The effect of spatial learning on the number of astrocytes in rat dentate gyrus

In this study, we evaluated the effect of spatial learning on the number of astrocytes in the rat dentate gyrus with Morris water maze. Fifteen male albino Wistar rats were divided into three groups as control, reference memory and working memory groups. Each group was consisted of 5 rats. After spatial learning, the brains were histologically examined; the slides were stained with phosphotungstic acid hematoxylin (PTAH) staining to show the astrocytes. We found significant difference in the number of astrocytes in dentate gyrus between control and reference memory groups, and between control and working memory groups as well. When compared two learning groups there was a significant difference in the number of astrocytes between them, being higher in the working memory group. We concluded that the number of astrocytes increased due to spatial learning and this increase can be affected to the period of learning. Our studies of spatial learning and effect of learning techniques (reference and working memory) showed that the technique that has longer period of learning has more effect on the number of astrocytes

The self-reference effect on memory in early childhood

The self-reference effect in memory is the advantage for information encoded about self, relative to other people. The early development of this effect was explored here using a concrete encoding paradigm. Trials comprised presentation of a self- or other-image paired with a concrete object. In Study 1, 4- to 6-year-old children (N = 53) were asked in each trial whether the child pictured would like the object. Recognition memory showed an advantage for self-paired objects. Study 2 (N = 55) replicated this finding in source memory. In Study 3 (N = 56), participants simply indicated object location. Again, recognition and source memory showed an advantage for self-paired items. These findings are discussed with reference to mechanisms that ensure information of potential self-relevance is reliably encoded

Simplex minimisation for multiple-reference motion estimation

This paper investigates the properties of the multiple-reference block motion field. Guided by the results of this investigation, the paper proposes three fast multiple-reference block matching motion estimation algorithms. The proposed algorithms are extensions of the single-reference simplex minimisation search (SMS) algorithm. The algorithms provide different degrees of compromise between prediction quality and computational complexity. Simulation results using a multi-frame memory of 50 frames indicate that the proposed multiple-reference SMS algorithms have a computational complexity comparable to that of single-reference full-search while still maintaining the prediction gain of multiple-reference motion estimatio

The Spatial Memory of African Elephants (\u3cem\u3eLoxodonta africana\u3c/em\u3e): Durability, Interference, and Response Biases

Women and elephants never forget an injury. -Saki (H. H. Munro), Reginald on besetting sins, in Reginald (1904) I am not sure whether the satirist H. H. Munro believed Saki\u27s claim, although it may well be true (at least with regard to elephants). This chapter will examine some characteristics of elephant memory more systematically than did Saki. In general, it is to an animal\u27s advantage to remember some aspects (usually the stable features) of a situation for long periods and to remember other aspects (usually the unstable features) only temporarily. Consistent with recent arguments questioning the value of cognitive constructs for studying animal behavior (Grau 2002; Staddon 2001a,b; Wright and Watkins 1987), I will use reference memory and working memory (Baddeley and Hitch 1974; Honig 1978) only as descriptive terms indicating formal task requirements. (See Olton, Becker, and Handelmann 1979.) The stable characteristics of the test situation (such as the shape of the spatial array of food sources) are said to involve reference memory; those features that vary across trials (such as the sequence of food sites visited on a trial) are said to involve working memory. My main goal is to demonstrate that elephants can remember which locations they have visited during a spatial memory test similar to the radial maze (Olton and Samuelson 1976). The data will show that elephants rely on memory to solve several spatial problems, rather than relying on their response biases (Dale and Innis 1986) or their excellent olfactory abilities (Rasmussen and Krishnamurthy 2000). In addition, I will describe research showing that performance on the memory task is susceptible to proactive interference and that the retention of reference memory components of the test procedures is durable

Distortions in memory for visual displays

Systematic errors in perception and memory present a challenge to theories of perception and memory and to applied psychologists interested in overcoming them as well. A number of systematic errors in memory for maps and graphs are reviewed, and they are accounted for by an analysis of the perceptual processing presumed to occur in comprehension of maps and graphs. Visual stimuli, like verbal stimuli, are organized in comprehension and memory. For visual stimuli, the organization is a consequence of perceptual processing, which is bottom-up or data-driven in its earlier stages, but top-down and affected by conceptual knowledge later on. Segregation of figure from ground is an early process, and figure recognition later; for both, symmetry is a rapidly detected and ecologically valid cue. Once isolated, figures are organized relative to one another and relative to a frame of reference. Both perceptual (e.g., salience) and conceptual factors (e.g., significance) seem likely to affect selection of a reference frame. Consistent with the analysis, subjects perceived and remembered curves in graphs and rivers in maps as more symmetric than they actually were. Symmetry, useful for detecting and recognizing figures, distorts map and graph figures alike. Top-down processes also seem to operate in that calling attention to the symmetry vs. asymmetry of a slightly asymmetric curve yielded memory errors in the direction of the description. Conceptual frame of reference effects were demonstrated in memory for lines embedded in graphs. In earlier work, the orientation of map figures was distorted in memory toward horizontal or vertical. In recent work, graph lines, but not map lines, were remembered as closer to an imaginary 45 deg line than they had been. Reference frames are determined by both perceptual and conceptual factors, leading to selection of the canonical axes as a reference frame in maps, but selection of the imaginary 45 deg as a reference frame in graphs

Analysing Compression Techniques for In-Memory Collaborative Filtering

Following the recent trend of in-memory data processing, it is a usual practice to maintain collaborative filtering data in the main memory when generating recommendations in academic and industrial recommender systems. In this paper, we study the impact of integer compression techniques for in-memory collaborative filtering data in terms of space and time efficiency. Our results provide relevant observations about when and how to compress collaborative filtering data. First, we observe that, depending on the memory constraints, compression techniques may speed up or slow down the performance of state-of-the art collaborative filtering algorithms. Second, after comparing different compression techniques, we find the Frame of Reference (FOR) technique to be the best option in terms of space and time efficiency under different memory constraints

A Java Reference Model of Transacted Memory for Smart Cards

Transacted Memory offers persistence, undoability and auditing. We present a Java/JML Reference Model of the Transacted Memory system on the basis of our earlier separate Z model and C implementation. We conclude that Java/JML combines the advantages of a high level specification in the JML part (based on our Z model), with a detailed implementation in the Java part (based on our C implementation)

Image correlators using optical memory disks

Image correlators are described and experimentally demonstrated that are implemented using optical memory disks to store a large library of reference images