Flexibility in children's use of spatial and categorical organizational strategies in recall.

Two studies investigated flexibility in children's use of spatial and categorical clustering strategies in recall. In Study 1, 10-, 12-, 14-, and 16-yr-olds and adults recalled the furniture from their home. 10-yr-olds organized furniture categorically, and 16-yr-olds and adults organized items spatially. 12- and 14-yr-olds exhibited equal levels of spatial and categorical organization. Study 2 investigated how encoding experiences and the recall task influenced the degree of spatial and categorical organization in 10- and 12-yr-olds' recall. When recalling objects, 10- and 12-yr-olds exhibited higher levels of categorical than spatial organization. When recalling objects and their locations, 12-yr-olds exhibited more spatial than categorical organization. Results are discussed in terms of age and task influences on flexibility of strategy use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Redistribution of spatial representation in the hippocampus of aged rats performing a spatial memory task.

Young and old rats performed on a maze according to a forced-choice and then a spatial memory procedure either in the same or a different environment. Aged rats were slower to learn the spatial memory task when tested in the same, but not in a different, room. One interpretation of this pattern of results is that although old rats learn new rules as quickly as young rats, they show less flexibility with old rules and familiar spatial information. Impaired choice accuracy during asymptote performance suggests poor processing of trial-unique information by old rats. Spatial correlates of hippocampal CA1 and hilar cells varied with task demand: CA1 cells of aged rats showed more spatially selective place fields, whereas hilar cells showed more diffuse location coding during spatial memory, and not forced-choice, tests. Such representational reorganization may reflect a compensatory response to age-related neurobiological changes in the hippocampus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Shift of laterality and compared analysis of paw performances in cats during practice of a visuomotor task.

Paw preference and performance were analyzed during early and late practice in 12 adult cats that reached toward a moving target. A strong preference for left-paw use was observed early in training. It was still present after practice despite a shift toward right-paw use. Comparing paw performance showed that the left paw was more accurate and quicker to trigger the movement during early practice, whereas after practice, it was the preferred paw (whether right or left) that triggered faster movement. The strong original left-paw bias could reflect the specialization of the right hemisphere in processing spatial information. Its weakening with practice could reflect the ability of the nonspecialized hemisphere to learn how to deal with the task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mental manipulation of spatial information in young and elderly adults.

Investigated the ability of 20-, 60-, and 70-yr-olds (12 men and 12 women at each age level) to mentally manipulate spatial information in a large-scale environment. In a perspective-taking task, Ss were asked to determine the location of target objects from imagined locations. In an array rotation task, Ss were asked to imagine that the array of objects rotated relative to their current position. Young and elderly Ss performed with equivalent accuracy on the array rotation task, but young Ss were more accurate on the perspective-taking task. Ss who were taken to each object location prior to testing were more accurate in the perspective-taking task than Ss who did not have this experience. There was no effect of prior experience on performance in the array rotation task. (4 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early success in using the relation between stimuli and rewards to deduce an abstract rule: Perceived physical connection is key.

Are spatial proximity (0.10-12.5 cm), temporal proximity (0-, 2-, and 5-s gaps), and/or perceived connectedness of stimulus and reward key to infants' ability to deduce an abstract nonmatching rule from reward feedback? In this investigation, 3 conditions of the delayed nonmatching to sample task were administered to infants 9, 12, and 15 months old, and 5 more conditions were administered just to 12-month-olds. Results showed that connectedness is key. In its presence, neither close spatial or temporal proximity was needed. In the absence of the perception that stimulus and reward were components of a single thing, even close spatial and temporal proximity were insufficient for infants in the 1st year to grasp the rule-based association between stimuli and rewards. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Performance of four-seed caching corvid species in operant tests of nonspatial and spatial memory.

The performance of 4 seed-caching corvid species was tested using 2 different operant nonmatching tasks. These species differ in their dependence on stored food, and differences in spatial memory tests have been correlated with better performance by the more cache-dependent species. Acquisition and retention of a color non-matching-to-sample task was tested in Experiment 1. Acquisition of the color task was not correlated with cache dependence, and no differences between species in performance during memory testing were found. Acquisition and retention of an operant spatial non-matching-to-sample task was tested in Experiment 2. Species differences in the spatial task were found for acquisition and during retention testing. The influence of natural history on the evolution of memory is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential involvement of the dorsal anterior cingulate and prelimbic–infralimbic areas of the rodent prefrontal cortex in spatial working memory.

[Correction Notice: An erratum for this article was reported in Vol 112(4) of Behavioral Neuroscience (see record 2008-09590-001). Figure 1 (page 295) and Figure 4 (page 299) were printed incorrectly. The corrected figure pages and corresponding captions are provided in the erratum.] The present study examined the effects of quinolinic acid lesions of the dorsal anterior cingulate and prelimbic–infralimbic cortices on spatial working memory and spatial discrimination using go/no-go procedures. All testing occurred in a 12-arm radial maze. In a working memory task, rats were allowed to enter 12 arms for a cereal reward. Three or 4 arms were presented for a 2nd time in a session, which did not result in a reward. In a spatial discrimination task, rats had successive access to 2 different arms. One arm always contained a reward, and the other never contained a reward. Prelimbic–infralimbic lesions impaired spatial working memory but only produced a transient spatial discrimination deficit. Dorsal anterior cingulate lesions did not induce a deficit in either task. These findings suggest that the prelimbic–infralimbic cortices, but not the anterior cingulate cortex, are important in spatial working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Critical periods for the effects of alcohol exposure on learning in rats.

Critical periods for alcohol-induced deficits in spatial navigation and passive avoidance learning were investigated with a rat model of fetal alcohol syndrome. Rats were exposed to alcohol prenatally (Gestational Days 1–10 or 11–22) or postnatally (Postnatal Days 2–10) or throughout all 3 periods. Offspring were tested in either a spatial navigation or an avoidance task as juveniles or adults. As juveniles, the combined exposure group took longer to learn the spatial navigation task compared with all other groups. This effect was not seen in adults. Passive avoidance performance was not affected. These results suggest that long-term exposure to alcohol during development has adverse effects on spatial learning. The lack of differences in the short-term exposure groups implies that there may not be 1 critical period of alcohol exposure, but that the adverse effects of alcohol during development may be cumulative on some behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pretraining does not ameliorate spatial learning deficits induced by intrahippocampal infusion of AP5.

Previous studies show discrepancies concerning the effects of pretraining on spatial learning deficits induced by blockade of the N-methyl-d-aspartate (NMDA) receptor. These inconsistencies might be attributed to the differences in the nature of the pretraining tasks and the method of blocking NMDA receptors. In the present study, the authors pretrained rats in a spatial water maze task. The authors then trained them with a novel spatial task in a novel environment under chronic blockade of hippocampal NMDA receptors by intrahippocampal infusion of 2-amino-5-phosphonopentanoic acid (AP5) using osmotic pumps. Although the rats had acquired the basic techniques needed to solve a water-maze spatial task during pretraining, those given high or low doses of AP5 showed acquisition deficits. As the spatial pretraining failed to ameliorate the acquisition deficits of a new task in a novel environment, it was suggested that NMDA receptors were necessary in forming spatial representations. Because neither dose of AP5 affected the performance of a spatial task in the retention phase, sensory motor disturbances could not have caused these deficits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The importance of gesture in children's spatial reasoning.

On average, men outperform women on mental rotation tasks. Even boys as young as 4 1/2 perform better than girls on simplified spatial transformation tasks. The goal of our study was to explore ways of improving 5-year-olds' performance on a spatial transformation task and to examine the strategies children use to solve this task. We found that boys performed better than girls before training and that both boys and girls improved with training, whether they were given explicit instruction or just practice. Regardless of training condition, the more children gestured about moving the pieces when asked to explain how they solved the spatial transformation task, the better they performed on the task, with boys gesturing about movement significantly more (and performing better) than girls. Gesture thus provides useful information about children's spatial strategies, raising the possibility that gesture training may be particularly effective in improving children's mental rotation skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Functional equivalence of verbal and spatial information in serial short-term memory.

Performance on a test of serial memory for the spatial position of a sequence of dots showed similarities to typical results from the serial recall of verbal material: a marked increase in error with increasing list length, a modest rise in error as retention interval increased, and bow-shaped serial position curves. This task was susceptible to interference from both a spatial task (rote tapping) and a verbal task (mouthed articulatory suppression) and also from the presence of irrelevant speech. Effects were comparable to those found with a serial verbal task that was generally similar in demand characteristics to the spatial task. As a generalization, disruption of the serial recall of visuospatial material was more marked if the interference conditions involved a changing sequence of actions or materials, but not if a single event (tap, mouthed utterance, or sound) was repeated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in learning and memory in mice: Effects of sequence of testing and cholinergic blockade.

Sexual dimorphism in spatial and cued navigation using the Morris water maze was examined in C57BL/6 mice both with and without administration of scopolamine, a cholinergic blocker. In Exp 1, female and male mice learned to perform first a spatial, then a cued, navigation task. Both performed a spatial task similarly; males, however, performed a cued task better than females. In Exp 2, the sequence of navigation testing was reversed. Both performed similarly on a cued task; however, males performed a spatial task better than females. In both experiments, females were more sensitive than males to the effects of scopolamine. No significant confounding sex differences were found in either spontaneous activity or passive avoidance retention. These data indicate that sex differences in spatial and cued tasks are dependent on the sequence of task presentation and implicate a role for the cholinergic system in these differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of muscarinic cholinergic receptor blockade in the rat anterior cingulate and Prelimbic/Infralimbic cortices on spatial working memory

Previous findings indicate that cholinergic input to the medial prefrontal cortex may modulate mnemonic processes. The present experiment determined whether blockade of muscarinic cholinergic receptors in the rodent anterior cingulate and prelimbic/infralimbic cortices impairs spatial working memory. In a 12-arm radial maze, a working memory for spatial locations task was employed using a continuous recognition go/no-go procedure. Rats were allowed to enter 12 arms for a reinforcement. Of the 12 arm presentations, 3 or 4 arms were presented for a second time in a session that did not contain a reinforcement. The number of trials between the first and second presentations of an arm ranged from 0 to 6 (lags). Infusions of scopolamine (1, 5, and 10 microgram), a muscarinic cholinergic antagonist, into the prelimbic/infralimbic cortices, but not the anterior cingulate cortex, significantly impaired spatial working memory in a lag- and dose-dependent manner. The deficit induced by scopolamine (10 microgram) was attenuated by concomitant intraprelimbic/infralimbic injections of oxotremorine (2 microgram) a muscarinic cholinergic agonist. A separate group of rats was tested on a successive spatial discrimination task. Injections of scopolamine (1, 5, and 10 microgram) into the prelimbic/infralimbic cortices did not impair performance on the spatial discrimination task. These findings suggest that muscarinic transmission in the prelimbic/infralimbic cortices, but not the anterior cingulate cortex, is important for spatial working memory.     

"Differential involvement of the dorsal anterior cingulate and prelimbic-infralimbic areas of the rodent prefrontal cortex in spatial working memory": Correction to Ragozzino et al. (1998).

Reports an error in "Differential involvement of the dorsal anterior cingulate and prelimbic-infralimbic areas of the rodent prefrontal cortex in spatial working memory" by Michael E. Ragozzino, Spencer Adams and Raymond P. Kesner (Behavioral Neuroscience, 1998[Apr], Vol 112[2], 293-303). Figure 1 (page 295) and Figure 4 (page 299) were printed incorrectly. The corrected figure pages and corresponding captions are provided in the erratum. (The following abstract of the original article appeared in record 1998-01023-003.) The present study examined the effects of quinolinic acid lesions of the dorsal anterior cingulate and prelimbic-infralimbic cortices on spatial working memory and spatial discrimination using go/no-go procedures. All testing occurred in a 12-arm radial maze. In a working memory task, rats were allowed to enter 12 arms for a cereal reward. Three or 4 arms were presented for a 2nd time in a session, which did not result in a reward. In a spatial discrimination task, rats had successive access to 2 different arms. One arm always contained a reward, and the other never contained a reward. Prelimbic-infralimbic lesions impaired spatial working memory but only produced a transient spatial discrimination deficit. Dorsal anterior cingulate lesions did not induce a deficit in either task. These findings suggest that the prelimbic-infralimbic cortices, but not the anterior cingulate cortex, are important in spatial working memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Posttraining paradoxical sleep in rats is increased after spatial learning in the Morris water maze.

The role of posttraining paradoxical sleep (PS) in spatial or nonspatial learning in the Morris water maze was evaluated. Sprague-Dawley rats were given a 12-trial training session in either the hidden or the visible platform versions of the task. Subgroups then underwent paradoxical sleep deprivation (PSD) beginning at different times after training. Rats with PSD imposed from 14 hr after spatial training had poorer retest scores than any other group. Other rats, implanted with electrodes to permit continuous recording of sleep electroencephalography, were found to undergo a prolonged period of elevated PS after spatial training. By contrast, rats trained in the nonspatial version of the water maze task did not show retention deficits after PSD or elevated PS after training. These results support a role for PS in spatial, but not nonspatial, learning in the Morris water maze. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microinfusions of neurotensin antagonist SR 48692 within the nucleus accumbens core impair spatial learning in rats.

The involvement of neurotensin (NT) within the nucleus accumbens core (NAC) in behavior has been sparsely investigated. Moreover, little is known of what role NT within the ventral striatum has on spatial learning. The present study investigated whether NT receptors in the NAC are implicated in learning of spatial information. Male Long-Evans rats were trained on a food search spatial learning task. Rats were microinfused with either NT antagonist SR 48692 (50 nM/0.5 =L) or saline in the NAC before each training session. Rats treated with SR 48692 made more reference and working memory errors during the acquisition of spatial learning than did rats infused with saline. These results suggest that NT receptors contribute to NAC-mediated spatial learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Episodic long-term memory in the rat: Effects of hippocampal stimulation.

Seven male Long-Evans rats with electrodes implanted in the dorsal hippocampus were trained to perform a delayed spatial matching-to-sample task on a radial arm maze. Subseizure-level electrical stimulation of the dorsal hippocampus applied during the study phase disrupted retention of a specific arm when tested at a 20-min delay but had no effects at 1- and 12-min delays. Subseizure-level stimulation of the hippocampus immediately after the study phase resulted in normal retention. In contrast, seizure-level stimulation of the hippocampus applied either during or immediately after the study phase disrupted retention at 1-, 12-, and 20-min delays. Data support the interpretation that the hippocampus is involved in the encoding of critical information (spatiotemporal attributes) in long-term working memory, but not in short-term memory. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Source memory and divided attention: Reciprocal costs to primary and secondary tasks.

Source memory, in comparison with item memory, is more sensitive to frontal lesions and may require more strategic processing. Divided attention was used to restrict attentional resources and strategic processing on memory tasks. Participants encoded and retrieved items (i.e., words) and source (i.e., voice or spatial location) while concurrently performing a fingertapping (FT) or visual reaction-time (VRT) task. Memory accuracy costs under divided attention were greater for retrieval of source than item and were greater with VRT than FT. Similarly, costs to the secondary task were greater when concurrently retrieving source as opposed to item and were greater for VRT than FT. Effects were stronger when spatial location was used as the source task. Findings support the idea that processing source information requires more attentional resources and effort than processing item information. Furthermore, concurrent performance of VRT produced greater interference with a task that was more dependent on intact frontal functioning and better simulated the performance of patients with frontal dysfunction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Renal proliferative and phenotypic changes in rats with two-kidney, one-clip Goldblatt hypertension

Previous research in this laboratory has shown that preweaning and postweaning juvenile meadow voles, Microtus pennsylvanicus, can acquire a spatial task, the Morris water-maze task. The present study examined the influence of age of juvenile acquisition ("before weaning" (BW; Day 10 and 15 after birth) and "after weaning" (AW; Day 20 and 25 after birth)) of a spatial task on subsequent re-acquisition of the same hidden-platform spatial water-maze task. This study also compared sex differences and litter sex-ratio effects on reacquisition performance. Fifteen litters of adults were re-tested in the same water maze 6 weeks after being initially tested as juveniles. All analyses were conducted using a covariate that removed the group differences in the original task performance. Adult voles from female-biased litters, that had previously learned the task at an older juvenile age (AW), reacquired the same task faster than adults that had previously learned the task at a younger juvenile age (BW). In the adult BW group there was also a significant litter sex-ratio effect such that voles born into a female-biased litter re-acquired the task more slowly than did voles born into a male-biased litter. There were no significant sex or litter sex-ratio effects on spatial learning in the AW group. These results show that adult meadow voles can require a spatial task more quickly if they initially learned the task at an older juvenile age, suggestive of a period of infantile amnesia. In addition, these results indicate that the litter sex-ratio can affect adult spatial performance, suggesting that the relative amount of androgens in utero may influence the development of sexually-dimorphic spatial ability in adulthood.     

Functional differentiation along the anterior-posterior axis of the hippocampus in monkeys

We tested whether the primate hippocampus was functionally heterogenous along its anterior-posterior axis. Two monkeys were trained on both a spatial and nonspatial memory task and the incidence of spatial and nonspatial delay activity in the anterior, middle, and posterior hippocampus was noted. Spatial delay activity (activity in the delay period after the sample stimulus on the spatial memory task) was more common in the posterior than the anterior hippocampus, whereas nonspatial delay activity (activity in the delay period after the sample stimulus on the nonspatial memory task) was evenly distributed throughout the hippocampus. Furthermore, delay neurons in the anterior hippocampus exhibited scalloping delay activity, whereas those in the middle and posterior hippocampus did not. These findings suggest that the hippocampus is functionally heterogeneous and that the posterior regions may be more important for processing spatial information, whereas the anterior regions may be more important for directing or coding movements to points in space.