Age dissociates recency and lag recency effects in free recall

The temporal relations among word-list items exert a powerful influence on episodic memory retrieval. Two experiments were conducted with younger and older adults in which the age-related recall deficit was examined by using a decomposition method to the serial position curve, partitioning performance into (a) the probability of first recall, illustrating the recency effect, and (b) the conditional response probability, illustrating the lag recency effect (M. W. Howard & M. J. Kahana, 1999). Although the older adults initiated recall in the same manner in both immediate and delayed free recall, temporal proximity of study items (contiguity) exerted a much weaker influence on recall transitions in older adults. This finding suggests that an associative deficit may be an important contributor to older adults' well-known impairment in free recall.     

A functional relation between learning and organization in free recall

It is well known that multitrial free recall is accompanied by increased organization of output over learning trials, even when the order of presentation is randomized. We compared the relation between learning and organization in 30 young and 30 older adults as they learned categorized materials to a criterion of 100% recall. The importance of this age manipulation was that it allowed us to examine, using two groups that differ significantly in their learning ability, whether organization and learning follow the same function. As was expected, older adults showed less organization on any given learning trial. However, when equated for degree of learning, the older adults showed approximately the same level of organization as the young. This finding suggests that the organization-learning relation remains invariant in the face of significant differences in participants’ mnemonic abilities.     

The temporal contiguity effect predicts episodic memory performance

One way to study the associative processes at work during episodic memory is to examine the order of participant responses, which reveal the strong tendency to transition between temporally contiguous or semantically proximal items on the study list. Here, we assessed the correlation between participants’ recall performance and their use of semantic and temporal associations to guide retrieval across nine delayed free recall studies. The size of the participants’ temporal contiguity effects predicted their recall performance. When interpreted in terms of two models of episodic memory, these results suggest that participants who more effectively form and retrieve associations between items that occur nearby in time perform better on episodic recall tasks. Sample code may be downloaded as a supplement for this article from http://mc.psychonomic-journals.org/content/ supplemental.     

PandaEPL: A library for programming spatial navigation experiments

Recent advances in neuroimaging and neural recording techniques have enabled researchers to make significant progress in understanding the neural mechanisms underlying human spatial navigation. Because these techniques generally require participants to remain stationary, computer-generated virtual environments are used. We introduce PandaEPL, a programming library for the Python language designed to simplify the creation of computer-controlled spatial-navigation experiments. PandaEPL is built on top of Panda3D, a modern open-source game engine. It allows users to construct three-dimensional environments that participants can navigate from a first-person perspective. Sound playback and recording and also joystick support are provided through the use of additional optional libraries. PandaEPL also handles many tasks common to all cognitive experiments, including managing configuration files, logging all internal and participant-generated events, and keeping track of the experiment state. We describe how PandaEPL compares with other software for building spatial-navigation experiments and walk the reader through the process of creating a fully functional experiment.     

Semantic cuing and the scale insensitivity of recency and contiguity

In recalling a set of previously experienced events, people exhibit striking effects of recency, contiguity, and similarity: Recent items tend to be recalled best and first, and items that were studied in neighboring positions or that are similar to one another in some other way tend to evoke one another during recall. Effects of recency and contiguity have most often been investigated in tasks that require people to recall random word lists. Similarity effects have most often been studied in tasks that require people to recall categorized word lists. Here we examine recency and contiguity effects in lists composed of items drawn from 3 distinct taxonomic categories and in which items from a given category are temporally separated from one another by items from other categories, all of which are tested for recall. We find evidence for long-term recency and for long-range contiguity, bolstering support for temporally sensitive models of memory and highlighting the importance of understanding the interaction between temporal and semantic information during memory search.     

PyParse: A semiautomated system for scoring spoken recall data

Studies of human memory often generate data on the sequence and timing of recalled items, but scoring such data using conventional methods is difficult or impossible. We describe a Python-based semiautomated system that greatly simplifies this task. This software, called PyParse, can easily be used in conjunction with many common experiment authoring systems. Scored data is output in a simple ASCII format and can be accessed with the programming language of choice, allowing for the identification of features such as correct responses, prior-list intrusions, extra-list intrusions, and repetitions.     

Spirituality and Healthy Lifestyle Behaviors: Stress Counter-balancing Effects on the Well-being of Older Adults

The goal of this study was to examine stress-ameliorating effects of religiosity, spirituality, and healthy lifestyle behaviors on the stressful relationship of chronic illness and the subjective physical well-being of 221 older adults. We also investigated whether the intervening variables functioned as coping behaviors and orientations or as adaptations in late life. Guided by the stress paradigm, path analysis was used to assess these relationships in a stress suppressor model and a distress deterrent model. No suppressor effects were found; however a number of distress deterrent relationships were detected. Spirituality, physical activities, and healthy diet all contributed to higher subjective physical well-being, as counter-balancing effects, in the distress deterrent model. The findings have implications for future research on the role of spirituality, religiosity and lifestyle behaviors on the well-being of chronically ill older adults. Findings also support the need for studying different dimensions of religiosity and spirituality in an effort to understand coping versus adaptation in behaviors and orientations. Gracie H. Boswell, Ph.D., M.Ed. (Case Western Reserve University) and (M. Ed.- Kent State University). She is a Carolina Program in Health and Aging Research Scientist at the Institute on Aging- University of North Carolina at Chapel Hill. Her research interests have been social gerontology and quality of life, emphasizing religiosity/spirituality. Eva Kahana, Ph.D. (University of Chicago) is Pierce T. and Elizabeth D. Robson Professor of Humanities and Director of the Elderly Care Research Center- Case Western Reserve University. Her research concentration has been the sociology of aging (coping & stress and institutionalization). Peggye Dilworth-Anderson, Ph.D. (Northwestern University) is Director- Center for Aging and Diversity, Institute on Aging, Professor- School of Public Health, Department of Health Policy and Administration at University of North Carolina at Chapel Hill. Her research interests have been caregiving and minority health disparities.     

Gamma oscillations distinguish true from false memories

ABSTRACT— To test whether distinct patterns of electrophysiological activity prior to a response can distinguish true from false memories, we analyzed intracranial electroencephalographic recordings while 52 patients undergoing treatment for epilepsy performed a verbal free-recall task. These analyses revealed that the same pattern of gamma-band (28–100 Hz) oscillatory activity that predicts successful memory formation at item encoding—increased gamma power in the hippocampus, prefrontal cortex, and left temporal lobe—reemerges at retrieval to distinguish correct from incorrect responses. The timing of these oscillatory effects suggests that self-cued memory retrieval begins in the hippocampus and then spreads to the cortex. Thus, retrieval of true, as compared with false, memories induces a distinct pattern of gamma oscillations, possibly reflecting recollection of contextual information associated with past experience.