Castleman disease in an 11-year-old girl appeared as a neck mass that grew despite antibiotic treatment. MR showed a well-defined solid mass, isointense with muscle on short-repetition-time/short-echo-time images, with a stellate area of central hypointensity on long-repetition-time/long-echo-time images, that did not enhance with gadolinium.

The effects of stimulus repetition often increase when repetitions are more common (i.e., when repeats become more predictable), consistent with the idea that repetition effects reflect expectations about the recurrence of recent items. In contrast, the present experiments found a surprising pattern in which the compressed subjective duration of repeated items was reduced, eliminated, and even ...

BACKGROUND The repeated presentation of stimuli typically attenuates neural responses (repetition suppression) or, less commonly, increases them (repetition enhancement) when stimuli are highly complex, degraded or presented under noisy conditions. In adult functional neuroimaging research, these repetition effects are considered as neural correlates of habituation. The development and respecti...

We examined whether behavioral and neural effects of repeating faces are modulated by independent factors of selective attention, emotion, and cholinergic enhancement, during functional MRI. Face repetition occurred either between task-relevant (spatially attended) or task-irrelevant (unattended) stimuli; faces could be fearful or neutral; subjects received either placebo or physostigmine. Unde...

Functional magnetic resonance imaging (fMRI) studies have shown that repetition priming of visual objects is typically accompanied by a reduction in activity for repeated compared to new stimuli (repetition suppression). However, the spatial distribution and direction (suppression vs. enhancement) of neural repetition effects can depend on the pre-experimental familiarity of stimuli. The first ...