R34D1NG W0RD5 W1TH NUMB3R5.

Letter identities and number identities are usually thought to imply different cortical mechanisms. Specifically, the left fusiform gyrus responds more to letters than to digits (T. A. Polk et al., 2002). However, a widely circulated statement on the internet illustrates that it is possible to use numbers (leet digits) as parts of words, 4ND TH3 R35ULT1NG S3NT3NC3 C4N B3 R34D W1TH0UT GR34T 3FF0RT. Two masked priming lexical decision experiments were conducted to determine whether leet digits produce (automatic) lexical activation. Results showed that words are identified substantially faster when they are preceded by a masked leet word (M4T3R14L-MATERIAL) than when they are preceded by a control condition with other letters or digits. In addition, there was only a negligible advantage of the identity condition over the related leet condition. This leet-priming effect is not specific to numbers: A prime in which leet digits are replaced by letter-like symbols (MΔT?!ΔL-MATERIAL) facilitates word processing to the same degree as an identity prime. Therefore, the cognitive system regularizes the shape of the leet digits and letter-like symbols embedded in words with very little cost. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional capture by salient color singleton distractors is modulated by top-down dimensional set.

Three experiments examined whether salient color singleton distractors automatically interfere with the detection singleton form targets in visual search (e.g., J. Theeuwes, 1992), or whether the degree of interference is top-down modulable. In Experiments 1 and 2, observers started with a pure block of trials, which contained either never a distractor or always a distractor (0% or 100% distractors)--varying the opportunity to learn distractor suppression. In the subsequent trial blocks, the proportion of distractors was systematically varied (within-subjects factor in Experiment 1, between-subjects factor in Experiment 2)--varying the incentive to use distractor suppression. In Experiment 3, observers started with 100% distractors in the first block and were presented with "rare" color or luminance distractors, in addition to "frequent" color distractors, in the second block. The results revealed distractor interference to vary as a function of both the initial experience with distractors and the incentive to suppress them: the interference was larger without relevant practice and with a lesser incentive to apply suppression (Experiments 1-3). This set of findings suggests that distractor interference is top-down modulable. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The subliminal mere exposure effect does not generalize to structurally related stimuli.

R. F. Bornstein (1994) questioned whether subliminal mere exposure effects might generalize to structurally related stimuli, thereby providing evidence for the existence of implicit learning. Two experiments examined this claim using letter string stimuli constructed according to the rules of an artificial grammar. Experiment 1 demonstrated that brief, masked exposure to grammatical strings impaired recognition but failed to produce a mere exposure effect on novel structurally related strings seen at test. Experiment 2 replicated this result but also demonstrated that a reliable mere exposure effect could be obtained, provided the same grammatical strings were presented at test. The results suggest that the structural relationship between training and test items prevents the mere exposure effect when participants are unaware of the exposure status of stimuli, and therefore provide no evidence for the existence of implicit learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

N200, N250r, and N400 Event-Related Brain Potentials Reveal Three Loci of Repetition Priming for Familiar Names.

The authors assessed immediate repetition effects on event-related potentials (ERPs) while participants performed familiarity decisions for written personal names. For immediately repeated familiar names, the authors observed 3 distinct ERP modulations. At 180-220 ms, a posterior N200 effect occurred for names preceded by same-font primes only. In addition, an increased left temporal negativity (N250r, 220-300 ms) and a reduced central-parietal negativity (N400, 300-400 ms) were seen both for same-font and different-font repetitions. In a 2nd experiment, when names were preceded by either their corresponding face or the face of a different celebrity, only the N400 effect was preserved. These findings suggest that the N200, N250r, and N400 effects reflect facilitated processing at font-specific featural, lexical, and semantic levels of processing, respectively. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pretraining does not ameliorate spatial learning deficits induced by intrahippocampal infusion of AP5.

Previous studies show discrepancies concerning the effects of pretraining on spatial learning deficits induced by blockade of the N-methyl-d-aspartate (NMDA) receptor. These inconsistencies might be attributed to the differences in the nature of the pretraining tasks and the method of blocking NMDA receptors. In the present study, the authors pretrained rats in a spatial water maze task. The authors then trained them with a novel spatial task in a novel environment under chronic blockade of hippocampal NMDA receptors by intrahippocampal infusion of 2-amino-5-phosphonopentanoic acid (AP5) using osmotic pumps. Although the rats had acquired the basic techniques needed to solve a water-maze spatial task during pretraining, those given high or low doses of AP5 showed acquisition deficits. As the spatial pretraining failed to ameliorate the acquisition deficits of a new task in a novel environment, it was suggested that NMDA receptors were necessary in forming spatial representations. Because neither dose of AP5 affected the performance of a spatial task in the retention phase, sensory motor disturbances could not have caused these deficits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)