Differential effects of electroconvulsive shock on concurrent spatial memories: "old" memories are impaired while "new" memories are spared

The effects of electroconvulsive shock (ECS) on spatial memory first reported by Shavalia, Dodge, and Beatty (1981, Behavioral and Neural Biology, 31, 261-273) were systematically replicated in two experiments. Rats acquired concurrent spatial memories in two 8-arm radial mazes. Each rat was allowed four choices in Maze 1 and then, after 2 h, four choices in Maze 2. After 2 h each rat was tested for retention in Maze 1 and, after 2 more h, was tested for retention in Maze 2. A single ECS was administered immediately after the fourth choice in Maze 2. Retention (as measured by accuracy of Choices 5-8) was diminished for Maze 1 but not for Maze 2. In the second experiment, the delay between the retention tests was eliminated (thus holding the ECS-Choice 5 interval constant for the two mazes). Once again retention of Maze 1 was impaired and retention of Maze 2 was spared; that finding suggests that ECS does not proactively affect radial-arm maze performance. The results of a third experiment converge on the same conclusion; ECS failed to reduce levels of spontaneous alternation. Therefore, ECS appears to interfere retroactively with relatively old spatial memories and newly established memories appear to be immune to the amnestic effects of ECS. Implications and various explanations are considered.     

Influence of Destabilization on the Temporal Characteristics of lquot;Volitionalrquot; Stepping

Previous work suggests that there may be fundamental differences between compensatory stepping responses evoked by postural perturbation and visually cued "volitional" stepping (e.g., gait initiation). In contrast to visual cueing, postural destabilization evokes an array of sensory inputs that are intrinsically linked to the mobilization of rapid compensatory responses. The hypothesis examined in this study was that this fundamental difference would lead to distinct changes in the temporal characteristics of the stepping response. Six healthy young adults were instructed to step quickly in response to either visual cueing or anterioposterior platform motion. Both forward and backward stepping responses were characterized, using measures of vertical ground reaction force. A stereotypical temporal patterning of the stepping response occurred in both stimulus conditions and both directions of stepping, and anticipatory postural adjustments were evident in all trials. However, postural destabilization led to a more rapid initiation and execution of the temporal pattern, in comparison with visually cued responses. The most pronounced effect was seen in the duration of the response, which was reduced by a factor of two, with approximately proportional foreshortening of both the preparatory and swing phases. The results suggest that sensory information conveying a state of instability has a distinct influence on the characteristics of a subsequent stepping reaction. The persistence of the anticipatory postural adjustments suggests that the failure to see this element of the response in previous studies may reflect fundamental differences between volitional and unplanned compensatory stepping.     

Demographic, clinical, and neurocognitive correlates of everyday functional impairment in severe mental illness

Although cognitive deficits often accompany severe mental illness, their implications for everyday functioning remain poorly understood. In this study, an occupational therapist (OT) rated the everyday functioning of 105 adult psychiatric patients. Using demographic, clinical, and cognitive variables, the authors tested alternative models to account for the observed variability in OT ratings. Although age, education, and the presence of schizophrenia each contributed to a model that accounted for 27% of the variation in functional independence, adding terms for auditory divided attention and verbal learning increased the proportion of explained variance to 45% and decreased the beta weights for age and education--but not schizophrenia--to nonsignificant levels. These findings demonstrate the relevance of cognitive performance to everyday functioning in severe mental illness. They are discussed with respect to hypothesized determinants of psychiatric disability.     

Influence of Destabilization on the Temporal Characteristics of “Volitional” Stepping

Previous work suggests that there may be fundamental differences between compensatory stepping responses evoked by postural perturbation and visually cued “volitional” stepping (e.g., gait initiation). In contrast to visual cueing, postural destabilization evokes an array of sensory inputs that are intrinsically linked to the mobilization of rapid compensatory responses. The hypothesis examined in this study was that this fundamental difference would lead to distinct changes in the temporal characteristics of the stepping response. Six healthy young adults were instructed to step quickly in response to either visual cueing or anterioposterior platform motion. Both forward and backward stepping responses were characterized, using measures of vertical ground reaction force. A stereotypical temporal patterning of the stepping response occurred in both stimulus conditions and both directions of stepping, and anticipatory postural adjustments were evident in all trials. However, postural destabilization led to a more rapid initiation and execution of the temporal pattern, in comparison with visually cued responses. The most pronounced effect was seen in the duration of the response, which was reduced by a factor of two, with approximately proportional foreshortening of both the preparatory and swing phases. The results suggest that sensory information conveying a state of instability has a distinct influence on the characteristics of a subsequent stepping reaction. The persistence of the anticipatory postural adjustments suggests that the failure to see this element of the response in previous studies may reflect fundamental differences between volitional and unplanned compensatory stepping.     

Evaluation of a Web-based introductory psychology course: II. Contingency management to increase use of on-line study aids

In a Web-based general psychology course, students were observed to postpone use of on-line study aids until 2 days prior to examinations, thus negating any influence of advance organizers (Taraban, Maki, & Rynearson, 1999). We attempted to modify this behavior by providing course credit in the form of short quizzes as rewards for using on-line study aids to preview each chapter. Some students received quizzes after previewing frequently asked questions (FAQ); other students received quizzes after previewing chapter outlines. Students who received quizzes for previewing FAQ pages accessed those pages more frequently than did students who received quizzes for previewing outline pages. Increased access to FAQs was associated with higher scores on FAQ-related midterm examination questions. However, the advantage on examination items was not apparent on a cumulative final examination. Navigational structures and reward values need to be considered when one is managing contingencies in Web courses.     

Egocentric spatial framework effects from single and multiple points of view

In three experiments, we tested the one-place, one-perspective rule formulated by Franklin, Tversky, and Coon (1992). This rule proposes that subjects take a neutral, external perspective when they must use multiple viewpoints to make decisions about the locations of objects in memorized scenes. We compared responding from a single viewpoint with responding from two viewpoints. In Experiments 1 and 2, we used a sentence verification procedure, and in Experiment 3, we compared a true-false verification procedure with a six-alternative forced-choice procedure. Under these various conditions, we observed egocentric spatial framework effects in that above-below judgments were faster than front-back judgments and front-back judgments were faster than right-left judgments. When responding from two points of view in a single place, our subjects took multiple intrinsic perspectives rather than one neutral external perspective as proposed by the one-place, one-perspective rule.     

Life history correlates of ministerial success

Life history or biodata correlates of ministerial success were investigated for a group of 92 Seventh-Day Adventist ministers. The criterion data reflected their current level of success and the predictors reflected their status as seminarians between the years 1940 to 1950. Two significant bivariate correlations indicated that successful ministers chose their career later than less successful ones and that earning college expenses was predictive of success. A stepwise multiple regression process was used to develop a weighted prediction model, but the model did not hold when cross-validated.     

Metamemory for narrative text

In this experiment, we investigated metamemory for narrative text passages. Subjects read two stories and made memory predictions for the idea units in one and rated the importance of ideas in the other. Half of the subjects were asked to recall the story immediately after reading the passages and half were asked to recall 1 week later; half received passages with single inconsistent idea units and half received passages with corresponding consistent idea units. All subjects made confidence judgments about the accuracy of their recall. Subjects’ prediction ratings were related to recall, as shown by significant prediction accuracy quotients. Importance ratings were related to recall on the delayed test but not on the immediate test. Memory prediction ratings predicted recall better than did importance ratings. The absolute level of memory predictions did not differ with delay, but subjects did give higher confidence judgments on an immediate than on a delayed test. Subjects recalled the inconsistent idea better than the consistent idea for one story but not for the other. For both stories, subjects predicted that they would remember the inconsistent ideas better, suggesting that they have avon Restorff-type view, rather than a schema view, of memory. We conclude that subjects can predict their memory for the idea units in narrative text.