Implicit Attentional Selection of Bound Visual Features

SummaryTraditionally, research on visual attention has been focused on the processes involved in conscious, explicit selection of task-relevant sensory input. Recently, however, it has been shown that attending to a specific feature of an object automatically increases neural sensitivity to this feature throughout the visual field. Here we show that directing attention to a specific color of an object results in attentional modulation of the processing of task-irrelevant and not consciously perceived motion signals that are spatiotemporally associated with this color throughout the visual field. Such implicit cross-feature spreading of attention takes place according to the veridical physical associations between the color and motion signals, even under special circumstances when they are perceptually misbound. These results imply that the units of implicit attentional selection are spatiotemporally colocalized feature clusters that are automatically bound throughout the visual field

Bela Julesz in Depth

A brief tribute to Bela Julesz (1928−2003) is made in words and images. In addition to a conventional stereophotographic portrait, his major contributions to vision research are commemorated by two ‘perceptual portraits’, which try to capture the spirit of his main accomplishments in stereopsis and the perception of texture

Adrenocortical neoplasia: evolving concepts in tumorigenesis with an emphasis on adrenal cortical carcinoma variants

Adrenocortical carcinoma (ACC) is a rare, heterogeneous malignancy with a poor prognosis. According to WHO classification 2004, ACC variants include oncocytic ACCs, myxoid ACCs and ACCs with sarcomatous areas. Herein, we provide a comprehensive review of these rare subtypes of adrenocortical malignancy and emphasize their clinicopathological features with the aim of elucidating aspects of diagnostic categorization, differential diagnostics and biological behavior. The issue of current terminology, applied to biphasic tumors with pleomorphic, sarcomatous or sarcomatoid elements arising in adrenal cortex, is also discussed. We additionally present emerging evidence concerning the adrenal cortical tumorigenesis and the putative adenoma–carcinoma sequence as well

Pseudosarcomatous myofibroblastic lesion of the urinary bladder: A rare entity posing a diagnostic challenge and therapeutic dilemma

<p>Abstract</p> <p>Background</p> <p>Pseudosarcomatous myofibroblastic lesions of the urinary bladder are relatively rare entities of an uncertain pathogenesis and benign indolent nature.</p> <p>Case presentation</p> <p>We present an extremely rare case of an ALK-1-positive pseudosarcomatous myofibroblastic lesion of the urinary bladder, which was initially misinterpreted as a low-grade leiomyosarcoma of myxoid subtype on histologic examination owing to prominent atypia, high mitotic activity, abnormal mitotic figures and infiltration of the bladder wall. Although the histologic features were suggestive of a sarcoma, the correct diagnosis was finally established and radical surgical treatment was subsequently avoided. The patient is currently free of disease without any evidence of tumor recurrence or metastasis at 3 years post-operatively.</p> <p>Conclusion</p> <p>The key differentiating point rests in distinguishing the aforementioned mass forming lesion from the myxoid subtype of low-grade leiomyosarcoma in order to avoid unnecessary radical therapy.</p

The effects of categorical and linguistic adaptation on binocular rivalry initial dominance

Binocular rivalry (BR) is a phenomenon in which visual perception alternates between two different monocular stimuli. There has been a long debate regarding its nature, with a special emphasis on whether low- or high-level mechanisms are involved. Prior adaptation to one of the two monocular stimuli is known to affect initial dominance in the subsequent dichoptic presentation. In the present work, we have used three different types of adaptation in order to investigate how each one affects initial dominance during BR. In the first adaptation type, adapting to a stimulus identical to the one used during rivalry has led to its consequent suppression, verifying previous findings. The binocular presentation which we have used excludes the possibility of eye-adaptation, suggesting that it is the specific stimulus that the brain adapts to. In the second adaptation type, we find suppression effects following adaptation to stimuli belonging to the same category (face or house) but are different from the specific ones used in the following BR presentation. In the final adaptation type, in which the words “face” or “house” are used as adaptors, no statistically significant effect was found. These results suggest that perceptual selection can be directly influenced by the prior presentation of visual stimuli different to the ones used during BR, and thus support a higher-level, cognitive influence on the latter