Mente Activa® Improves Impaired Spatial Memory in Aging Rats.

OBJECTIVES: Aging is accompanied by a decline in several aspects of the cognitive function, having negative personal and socioeconomic impacts. Dietary supplements could be beneficial for preventing age-related cognitive decline. In this context, we examined whether the nutritional supplement Mente Activa® has beneficial effects on aging-related cognitive deficits without inducing side effects. METHODS: Mente Activa® was administered to old rats (n= 30 treated rats and n= 30 control rats) during 5 months, and the Morris water maze was used to test the learning capacities of the animals. The first assessment was conducted before the nutritional intervention (age of 18-19 months), to determine the baseline of the performance of animals on this test, and the second assessment was performed at the end of the treatment (23-24 moths). In order to examine possible secondary effects of this nutritional supplement, plasma, heart anatomy and liver parameters were evaluated. RESULTS: Our data indicate that supplemented rats showed less escape latency, distance swum, higher use of spatial search strategies, and crossed the former platform location with higher frequency than control rats. These effects were specific of the treatment, indicating that this nutritional supplement has a beneficial effect on spatial memory. On the other hand, the regular intake of Mente Activa® did not induce any negative effects in plasma parameters and heart size. CONCLUSIONS: Aged rats under a sustained dietary intake of the nutritional supplement Mente Activa® displayed improved learning and memory abilities compared to the non-treated rats. These results suggest the therapeutic potential and safety of use of Mente Activa® for age-related cognitive deficits, particularly, in the onset of the first cognitive dysfunction symptoms.

Medio Michel para inmunofluorescencia / Michel’s transport medium for immunofluorescence

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A virtual pattern generator for designing motor behavior tasks.

A description of the hardware and software used to create movement patterns that differ spatially and temporally is explained. These tasks are presented to participants using a virtual pattern generator.

Does retroactive inhibition influence contextual interference effects?

Two unique methodological strategies were used to investigate the influence of retroactive inhibition on recall within a contextual interference paradigm. Three independent blocked groups, blocked without retroactive inhibition (BL-without), blocked with 18 trials of retroactive inhibition (BL-18), and blocked with 36 trials of retroactive inhibition (BL-36), were created that varied in order of presentation of tasks. By testing a single task in retention and creating three independent blocked groups, varying amounts of retroactive inhibition were produced. This isolated the effects of retroactive inhibition on blocked compared to control and random subjects' retention. The Acquisition Group x Retention Trials interaction indicated that random and BL-without subjects had shorter reaction time than BL-18 and BL-36 subjects. Thus, blocked subjects with retroactive inhibition exhibited a retention deficit compared to BL-without subjects. The results support previous contextual interference findings and suggest that retroactive inhibition influences the retention deficits demonstrated by blocked compared to random subjects in typical contextual interference investigations.

[Solitary metachronous pancreatic metastasis of renal adenocarcinoma]. / Metástasis solitaria pancreática metacrónica de un adenocarcinoma renal.

We report the case of a patient who underwent a left nephrectomy for clear cell adenocarcinoma. Four years later he presented with jaundice due to a single metastasis of the same tumour in the head of the pancreas which was resected. The favourable prognosis with surgery encourages a radical approach.

Appropriate summary KR for learning timing tasks under conditions of high and low contextual interference.

Recall and retrieval processes of timing tasks were investigated in a multitask learning experiment using blocked (BL) and random (RA) practice schedules (Battig 1979). The extent to which summary knowledge of results (KR) interacts with order of presentation of practice tasks was the primary topic under investigation. It has been suggested that summary KR may enhance processing of task-relevant information (Schmidt 1991). The processing benefits of summary KR however may be dependent on the presentation order of practice tasks. Seventy-two females responded to the apparent motion of illuminated lights set at three speeds of 224, 313, and 492 cm/s during 90 acquisition, 30 no-KR retention and 20 transfer trials. Subjects' tasks was to push a ball hinged to a lever to coincide with the arrival of a light at a predetermined intercept point. Retrospective verbal reports were obtained immediately following transfer to ascertain the nature of subjects' processing activities. Error data were analyzed on four dependent variables. The most important finding was that longer summary KR lengths for RA subjects (KR10) were beneficial in acquisition and transfer. In contrast, BL subjects were more consistent in transfer if they received KR after each practice trial. A similar trend (p = 0.15) in retention was found in that BL subjects were more consistent as compared to RA, when they learned the tasks with 100% KR. Given the differential results of summary KR for BL and RA, the importance of considering the order of task presentation when investigating summary KR was supported.

Training and contextual interference effects on memory and transfer.

An experimental intervention program to train subjects on coincidence anticipation and prediction skills was administered to novice females. An attempt was undertaken to study the effects of this sports training and training on laboratory tasks. According to Battig's predictions on the structure of practice sessions, both random and blocked contexts were presented. These acquisition contexts were viewed as orienting tasks that preceded sports training. The effects of high-contextual interference and sports training on acquisition, retention, and transfer were investigated. Practice conditions in the intervention were selected because of processing demands similar to random acquisition. Other research has shown that acquisition in random is influenced by sport-skill expertise and further indicates that processing of events occurring outside the laboratory influences performance of laboratory tasks. Observed results supported prior theoretical predictions and empirical findings on contextual interference. Predicted hypotheses were supported, and the effects of sports training were most profound during retention and transfer if the acquisition context for the trained subjects was random. Supported by prior research, activities performed outside the laboratory influenced performance on laboratory tasks. These results shift more emphasis on the learner as an active processor of information, which relates to Lee's (1988) views on transfer-appropriate processing.

Effects of contextual interference, task difficulty, and levels of processing on pursuit tracking.

Based on an activity questionnaire, 48 females without experience in open sports skills were selected to track a moving light beam through either a circle, square, or triangular target area on a pursuit rotor. Contextual interference was created by presenting 5 velocities in either a random or a blocked context during acquisition. Level of processing was manipulated by having half of all subjects classify acquisition velocities by a predetermined numerical code. Time-on-target (TOT) was measured after each acquisition, retention, and transfer trial. Subjects tracking the circle produced higher TOTs than those who tracked the square or triangle (which did not differ from one another) across all three phases of the experiment; blocked and random acquisition groups were not significantly different from one another in acquisition, retention, or transfer. Subjects who classified acquisition velocities and tracked the circle under the blocked acquisition context produced significantly higher retention scores than those who tracked the circle but did not classify acquisition velocities. Transfer was facilitated for subjects who tracked the triangle in a random transfer context and classified velocities during acquisition. Results were discussed as providing support for the manipulation of the level of cognitive processing during the initial stage of learning. In addition, manipulating task difficulty was discussed.

Effects of contextual interference on the memory of older females differing in levels of physical activity.

The acquisition and retention effects of contextual interference on a coincidence anticipation task over long retention intervals were investigated on older females (54 to 83 yr.) differing in levels of physical activity. Half of the subjects were regular participants in an exercise program for older adults. The other half did not participate in the program and through a self-report instrument indicated minimal involvement in physical activities. Active subjects recalled the tasks after 10 min. better than the less active subjects, but no differences were found at the longer intervals (1 wk. or 40 days). A significant interaction occurred between activity level and contextual interference in retention supporting Battig's (1979) views on memory. High contextual interference facilitated retention for active subjects. Responding to variable input over trials (high contextual interference) is considered by Battig to induce multiple and variable processing strategies which would facilitate retention. These results support a relationship between levels of activity and cognitive functioning of aged subjects.

Sex, video-taped feedback and modeling effects on motor performance.

Two experiments were conducted to investigate the interaction of augmented information feedback and sex on accuracy and form of an overarm throwing pattern. In Exp. 1, a female model on video-tape was employed for instruction and recall of imposed form by 16 male and 16 female undergraduates. The original hypothesis that indeed there would be an interaction between the subjects' sex and type of augmented information feedback was not observed. In Exp. 2, essentially the same procedures were employed with another, similar group of subjects and several significant results were observed. The data suggest successive investigations to explore the possible effects of the model's sex on motor performance.

The effects of video-taped feedback on form, accuracy, and latency in an open and closed environment.

40 college women performed a modification of the classical fencing lunge against 2 laterally-arranged targets, under closed and open environmental conditions. Form (rating scale), accuracy (proximity to target center), and response latency were taken to measure the effects of video-taped feedback (VT). Administration of VT with specific instructions to direct S's attention to parts of the display resulted in closer approximation of the externally-imposed form, higher accuracy, and shorter response latency. Performing the skill in the closed environmental condition resulted in less deviation from the imposed form, higher accuracy scores, and longer response latency. No significant correlations were found between imposed form and accuracy.