von Restorff revisited: Isolation, generation, and memory for order.

The effects of isolation and generation on memory for order were investigated in 4 experiments. Exp 1 and 2 examined the effect of isolation on order retention. Previous investigations in this area have yielded equivocal results. Experiments 1 and 2 revealed that isolation enhances memory for order: Isolated items were repositioned more accurately than comparable items in control lists. Experiments 3 and 4 investigated the effect of generation on order retention. These experiments revealed that generation can enhance, disrupt, or have no effect on memory for order, depending on the relative number of generated items appearing within a list. Implications of these results for general theoretical accounts of isolation effects in memory are discussed. A simplified feature model (J. S. Nairne, see record 1990-27505-001) is shown to provide a general account of isolation effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Juice from king palm (Archontophoenix alexandrae) leaf sheathes: chemical characterisation and use in soft drink formulation

The heart of palm is a food extracted from several species of palm trees. Only 10–20% of the raw material is transformed into canned hearts of palm, therefore this agro‐industry generates a large quantity of solid residue. The aim of this work was to extract and characterise a juice produced from this solid residue. This extract is compared with the traditional fruit juices (orange and pineapple juices), obtaining higher contents of minerals, such as magnesium (22.80 mg/100 g) and potassium (276.90 mg/100 g), phenolic compounds (gallic, 3,4‐dihydroxybenzoic, chlorogenic, syringic and caffeic acids) and high free radical scavenging capacity (expressed as 2,2‐diphenyl‐1‐picrylhydrazyl), which suggest high antioxidant activity. Additionally, a new soft drink was formulated using this king palm juice as its main ingredient. The soft drink samples formulated with this juice had high sensory acceptability and high intention of consumption, which suggests an important and low‐cost application for this industrial residue.     

Generation effects with nonwords: The role of test appropriateness.

Assessed the role of test appropriateness by studying generation effects with nonwords in 2 experiments, using 96 undergraduates. In Exp I, which used the switching of 2 letters as the generate task, Ss showed better memory for generated nonwords when the retention test assessed memory for which letters had been switched; in Exp II, a generation effect for nonwords emerged when Ss were required to generate items again at test, prior to the recognition decision. Results demonstrate that a robust generation effect can occur with meaningless items, as long as retention tests show sensitivity to what Ss actually generate in the nonword case. It is suggested that to allow for a generation effect to emerge, it is necessary to match what is actually generated with what is tested in the retention environment. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Citrate vs. acetate dialysate on intradialytic heparin dose: A double blind randomized crossover study

Introduction Citrate containing dialysate has a calcium‐binding anticoagulant effect compared to standard acetic acid containing dialysate. We performed a randomized, double‐blind, crossover trial in maintenance HD patients to determine if citrate dialysate (“citrate”) safely allows for a lower cumulative heparin dose (“heparin dose”). Methods Intradialytic heparin was adjusted to the minimum during a 2‐week run‐in phase. Patients remaining on heparin at the end of the run‐in phase were then randomized to two weeks of HD with acetate dialysate (“acetate”) followed by two weeks of citrate (sequence 1) or two weeks of citrate followed by two weeks of acetate (sequence 2). We estimated a minimum of 14 patients are required to show a 30% reduction in heparin dose per HD session with citrate compared with acetate. Twenty‐five patients entered the run‐in phase, 20 were randomized, and 19 completed the study. Findings The mean heparin dose was reduced by 19% (656 units, 95% CI ?174 to ?1139 units, P = 0.011) in the acetate group, and 30% (1046 units 95% CI ?498 to 1594 units, P < 0.001) in the citrate group. There was no difference in the mean heparin dose reduction between the two dialysates (P > 0.05). The intradialytic ionized calcium in the citrate group was lowered by 0.10 mmol/L (95% CI 0.07 to 0.14 mmol/L, P < 0.001), and remained unchanged in the acetate group. Discussion Although citrate is a safe alternative to acetate, it does not result in additional heparin dose reduction.     

Critique of the retrieval/deblurring assumptions of the theory of distributed associative memory.

Critiques the retrieval assumptions proposed by S. Lewandowsky and B. B. Murdock (see record 1989-14457-001) in their application of Murdock's theory of distributed associative memory (TODAM) to problems in serial-order recall. Two different methods for "deblurring" the products of retrieval are described, along with simulations appropriate for each. It is demonstrated that the deblurring assumptions used by Lewandowsky and Murdock in their simulation version of the model, although appropriate for some aspects of serial-anticipation learning, provide an inadequate account of general serial recall and, in fact, predict several trends that are inconsistent with known data. The analytic version of the model is considered and some additional problems are noted. Overall, the deblurring assumptions critically affect the performance of TODAM, and it is these assumptions rather than the model per se that determine a sizable proportion of its behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The mnemonic value of perceptual identification.

In four experiments, subjects were required to name words presented on a CRT screen. On generate trials, the words were presented quickly, at a point where roughly half could be identified correctly; on read trials, the items were presented for a full second, allowing for rapid and easy naming. A surprise recognition test for the presented items then revealed a substantial retention advantage for the briefly presented items, but no similar advantage was produced in recall. It is argued that under rapid viewing conditions subjects may fail to extract enough visual features to allow for immediate resolution, requiring the initiation of a kind of data-driven generation process. This latter process then produces a generation effect for the briefly presented items compared with the read items, but only on a retention test that shows sensitivity to data-driven processing. These results are discussed from the standpoint of current theoretical views on the generation effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Congruity effects in the survival processing paradigm.

Five experiments were conducted to investigate a proposal by Butler, Kang, and Roediger (2009) that congruity (or fit) between target items and processing tasks might contribute, at least partly, to the mnemonic advantages typically produced by survival processing. In their research, no significant survival advantages were found when words were preselected to be highly congruent or incongruent with a survival and control (robbery) scenario. Experiments 1a and 1b of the present report show that survival advantages, in fact, generalize across a wide set of selected target words; each participant received a unique set of words, sampled without replacement from a large pool, yet significant survival advantages remained. In Experiment 2, we found a significant survival advantage using words that had been preselected by Butler et al. to be highly unrelated (or irrelevant) to both the survival and control scenarios. Experiment 3 showed a significant survival advantage using word sets that had been preselected to be highly congruent with both scenarios. Finally, Experiment 4 mixed congruent and incongruent words in the same list, more closely replicating the design used by Butler et al., and a highly reliable main effect of survival processing was still obtained (although the survival advantage for the congruent words did not reach conventional levels of statistical significance). Our results suggest that the null effects of survival processing obtained by Butler et al. may not generalize beyond their particular experimental design. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Adaptive memory: Survival processing enhances retention.

The authors investigated the idea that memory systems might have evolved to help us remember fitness-relevant information--specifically, information relevant to survival. In 4 incidental learning experiments, people were asked to rate common nouns for their survival relevance (e.g., in securing food, water, or protection from predators); in control conditions, the same words were rated for pleasantness, relevance to moving to a foreign land, or personal relevance. In surprise retention tests, participants consistently showed the best memory when words were rated for survival; the survival advantage held across recall, recognition, and for both within-subject and between-subjects designs. These findings suggest that memory systems are "tuned" to remember information that is processed for fitness, perhaps as a result of survival advantages accrued in the past. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Concentration of biologically active compounds extracted from Ilex paraguariensis St. Hil. by nanofiltration

The aim of this study was to characterise the bioactive compounds in mate (Ilex paraguariensis St. Hil) extract and in concentrated mate extract obtained by nanofiltration (NF). Also, the impact of NF on the antioxidant activity of both mate extracts was evaluated in vitro and using eukaryotic cells of Saccharomyces cerevisiae (yeast assay). The results showed a significant increase in the contents of total phenolics (338%), chlorogenic acid (483%), theobromine (323%), caffeine (251%), chlorophyll (321%), condensed tannins (278%) and saponins (211%) in the concentrated mate extract. The concentrated mate extract showed higher in vitro antioxidant activity than the mate extract. According to the results obtained, it can be stated that the use of nanofiltration membrane is a valid approach for the concentration of biologically active compounds in aqueous extract of mate.