Instrumental learning in preschool children as a function of type of task, type of reward, and some organismic variables

The effects on instrumental behavior of differences in type of task, type of reward and three organismic variables were investigated in preschool children. The main results were that: (a) an imitative task was acquired in fewer trials than a nonimitative task; (b) social reward in acquisition led to greater resistance to extinction; (c) a history of frequent social reinforcement from peers led to persistence in responding during extinction for boys only; (d) extraversion was found to interact with the variables of task and reward in errors made during extinction; and (e) intelligence was not found to be a reliable predictor of main acquisition and extinction measures or related errors. Detailed analysis of the different types of errors contributed directly to the interpretation of these findings.     

Novelty as a reinforcer for position learning in children

The stimulus-familiarization-effect (SFE) paradigm, a reaction-time (RT) task based on a response to novelty procedure, was modified to assess response for novelty, i.e., a response-reinforcement sequence. Ninetysix kindergarten children were familiarized on one of two colored lights. Then Ss were confronted with a simple position discrimination task in which they could choose between two response buttons which produced either the previously familiarized light or a new (i.e., novel) light. Results showed that the choice response for the novel stimulus (NS) was facilitated by three variables: number of exposures to and duration per exposure of the familiar stimulus (FS), and degree of change provided by the NS relative to the FS. The parallel between the effective variables of this study and those which produce the SFE was noted, implicating an attention interpretation of the function of novelty as a reinforcer. The potential implications of attention for reinforcement theory and learning in general are discussed.     

Stochastic PERT networks as models of cognition: Derivation of the mean,variance, and distribution of reaction time using Order-of-Processing (OP) diagrams

It is frequently assumed that the mental activity which leads to a given response is made up of separable components or processes. One or more of the processes are assumed to contribute to the time required to respond. Computation of the mean, variance, and distribution of the reaction time is relatively straightforward when all processes are arranged in series or parallel. However, such is not the case when the processes have complex arrangements. A solution to a useful special case of the above problem is proposed. Specifically, it is shown that simple computations yield closed form expressions for the mean, variance, and distribution of reaction time when the processes can be arranged in a stochastic PERT network and when the durations of individual processes are sums of mutually independent, exponentially distributed random variables. The method of solution relies on the construction of an Order-of-Processing (OP) diagram from the original PERT network representation of behavior.     

Prosopagnosia and visual object agnosia: A behavioral study

A left-handed woman developed visual object agnosia, prosopagnosia, and visual disorientation after resection of the right occipital lobe. Color agnosia and alexia were absent. When asked to identify objects presented visually, the patient's errors represented visually related objects (underspecifications) or perseverations. Identification was facilitated when she observed the object being used in a natural way. Identification was impaired by surrounding the object with unrelated objects, decreasing the background illumination, decreasing the duration of exposure of the object to the patient, and probably also by decreasing the visual angle subtended by the object. In addition, there were disturbances of visualization (i.e., imaging in the absence of a visual stimulus) that paralleled the perceptual difficulties. We conclude that: (1) A deficit in visual perception, characterized by insufficient feature analysis of visual stimuli, was the basis of the visual agnosia in this case. (2) The visual agnosia could not be explained by (a) a vision-language disconnection syndrome, (b) decay of visual memory traces, or (c) deficiencies in the visual fields (pathologic Funktionswandel). (3) The ability to visualize (visual imagery) probably utilizes some of the same neural pathways used in perception. (4) The results in this case probably can be generalized to some but not all cases of visual agnosia; in particular, the deficit in most previously reported patients with prosopagnosia is similar to that of our case. However, agnosic alexia and color agnosia usually have a different neuropsychological basis.     

Moral cognition and moral action: A theoretical perspective

Considerable theoretical work has been done in the area of moral reasoning. However, little conceptual thinking has been done about the relations between moral cognition and moral action. As a result, empirical research in this area has been unsystematic and difficult to interpret. A theoretical model, the Self Model, is proposed here, starting from the assumption that moral reasons are functionally related to action. First, a concept of cognitive motivation is presented as necessary for any cognitive account of morality. Two cognitive approaches to moral conduct, Piaget's and Haan's, are then discussed in their positive contributions and in their limitations. The Self Model is finally described through a set of empirically testable propositions. Its major theoretical characteristics are: it is cognitive, recognizing as the central function of human cognition the appraisal of truth; it acknowledges a basic duality of motivation, but stresses the normative pull of cognitive motivation; it is developmental; it uses the self as the central explanatory concept, establishing both the sense of personal responsibility and the dynamism of self-consistency.     

Another psychobiological view of sexual differentiation

The major psychobiological theory of sex differences is based on the hypothesis that hormones induce sex differences in neural organization. Hormonally masculinized or feminized brains are thought to underlie subsequent behavioral sex differences. This theory and the constructs, arguments, and evidence used in its support are closely examined. Some conceptual problems with widely used arguments are identified and discussed. Behavioral, physiological, and anatomical evidence from studies of animal sexual behavior is reviewed. It is concluded that the evidence fails to support generally accepted views that early hormones affect behavior through direct effects on brain differentiation and that behavioral differences must be located in the brain. It is argued instead that hormones coact and interact with other factors throughout development, that brain differences may result from as well as cause functional differences, and that hormone-based sources of sex differences may be located throughout the body and in the social surround. Directions for new research are suggested and implications for interpretation of human sex differences are discussed.     

Structure-mapping: A theoretical framework for analogy

A theory of analogy must describe how the meaning of an analogy is derived from the meanings of its parts. In the structure-mapping theory, the interpretation rules are characterized as implicit rules for mapping knowledge about a base domain into a target domain. Two important features of the theory are (a) the rules depend only on syntactic properties of the knowledge representation, and not on the specific content of the domains; and (b) the theoretical framework allows analogies to be distinguished cleanly from literal similarity statements, applications of abstractions, and other kinds of comparisons. Two mapping principles are described: (a) Relations between objects, rather than attributes of objects, are mapped from base to target; and (b) The particular relations mapped are determined by systematicity, as defined by the existence of higher-order relations.