In three experiments, we examined the internal processing mechanisms of relatively independent visual-form subsystems. Participants first viewed centrally presented word pairs and then completed word stems presented beneath context words in the left or right visual field. Letter-case-specific priming in stem completion was found only when the context word was the same word that had previously appeared above the primed completion word and the items were presented directly to the right cerebral hemisphere. This pattern of results was not found when participants deliberately recollected previously presented words when completing the stems. Results suggest that holistic processing, not parts-based processing as assumed in many contemporary theories of visual-form recognition, is performed in a subsystem that distinguishes specific instances in the same abstract category of form and that operates more effectively in the right hemisphere than in the left hemisphere.The ability to distinguish specific instances in the same abstract category of visual form is an important human faculty. One can differentiate a particular cup from other cups as well as an individual's signature from other written versions of the same set ofletters. An interesting aspect of this ability is that most theories of visual-form recognition, aside from theories that address only face recognition (e.g., Bruce & Young, 1986;Rhodes, 1985), do not focus on how it is accomplished. Most theories focus instead on the ability to distinguish different abstract types of visual forms (e.g., Biederman, 1987;Morton, 1979). Of course, the latter ability is also important and interesting. One can distinguish a cup from a pen, as well as the word form "cup" from the word form "pen," even when the input is an instance that has not been seen before. In the research reported in this article, we tested whether at least relatively independent processing subsystems support the two abilities. More importantly, we examined form-specific priming for novel holistic structures to test whether holistic processing, as opposed to parts-based processing of the sort assumed in many contemporary theories of visual form recognition (e.g., Biederman, 1987;Morton, 1979), characterizes the operations in a subsystem that distinguishes specific instances in an abstract category of form. VISUAL-FORM SUBSYSTEMSWe hypothesize that a specific visual-form (SVF) subsystem underlies recognition of specific instances of forms and operates more effectively in the right cerebral hemisphere (RH) than in the left cerebral hemisphere (LH). In contrast, an abstract visual-form (AVF) subsystem supports recognition of abstract categories of forms and operates more effectively in the LH than in the RH. These subsystems likely focus on different properties of visual-form inputs to achieve different goals. SVF SubsystemIn order to produce different outputs when different instances in the same abstract category appear as inputs, an SVF subsystem must process a form's visually distinctive information ef...

The I locus controls inhibition of anthocyanin accumulation in the epidermal cells of the soybean seed coat and affects abundance of PRP1, a proline-rich cell wall protein in the seed coat. Saline-soluble PRP1 is abundant in the developing seed coats of cultivar Richland (homozygous I, yellow), while it is significantly decreased in the pigmented isogenic mutant T157 (homozygous i, imperfect black). In this report, we examined soluble PRP1 in several cultivars containing alleles of the I locus which affect spatial distribution of pigmentation in the seed coat. We also characterized PRP1 in isolines with allelic variants of several other loci involved in seed coat pigmentation, including T and Im. The T gene is pleiotropic and affects both pubesence color and seed coat pigmentation and structure. Soluble PRP1 was abundant in the developing seed coats of lines with yellow seed (I or ii alleles) regardless of pubescence color, just as in Richland. Likewise, soluble PRP1 was decreased in pigmented seed coats (ik or i alleles) with grey (t) pubescence, as in T157. However, the total seed coat proteins were not extractable from pigmented seed coats with tawny pubescence (i, T genotypes) because they have proanthocyanidins that exhibit tannin properties. The dominant Im allele inhibits seed coat mottling (irregular patches of pigmentation) that occurs if plants are infected with soybean mosaic virus. PRP1 was 35 kDa in mottled (im) isolines and 34 kDa in non-mottled (Im) isolines. PRP2, which is expressed later in seed coat development and in the hypocotyl hooks of soybean seedlings, was also smaller in Im isolines. In summary, some of the anthocyanin mutations affect the quantity of soluble PRP1 polypeptides. while others correlate with structural changes in developmentally regulated proline-rich proteins.

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The placement of postpyloric feeding tubes has been clinically difficult. A study was undertaken to identify a reliable bedside manual technique. One hundred one consecutive enteral feeding tubes were placed in 93 patients at the bedside. One patient was not available for radiographic evaluation. Nonweighted, straight tubes were used in supine patients premedicated with metoclopramide. Two additional stock wire stylets were used to stiffen the tubes. The tubes were simply advanced. If resistance was encountered, the tube was backed up and advanced again. Tip location was checked by injection of blue dye and plain roentgenography. Sixty-nine percent of tubes were placed to the ligament of Treitz or jejunum, 15% in the third or fourth portion of the duodenum (D3/D4), 11% in DlfD2, and 5% in the pylorus or stomach. Ninety-five percent of tubes were used successfully for enteral nutrition. Time for placement was 28 ? 22 minutes (mean k SD). Blue saline injection localized tube position correctly relative to the pylorus more frequently than plain roentgenography 198% us 95%, not statistically significant (NSS)]. Ninety-five percent of feeding tubes were positioned distal to the stomach. Simple bedside placement of stiffened feeding tubes is effective and reliable.

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