A Sequence of events model of episodic memory shows parallels in rats and humans

A critical feature of episodic memory is the ability to remember the order of events as they occurred in time, a capacity shared across species including humans, nonhuman primates, and rodents. Accumulating evidence suggests that this capacity depends on a network of structures including the hippocampus and the prefrontal cortex, but their respective contributions remain poorly understood. As addressing this important issue will require converging evidence from complementary investigative techniques, we developed a cross‐species, nonspatial sequence memory task suitable for behavioral and neurophysiological studies in rodents and in humans. The task involves the repeated presentation of sequences of items (odors in rats and images in humans) and requires subjects to make a judgment as to whether each item is presented “in sequence” or “out of sequence.” To shed light on the cognitive processes and sequence representations supporting performance, different types of “out of sequence” probe trials were used including: (i) repeating an item from earlier in the sequence (Repeats; e.g., ABA D), (ii) skipping ahead in the sequence (Skips; e.g., ABD ), and (iii) inserting an item from a different sequence into the same ordinal position (Ordinal Transfers; e.g., A2 CD). We found a remarkable similarity in the performance of rats and humans, particularly in the pattern of results across probe trial types. Thus, the results suggest that rats and humans not only remember the sequences of events, but also use similar underlying cognitive processes and mnemonic representations. This strong cross‐species correspondence validates this task for use in future basic and clinical interdisciplinary studies aimed at examining the neural mechanisms underlying episodic memory. © 2014 Wiley Periodicals, Inc.     

Infant rats can acquire,but not retain contextual associations in object-in-context and contextual fear conditioning paradigms

Context learning in postnatal day (PD) 16–18 rats has been taken by Revillo, Cotella, Paglini, and Arias (2015, Physiology & Behavior, 148 , 6–21) to challenge the view that the ontogeny of contextual learning is related to the development of the hippocampal system (Rudy, 1993, Behavioral Neuroscience, 107 (5), 887–891; Schiffino, Murawski, Rosen, & Stanton, 2011 Neurobiology of Learning and Memory, 95 (2), 190–198). Whether context learning is “incidental” or “reinforcement-driven” may determine the ontogeny and neural systems involved (Rudy, 2009, Learning & Memory (Cold Spring Harbor, N.Y.), 16 , 573–585). However, we have shown differential ontogeny of two different forms of incidental context learning, the context pre-exposure facilitation effect (CPFE; Jablonski, Schiffino, & Stanton, 2012, Developmental Psychobiology, 54 (7), 714–722), which emerges between PD 17 and 21; and object-in-context recognition (OiC, Ramsaran, Westbrook, & Stanton, 2016, Developmental Psychobiology, 58 (7), 883–895; Ramsaran, Sanders, & Stanton, 2016, Behavioural Brain Research, 298 , 37–47), which is present on PD17. We investigated whether this task-dissociation reflects an encoding or a retention deficit, by varying the sample-to-testing intervals for both tasks. Experiment 1A found that PD17 rats were able to perform the OiC task after short (5 min) but not long (24 hr) sample-to-test intervals. Experiments 1B and 1C found that PD17 rats trained on the CPFE are able to acquire and express context-shock associations after short but not long retention intervals. These findings suggest that pre-weanling rats encode contexts but show poor consolidation or retrieval after longer retention intervals.     

The impact of the integrative perceptual approach on the teaching of Chinese characters in a Hong Kong kindergarten

This study investigated the effectiveness of the integrative perceptual approach (IPA) to enhancing Hong Kong kindergarten children’s Chinese character learning. The study applied the IPA to an experimental group of 29 lower form (K2) children. A group of 30 upper form children taught via traditional methods the year before, served as the control group. Quantitative data consisted of pre‐ and post‐test scores, analysed using dependent and independent t‐testing. It was found that the pupils in the experimental group had significantly improved their ability between pre‐ and post‐testing in three aspects of Chinese character mastery: shape, sound and meaning recognition. The progress made was significantly superior to that made by control group counterparts. Qualitative data gathered through teacher and parent interviews indicated that the pupils in the experimental group displayed increased awareness of the composition of several components and structures of Chinese characters.     

Functional specialization and dynamic resource allocation in visual cortex

We studied the spatiotemporal characteristics of cortical activity in early visual areas and the fusiform gyri (FG) by means of magnetoencephalography (MEG). Subjects performed a visual classification task, in which letters and visually similar pseudoletters were presented in different surrounds and under different task demands. The stimuli appeared in a cued half of the visual field (VF). We observed prestimulus effects on amplitudes in V1 and Cuneus relating to VF and task demands, suggesting a combination of active anticipation and specialized routing of activity in visual processing. Amplitudes in the right FG between 150 and 350 ms after stimulus onset reflected task demands, while those in the left FG between 300 and 400 ms showed selectivity for graphemes. The contrasting stimulus‐evoked effects in the right and left FG show that the former area is sensitive to task demands irrespective of stimulus content, whereas the left FG is sensitive to stimulus content irrespectively of task demand. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.     

EMPHASIZING AFFECTIVE OUTCOMES IN AN INTRODUCTORY GERONTOLOGY COURSE

No abstract available for this article.     

Influences of context, process and individual differences on nurses' readiness for change to Magnet status

Title.  Influences of context, process and individual differences on nurses' readiness for change to Magnet status.
Aim.  The aim of this study was to test hypotheses associated with a model which explains individuals' readiness in early stages of a change.
Background.  In an effort to improve the quality of nursing care, hospitals in the United States of America seek to obtain Magnet recognition. While it is commonly known that Magnet hospitals provide higher quality patient care, little is known about the variability in nurses' attitudes and behaviour within Magnet hospitals.
Method.  We collected data in 2006 from 310 Registered Nurses to investigate the factors that influence their willingness to embrace the changes necessary for the high levels of excellence accompanying Magnet status. Hierarchical linear modelling was used because the data were multi-level.
Results.  Both change-specific context, such as a culture of research exhibited by the manager, and formal education of the nurse moderated the positive influences of the organization's procedural justice actions. Specifically, procedural justice was stronger when the nurse manager demonstrated a culture of research, and negative effects of low justice were mitigated when nurses had a higher level of formal education.
Conclusion.  Preparing managers beforehand to appreciate and adopt new behaviours associated with a forthcoming organizational change should enhance the success of change practices as new changes are initiated. Moreover, education that exposes employees to the pending realities of their industry, such as nursing research, can play an important role in the development of positive beliefs about changes facing their organizations.     

Impact of water supply and sanitation on diarrheal morbidity among young children in the socioeconomic and cultural context of Rwanda (Africa)

This project studied the frequency and intensity of water contamination at the source, during transportation, and at home to determine the causes of contamination and its impact on the health of children aged 0 to 5 years. The methods used were construction of the infrastructure for three sources of potable water, administration of a questionnaire about socioeconomic status and sanitation behavior, anthropometric measurement of children, and analysis of water and feces. The contamination, first thought to be only a function of rainfall, turned out to be a very complex phenomenon. Water in homes was contaminated (43.4%) with more than 1100 total coliforms/100 ml due to the use of unclean utensils to transport and store water. This socioeconomic and cultural problem should be addressed with health education about sanitation. The latrines (found in 43.8% of families) presented a double-edged problem. The extremely high population density reduced the surface area of land per family, which resulted in a severe nutritional deficit (15% of the children) affecting mainly young children, rendering them more susceptible to diarrhea (three episodes/child/year).     

Medial temporal lobe activation during context-dependent relational processes in episodic retrieval: an fMRI study. Functional magnetic resonance imaging

Previous studies have reported that the medial temporal lobe (MTL) structures contribute to the processing of relations among multiple stimuli in episodic encoding. There have been few studies, however, on the episodic retrieval requiring processing of relations among multiple components that was involved in our events. We used functional magnetic resonance imaging (fMRI) to investigate neural activities during the retrieval of relations within an organized episode and the recognition of an episodic component. Healthy, normal participants memorized 50 four-scene comic strips before fMRI scanning. In the retrieval phase with fMRI scanning, participants were engaged in three tasks: a visual identification (VI) task, a story recall (SR) task, and a picture recognition (PRe) task. In the VI task, participants were asked to judge whether they could identify at least one female character in the two scenes presented vertically. In the SR task, participants were shown the first and last scenes from strips memorized previously and asked to judge whether or not the two scenes were from the same strip. In the PRe task, participants were shown two scenes and asked to judge whether they both belonged to the memorized scenes. The two contrasts of SR with VI and PRe with VI demonstrated some commonly activated areas, such as the bilateral middle frontal gyrus and cerebellum. More importantly, the SR task differentially activated the bilateral parahippocampal gyrus, whereas the PRe task differentially activated right prefrontal areas, including the inferior frontal and precentral gyri. The results suggest that the activity of the MTL structures may be strongly associated with episodic memory retrieval requiring context-dependent relational processing.     

Parent-child interaction and children's number learning

Two groups of Chinese four-year-olds and their parents' interaction in joint activities were analyzed and compared. The children in Group 1 were high scorers in written number skills and the children in Group 2 were low scorers. Eighty-five dyads participated in four separate 15-minute joint activities such as book reading, mathematical worksheets, blank paper and blocks. A mini-questionnaire was also administered. The results indicated that a wide variety of mathematics and interactive strategies were involved in the activities, that there was no difference in the frequency of mathematical events occurring in the activities between the two groups, that more parents in Group 1 used several more positive strategies than the parents in Group 2, that more children in Group 2 had trouble remaining engaged in the activity, and that the frequency and the quality of parent-child joint activities at home, such as book reading and mathematical worksheets, were possible contributors to children's development of mathematics.