Acquisition of navigation by chimpanzees (Pan troglodytes) in an automated fingermaze task

These experiments investigated how chimpanzees learn to navigate visual fingermazes presented on a touch monitor. The aim was to determine whether training the subjects to solve several different mazes would establish a generalized map-reading skill such that they would solve new mazes correctly on the first presentation. In experiment 1, two captive adult female chimpanzees were trained to move a visual object (a ball) with a finger over the monitor surface toward a target through a grid of obstacles that formed a maze. The task was fully automated with storage of movement paths on individual trials. Training progressed from very simple mazes with one obstacle to complex mazes with several obstacles. The subjects learned to move the ball to the target in a curved path so as to avoid obstacles and blind alleys. After training on several mazes, both subjects developed a high level of efficiency in moving the ball to the target in a path that closely approached the ideal shortest path. New mazes were then presented to determine whether the subjects had acquired a more generalized maze-solving performance. The subjects solved 65–100% of the new mazes the first time they were presented by moving the ball around obstacles to the target without making detours into blind alleys. In experiment 2, one of the chimpanzees was trained using mazes with two routes to the target. One of the routes was blocked at one of many possible locations. After training to avoid the blind alley in different mazes, new mazes were presented that also had one route blocked. The subject correctly solved 90.7% of the novel mazes. When the mazes had one short and one long open route to the target the subject preferred the shorter route. When the short route was blocked, the subject solved only 53.3% of the mazes because of the preference for the shorter route even when blocked. The overall results suggest that with the training methods used the subjects learned to solve specific mazes with a trial-and-error method. Although both subjects were able to solve many of the novel mazes they did not fully develop a more general "map-reading" skill. Accepted after revision: 30 July 2001 Electronic Publication     

Experimental evidence for spatial learning in cuttlefish (Sepia officinalis)

Laboratory mazes were used to study spatial-learning capabilities in cuttlefish (Sepia offcinalis), using escape for reinforcement. In preliminary observations, cuttlefish in an artificial pond moved actively around the environment and appeared to learn about features of their environment. In laboratory experiments, cuttlefish exited a simple alley maze more quickly with experience and retained the learned information. Similar improvement was not found in open-field mazes or T mazes, perhaps because of motor problems. Cuttlefish learned to exit a maze that required them to find openings in a vertical wall. The wall maze was modified to an arena, and simultaneous discrimination learning and reversal learning were demonstrated. These experiments indicate that cuttlefish improve performance over serial reversals of a simultaneous, visual-spatial discrimination problem.     

Maze navigation by honeybees: learning path regularity

We investigated the ability of honeybees to learn mazes of four types: constant-turn mazes, in which the appropriate turn is always in the same direction in each decision chamber; zig-zag mazes, in which the appropriate turn is alternately left and right in successive decision chambers; irregular mazes, in which there is no readily apparent pattern to the turns; and variable irregular mazes, in which the bees were trained to learn several irregular mazes simultaneously. The bees were able to learn to navigate all four types of maze. Performance was best in the constant-turn mazes, somewhat poorer in the zig-zag mazes, poorer still in the irregular mazes, and poorest in the variable irregular mazes. These results demonstrate that bees do not navigate such mazes simply by memorizing the entire sequence of appropriate turns. Rather, performance in the various configurations depends on the existence of regularity in the structure of the maze and on the ease with which this regularity is recognized and learned.     

An integrated circuit photocell detector and sequencer

A simple, inexpensive, and reliable apparatus for photocell detection and amplification is described. The sensitivity, voltage and current amplification, and speed of this apparatus, make it well suited to application in latency measurement in animal mazes. The apparatus can be used in any sort of application where a resistive type of transducer is needed to trigger some other event at higher voltage and current levels than can be done directly by the transducer alone.     

Content mazes and filled pauses in narrative language samples of children with specific language impairment

Linguistic nonfluencies known as mazes (filled pauses, repetitions, revisions, and abandoned utterances) have been used to draw inferences about processing difficulties associated with the production of language. In children with normal language development (NL), maze frequency in general increases with linguistic complexity, being greater in narrative than conversational contexts and in longer utterances. The same tendency has been found for children with specific language impairment (SLI). However, the frequency of mazes produced by children with NL and SLI has not been compared directly at equivalent utterance lengths in narration. This study compared the frequency of filled pauses and content mazes in narrative language samples of school-age children with SLI. The children with SLI used significantly more content mazes than the children with NL, but fewer filled pauses. Unlike content mazes, the frequency of filled pauses remained stable across samples of different utterance lengths among children with SLI. This indicates that filled pauses and content mazes have different origins and should not be analyzed or interpreted in the same way.     

Exploration of virtual mazes by rhesus monkeys (<Emphasis Type="Italic">Macaca mulatta</Emphasis>)

A chasm divides the huge corpus of maze studies found in the literature, with animals tested in mazes on the one side and humans tested with mazes on the other. Advances in technology and software have made possible the production and use of virtual mazes, which allow humans to navigate computerized environments and thus for humans and nonhuman animals to be tested in comparable spatial domains. In the present experiment, this comparability is extended even further by examining whether rhesus monkeys (Macaca mulatta) can learn to explore virtual mazes. Four male macaques were trained to manipulate a joystick so as to move through a virtual environment and to locate a computer-generated target. The animals succeeded in learning this task, and located the target even when it was located in novel alleys. The search pattern within the maze for these animals resembled the pattern of maze navigation observed for monkeys that were tested on more traditional two-dimensional computerized mazes.     

A programmable proximity-contact sensor to detect location or locomotion of animals

A simple electronic device to detect location or to track locomotion of small animals is described. The device is based on anantenna effect—it responds to a change in capacitance as the body of the animal passes between an antenna and one of a series of contact plates. A digital address system is incorporated that is capable of electronically polling the contact plates according to instructions from a data-acquisition system (DAS). Any DAS capable of generating an address of two bits or more and of reading a one-bit data line may be employed. The device is ideal for mazes or other apparatus in which the exclusion of stereotypical behaviors is desired.     

Effects of neocortical ectopias and environmental enrichment on Hebb-Williams maze learning in BXSB mice

Approximately 40-60% of BXSB mice have neocortical ectopias, a developmental anomaly characterized by migration of neurons into the neuron-sparse layer I of cortex. Previous studies have shown that ectopic BXSB mice have superior reference, but inferior working, memory on spatial tasks. Female BXSB mice were housed either in an enriched environment or in standard cages at weaning. Subsequently, these animals were tested on four of the Hebb-Williams mazes in a water-based version of this maze. Theoretically, two of the maze configurations placed greater emphasis on reference memory to find the goal, whereas the other two favored working memory. Ectopics reared in standard housing conditions were better than nonectopics on mazes that favored the use of reference memory, but poorer on mazes that favored working memory. In contrast, subjects raised in the enriched environment showed no ectopia differences. A comparison of enriched and standard housing conditions found that the enriched animals had better reference memory but poorer working memory. The latter effect may be because the enriched environment, although more stimulating, did not change in time or space; and other researchers have shown that daily replacement of stimuli in complex environments is correlated with better working memory.     

Strategic navigation of two-dimensional alley mazes: comparing capuchin monkeys and chimpanzees

Planning is an important component of cognition that contributes, for example, to efficient movement through space. In the current study we presented novel two-dimensional alley mazes to four chimpanzees and three capuchin monkeys to identify the nature and efficiency of planning in relation to varying task parameters. All the subjects solved more mazes without error than expected by chance, providing compelling evidence that both species planned their choices in some manner. The probability of making a correct choice on mazes designed to be more demanding and presented later in the testing series was higher than on earlier, simpler mazes (chimpanzees), or unchanged (capuchin monkeys), suggesting microdevelopment of strategic choice. Structural properties of the mazes affected both species' choices. Capuchin monkeys were less likely than chimpanzees to take a correct path that initially led away from the goal but that eventually led to the goal. Chimpanzees were more likely to make an error by passing a correct path than by turning onto a wrong path. Chimpanzees and one capuchin made more errors on choices farther in sequence from the goal. Each species corrected errors before running into the end of an alley in approximately 40% of cases. Together, these findings suggest nascent planning abilities in each species, and the prospect for significant development of strategic planning capabilities on tasks presenting multiple simultaneous or sequential spatial relations. The computerized maze paradigm appears well suited to investigate movement planning and spatial perception in human and nonhuman primates alike.     

The effects of variation of intertrial interval on exploration of elevatd and enclosed mazes

The interval between exploratory trials was varied in experiments using simple elevated or enclosed mazes. Activity on the second trial was depressed for short intertrial intervals but had recovered after about 10 min.; the degree of recovery was different in the two types of maze. A second decrease in second trial activity was found with inter-trial intervals of more than 20 min., but a further experiment suggested this was due to the effects of delay itself, rather than to previous experience of the environment.     

Validating the Electric Maze Task as a Measure of Planning

The Electric Maze Task (EMT) is a novel planning task designed to allow flexible testing of planning abilities across a broad age range and to incorporate manipulations to test underlying planning abilities, such as working-memory and inhibitory control skills. The EMT was tested in a group of 63 typically developing 7- to 12-year-olds. Participants completed 4 mazes designed to alter working-memory demands (by increasing the number of steps required from 6 to 8) and inhibitory control demands (by using a modified Dimensional Change Card Sort task) and 3 standardized measures using the Cambridge Neuropsychological Test Automated Battery. The EMT was found to correlate with measures of visual memory, working memory, and planning. The 6-step mazes were simpler for participants to solve and mapped on to performance on the visual memory task. The 8-step mazes were more difficult and mapped on to performance on the spatial working-memory and planning tasks. Children who were 10 to 12 years old were also better than 7- to 9-year-olds at solving all mazes, as evidenced by fewer errors and fewer errors later in solving the mazes. Younger children also struggled more than older children after a rule switch. Performance on the maze task differentiated 7- to 12-year-old children with better planning skills, and manipulations of the maze task were successful in altering the working-memory and inhibitory control demands.     

Learned Industriousness: Replication in Principle

Undergraduate students completed a series of training tasks consisting of solving anagrams, performing addition problems, and making perceptual discriminations, to validate findings of learned industriousness. The group that received high-effort training was given difficult and demanding tasks, whereas the group that received low-effort training was given easy tasks. Controls were given no preliminary training activity. For the criterion task, all participants were provided with a series of pencil and paper mazes to complete. They were allowed to “pass” on whatever mazes they wished (they could progress to the next maze but could not return to any that had been passed). Participants who had received high-effort training passed on significantly fewer mazes than did those in the control and low-effort conditions, thus supporting the generality of effects of reinforced high effort.     

Of mice and men: virtual Hebb-Williams mazes permit comparison of spatial learning across species

We developed a computer-generated virtual environment to test humans, for the first time, on the Hebb-Williams mazes. The goal was to provide a standardized test that could be used to directly compare human performance with that of C57BL/6J mice performing in real versions of the mazes. Such a comparison seems crucial if conclusions regarding genetic manipulations of rodents are to be mapped onto human cognitive disorders. The learning curves across species were strikingly similar, lending support to the rodent model of human spatial memory. Humans learned faster than rodents in both the acquisition and the test portions of the protocol, and females of both species were less efficient in solving these problems than males. These results represent the first modern comparison of human and rodent learning that uses the same test of spatial problem solving.     

Development of memory for pattern and path: Further evidence for the fractionation of visuo-spatial memory

Evidence from a number of sources now suggests that the visuo-spatial sketchpad (VSSP) of working memory may be composed of two subsystems: one for maintaining visual information and the other for spatial information. In this paper we present three experiments that examine this fractionation using a developmental approach. In Experiment 1, 5-, 8-, and 10-year old children were presented with a visuo-spatial working memory task (the matrices task) with two presentation formats (static and dynamic). A developmental dissociation in performance was found for the static and dynamic conditions of both tasks, suggesting that the activation of separable subsystems of the VSSP is dependent upon a static/dynamic distinction in information content rather than a visual/spatial one. A highly similar pattern of performance was found for a mazes task with static and dynamic formats. However, one strategic activity, the use of simple verbal recoding, may also have been responsible for the observed pattern of performance in the matrices task. In Experiments 2 and 3 this was investigated using concurrent articulatory suppression. No evidence to support this notion was found, and it is therefore proposed that static and dynamic visuo-spatial information is maintained in working memory by separable subcomponents of the VSSP.     

Navigating two-dimensional mazes: chimpanzees (Pan troglodytes) and capuchins (Cebus apella sp.) profit from experience differently

We examined whether navigation is impacted by experience in two species of nonhuman primates. Five chimpanzees (Pan troglodytes) and seven capuchin monkeys (Cebus apella) navigated a cursor, using a joystick, through two-dimensional mazes presented on a computer monitor. Subjects completed 192 mazes, each one time. Each maze contained one to five choices, and in up to three of these choices, the correct path required moving the cursor away from the Euclidean direction toward the goal. Some subjects completed these mazes in a random order (Random group); others in a fixed order by ascending number of choices and ascending number of turns away from goal (Ordered group). Chimpanzees in both groups performed equivalently, demonstrated fewer errors and a higher rate of self-correcting errors with increasing experience at solving the mazes, and made significantly fewer errors than capuchin monkeys. Capuchins were more sensitive to the mode of presentation than chimpanzees; monkeys in the Ordered group made fewer errors than monkeys in the Random group. However, capuchins’ performance across testing changed little, and they remained particularly susceptible to making errors when the correct path required moving away from the goal. Thus, these two species responded differently to the same spatial challenges and same learning contexts. The findings indicate that chimpanzees have a strong advantage in this task compared to capuchins, no matter how the task is presented. We suggest that differences between the species in the dynamic organization of attention and motor processes contribute to their differences in performance on this task, and predict similar differences in other tasks requiring, as this one does, sustained attention to a dynamic visual display and self-produced movements variably towards and away from a goal.     

A model of working memory capacity in the radial-arm maze task

The radial arm maze is one of the most commonly used tests for assessing working memory in laboratory animals. However, to date, there exists no quantitative method of estimating working memory capacity from performance on this task. Here, we present a mathematical model of performance on the radial arm maze from which we can derive estimates of capacity. We derive explicit results for the two most commonly used measures of performance as functions of number of arms in the maze and memory capacity, assuming a uniform random search. We simulate random non-uniform search strategies. Comparing our model to previous experiments, we show that our model predicts a working memory capacity in the range of 3-9 at the level of performance observed in these experiments. This estimate is within the typical estimate of human working memory capacity. Performance of rats on large mazes (e.g. 48 arms) has been used as evidence that the working memory capacity of rats may be significantly larger than that of humans. We report that memory capacity in the range 3-9 is sufficient to explain the performance of rats in very large radial mazes. Furthermore, when we simulate non-uniform random search strategies observed in the experiments, the resulting estimates do not differ significantly from those assuming a uniform random search. We conclude that a list-based model of working memory with modest capacity is more powerful than previously expected.     

Tacit knowledge and the effect of pattern configuration on mental scanning

Two opposing hypotheses are that estimated distances may be used to predict scanning times in mental scanning experiments (Mitchell & Richman, 1980; Pylyshyn, 1981) and that scanning times may be used to estimate distances on maps (Thorndyke, 1981). We tested these hypotheses by having people both estimate lengths and mentally scan diagonal lines, spirals, and mazes. There were large and consistent differences in the rate of scanning the three configurations, regardless of whether people scanned percepts or images. These differences could not be accounted for by differences in length estimates or by people’s tacit knowledge of their scanning rates. We propose that people actually do mental scanning in a mental scanning task rather than use length estimates to generate scanning time and that they do not rely on scanning times to estimate length in a length estimation task.     

Children's theories of intelligence: beliefs, goals, and motivation in the elementary years

The authors tested a developmental model of children's theories about intelligence in kindergarten, second grade, and fourth grade children by using paper-and-pencil maze tasks. Older children were more likely than younger children to espouse learning goals (e.g., that they preferred difficult mazes to improve their skill), and less likely to espouse performance goals (e.g., that they preferred easy mazes to be successful). Children in all 3 age groups reported stronger beliefs in the malleability of intelligence than the stability of intelligence. In general, the results supported the authors' hypotheses about developmental change in children's theory-like conceptions of intelligence: Beliefs, goals, and motivation were related in expected ways for second and fourth graders more than for kindergartners. The authors discussed contextual influences on children's beliefs and the development of children's conceptualizations of intelligence.     

The effects of test anxiety, sex of subject, and type of verbal reinforcement on maze performance of elementary school children

The purpose of this study was to account for children's performance in an educational setting by evaluating individual difference factors and the subjects' differential responsivities to social reinforcement The child subjects performed on Porteus mazes, which were viewed as complex, stress-inducing tasks They were differentiated in terms of sex and test anxiety levels. Each child received the same number of noncontingent reinforcements, which consisted of either verbal praise or verbal criticism or no feedback The data yielded significant triple interaction effects among anxiety, sex, and social reinforcement for the time and error scores on the mazes The data were discussed in terms of their implications for remediating performance in educational settings and their support for the theoretical conception of test anxiety as a chronic drive state The authors concluded that the extrinsic, motivating effects of verbal reinforcement can be reasonably characterized, but only if one attends to individual differences among those subjects being reinforced.     

A simple decoder arrays to a for linking photocell microcomputer

Inputs from photocell arrays (such as those incorporated in mazes) to a microcomputer must be decoded. For up to 31 channels, this can be conveniently done by using cascaded 8-to-3 line priority encoders (74LS148) and five lines on a parallel data bus. The arrangement is expandable. It is currently used in an automatized Y-maze for vibrisso-tactile discrimination learning in mice.