The functions of the orbitofrontal cortex

The orbitofrontal cortex contains the secondary taste cortex, in which the reward value of taste is represented. It also contains the secondary and tertiary olfactory cortical areas, in which information about the identity and also about the reward value of odours is represented. The orbitofrontal cortex also receives information about the sight of objects from the temporal lobe cortical visual areas, and neurons in it learn and reverse the visual stimulus to which they respond when the association of the visual stimulus with a primary reinforcing stimulus (such as taste) is reversed. This is an example of stimulus-reinforcement association learning, and is a type of stimulus-stimulus association learning. More generally, the stimulus might be a visual or olfactory stimulus, and the primary (unlearned) positive or negative reinforcer a taste or touch. A somatosensory input is revealed by neurons that respond to the texture of food in the mouth, including a population that responds to the mouth feel of fat. In complementary neuroimaging studies in humans, it is being found that areas of the orbitofrontal cortex are activated by pleasant touch, by painful touch, by taste, by smell, and by more abstract reinforcers such as winning or losing money. Damage to the orbitofrontal cortex can impair the learning and reversal of stimulus-reinforcement associations, and thus the correction of behavioural responses when there are no longer appropriate because previous reinforcement contingencies change. The information which reaches the orbitofrontal cortex for these functions includes information about faces, and damage to the orbitofrontal cortex can impair face (and voice) expression identification. This evidence thus shows that the orbitofrontal cortex is involved in decoding and representing some primary reinforcers such as taste and touch; in learning and reversing associations of visual and other stimuli to these primary reinforcers; and in controlling and correcting reward-related and punishment-related behavior, and thus in emotion. The approach described here is aimed at providing a fundamental understanding of how the orbitofrontal cortex actually functions, and thus in how it is involved in motivational behavior such as feeding and drinking, in emotional behavior, and in social behavior.     

Reinventing the University to Teach Both Mind and Heart (Part I)

The objectives of this special two-part issue are summarized, and the articles within the issue are shown to contribute to the theme. The university must serve adults of all ages who are developing within a global society. Interpersonal interactions are important processes for development. The university might respond to current criticisms of it as an institution, in part, by teaching and studying interpersonal and emotional skills in combination with intellectual skills that are already emphasized. A better balance such as this would make the university, its research, and its students more viable in the next century.     

Reinventing the University to Teach Both Mind and Heart (Part II)

The articles in this issue continue the theme of university reform begun in Part I, published in this journal in July. The university might well respond to current criticisms by teaching and studying interpersonal and emotional skills in combination with intellectual skills, which are already emphasized. Such a change would assist the adult development of university students and prepare the university and its students for the global society of the next century. The concept of the university as providing nourishment for life is described. This second part of the Special Issue includes both empirical studies and responses to all the articles in both this part and Part I.     

Sortal continuity of material things

Spatiotemporal and qualitative continuity are not sufficient to trace the career or path of one and the same object through its history. One needs sortal continuity, guaranteed by the form-token of the object. In this paper I concentrate on the question of sortal continuity linked to the problem of the cohabitation of objects. I intend to test whether it is possible to stick to the belief in continuants or endurers as well as the sortal dependence of identity and at the same time avoid an undesirable multiplication of spatially coinciding objects, i.e., avoid the thesis of cohabitation. I abandon the philosophical view – this is the price to be paid – that the set of the material constituents making up an object is an object proper. The basic units of reality are the objects falling under sortals and not the ultimate components thereof. That a determinate piece of copper is not identical with the statue made from it, therefore, does not imply that we have a cohabitation of two numerically different objects. This revised version was published online in August 2006 with corrections to the Cover Date.     

Development and yearning: Cognitive aspects of spiritual development

Spirituality is important to humans but gets little attention in experimental studies of life span cognitive development. One way to integrate such studies is to examine cognitive aspects of spiritual development using complex postformal Piagetian models. Four possible points of interface within postformal models are: developmental stages; elements of emotion and will; multiperson cognition; and forms taken by the processes used. Testable hypotheses are outlined and some possible difficulties to be expected within such research are discussed.     

Varieties of preschool hyperactivity: multiple pathways from risk to disorder

In this paper we examine the characteristics of preschool attention deficit hyperactivity disorder (ADHD) from both mental disorder and developmental psychopathology points of view. The equivalence of preschool and school-aged hyperactivity as a behavioral dimension is highlighted together with the potential value of extending the use of the ADHD diagnostic category to the preschool period where these behaviours take an extreme and impairing form (assuming age appropriate diagnostic items and thresholds can be developed). At the same time, the importance of identifying pathways between risk and later ADHD is emphasized. Developmental discontinuity and heterogeneity are identified as major characteristics of these pathways. We argue that models that distinguish among different developmental types of early-emerging problems are needed. An illustrative taxonomy of four developmental pathways implicating preschool hyperactivity is presented to provide a framework for future research.     

Representations In The Brain

The representation of objects and faces by neurons in the temporal lobe visualcortical areas of primates has the property that the neurons encode relativelyindependent information in their firing rates. This means that the number ofstimuli that can be encoded increases exponentially with the number of neuronsin an ensemble. Moreover, the information can be read by receiving neurons thatperform just a synaptically weighted sum of the firing rates being received. Someways in which these representations become grounded in the world are described.The issue of syntactic binding in representations, and of its value for a higher orderthought system, is discussed.