m assay demonstrated excellent performance characteristics and identifies CT, NG, and TV accurately compared with a well-established comparator.

Human neuroimaging studies have revealed a dedicated cortical system for visual scene processing. But what is a “scene”? Here, we use a stimulus-driven approach to identify a stimulus feature that selectively drives cortical scene processing. Specifically, using fMRI data from BOLD5000, we examined the images that elicited the greatest response in the cortical scene processing system, and found that there is a common “vertical luminance gradient” (VLG), with the top half of a scene image brighter than the bottom half; moreover, across the entire set of images, VLG systematically increases with the neural response in the scene-selective regions (Study 1). Thus, we hypothesized that VLG is a stimulus feature that selectively engages cortical scene processing, and directly tested the role of VLG in driving cortical scene selectivity using tightly controlled VLG stimuli (Study 2). Consistent with our hypothesis, we found that the scene-selective cortical regions—but not an object-selective region or early visual cortex—responded significantly more to images of VLG over control stimuli with minimal VLG. Interestingly, such selectivity was also found for images with an “inverted” VLG, resembling the luminance gradient in night scenes. Finally, we also tested the behavioral relevance of VLG for visual scene recognition (Study 3); we found that participants even categorized tightly controlled stimuli of both upright and inverted VLG to be a place more than an object, indicating that VLG is also used for behavioral scene recognition. Taken together, these results reveal that VLG is a stimulus feature that selectively engages cortical scene processing, and provide evidence for a recent proposal that visual scenes can be characterized by a set of common and unique visual features.

Despite over two decades of research on the neural mechanisms underlying human visual scene, or place, processing, it remains unknown what exactly a “scene” is. Intuitively, we are always inside a scene, while interacting with the outside of objects. Hence, we hypothesize that one diagnostic feature of a scene may be concavity, portraying “inside”, and predict that if concavity is a scene-diagnostic feature, then: 1) images that depict concavity, even non-scene images (e.g., the “inside” of an object – or concave object), will be behaviorally categorized as scenes more often than those that depict convexity, and 2) the cortical scene-processing system will respond more to concave images than to convex images. As predicted, participants categorized concave objects as scenes more often than convex objects, and, using functional magnetic resonance imaging (fMRI), two scene-selective cortical regions (the parahippocampal place area, PPA, and the occipital place area, OPA) responded significantly more to concave than convex objects. Surprisingly, we found no behavioral or neural differences between images of concave versus convex buildings. However, in a follow-up experiment, using tightly-controlled images, we unmasked a selective sensitivity to concavity over convexity of scene boundaries (i.e., walls) in PPA and OPA. Furthermore, we found that even highly impoverished line drawings of concave shapes are behaviorally categorized as scenes more often than convex shapes. Together, these results provide converging behavioral and neural evidence that concavity is a diagnostic feature of visual scenes.