Understanding the dorsal and ventral systems of the human cerebral cortex: beyond dichotomies

Traditionally, characterizations of the macrolevel functional organization of the human cerebral cortex have focused on the left and right cerebral hemispheres. However, the idea of left brain versus right brain functions has been shown to be an oversimplification. We argue here that a top-bottom divide, rather than a left-right divide, is a more fruitful way to organize human cortical brain functions. However, current characterizations of the functions of the dorsal (top) and ventral (bottom) systems have rested on dichotomies, namely where versus what and how versus what. We propose that characterizing information-processing systems leads to a better macrolevel organization of cortical function; specifically, we hypothesize that the dorsal system is driven by expectations and processes sequences, relations, and movement, whereas the ventral system categorizes stimuli in parallel, focuses on individual events, and processes object properties (such as shape in vision and pitch in audition). To test this hypothesis, we reviewed over 100 relevant studies in the human neuroimaging and neuropsychological literatures and coded them relative to 11 variables, some of which characterized our hypothesis and some of which characterized the previous dichotomies. The results of forward stepwise logistic regressions supported our characterization of the 2 systems and showed that this model predicted the empirical findings better than either the traditional dichotomies or a left-right difference.     

Age-relevance of person characteristics: persons' beliefs about developmental change across the lifespan

The authors investigated normative beliefs about personality development. Young, middle-aged, and older adults indicated the age-relevance of 835 French adjectives by specifying person characteristics as typical for any age decade from 0 to 99 years. With this paradigm, the authors determined age-relevance (How typical is a characteristic for a given age decade?). Most characteristics were ascribed to young adulthood. The pattern differed across the lifespan, however, for positive and negative person characteristics as well as for physical, cognitive, and personal/expressive characteristics. Whereas the total number of ascribed positive characteristics peaked in young adulthood and declined thereafter, the number of ascribed negative person characteristics peaked during adolescence, remained fairly low during middle adulthood, and increased slightly in old age (70+ years). As a consequence, the most positive profile was ascribed to young olds (60 to 69 years), whereas the most negative personality profiles were ascribed to the oldest age groups (70+ years) and to adolescence (10 to 19 years). The negative profiles are primarily due to more negative physical characteristics ascribed to older adults and more negative cognitive characteristics ascribed to adolescence.     

Trying and the Arguments from Total Failure

New Volitionalism is a name for certain widespread conception of the nature of intentional action. Some of the standard arguments for New Volitionalism, the so-called arguments from total failure, have even acquired the status of basic assumptions for many other kinds of philosophers. It is therefore of singular interest to investigate some of the most important arguments from total failure. This is what I propose to do in this paper. My aim is not be to demonstrate that these arguments are inconsistent or that total failure and naked tryings are metaphysically impossible. Rather, my aim is be to build a case against the possibility of naked, independently existing tryings, by questioning how well we understand the scenarios invoked in their favour. Thus, rather than attempting to present a definitive metaphysical refutation of New Volitionalism, I attempt to diminish or demolish its underlying motivation.

How goal instrumentality shapes relationship evaluations

Findings from 6 experiments support the hypothesis that relationship evaluations and behavioral tendencies are goal dependent, reflecting the instrumentality of significant others for the self's progress toward currently active goals. Experiments 1 and 3 found that active goals can automatically bring to mind significant others who are instrumental for the activated goal, heightening their accessibility relative to noninstrumental others. Experiments 2-5 found that active goals cause individuals to evaluate instrumental others more positively, draw closer to them, and approach them more readily, compared with noninstrumental others. Experiment 6 found that people who engage in goal-dependent interpersonal evaluations are more successful, receiving higher grades. Implications for understanding the social nature of self-regulation and the impact of personal goals on interpersonal relationships are discussed.     

The explanatory potential of artificial societies

It is often claimed that artificial society simulations contribute to the explanation of social phenomena. At the hand of a particular example, this paper argues that artificial societies often cannot provide full explanations, because their models are not or cannot be validated. Despite that, many feel that such simulations somehow contribute to our understanding. This paper tries to clarify this intuition by investigating whether artificial societies provide potential explanations. It is shown that these potential explanations, if they contribute to our understanding, considerably differ from potential causal explanations. Instead of possible causal histories, simulations offer possible functional analyses of the explanandum. The paper discusses how these two kinds explanatory strategies differ, and how potential functional explanations can be appraised.     

Learning from Minimal Economic Models

It is argued that one can learn from minimal economic models. Minimal models are models that are not similar to the real world, do not resemble some of its features, and do not adhere to accepted regularities. One learns from a model if constructing and analysing the model affects one’s confidence in hypotheses about the world. Economic models, I argue, are often assessed for their credibility. If a model is judged credible, it is considered to be a relevant possibility. Considering such relevant possibilities may affect one’s confidence in necessity or impossibility hypotheses. Thus, one can learn from minimal economic models.

---