A new method for studying problem solving and tool use in stingrays (Potamotrygon castexi)

Testing the cognitive abilities of cartilaginous fishes is important in understanding the evolutionary origins of cognitive functions in higher vertebrates. We used five South American fresh water stingrays (Potamotrygon castexi) in a learning and problem-solving task. A tube test apparatus was developed to provide a simple but sophisticated procedure for testing cognitive abilities of aquatic animals. All five subjects quickly learned to use water as a tool to extract food from the testing apparatus. The experimental protocol, which gave the animals the opportunity of correcting a wrong visual cue decision, resulted in four out of five subjects correcting an error rather than making an initial right choice. One of five subjects reached 100% correct trials in the visual discrimination task. The ability to use water as an agent to extract food from the testing apparatus is a first indication of tool use in batoid fishes. Performance in the instrumental task of retrieving food from a novel testing apparatus and the rapid learning in the subsequent discrimination/error correction task shows that cartilaginous fish can be used to study the origins of cognitive functions in the vertebrate lineage.     

Where am I? Distal cues use requires sensitivity to start location change in the rat

Place learning is impaired when a single plus maze is moved between adjacent locations 33-120 cm apart. This maze translation creates distinct start locations but maintains a single goal location with respect to distal cues. Hippocampal cell recording data suggest the majority of place fields are tied to apparatus boundaries, not to distal cues, when an apparatus is moved these distances to the left or right. Thus, rats may fail to appreciate the existence of multiple start locations with respect to distal cues when the maze is moved in this way and their start location on the surface is constant. Performance on the single plus maze problem was improved when texture cues were correlated with different start locations. Place learning was supported when multiple start locations were provided on a single large surface (double plus maze), even though rats did not explore the entire surface. Place learning was also supported when random extensions were added to a double plus maze such that start locations, relative to surface boundaries, were not informative as to goal location. This outcome suggests sensitivity to multiple start locations is required for distal cue use in translational place problems.     

A one-trial inhibitory avoidance task to zebrafish: Rapid acquisition of an NMDA-dependent long-term memory

The behavioral tasks aiming to evaluate learning and memory mechanisms currently available to zebrafish (Danio rerio) involve long training sessions frequently along multiple days and are based on shuttle box or active-avoidance protocols, preventing a detailed analysis of cellular and molecular time-dependent processes involved in memory acquisition and consolidation. In order to explore zebrafish’s potential contribution to the characterization of the molecular machinery underlying learning and memory rapidly acquired and reliable paradigms are necessary. In this study we present a rapid and effective learning protocol in a single-trial inhibitory avoidance in zebrafish. In a simple apparatus, adult animals learned to refrain from swimming from a white into a dark compartment in order to avoid an electric shock during a single-trial training session that lasted less than 2 min. The resulting memory is robust, long-lasting and sensitive to NMDA-receptor antagonist MK-801 given in the tank water immediately after training. Experiments aiming to further characterize the events underlying memory formation, retrieval or extinction or those looking for cognitive profiling of mutants, neurotoxicological studies and disease models may benefit from this task, and together with complementary strategies available for zebrafish may significantly improve our current knowledge on learning and memory mechanisms.     

Failure to replicate visual discrimination learning with a 1-min delay of reward

Two experiments were carried out in an attempt to replicate Lett's (1974) demonstration of visual discrimination learning with a 1-min delay of reward. In Experiment 1, controls for olfactory cues were introduced by testing animals in different orders from day to day and by reversing the positions of the discrimination chambers within days; also, secondary reinforcement effects were precluded by the use of opaque rather than transparent doors to the discrimination chambers. No evidence of learning was found either in a group of rats returned to the home cage during the delay or in a group left in the apparatus during the delay. It was hypothesized that the failure to find improvement in Experiment 1 might have resulted from either the controls for odor cues or from a lack of memory retrieval cues provided by the apparatus. In Experiment 2, both of these hypotheses were tested and neither was supported. The Lett group in Experiment 2 was run according to the exact procedures used by Lett and still no learning was demonstrated. It was concluded that further demonstrations of visual discrimination learning with a 1-min delay of reward will be necessary for the acceptance of the validity of this phenomenon.     

A theory of causal learning in children: causal maps and Bayes nets

The authors outline a cognitive and computational account of causal learning in children. They propose that children use specialized cognitive systems that allow them to recover an accurate "causal map" of the world: an abstract, coherent, learned representation of the causal relations among events. This kind of knowledge can be perspicuously understood in terms of the formalism of directed graphical causal models, or Bayes nets. Children's causal learning and inference may involve computations similar to those for learning causal Bayes nets and for predicting with them. Experimental results suggest that 2- to 4-year-old children construct new causal maps and that their learning is consistent with the Bayes net formalism.     

An automated apparatus for presenting depth-rotated three-dimensional objects in human and animal object recognition research

For practical reasons, research on the recognition of objects from different viewpoints has relied almost exclusively on the use of two-dimensional representations of three-dimensional objects. We describe an apparatus that enables the presentation of three-dimensional objects in a discrimination learning paradigm. Three chambers positioned on a movable table allow each of two objects to be presented on either the left or the right side; a viewing window exposes only two of the objects at a time. The objects can be arbitrarily designated as either an S+ or an S−. In addition, they can be placed precisely in any arbitrary Startposition and rotated in depth in 100 steps of 3.6° each. We have successfully used this apparatus to investigate recognition of depth-rotated objects by both pigeons and humans. By varying the stimuli, number of stimulus chambers, and software programs, the apparatus can be used for other types of tasks and to investigate other types of processes.     

Formation of excitatory and inhibitory associations between absent events

Considerable evidence indicates that associations may be formed between two events even when one or both of them is absent at the time of learning. Previously, some researchers asserted that excitatory associations are formed when associatively activated representations for two events are paired, whereas others claimed that inhibitory associations are formed. In three experiments, the authors investigated the nature of tone-sucrose learning when associatively activated representations of those events were paired in the absence of either of the events themselves. Experiment 1 found substantial excitatory learning when the tone surrogate preceded the sucrose surrogate in training. Experiment 2 evaluated other accounts for the results of Experiment 1, and Experiment 3 found evidence for inhibitory tone-sucrose learning when the tone and sucrose surrogates were presented in simultaneous or backward order. The results indicated that the nature of representation-mediated learning is influenced by some of the same variables as more standard associative learning.     

Effects of excitotoxic brain lesions on taste-mediated odor learning in the rat

The association learning between taste and odor is important in ingestive behavior. For a better understanding of this learning, we have developed a convenient and useful paradigm to assess the taste-mediated odor learning. In the training session, Wistar male rats drank water from two bottles in their home cages and from eight small glass dishes. In the learning session they were exposed in their home cages and also in a circular open-field apparatus to 0.005 M Na-saccharin and 0.02 M quinine hydrochloride which contained either banana or almond odors. One learning trial consisted of this pair of exposures. The preceding behavioral experiment has shown that these two odors are not aversive and are differentially perceived by rats. In the test session, the animals were put in the open-field apparatus equipped with eight dishes: four contained water with banana, and another four, with almond. Normal control rats preferred to drink water with the odor previously associated with saccharin. Stronger and more persistent preference was attained after two or three learning trials. To elucidate the brain sites responsible for this taste-mediated odor learning, the same procedure was assessed on brain-lesioned rats. Rats with lesions in the amygdala showed rapid extinction of preference to the saccharin-associated odor, whereas control rats did not. However, rats with lesions in the insular cortex showed retention of learning similar to that of the control rats. Rats with lesions in the sulcal prefrontal or cingulate cortices showed moderate disruptive effects on preference to the saccharin-associated odor. In conclusion, the odor learning established in our experimental paradigm is based on the association between the quality of odor and hedonics of taste. The amygdala may play a role in the formation, at least in the retention process, of this taste-odor association learning.     

Studies in olfactory acuity. I: Measurement of olfactory thresholds in the rat

The capacity of the rat to respond to olfactory cues has been studied in three experimental situations: (i) an elevated Y-maze, (ii) a rectangular choice apparatus in which extraneous environmental cues were present, and (iii) a circular choice apparatus from which such cues were either excluded or randomized.

No rat showed any sign of learning on the Y-maze even after extensive training and the application of electric shock as deterrent for error.

Some rats succeeded in performing an olfactory discrimination in the rectangular choice apparatus but learning was retarded, and in some cases inhibited, by the counter-influence of non-olfactory factors.

All rats readily learned an identical discrimination when shielded from such cues in the circular choice apparatus which provides a satisfactory medium both for training and for the study of olfactory acuity.

Differences in the behaviour of rats on these three types of apparatus suggest first, that the formation of learned habits based on olfaction depends on the close contiguity of stimulus and reward, and second that the sense of smell possesses weak orientating properties by comparison with those exerted by other modalities. The findings thus help to explain differences in the ease or di+culty uith which olfactory discriminations have been established by earlier workers.     

Basing Categorization on Individuals and Events

Exemplar, prototype, and connectionist models typically assume that events constitute the basic unit of learning and representation in categorization. In these models, each learning event updates a statistical representation of a category independently of other learning events. An implication is that events involving the same individual affect learning independently and are not integrated into a single structure that represents the individual in an internal model of the world. A series of experiments demonstrates that human subjects track individuals across events, establish representations of them, and use these representations in categorization. These findings are consistent with “representationalism,” the view that an internal model of the world constitutes a physical level of representation in the brain, and that the brain does not simply capture the statistical properties of events in an undifferentiated dynamical system. Although categorization is an inherently statistical process that produces generalization, pattern completion, frequency effects, and adaptive learning, it is also an inherently representational process that establishes an internal model of the world. As a result, representational structures evolve in memory to track the histories of individuals, accumulate information about them, and simulate them in events.     

The effects of preexposure to a learning apparatus

ICR mice were given exposure to a one-way shuttle apparatus until locomotor activity had been habituated. When compared with nonexposed animals, the exposed animals displayed superior shuttle avoidance learning. Animals exposed to both the apparatus and the CS did not differ from the nonexposed group. It was concluded that preexposure to the learning apparatus facilitated acquisition, while preexposure to the apparatus in the presence of the CS did not. The relationship between this effect and habituation was considered.     

Implementation of experimental procedures in the PACER system of on-line control

PACER comprises an Executive and associated routines that together provide the run-time facilities commonly needed by experiment control programs. Although the implementation is specific to a particular PDP-11 installation, the nature of the support provided is of more general interest. Simple experimental procedures are straightforwardly handled by direct program control of timing and of external apparatus, and by direct inspection of the states of input lines connected to such apparatus. For more complicated situations, where events may not occur in a strict sequence, it becomes more convenient to make use of priority interrupts to inititiate response to events. Tasks to be performed under interrupt control are coded by the user as special subroutines known as “Actions.” It is a feature of PACER that the user can arrange for the Executive to run Actions automatically at specified times. The main program is then able to carry out processing that it would not be able to undertake if it had to make repeated checks on the time.     

Visual discrimination learning in rats with lesions of superior colliculus: Door-push and approach errors in modified jumping stand

It has been suggested that, for some species, lesions of the superior colliculus affect visual discrimination learning, but only in certain conditions: (a) when problems are first learnt only after operation, or (b) when discriminanda require detailed scanning, or (c) when “approach” responses to the discriminanda are measured, rather than the response of actually touching them. These suggestions were examined in rats learning visual discriminations in a modified jumping-stand apparatus, after sustaining large lesions of the superior colliculus (and in some cases also of the pretectum). The lesions produced open-field hyperactivity and reduced exploration, indicating effective tectal damage, but the rats learnt a series of difficult discriminations in a door-push task as fast as normal rats, and they did not make more approach errors. Their main abnormality in the discrimination apparatus was that they looked less often between the stimulus doors before stepping across to one of them from the central platform. It is suggested that in rats, as in other animals, lesions of the superior colliculus disrupt the control of scanning head and eye movements; in rats, however, such disruption need not affect discrimination learning (at least in some kinds of apparatus), possibly because the retina of the rat has a relatively poorly developed area centralis.     

Implicit learning of predictive relationships in three-element visual sequences by young and old adults

Knowledge of sequential relationships enables future events to be anticipated and processed efficiently. Research with the serial reaction time task (SRTT) has shown that sequence learning often occurs implicitly without effort or awareness. Here, the authors report 4 experiments that use a triplet-learning task (TLT) to investigate sequence learning in young and older adults. In the TLT, people respond only to the last target event in a series of discrete, 3-event sequences or triplets. Target predictability is manipulated by varying the triplet frequency (joint probability) and/or the statistical relationships (conditional probabilities) among events within the triplets. Results reveal that both groups learned, though older adults showed less learning of both joint and conditional probabilities. Young people used the statistical information in both cues, but older adults relied primarily on information in the 2nd cue alone. The authors conclude that the TLT complements and extends the SRTT and other tasks by offering flexibility in the kinds of sequential statistical regularities that may be studied as well as by controlling event timing and eliminating motor response sequencing.     

Outcome-based observational learning in human infants

Previous work shows that infants manifest emulation learning in the use of end-state information. Outcome-based emulation has been interpreted as affordance learning or goal attribution. The present paper explores whether these two learning possibilities might be related. In 3 experiments, 17-month-old infants (N = 180) were presented with action outcomes across a variety of contexts and tasks: They observed either the full demonstration or the model's starting and final postures, plus the initial and end states of the object, or the latter portion of the foregoing display, or the end state of the object alone. The tasks included combinatory, noncombinatory, and body movement acts. Infants reproduced observed outcomes most often by observing the full demonstration. A similar effect was attained by exposure to both posture and configuration changes, but the effect was subject to the combinatory nature of the apparatus. In contrast, performance was less efficient after seeing the object's end state alone, suggesting that infants in the previous conditions did not simply emulate in association with the affordances. These findings support the notion that goal attribution based on sensitivity to bodily cues is reliant on the clarity of the affordances of a task.     

Enhanced Implicit Sequence Learning in College‐age Video Game Players and Musicians

We examined whether college‐age video game players and musicians are better than controls at implicit sequence learning in the Alternating Serial Reaction Time Task. People learn to use subtle sequence regularities to respond more accurately and quickly to predictable versus non‐predictable events. Although previous studies have shown experts' enhanced processing speed and perception, this is the first to demonstrate that people who regularly play video games or a musical instrument showed greater implicit sequence learning, suggesting that experience playing games or music may improve the efficiency with which people learn sequential regularities in the environment. Copyright © 2011 John Wiley & Sons, Ltd.     

A Dynamical Systems Approach to Skill Acquisition

This paper argues that the answer to the question, what has to be learned, needs to be established before the question, how is it learned, can be meaningfully addressed. Based on this conviction, some of the limitations of current and past research on skill acquisition are discussed. Motivated by the dynamical systems approach, the question of “what has to be learned” was tackled by setting up a non-linear mathematical model of the task (i.e. learning to make sideways movements on a ski apparatus). On the basis of this model, the phase lag between movements of the platform of the apparatus and the actions of the subject was isolated as an ensemble variable reflecting the timing of the subject in relation to the dynamics of the apparatus. This variable was subsequently used to study “how” the task was learned in a discovery learning experiment, in which predictions stemming from the model were tested and confirmed. Overall, these findings provided support for the hypothesis, formulated by Bernstein (1967), that one of the important effects of practice is learning to make use of reactive forces, thereby reducing the need for active muscular forces.

In addition, the data from a previous learning experiment on the ski apparatus—the results of which had been equivocal—were reconsidered. The use of phase lag as a dependent variable provided a resolution of those findings.

On the basis of the confirmatory testing of predictions stemming from the model and the clarification of findings from a previous experiment, it is argued that the dynamical systems approach put forward here provides a powerful method for pursuing issues in skill acquisition. Suggestions are made as to how this approach can be used to systematically pursue the questions that arise as a natural outcome of the experimental evidence presented here.     

Lifelong Learning: A Pacification of ‘Know How’

A tendency of previous studies of lifelong learning to focus on learning and learning subjectivities may have led to an underestimation of potential effects in terms of a system of knowledge constitutive processes that operates powerfully to shape our societies. In this paper we explore lifelong learning and practices in the construction of knowledge at the point where a new relationship is being attempted between university courses and workplaces through programmes for learning. Drawing from Foucault and others we argue a strategic relation between discourses of lifelong learning and knowledge practices in such locations. Discourses of lifelong learning appear to support the reaching out of disciplinary practices into the workplace where theoretical knowledge is combined with knowledge derived from work experience, as a new form of knowledge that has use value. Discipline as a modality of power appears reconfigured and multiplied in new power-knowledge constellations which aim to subdue the desire and power of know how. Rather than lifelong learning as learning apparatus and strategy in the promotion of a will to learn as has been suggested elsewhere, we offer an alternative account. Here the promotion of a will to learn articulates with the will to knowledge in part through discourses of lifelong learning. Practices of knowledge constitution support the pacification of know how through its reconfiguration as knowledge that can be codified and mobilized for economic innovation.     

Word learning does not end at fast-mapping: evolution of verb meanings through reorganization of an entire semantic domain

This paper explores the process through which children sort out the relations among verbs belonging to the same semantic domain. Using a set of Chinese verbs denoting a range of action events that are labeled by carrying or holding in English as a test case, we looked at how Chinese-speaking 3-, 5-, and 7-year-olds and adults apply 13 different verbs to a range of carrying/holding events. We asked how children learning Chinese originally divide and label the semantic space in this domain, how they discover the boundaries between different words, and how the meanings of verbs in the domain as a whole evolve toward the representations of adults. We also addressed the question of what factors make verb meaning acquisition easy or hard. Results showed that the pattern of children’s verb use is largely different from that of adults and that it takes a long time for children to be able to use all verbs in this domain in the way adults do. We also found that children start to use broad-covering and frequent verbs the earliest, but use of these verbs tends to converge on adult use more slowly because children could not use these verbs as adults did until they had identified boundaries between these verbs and other near-synonyms with more specific meanings. This research highlights the importance of systematic investigation of words that belong to the same domain as a whole, examining how word meanings in a domain develop as parts of a connected system, instead of examining each word on its own: learning the meaning of a verb invites restructuring of the meanings of related, neighboring verbs.     

Children At-Risk for Borderline Personality Disorder

Adult patients who have been diagnosed with borderline personality disorder (BPD) have provided valuable information about events and family dynamics that are frequently associated with BPD. Clinicians who work with children are frequently aware of family or individual characteristics that may put a child at risk for developing BPD. Such situations frequently involve attachment issues with the child's caregivers and can include sexual abuse, divorce, alcoholism/substance use, illness/ death, and neglect. Child characteristics such as learning difficulties and temperament may also predict BPD. Yet, many children are resilient and seemingly unaffected by these events or situations, especially when early intervention may prevent development of BPD.