Medial Temporal Lobe Volume Predicts Elders’ Everyday Memory

Deficits in memory for everyday activities are common complaints among healthy and demented older adults. The medial temporal lobes and dorsolateral prefrontal cortex are both affected by aging and early-stage Alzheimer’s disease, and are known to influence performance on laboratory memory tasks. We investigated whether the volume of these structures predicts everyday memory. Cognitively healthy older adults and older adults with mild Alzheimer’s-type dementia watched movies of everyday activities and completed memory tests on the activities. Structural MRI was used to measure brain volume. Medial temporal but not prefrontal volume strongly predicted subsequent memory. Everyday memory depends on segmenting activity into discrete events during perception, and medial temporal volume partially accounted for the relationship between performance on the memory tests and performance on an event-segmentation task. The everyday-memory measures used in this study involve retrieval of episodic and semantic information as well as working memory updating. Thus, the current findings suggest that during perception, the medial temporal lobes support the construction of event representations that determine subsequent memory

How does aging influence object-location and name-location binding during a visual short-term memory task?

Objective: Age-related impairments in human visual short-term memory (VSTM) may reflect a reduced ability to retain bound object representations, viz., object form, name, spatial, and temporal location (so called ‘memory sources’). Our objective is to examine how healthy aging affects VSTM in a battery of memory recognition tasks in which sequentially presented objects, locations, and names (as auditory stimuli) were learned, with one component cued at test. Methods: Thirty-six young healthy adults (18-30 years) and 36 normally aging older adults (>60 years with no underlying health and vision issues) completed five VSTM tasks: 1. Object recognition for two or four objects; 2. Spatial location recognition for two or four objects; 3. Bound object-location recognition for two or four objects; 4. Object recognition with location priming for two or four objects; 5. Bound name (auditory)-location (cross-modal) recognition for four objects. Results: Significantly lower performance for older adults was found in spatial location recognition [task 2, p=0.03, 2 (memory loads) × 2 (age groups) ANOVA], bound object-location recognition [task 3, p˂0.001, 2 (memory loads) × 2 (age groups) ANOVA], object recognition with location priming [task 4, p=0.02, 2 (memory loads) × 2 (age groups) ANOVA], and bound name-location recognition [task 5, p=0.001, independent samples t-test] tasks. A significant age group-task interaction was found (p =0.02) Conclusion: Performance for all tests except test 1 was impaired in older adults. Lower performance for older adults was most significant in VSTM tasks requiring object-location (visual only) or name-location (auditory and visual) binding. The findings are compatible with the ‘memory source’ model, demonstrating that age-related binding performance is influenced by spatial coding and location priming deficits

A Theoretical Analysis of How Segmentation of Dynamic Visualizations Optimizes Students' Learning

This article reviews studies investigating segmentation of dynamic visualizations (i.e., showing dynamic visualizations in pieces with pauses in between) and discusses two not mutually exclusive processes that might underlie the effectiveness of segmentation. First, cognitive activities needed for dealing with the transience of dynamic visualizations impose extraneous cognitive load, which may hinder learning. Segmentation may reduce the negative effect of this load by dividing animations into smaller units of information and providing pauses between segments that give students time for the necessary cognitive activities after each of those units of information. Second, event segmentation theory states that people mentally segment dynamic visualizations during perception (i.e., divide the information shown in pieces). Segmentation of dynamic visualisation could cue relevant segments to students, which may aid them in perceiving the structure underlying the process or procedure shown

Timelines of past events: Reconstructive retrieval of temporal patterns

Most naturalistic events are temporally and structurally complex in that they comprise a number of elements and that each element may have different onset and offset times within the event. This study examined temporal information processing of complex patterns of partially overlapping stimulus events by using 2 tasks of temporal processing. Specifically, participants observed a pantomime in which 5 actors appeared on the scene for different periods of time. At test, they estimated the duration each actor was present or reconstructed the temporal pattern of the pantomime by drawing a timeline for each actor. Participants made large errors in the time estimation task, but they provided relatively accurate responses by using the timeline as a retrieval support. These findings suggest that temporal processing of complex asynchronous events is a challenging cognitive task, but that reliance on visuo-spatial retrieval support, possibly in combination with other temporal heuristics, may produce functional approximations of complex temporal patterns

Koliko su studenti više medicinske škole u Bitoli upoznati s problemom infekcije HCV-om

Healthcare workers are at risk of occupationally-acquired viral infections such as human immunodefi ciency virus (HIV), hepatitis B (HBV), and hepatitis C (HCV). HCV is parenterally transmitted and has been found in every part of the world. This cross-sectional study was conducted to establish the awareness and attitude about HCV infections among 210 full-time and part-time nursing students of the Medical College in Bitola, Macedonia ‘from May to June 2009. For this purpose we used a self-administered questionnaire which consisted of three parts. The fi rst included demographic data, the second included questions about causes of infection, mode of transmission, symptoms, acute and chronic hepatitis, and prevention, and the third questions about students’ attitude toward patients with suspect or confi rmed HCV infection. Full-time students showed higher HCV awareness (84 %) than part-time students (69 %). 58 % of the full-time and 79 % of the part-time students said they would not avoid professional contact with suspect or HCV infected patients. Our study has shown that even though both groups of students have a suffi cient knowledge about HCV to face future challenges, they need further education on the subject. Practical recommendations would help to reduce stigmatising behaviour still further.Zdravstveni su radnici izloženi profesionalnomu riziku od infekcije virusom humane imunodefi cijencije (HIV-om), hepatitis B virusom (HBV-om) te hepatitis C virusom (HCV-om). HCV se prenosi parenteralno i ima ga posvuda u svijetu. Ovo smo presječno ispitivanje proveli da utvrdimo koliko su studenti za medicinske tehničare i sestre upoznati s infekcijom HCV-om i saznamo njihove stavove o tome. Ispitivanje je obuhvatilo 210 redovitih i izvanrednih studenata Visoke medicinske škole u Bitoli i trajalo je od svibnja do lipnja 2009. Za ispitivanje je rabljen opširan upitnik. Odgovori su pokazali da redoviti studenti imaju bolji uvid u predmet (s 84 % točnih odgovora) od izvanrednih studenata (69 %). U pogledu stava prema pacijentima 58 % redovitih i 79 % izvanrednih studenata ne izbjegava dodir s pacijentima koji su infi cirani HCV-om. Ispitivanje je pokazalo da su studenti iz obje skupine dovoljno upoznati s infekcijom HCV-om, rizičnim čimbenicima i načinom prijenosa, ali je potrebno to znanje nadograditi

Cognitive Load Theory: Advances in Research on Worked Examples, Animations, and Cognitive Load Measurement

The contributions to this special issue document some recent advances of cognitive load theory, and are based on contributions to the Third International Cognitive Load Theory Conference (2009), Heerlen, The Netherlands. The contributions focus on developments in example-based learning, amongst others on the effects of integrating worked examples in cognitive tutoring systems; specify the effects of transience on cognitive load and why segmentation may help counteract these effects in terms of the role of time in working memory load; and discuss the possibilities offered by electroencephalography (EEG) to provide a continuous and objective measure of cognitive load. This article provides a short introduction to the contributions in this issue

My Hand or Yours? Markedly Different Sensitivity to Egocentric and Allocentric Views in the Hand Laterality Task

In the hand laterality task participants judge the handedness of visually presented stimuli – images of hands shown in a variety of postures and views - and indicate whether they perceive a right or left hand. The task engages kinaesthetic and sensorimotor processes and is considered a standard example of motor imagery. However, in this study we find that while motor imagery holds across egocentric views of the stimuli (where the hands are likely to be one's own), it does not appear to hold across allocentric views (where the hands are likely to be another person's). First, we find that psychophysical sensitivity, d', is clearly demarcated between egocentric and allocentric views, being high for the former and low for the latter. Secondly, using mixed effects methods to analyse the chronometric data, we find high positive correlation between response times across egocentric views, suggesting a common use of motor imagery across these views. Correlations are, however, considerably lower between egocentric and allocentric views, suggesting a switch from motor imagery across these perspectives. We relate these findings to research showing that the extrastriate body area discriminates egocentric (‘self’) and allocentric (‘other’) views of the human body and of body parts, including hands

Match-action: the role of motion and audio in creating global change blindness in film

An everyday example of change blindness is our difficulty to detect cuts in an edited moving-image. Edit Blindness (Smith & Henderson, 2008) is created by adhering to the continuity editing conventions of Hollywood, e.g. coinciding a cut with a sudden onset of motion (Match-Action). In this study we isolated the roles motion and audio play in limiting awareness of match-action cuts by removing motion before and/or after cuts in existing Hollywood film clips and presenting the clips with or without the original soundtrack whilst participants tried to detect cuts. Removing post-cut motion significantly decreased cut detection time and the probability of missing the cut. By comparison, removing pre-cut motion had no effect suggesting, contrary to the editing literature, that the onset of motion before a cut may not be as critical for creating edit blindness as the motion after a cut. Analysis of eye movements indicated that viewers reoriented less to new content across intact match-action cuts than shots with motion removed. Audio played a surprisingly large part in creating edit blindness with edit blindness mostly disappearing without audio. These results extend film editor intuitions and are discussed in the context of the Attentional Theory of Cinematic Continuity (Smith, 2012a)