Unlearning Aristotelian physics: a study of knowledge-based learning

A study of a group of elementary school students learning to control a computer-implemented Newtonian object reveals a surprisingly uniform and detailed collection of strategies, at the core of which is a robust “Aristotelian” expectation that things should move in the direction they are last pushed. A protocol of an undergraduate dealing with the same situation shows a large overlap with the set of strategies used by the elementary school children and thus a marked lack of influence of classroom physics training on this student's naive physics. The data from these two studies are pooled and elaborated into a “genetic task analysis” of how one might come to understand Newtonian dynamics as a more or less natural evolution from the naive state.     

On Some Aristotelian Sources of Modern Argumentation Theory

Although he does not provide a general analysis of argumentation, Aristotle is a highly influential source of modern argumentation theory. In his treatises the Topics, the Sophistical Refutations and the Rhetoric, Aristotle presents complementary aspects of a theory of sound arguments that are seen as the most effective means of persuasion. Aristotle’s central notion of a deductive argument (sullogismos) does not include references to an addressee, the situative context or non-verbal aspects of communication, and thus differs from some modern views on argumentation. A deductive argument in the Aristotelian sense is a sequence of intellectual steps where the conclusion follows of necessity from the premises. Aristotle does not relativize or relax this notion but takes other factors into account by providing supplementary theoretical elements. For example, he reflects on acceptable premises (endoxa), the adjustment of rhetorical arguments to the horizon of the audience, methods of finding premises on the basis of argumentative schemes (topoi), the use of non-argumentative means of persuasion, and a framework of implicit discourse rules. Many of these themes are, albeit under a different name, still discussed in modern argumentation theory.     

Multiple views of spatial memory

Recent evidence indicates that mental representations of large (i.e., navigable) spaces are viewpoint dependent when observers are restricted to a single view. The purpose of the present study was to determine whether two views of a space would produce a single viewpoint-independent representation or two viewpoint-dependent representations. Participants learned the locations of objects in a room from two viewpoints and then made judgments of relative direction from imagined headings either aligned or misaligned with the studied views. The results indicated that mental representations of large spaces were viewpoint dependent, and that two views of a spatial layout appeared to produce two viewpoint-dependent representations in memory. Imagined headings aligned with the study views were more accessible than were novel headings in terms of both speed and accuracy of pointing judgments.     

Animal learning and memory and their relation to human learning and memory

For some three decades now, the experimental study of learning and memory has been conducted as two entirely separate endeavors, one using humans as subjects and the other using animals. The separation is placed in historical context, and consideration is given to recent movements by those in the animal camp toward adopting some of the theorizing as well as some of the list memory procedures from those in the human camp. It is argued that exploring list memory in animals should do much to further our understanding of both animal cognition and its relation to human cognition. The trend toward more complex theorizing and more liberal use of hypothetical constructs, on the other hand, is regarded with concern. It is argued that hypothetical constructs have contributed little to an enduring understanding of human learning and memory, and that they are unlikely to be any more helpful with animals.     

Schematic influences on category learning and recognition memory

The results from 3 category learning experiments suggest that items are better remembered when they violate a salient knowledge structure such as a rule. The more salient the knowledge structure, the stronger the memory for deviant items. The effect of learning errors on subsequent recognition appears to be mediated through the imposed knowledge structure. The recognition advantage for deviant items extends to unsupervised learning situations. Exemplar-based and hypothesis-testing models cannot account for these results. The authors propose a clustering account in which deviant items are better remembered because they are differentiated from clusters that capture regularities. The function of clusters is akin to that of schemas. Their results and analyses expose connections among research in category learning, schemas, stereotypes, and analogy.     

Effects of acetoxycycloheximide on appetitive learning and memory

The effects of direct brain infusions of acetoxycycloheximide (an inhibitor of protein synthesis; ACXH) on acquisition, storage and recall of memory for one-trial appetitive learning were examined in five experiments. ACXH was infused into the rats' hippocampi through implanted cannulas. Control subjects received an equal volume of physiological saline. ACXH was infused (a) 5 h before acquisition, (b) 5 hr before commencement of recall tests, and (c) immediately after acquisition. Each subject's general motor activity was recording during testing. The results indicate that (1) ACXH has similar effects on appetitive and avoidance learning. (2) ACXH administered immediately after acquisition, has no effect on memory. (3) At 4 hr after acquisition memory is affected by ACXH. (4) Short-term memory is unaffected by ACXH and can exist independently of long-term memory. (5) ACXH consistently reduces general motor activity.     

Category learning and multiple memory systems

Categorization is a vitally important skill that people use every day. Early theories of category learning assumed a single learning system, but recent evidence suggests that human category learning may depend on many of the major memory systems that have been hypothesized by memory researchers. As different memory systems flourish under different conditions, an understanding of how categorization uses available memory systems will improve our understanding of a basic human skill, lead to better insights into the cognitive changes that result from a variety of neurological disorders, and suggest improvements in training procedures for complex categorization tasks.     

Extinction in human learning and memory

In two experiments, participants were given extinction training in a human causal learning task. In both experiments, three critical experimental cues were paired with different outcomes in a first phase of training and were then extinguished in a second phase. Three control cues were given the same treatment in the first phase of training, but were not then presented in the second phase. Participants' ability to correctly identify the outcome with which each cue had been paired in the first phase was lower for extinguished than for control cues. Causal attributions to the extinguished cues were also lower than those to the control cues, a difference that correlated with outcome memory. These data are consistent with the idea that extinction in causal judgement is due, at least in part, to a failure to remember the cue-outcome relationship encoded in the first phase of training.     

Extinction in human learning and memory

In two experiments, participants were given extinction training in a human causal learning task. In both experiments, three critical experimental cues were paired with different outcomes in a first phase of training and were then extinguished in a second phase. Three control cues were given the same treatment in the first phase of training, but were not then presented in the second phase. Participants' ability to correctly identify the outcome with which each cue had been paired in the first phase was lower for extinguished than for control cues. Causal attributions to the extinguished cues were also lower than those to the control cues, a difference that correlated with outcome memory. These data are consistent with the idea that extinction in causal judgement is due, at least in part, to a failure to remember the cue–outcome relationship encoded in the first phase of training.     

Aberrant learning and memory in addiction

Over the past several years, drug addiction has increasingly been accepted to be a disease of the brain as opposed to simply being due to a lack of willpower or personality flaw. Exposure to addictive substances has been shown to create enduring changes in brain structure and function that are thought to underlie the transition to addiction. Specific genetic and environmental vulnerability factors also influence the impact of drugs of abuse on the brain and can enhance the likelihood of becoming an addict. Long-lasting alterations in brain function have been found in neural circuits that are known to be responsible for normal appetitive learning and memory processes and it has been hypothesized that drugs of abuse enhance positive learning and memory about the drug while inhibiting learning about the negative consequences of drug use. Therefore, the addict's behavior becomes increasingly directed towards obtaining and using drugs of abuse, while at the same time developing a poorer ability to stop using, even when the drug is less rewarding or interferes with functioning in other facets of life. In this review we will discuss the clinical evidence that addicted individuals have altered learning and memory and describe the possible neural substrates of this dysfunction. In addition, we will explore the pre-clinical evidence that drugs of abuse cause a progressive disorder of learning and memory, review the molecular and neurobiological changes that may underlie this disorder, determine the genetic and environmental factors that may increase vulnerability to addiction, and suggest potential strategies for treating addiction through manipulations of learning and memory.     

Contextual inference in learning and memory

Context is widely regarded as a major determinant of learning and memory across numerous domains, including classical and instrumental conditioning, episodic memory, economic decision-making, and motor learning. However, studies across these domains remain disconnected due to the lack of a unifying framework formalizing the concept of context and its role in learning. Here, we develop a unified vernacular allowing direct comparisons between different domains of contextual learning. This leads to a Bayesian model positing that context is unobserved and needs to be inferred. Contextual inference then controls the creation, expression, and updating of memories. This theoretical approach reveals two distinct components that underlie adaptation, proper and apparent learning, respectively referring to the creation and updating of memories versus time-varying adjustments in their expression. We review a number of extensions of the basic Bayesian model that allow it to account for increasingly complex forms of contextual learning.     

The neurobiology of learning and memory

The study of memory is a great challenge, perhaps the greatest in biological sciences. Memory involves changes in a tiny fraction of an extremely large pool of elements, a conclusion that makes the task of finding those changes using current technologies formidable. What can be done about this roadblock to neurological investigations of learning? One response that has become particularly productive in recent years is to study learning or learning-like phenomena in relatively simple "model" systems. The idea is to extract basic principles from these models in which molecular and anatomical details can be studied and then to use these in analyzing learning in higher regions of the brain. In this article we discuss current progress and emerging concepts derived from the simple system approach using animal models.     

Assessing learning and memory in pigs

In recent years, there has been a surge of interest in (mini) pigs (Sus scrofa) as species for cognitive research. A major reason for this is their physiological and anatomical similarity with humans. For example, pigs possess a well-developed, large brain. Assessment of the learning and memory functions of pigs is not only relevant to human research but also to animal welfare, given the nature of current farming practices and the demands they make on animal health and behavior. In this article, we review studies of pig cognition, focusing on the underlying processes and mechanisms, with a view to identifying. Our goal is to aid the selection of appropriate cognitive tasks for research into pig cognition. To this end, we formulated several basic criteria for pig cognition tests and then applied these criteria and knowledge about pig-specific sensorimotor abilities and behavior to evaluate the merits, drawbacks, and limitations of the different types of tests used to date. While behavioral studies using (mini) pigs have shown that this species can perform learning and memory tasks, and much has been learned about pig cognition, results have not been replicated or proven replicable because of the lack of validated, translational behavioral paradigms that are specially suited to tap specific aspects of pig cognition. We identified several promising types of tasks for use in studies of pig cognition, such as versatile spatial free-choice type tasks that allow the simultaneous measurement of several behavioral domains. The use of appropriate tasks will facilitate the collection of reliable and valid data on pig cognition.     

Integrating working memory capacity and context-processing views of cognitive control

Individuals low in working memory capacity (WMC) exhibit impaired performance on a variety of cognitive control tasks. The executive-attention theory of WMC (Engle & Kane, [2004[) accounts for these findings as failures of goal maintenance and response conflict resolution. Similarly, the context-processing view (Braver et al., [2001]) provides an explanation of cognitive control deficits observed in schizophrenia patients and older adults that is based on the ability to maintain context information. Instead of maintenance deficits, the inhibition view (Hasher, Lustig, & Zacks, [2007]) states that older adults and individuals low in WMC primarily have an impairment in the ability to inhibit information. In the current experiment, we explored the relationships among these theories. Individuals differing in performance on complex span measures of WMC performed the AX-Continuous Performance Test to measure context-processing performance. High-WMC individuals were predicted to maintain the context afforded by the cue, whereas low-WMC individuals were predicted to fail to maintain the context information. Low-WMC individuals made more errors on AX and BX trials and were slower to respond correctly on AX, BX, and BY trials. The overall pattern of results is most consistent with both the executive-attention and context-processing theories of cognitive control.     

Aging and memory for faces versus single views of faces

Differences in the ability of young adults and elderly to recognize faces were examined under two conditions. In a standard single-view condition, in which each input face was shown as one photograph, we confirmed prior findings that young adults perform better than the elderly at distinguishing photographs seen before from photographs of new faces. We also found that the elderly had more trouble distinguishing photographs seen before from photographs of(l) old faces changed in facial expression and (2) old faces changed in expression and pose. Yet there were no reliable age differences in distinguishing old-but-changed faces from entirely new faces. In a more naturalistic multi-view condition, in which each input face was shown in four poses and with two expressions, no age differences were found. A second experiment ruled out the possibility that varied repetition, by itself, removes age differences in recognizing faces. These data supported age differences in remembering facial expressions and possibly other details of photographs of faces, but not in remembering faces perse.     

Integrating working memory capacity and context-processing views of cognitive control

Individuals low in working memory capacity (WMC) exhibit impaired performance on a variety of cognitive control tasks. The executive-attention theory of WMC (Engle & Kane, 2004) accounts for these findings as failures of goal maintenance and response conflict resolution. Similarly, the context-processing view (Braver et al., 2001) provides an explanation of cognitive control deficits observed in schizophrenia patients and older adults that is based on the ability to maintain context information. Instead of maintenance deficits, the inhibition view (Hasher, Lustig, & Zacks, 2007) states that older adults and individuals low in WMC primarily have an impairment in the ability to inhibit information. In the current experiment, we explored the relationships among these theories. Individuals differing in performance on complex span measures of WMC performed the AX-Continuous Performance Test to measure context-processing performance. High-WMC individuals were predicted to maintain the context afforded by the cue, whereas low-WMC individuals were predicted to fail to maintain the context information. Low-WMC individuals made more errors on AX and BX trials and were slower to respond correctly on AX, BX, and BY trials. The overall pattern of results is most consistent with both the executive-attention and context-processing theories of cognitive control.