An algebra of human concept learning

An important element of learning from examples is the extraction of patterns and regularities from data. This paper investigates the structure of patterns in data defined over discrete features, i.e. features with two or more qualitatively distinct values. Any such pattern can be algebraically decomposed into a spectrum of component patterns, each of which is a simpler or more atomic “regularity.” Each component regularity involves a certain number of features, referred to as its degree. Regularities of lower degree represent simpler or more coarse patterns in the original pattern, while regularities of higher degree represent finer or more idiosyncratic patterns. The full spectral breakdown of a pattern into component regularities of minimal degree, referred to as its power series, expresses the original pattern in terms of the regular rules or patterns it obeys, amounting to a kind of “theory” of the pattern. The number of regularities at various degrees necessary to represent the pattern is tabulated in its power spectrum, which expresses how much of a pattern's structure can be explained by regularities of various levels of complexity. A weighted mean of the pattern's spectral power gives a useful numeric summary of its overall complexity, called its algebraic complexity. The basic theory of algebraic decomposition is extended in several ways, including algebraic accounts of the typicality of individual objects within concepts, and estimation of the power series from noisy data. Finally some relations between these algebraic quantities and empirical data are discussed.     

From a Distance: Pastoral Care and Theological Education

Abstract. This article is a presentation and discussion of a seminary course on the Corinthian Correspondence. The pedagogical model for this course was structured to parallel the pattern of Paul's pastoral care from a distance as he relates to the Corinthian congregation by personal visits, delegations from and to the congregation, letters from and to the congregation, and unofficial grapevine types of communication. The course was designed for dispersed students to interact with the Corinthian letters, with each other, and with myself as instructor in ways that 1) simulate a first‐century exchange between congregation and apostle and 2) facilitate careful interpretive work on the message of these letters, including their contemporary relevance.     

Deconstructing executive deficits among persons with autism: implications for cognitive neuroscience

Individuals with autism demonstrate impairments on measures of executive function (EF) relative to typically developing comparison participants. EF is comprised of several processes including inhibition, working memory and set shifting that develop throughout the lifespan. Impairments in EF may appear early in development and persist, or may represent a more transient delay which resolves with time. Given the unevenness of the cognitive profile of persons with autism, understanding the development of EF poses methodological challenges. These issues include those related to matching measures and the choice of comparison participants to which the performance of persons with autism will be compared. In the current review, we attempt to break down the processes of inhibition, working memory and set shifting among persons with autism. We propose to do this within a developmental perspective that highlights how matching measures and comparison participants can affect the interpretation of research findings.     

Formal distinctiveness of high- and low-imageability nouns: analyses and theoretical implications

Words associated with perceptually salient, highly imageable concepts are learned earlier in life, more accurately recalled, and more rapidly named than abstract words (R. W. Brown, 1976; Walker & Hulme, 1999). Theories accounting for this concreteness effect have focused exclusively on semantic properties of word referents. A novel possibility is that word structure may also contribute to the effect. We report a corpus-based analysis of the phonological and morphological structures of a large set of nouns with imageability ratings (N = 2,023). High- and low-imageability nouns differed by length, etymology, prosody, affixation, phonological neighborhood density, and rates of consonant clustering. On average, nouns denoting abstract concepts were longer, more derivationally complex, and emerged in English from a different distribution of languages than did concrete nouns. We address implications for interactivity of word form and meaning as pertain to theories of word concreteness, lexical acquisition, and word processing.     

Formation of visual "objects" in the early computation of spatial relations

Perceptual grouping is the process by which elements in the visual image are aggregated into larger and more complex structures, i.e., "objects." This paper reports a study of the spatial factors and time-course of the development of objects over the course of the first few hundred milliseconds of visual processing. The methodology uses the now well-established idea of an "object benefit" for certain kinds of tasks (here, faster within-object than between-objects probe comparisons) to test what the visual system in fact treats as an object at each point during processing. The study tested line segment pairs in a wide variety of spatial configurations at a range of exposure times, in each case measuring the strength of perceptual grouping as reflected in the magnitude of the object benefit. Factors tested included nonaccidental properties such as collinearity, cotermination, and parallelism; contour relatability; Gestalt factors such as symmetry and skew symmetry, and several others, all tested at fine (25 msec) time-slices over the course of processing. The data provide detailed information about the comparative strength of these factors in inducing grouping at each point in processing. The result is a vivid picture of the chronology of object formation, as objects progressively coalesce, with fully bound visual objects completed by about 200 msec of processing.     

Neonatal physiological regulation is associated with perinatal factors: A study of neonates born to healthy African American women living in poverty

Maternal mental health and prenatal stress are linked with neurobehavioral differences in the offspring. The majority of studies documenting this effect have been conducted using either predominantly European American infants or minority infants exposed to teratogens in utero. In this study, we focus on healthy African American women from low‐income environments to investigate the earliest individual differences in biobehavioral regulation, including resting heart rate and variability (HRV). In 87 neonates, HRV was significantly lower in those born to mothers reporting past major depressive disorder (p = .01). The number of maternal life stressors also was associated with lower neonatal HRV (p = .03). Obstetrical complications were not associated with significant differences, but breast‐ versus bottle‐feeding in the first few days of life was related to higher HRV (p = .04). Early variation in physiological regulation may be linked to subsequent individual differences in response to stress. Thus, identifying the earliest point in development when such differences can be reliably measured may result in opportunities for prevention of later deficits in regulating response to stress.     

Spatial navigation: Cognitive variables involved in route retracing among an elderly population

The cognitive processes involved in route retracing are not well known. This study aims to highlight them in an elderly population in which contradictory results have been obtained, certain studies showing specific difficulties for route retracing, others not. Thirty-nine elderly subjects performed a route-learning task (forward-backward) in a garden, then completed spatial knowledge tasks and standardised cognitive tests. Results show four factors that were predictive of route retracing performance: route repetition, the pointing task, and two standardised cognitive tests, one assessing spatial working memory, and another global cognitive efficiency. According to these results, route retracing involves route and survey knowledge (i.e., egocentric and allocentric strategy), and the integration of forward-backward perspectives is underpinned by the spatial working memory. Moreover, the subjects did not make more errors in route retracing than in the route repetition task, suggesting that a real environment could compensate for a failing allocentric strategy.