How similar are recognition memory and inductive reasoning?

Conventionally, memory and reasoning are seen as different types of cognitive activities driven by different processes. In two experiments, we challenged this view by examining the relationship between recognition memory and inductive reasoning involving multiple forms of similarity. A common study set (members of a conjunctive category) was followed by a test set containing old and new category members, as well as items that matched the study set on only one dimension. The study and test sets were presented under recognition or induction instructions. In Experiments 1 and 2, the inductive property being generalized was varied in order to direct attention to different dimensions of similarity. When there was no time pressure on decisions, patterns of positive responding were strongly affected by property type, indicating that different types of similarity were driving recognition and induction. By comparison, speeded judgments showed weaker property effects and could be explained by generalization based on overall similarity. An exemplar model, GEN-EX (GENeralization from EXamples), could account for both the induction and recognition data. These findings show that induction and recognition share core component processes, even when the tasks involve flexible forms of similarity.     

A connectionist model of category learning by individuals with high-functioning autism spectrum disorder

Individuals with autism spectrum disorder (ASD) show atypical patterns of learning and generalization. We explored the possible impacts of autism-related neural abnormalities on perceptual category learning using a neural network model of visual cortical processing. When applied to experiments in which children or adults were trained to classify complex two-dimensional images, the model can account for atypical patterns of perceptual generalization. This is only possible, however, when individual differences in learning are taken into account. In particular, analyses performed with a self-organizing map suggested that individuals with high-functioning ASD show two distinct generalization patterns: one that is comparable to typical patterns, and a second in which there is almost no generalization. The model leads to novel predictions about how individuals will generalize when trained with simplified input sets and can explain why some researchers have failed to detect learning or generalization deficits in prior studies of category learning by individuals with autism. On the basis of these simulations, we propose that deficits in basic neural plasticity mechanisms may be sufficient to account for the atypical patterns of perceptual category learning and generalization associated with autism, but they do not account for why only a subset of individuals with autism would show such deficits. If variations in performance across subgroups reflect heterogeneous neural abnormalities, then future behavioral and neuroimaging studies of individuals with ASD will need to account for such disparities.     

When similarity and causality compete in category-based property generalization

Five experiments were performed to investigate the category-based generalization of nonblank properties, properties that were novel but that were attributed to existing category features with causal explanations. Experiments 1-3 tested how such explanations interact with the well-known effects of similarity on such generalizations. The results showed that when the causal explanations were used, standard effects of typicality (Experiment 1), diversity (Experiment 2), or similarity itself (Experiment 3) were almost completely eliminated. Experiments 4 and 5 demonstrated that category-based generalizations exhibit some of the standard properties of causal reasoning; for example, an effect (i.e., a novel category property) is judged to be more prevalent when its cause (i.e., an existing category feature) is also prevalent. These findings suggest that category-based property generalization is often an instance of causal inference.     

Does category-training facilitate 11-month-olds’ acquisition of unfamiliar category-property associations?

The ability to form category-property links allows infants to extend a property from one category member to another. In two experiments, we examined whether orienting infants to the demands of the task, through categorization training, would facilitate 11-month-old infants’ category-property extensions when familiarized with a single exemplar of an unfamiliar animal category. In Experiment 1, 11-month-olds (N = 35) were trained with two familiar animal-sound pairings (i.e., dog-bark, cat-meow), familiarized with two unfamiliar animal-sound pairings and then tested on their learning and generalization of the unfamiliar animal-sound associations. Across two conditions, Experiment 2 familiarized 11-month-olds (N = 69) to one familiar (i.e., dog-bark) and one novel animal-sound pairing. Conditions differed in their presentation of familiarization trials (i.e., random or blocked). Infants were then tested on their learning and extension of the animal-sound associations. In both experiments, infants did not demonstrate learning of the original animal sound pairing, nor generalization of the sound property to new members of the animal categories. These results indicate that the two category training paradigms implemented in the current studies did not facilitate 11-month-olds’ ability to learn or generalize an unfamiliar animal-sound association, when familiarized with a single exemplar.     

Adding Types,But Not Tokens,Affects Property Induction

The extent to which we generalize a novel property from a sample of familiar instances to novel instances depends on the sample composition. Previous property induction experiments have only used samples consisting of novel types (unique entities). Because real-world evidence samples often contain redundant tokens (repetitions of the same entity), we studied the effects on property induction of adding types and tokens to an observed sample. In Experiments 1–3, we presented participants with a sample of birds or flowers known to have a novel property and probed whether this property generalized to novel items varying in similarity to the initial sample. Increasing the number of novel types (e.g., new birds with the target property) in a sample produced tightening, promoting property generalization to highly similar stimuli but decreasing generalization to less similar stimuli. On the other hand, increasing the number of tokens (e.g., repeated presentations of the same bird with the target property) had little effect on generalization. Experiment 4 showed that repeated tokens are encoded and can benefit recognition, but appear to be given little weight when inferring property generalization. We modified an existing Bayesian model of induction (Navarro, Dry, & Lee, 2012) to account for both the information added by new types and the discounting of information conveyed by tokens.     

Feature-based versus category-based induction with uncertain categories

Previous research has suggested that when feature inferences have to be made about an instance whose category membership is uncertain, feature-based inductive reasoning is used to the exclusion of category-based induction. These results contrast with the observation that people can and do use category-based induction when category membership is known. The present experiments examined the conditions that drive feature-based and category-based strategies in induction under category uncertainty. Specifically, 2 experiments investigated whether reliance on feature-based inductive strategies is a product of the lack of coherence in the categories used in previous research or is due to the use of a decision-only induction procedure. Experiment 1 found that feature-based reasoning remained the preferred strategy even when categories with relatively high internal coherence were used. Experiment 2 found a shift toward category-based reasoning when participants were trained to classify category members prior to feature induction. Together, these results suggest that an appropriate conceptual representation must be formed through experience with a category before it is likely to be used as a basis for feature induction.     

On the causal role of privation in Thomas Aquinas's metaphysics

“Privation” (privatio) is defined by Thomas Aquinas as the want of some property in a subject that ought naturally to possess that property. In this paper, I explicate the ontological status of privation as a form of nonbeing in order to shed light on the challenging question whether privation, as a kind of absence, can play a causal role for Aquinas, and if so, how. According to Aquinas, I argue, privations in a subject serve to determine what sort of (efficient) causal relations that subject can enter into, but, as nonbeings, privations cannot be the cause of the subject's entering into those relations, and in this way, they cannot be efficient causes of effects distinct from the subject.     

The influence of category coherence on inference about cross-classified entities

A critical function of categories is their use in property inference (Heit, 2000). However, one challenge to using categories in inference is that most entities in the world belong to multiple categories (e.g., Fido could be a dog, a pet, a mammal, or a security system). Building on Patalano, Chin-Parker, and Ross (2006), we tested the hypothesis that category coherence (the extent to which category features go together in light of prior knowledge) influences the selection of categories for use in property inference about cross-classified entities. In two experiments, we directly contrasted coherent and incoherent categories, both of which included cross-classified entities as members, and we found that the coherent categories were used more readily as the source of both property transfer and property extension. We conclude that category coherence, which has been found to be a potent influence on strength of inference for singly classified entities (Rehder & Hastie, 2004), is also central to category use in reasoning about novel cross-classified ones.     

Carrot eaters or moving heads: inductive inference is better supported by salient features than by category labels

How do words affect generalization, and how do these effects change during development? One theory posits that even early in development, linguistic labels function as category markers and thus are different from the features of the stimuli they represent. Another theory holds that early in development, labels are akin to other features, but that they may become category markers in the course of development. We addressed this issue in two experiments with 4- to 5-year-olds and adults. In both experiments, participants performed a categorization task (in which they predicted a category label) and an induction task (in which they predicted a missing feature). In the latter task, the category label was pitted against a highly salient feature, such that reliance on the label and reliance on the salient feature would result in different patterns of responses. Results indicated that children relied on the salient feature when performing induction, whereas many adults relied on the category label. These results suggest that early in development, labels are no more than features, but that they may become category markers in the course of development.     

Acquisition and generalization of manual signs by hearing-impaired adults with mental retardation

Behavioral procedures have been used to teach manual communication skills to individuals with mental retardation, although few studies have examined the assessment of generalization of such skills beyond the teaching environment. In this study, we investigated the effectiveness of directed rehearsal for teaching and facilitating the generalization of manual signs by six hearing-impaired adults with mental retardation. The effects of directed rehearsal, alone and combined with positive reinforcement for correct responses, were compared to a no-training control condition in an alternating treatments design. Although directed rehearsal was superior to the no-training control condition in teaching manual signs, the procedure was more effective when combined with positive reinforcement. The combined procedure was used to facilitate the generalization of learned signs across a number of variables. The results showed that there were high levels of generalization by all participants across novel phrases, settings, and trainers but variable levels of generalization to another response mode by some subjects. Further, increased levels in overall vocal communication were found for most participants.     

A sequential exploratory diagnostic model using a Pólya-gamma data augmentation strategy

Cognitive diagnostic models provide a framework for classifying individuals into latent proficiency classes, also known as attribute profiles. Recent research has examined the implementation of a Pólya-gamma data augmentation strategy binary response model using logistic item response functions within a Bayesian Gibbs sampling procedure. In this paper, we propose a sequential exploratory diagnostic model for ordinal response data using a logit-link parameterization at the category level and extend the Pólya-gamma data augmentation strategy to ordinal response processes. A Gibbs sampling procedure is presented for efficient Markov chain Monte Carlo (MCMC) estimation methods. We provide results from a Monte Carlo study for model performance and present an application of the model.     

Continuation of training as a variable influencing the generalization of speech in a retarded child

Imitation and differential reinforcement were applied in training a speech-deficient retarded child 4 separate verbal answers to 4 “everyday” questions. Training was provided in only one setting with one experimenter. After the subject had acquired each answer-response in the training situation, probes for stimulus generalization were given by both the trainer and nontrainers. These probes tested the usage of both trained and nontrained question-answering responses under nontraining conditions. Use of the separately trained responses in nontraining contexts increased as training continued beyond the established learning criteria. A concurrent reinforcement procedure for all 4 answerresponses increased the overall generalization effects across individuals and settings; the use of differential reinforcement of nonverbal responses in the training setting decreased the overall generalization effects.     

Developing knowledge of objects' motion properties in infancy

Three experiments with a novel variation of the inductive generalization procedure examined 18- and 22-month-olds' knowledge of objects' motion properties. Infants observed simple air and land movements modeled with an appropriate category member (e.g. dog) or an ambiguous block and were allowed to imitate with one or more of four exemplars. The experiments show that 18-month-olds' knowledge of land motions is grounded in causally relevant object parts, whereas 22-month-olds relate such motions more broadly to appropriate category members. Infants' basis for generalizing air motions suggested that at 22 months they have little knowledge about objects from that domain. The results are discussed in relation to the early development of the animate-inanimate distinction and the nature of the inductive generalization task.     

Conditioning and post-hospital generalization of nondelusional responses in a chronic psychotic patient

An operant conditioning approach was successful in getting a chronic psychotic patient to give factual answers to direct questions that had previously elicited only delusional responses. Multiple baseline and reversal controls established that the changes were due to the experimental procedure. The subject was a female patient classified as paranoid schizophrenic who had persisted in giving bizarre responses to direct questions regarding her identity, age, and personal history during 26 yr of hospitalization. She was discharged after factual answers to these questions had been obtained, but operant conditioning trials were continued in the community to promote generalization. Two follow-up interviews were conducted 36 and 52 days after discharge to evaluate generalization. No generalization was found in the first interview, but the second gave evidence of some generalization.     

A semi-orthogonal dependent factor solution

The paper presents a general framework for the dependent factor method in which judgmental as well as analytic criteria may be employed.The procedure involves a semi-orthogonal transformation of an oblique solution comprising a number of reference factors and a number of experimental factors (composites). It determines analytically the residual factors in the experimental field keeping the reference field constant. The method is shown to be a generalization of the multiple factor procedure [Thurstone, 1947] in so far as it depends on the use of generalized inverse in derivingpartial structure from total pattern. It is also shown to provide an example of the previously empty category (Case III) of the Harris-Kaiser generalization [1964]. A convenient computational procedure is provided. It is based on an extension of Aitken's [1937] method of pivotal condensation of a triple-product matrix to the evaluation of a matrix of the formH — VA ^–1 U' (for a nonsingularA).     

The role of linguistic labels in inductive generalization

What is the role of linguistic labels in inductive generalization? According to one approach labels denote categories and differ from object features, whereas according to another approach labels start out as features and may become category markers in the course of development. This issue was addressed in four experiments with 4- and 5-year-olds and adults. In Experiments 1 to 3, we replicated Yamauchi and Markman’s findings with adults (Journal of Memory and Language, 1998, Vol. 39, pp. 124–148, and Journal of Experimental Psychology: Learning, Memory, and Cognition, 2000, Vol. 26, pp. 776–795) and extended the paradigm to young children. In Experiment 4, we compared effects of labels with those of highly salient visual features. Overall, results of these experiments provide strong support for the idea that early in development labels function the same way as other features, but they may become category markers in the course of development. A related finding is that whereas categorization and induction may be different processes in adults, they seem to be equivalent in young children. These results are discussed with respect to theories of development of inductive generalization.     

Constraints and Preferences in Inductive Learning: An Experimental Study of Human and Machine Performance

The paper examines constraints and preferences employed by people in learning decision rules from preclassified examples. Results from four experiments with human subjects were analyzed and compared with artificial intelligence (AI) inductive learning programs. The results showed the people's rule inductions tended to emphasize category validity (probability of some property, given a category) more than cue validity (probability that an entity is a member of a category given that it has some property) to a greater extent than did the AI programs. Although the relative proportions of different rule types (e.g., conjunctive vs. disjunctive) changed across experiments, a single process model provided a good account of the data from each study. These observations are used to argue for describing constraints in terms of processes embodied in models rather than in terms of products or outputs. Thus AI induction programs become candidate psychological process models and results from inductive learning experiments can suggest new algorithms. More generally, the results show that human inductive generalizations tend toward greater specificity than would be expected if conceptual simplicity were the key constraint on inductions. This bias toward specificity may be due to the fact that this criterion both maximizes inferences that may be drawn from category membership and protects rule induction systems from developing over-generalizations.     

Information about the logical structure of a category affects generalization

This paper considers whether information about the logical structure of a category affects how people generalize. We carried out three experiments with the following structure: participants were first presented with a set of training items, and were subsequently asked to decide whether new items belonged to the same category as the training items. Each experiment had two conditions that differed only in terms of the category label provided for the training items; different category labels conveyed different information about the logical structure of the category to which the training items were supposed to belong. In all cases, participants' generalization was greatly affected by such information. Our results suggest that people make the default assumption that category labels correspond to groupings of highly similar objects.     

Horse (Equus caballus) whinnies: a source of social information

Many animal species that rely mainly on calls to communicate produce individual acoustic structures, but we wondered whether individuals of species better known as visual communicants, with small vocal repertoires, would also exhibit individual distinctiveness in calls. Moreover, theoretical advances concerning the evolution of social intelligence are usually based on primate species data, but relatively little is known about the social cognitive capacities of non-primate mammals. However, some non-primate species demonstrate auditory recognition of social categories and possess mental representation of their social network. Horses (Equus caballus) form stable social networks and although they display a large range of visual signals, they also use long-distance whinny calls to maintain contact. Here, we investigated the potential existence of individual acoustic signatures in whinny calls and the ability of horses to discriminate by ear individuals varying in their degree of familiarity. Our analysis of the acoustic structure of whinnies of 30 adult domestic horses (ten stallions, ten geldings, ten mares) revealed that some of the frequency and temporal parameters carried reliable information about the caller’s sex, body size and identity. However, no correlations with age were found. Playback experiments evaluated the behavioural significance of this variability. Twelve horses heard either control white noise or whinnies emitted by group members, familiar neighbours or unfamiliar horses. While control sounds did not induce any particular response, horses discriminated the social category of the callers and reacted with a sound-specific behaviour (vigilance and attraction varied with familiarity). Our results support the existence of social knowledge in horses and suggest a process of vocal coding/decoding of information.