Parietal activation during visual search in the absence of multiple distractors.

Search for a target object embedded in a visual scene involves the posterior parietal cortex. This region is thought to play a role in visual attention by counteracting the effects of distractors on targets or by inhibiting distractors. Using fMRI, we investigated whether the parietal cortex is also engaged in visual search without distractors.

A perceptual interference account of acquisition difficulties for non-native phonemes.

This article presents an account of how early language experience can impede the acquisition of non-native phonemes during adulthood. The hypothesis is that early language experience alters relatively low-level perceptual processing, and that these changes interfere with the formation and adaptability of higher-level linguistic representations. Supporting data are presented from an experiment that tested the perception of English /r/ and /l/ by Japanese, German, and American adults.

Visual feature and conjunction searches of equal difficulty engage only partially overlapping frontoparietal networks.

According to a classical view of visual object recognition, targets are detected "pre-attentively" if they carry unique features, whereas attention has to be deployed serially to object locations for feature binding if the targets can be distinguished from distracters only in terms of their feature conjunctions. Consistent with this view, recent reports suggest a contribution of the posterior parietal cortex (PPC; one major region controlling spatial attention) to conjunction search as opposed to feature search. However, PPC engagement in conjunction search might also reflect feature-based attention or the difficulty of target selection.