Members Of Different Categories Research Articles

An Object Lesson: Objects, Non-Objects, and the Power of Conceptual Construal in Adjective Extension

ABSTRACT Despite the seemingly simple mapping between adjectives and perceptual properties (e.g., color, texture), preschool children have difficulty establishing the appropriate extension of novel adjectives. When children hear a novel adjective applied to an individual object, they successfully extend the adjective to other members of the same object category but have difficulty extending it more broadly to members of different categories. We propose that the source of this difficulty lies at the interface of the linguistic and conceptual systems: children initially limit the extension of an adjective to the category of the object on which it was introduced. To test this hypothesis, we manipulated whether participants construed images as “pictures of things” (objects) or “blobs of stuff” (non-objects). For both 36-month-old children (Experiments 1 and 2) and adults (Experiment 3), the conceptual status of an image influenced how they extended an adjective applied to that image. Children extended novel adjectives more successfully when they construed the images as non-objects than when they construed the same images as objects. Similarly, adults were faster to make adjective extensions when construing the images as non-objects rather than objects. Learners of all ages must navigate this linguistic-conceptual interface in assessing whether and how novel adjectives should be extended to new individuals.

Category learning can alter perception and its neural correlates.

Learned Categorical Perception (CP) occurs when the members of different categories come to look more dissimilar (“between-category separation”) and/or members of the same category come to look more similar (“within-category compression”) after a new category has been learned. To measure learned CP and its physiological correlates we compared dissimilarity judgments and Event Related Potentials (ERPs) before and after learning to sort multi-featured visual textures into two categories by trial and error with corrective feedback. With the same number of training trials and feedback, about half the subjects succeeded in learning the categories (“Learners”: criterion 80% accuracy) and the rest did not (“Non-Learners”). At both lower and higher levels of difficulty, successful Learners showed significant between-category separation—and, to a lesser extent, within-category compression—in pairwise dissimilarity judgments after learning, compared to before; their late parietal ERP positivity (LPC, usually interpreted as decisional) also increased and their occipital N1 amplitude (usually interpreted as perceptual) decreased. LPC amplitude increased with response accuracy and N1 amplitude decreased with between-category separation for the Learners. Non-Learners showed no significant changes in dissimilarity judgments, LPC or N1, within or between categories. This is behavioral and physiological evidence that category learning can alter perception. We sketch a neural net model predictive of this effect.

Children's explanations as a window into their intuitive theories of the social world.

Social categorization is an early emerging and robust component of social cognition, yet the role that social categories play in children's understanding of the social world has remained unclear. The present studies examined children's (N = 52 four- and five-year olds) explanations of social behavior to provide a window into their intuitive theories of how social categories constrain human action. Children systematically referenced category memberships and social relationships as causal-explanatory factors for specific types of social interactions: harm among members of different categories more than harm among members of the same category. In contrast, they systematically referred to agents' mental states to explain the reverse patterns of behaviors: harm among members of the same category more than harm among members of different categories. These data suggest that children view social category memberships as playing a causal-explanatory role in constraining social interactions.

Distinct labels attenuate 15-month-olds' attention to shape in an inductive inference task.

We examined the role of distinct labels on infants’ inductive inferences. Thirty-six 15-month-old infants were presented with target objects that possessed a non-obvious property, followed by test objects that varied in shape similarity relative to the target. Infants were tested in one of two groups, a Same Label group in which target and test objects were labeled with the same noun, and a Distinct Label group in which target and test objects were labeled with different nouns. When target and test objects were labeled with the same count noun, infants generalized the non-obvious property to both test objects, regardless of similarity to the target. In contrast, labeling the target and test objects with different count nouns attenuated infants’ generalization of the non-obvious property to both high and low-similarity test objects. Our results suggest that by 15 months, infants recognize that object labels provide information about underlying object kind and appreciate that distinct labels are used to designate members of different categories.

Differential category learning processes: The neural basis of comparison-based learning and induction

Findings from numerous studies suggest that multiple neural systems are involved in category learning. Specifically, it is often argued that acquiring a representation of different category structures (e.g., rule-based vs. prototype-based representation) involves different computational challenges, which are resolved by different neural circuitries in the human brain. Here we present an alternative approach for studying neural mechanisms of category learning: We refer to the idea that any category learning task involves mapping common features shared by same-category members, distinctive features discriminating members of different categories, or both. We argue that since these processes are psychologically and computationally distinct, they differ in their usability for category learning. Our participants learned novel categories of complex visual stimuli by comparing either pairs of objects from the same novel category or pairs of objects from different categories. Object pairs were chosen so that the objective amount of information they contained was identical in the two category learning conditions, equally enabling learning the predefined objective category structure. We find that the neural circuitry involved in detecting important between-categories differences is associated mainly with the dorsal striatum (bilaterally) and the right hippocampus. On the other hand, mapping within-category similarities and differences is restricted to high-level visual brain areas. We suggest that multiple neural mechanisms are involved in category learning enabling us to face different computational challenges associated with different basic types of induction processes that differ in their usability for learning different category structures.

The Neural Basis of Perceptual Category Learning in Human Infants

We measured looking times and ERPs to examine the cognitive and brain bases of perceptual category learning in 6-month-old infants. In Experiment 1, we showed that categorization and exemplar discrimination rely on different cortical processes. Specifically, the repetition of individual exemplars resulted in differential cortical processing at posterior channels at an early stage during object processing (100-300 msec), whereas discriminating among members of different categories was reflected in ERP differences over anterior cortical regions occurring later in time (300-500 msec) than the repetition effects. In Experiment 2, replicating the findings of Study 1, we found that infants engage the same cortical processes to categorize visual objects into basic-level categories, regardless of whether a basic (bird vs. fish) or global level is crossed (birds vs. cars). This pattern of findings is consistent with perceptual accounts of infant categorization [Quinn, P. C., & Eimas, P. D. Perceptual organization and categorization in young infants. In C. Rovee-Collier & L. P. Lipsitt (Eds.), Advances in infancy research ( pp. 1-36). Norwood, NJ: Ablex, 1996] and accords with recent adult neural-level models of perceptual categorization.

Extremely selective attention: Eye-tracking studies of the dynamic allocation of attention to stimulus features in categorization.

Humans have an extremely flexible ability to categorize regularities in their environment, in part because of attentional systems that allow them to focus on important perceptual information. In formal theories of categorization, attention is typically modeled with weights that selectively bias the processing of stimulus features. These theories make differing predictions about the degree of flexibility with which attention can be deployed in response to stimulus properties. Results from 2 eye-tracking studies show that humans can rapidly learn to differently allocate attention to members of different categories. These results provide the first unequivocal demonstration of stimulus-responsive attention in a categorization task. Furthermore, the authors found clear temporal patterns in the shifting of attention within trials that follow from the informativeness of particular stimulus features. These data provide new insights into the attention processes involved in categorization.

Preschoolers' Responses to Social Comparisons Involving Relative Failure

Prior work indicates that preschoolers (ages 4-5) maintain high self-appraisals and behavioral engagement after performing less well than their peers. This study tested the hypothesis that relative failure has more negative consequences for preschoolers when they interpret achievement differences as being tied to membership in social categories (e.g., when members of different categories have different achievement levels), as opposed to variations in individual effort. Preschoolers (N= 58) were randomly assigned to receive feedback that a same-gender, other-gender, or gender-unidentified peer performed better than they did on a novel task. Experiences of failure relative to other-gender peers resulted in impaired performance on a subsequent task trial, as well as lack of improvement in self-evaluations after children received more positive feedback. These findings have implications for the origins of social comparisons, category-based reasoning, and the development of gender stereotypes and achievement motivation.

Male perspective on induced abortion

To analyze the perspective on induced abortion of men of a university community living in legal or consensual wedlock. A descriptive cross-sectional study was carried out and 361 members of different categories of an university were interviewed. Chi-square test was used to assess the association between dependent and independent variables. Fifth-three percent of the participants acknowledged that women have the right to end pregnancy. Men were more favorable to abortion when there is a risk to woman's life (85%); rape-related pregnancy (80%); and fetal anomalies (75%). Higher schooling of both men and their partners and the interviewees' position (teacher/student) were associated to a positive attitude towards abortion. Men tended to be more prone to abortion in legally and/or socially accepted instances. Better education of both men and their partners was relevant to determine their attitude towards abortion.

The “search for adultness”: Membership work in Adolescent-adult talk

Introducing some possibilities in the use of the notions "membership categorization device" and "category-bound activity" for ethnometh? odology, Sacks (1974) sketched out features and uses of, among others, the "stage of life" collection. A complement to this work, and a useful expansion of it, is found in Atkinson's (1980) analysis of "the prac? tical uses of a 'natural lifetime'." Both Sacks and Atkinson discuss how notions of life stages are used in practical reasoning, and describe the tying of activities to categories within the collection or to location in the "natural lifetime." My purpose in this paper is to develop these sources by observing membership categorization activity in conserva? tions between members of different categories within the device "stage of life," where membership/potential membership in these categories is also the topic of the talk. In particular, I give attention to the com? monsense category "adolescence" by witnessing some methods "ado? lescents" use in interview conversations about their passage through the "natural lifetime," and connect these observations to points raised in Hadden and Lester's (1978) analysis of identity as an interpretive accomplishment. Descriptions of how the "stage of life" device is used conversationally make possible some purchase on how "ado? lescence" is constituted as a commonsense category in everyday life, and some exploration of how biographical identities (identities tied to the device) serve as resources as well as topics in conversation. This kind of analysis is prior to all constructivist theorizing about "ado? lescence," since the social "fact" of an adolescence is produced and sustained through the work persons do with devices like "stage of life" and "natural lifetime." For ethnomethodology, this describes the practical and even the strategic uses of these devices by "positioned" members, who can at the same time be characterized as "transitional" within the device. "Adolescent" talk, and talk about or with "ado

The Collective Approach to Psychiatric Practice in the People's Republic of China

This paper describes and analyzes the effects of the dramatic changes of social values in China on the approach to treatment of the mentally ill since the 1949 revolution. It is mainly based on observations, interviews, and experiences in mental hospitals during three recent trips to the People's Republic of China. Attention here is focused on the effects of four new social values on psychiatric practice: first, the value of collective responsibility as reflected in the new program to integrate mental hospitals with the community; second, the application of the value of sharing and "serving the people" to methods of psychiatric therapy; third, the value of "minimization of elitism" as practiced in the role relationships among members of different categories in mental hospitals; and fourth, the reaffirmation of faith in human ability to conquer difficulties, as shown in changes of patients' outlook on life and behavior. Finally, the implications of this alternative approach on our established assumptions and methods of psychiatric therapy in the West are discussed, and the future direction of theoretical formulation is suggested.

Categories and boundaries in speech and music*

Perceptual categories and boundaries arise when Ss respond to continuous variation on a physical dimension in a discontinuous fashion. It is more difficult to discriminate between members of the same category than to discriminate between members of different categories, even though the amount of physical difference between both pairs is the same. Speech stimuli have been the sole class of auditory signals to yield such perception; for example, each different consonant phoneme serves as a category label. Experiment I demonstrates that categories and boundaries occur for both speechand nonspeech stimuli differing in rise time. Experiment II shows that rise time cues categorical differences in both complex and simple nonspeech waveforms. Taken together, these results suggest that certain aspects of speech perception are intimately related to processes and mechanisms exploited in other domains. The many categories in speech may be based on categories that occur elsewhere in auditory perception.