A note on stove and adding machine arrangement preferences as a function of sex and handedness

Some stove and adding machine arrangements chosen by our subjects were influenced by both their sex and handedness.     

Higher-order factors of the big five model of personality: a reanalysis of Digman (1997)

Based on the results from factor analyses conducted on 14 different data sets, Digman proposed a model of two higher-order factors, or metatraits, that subsumed the Big Five personality traits. In the current article, problems in Digman's analyses were explicated, and more appropriate analyses were then conducted using the same 14 correlation matrices from Digman's study. The resultant two-factor model produced improper solutions, poor model fit indices, or both, in almost all of the 14 data sets and thus raised serious doubts about the veracity of Digman's proposed model.     

A rational model of the effects of distributional information on feature learning

Most psychological theories treat the features of objects as being fixed and immediately available to observers. However, novel objects have an infinite array of properties that could potentially be encoded as features, raising the question of how people learn which features to use in representing those objects. We focus on the effects of distributional information on feature learning, considering how a rational agent should use statistical information about the properties of objects in identifying features. Inspired by previous behavioral results on human feature learning, we present an ideal observer model based on nonparametric Bayesian statistics. This model balances the idea that objects have potentially infinitely many features with the goal of using a relatively small number of features to represent any finite set of objects. We then explore the predictions of this ideal observer model. In particular, we investigate whether people are sensitive to how parts co-vary over objects they observe. In a series of four behavioral experiments (three using visual stimuli, one using conceptual stimuli), we demonstrate that people infer different features to represent the same four objects depending on the distribution of parts over the objects they observe. Additionally in all four experiments, the features people infer have consequences for how they generalize properties to novel objects. We also show that simple models that use the raw sensory data as inputs and standard dimensionality reduction techniques (principal component analysis and independent component analysis) are insufficient to explain our results.     

A rational model of the effects of distributional information on feature learning

Most psychological theories treat the features of objects as being fixed and immediately available to observers. However, novel objects have an infinite array of properties that could potentially be encoded as features, raising the question of how people learn which features to use in representing those objects. We focus on the effects of distributional information on feature learning, considering how a rational agent should use statistical information about the properties of objects in identifying features. Inspired by previous behavioral results on human feature learning, we present an ideal observer model based on nonparametric Bayesian statistics. This model balances the idea that objects have potentially infinitely many features with the goal of using a relatively small number of features to represent any finite set of objects. We then explore the predictions of this ideal observer model. In particular, we investigate whether people are sensitive to how parts co-vary over objects they observe. In a series of four behavioral experiments (three using visual stimuli, one using conceptual stimuli), we demonstrate that people infer different features to represent the same four objects depending on the distribution of parts over the objects they observe. Additionally in all four experiments, the features people infer have consequences for how they generalize properties to novel objects. We also show that simple models that use the raw sensory data as inputs and standard dimensionality reduction techniques (principal component analysis and independent component analysis) are insufficient to explain our results.     

Neuroanatomical correlates of handedness for tool use in chimpanzees (Pan troglodytes): implication for theories on the evolution of language

It has been hypothesized that cognitive mechanisms underlying lateralized complex motor actions associated with tool use in chimpanzees may have set the stage for the evolution of left-hemisphere specialization for language and speech in humans. Here we report evidence that asymmetries in the homologues to Broca's and Wernicke's areas are associated with handedness for tool use in chimpanzees. These results suggest that the neural substrates of tool use may have served as a preadaptation for the evolution of language and speech in modern humans.     

On the evolution of handedness: a speculative analysis of Darwin's views and a review of early studies of handedness in "the nearest allies of man"

Scientists today who seek clues into the evolutionary origins of human handedness make extensive use of evidence from comparative studies, that is, studies that ask whether handedness occurs in other species, especially apes and monkeys, as the Darwinian principle of continuity would seem to imply, or whether it is uniquely human. Early investigations had the same goal and drew on much the same kind of evidence. In this article, I review studies of animal handedness in the period before 1859, when Darwin published On the Origin of Species, and afterward, through the 1st decade of the 20th century. Inasmuch as Darwin's published writings contain hardly any statements about handedness and none at all about its evolution and continuity across species, I also speculate about what Darwin himself might have said on the subject. To do this, I draw on his statements on related matters, such as the form and structure of the hand and the transition from a quadrupedal to bipedal stance, on other writers' reports and opinions about handedness with which he was familiar or likely to have been familiar, and finally, on clues from his own and only statement about animal handedness in an unpublished letter. I conclude by asking whether and how early investigators, lacking any statement by Darwin on the evolution of handedness, invoked his theory of evolution and his views on related matters in the interpretation of their findings.     

Once more on the equilibrium-point hypothesis (lambda model) for motor control

The equilibrium control hypothesis (lambda model) is considered with special reference to the following concepts: (a) the length-force invariant characteristic (IC) of the muscle together with central and reflex systems subserving its activity; (b) the tonic stretch reflex threshold (lambda) as an independent measure of central commands descending to alpha and gamma motoneurons; (c) the equilibrium point, defined in terms of lambda, IC and static load characteristics, which is associated with the notion that posture and movement are controlled by a single mechanism; and (d) the muscle activation area (a reformulation of the "size principle")--the area of kinematic and command variables in which a rank-ordered recruitment of motor units takes place. The model is used for the interpretation of various motor phenomena, particularly electromyographic patterns. The stretch reflex in the lambda model has no mechanism to follow-up a certain muscle length prescribed by central commands. Rather, its task is to bring the system to an equilibrium, load-dependent position. Another currently popular version defines the equilibrium point concept in terms of alpha motoneuron activity alone (the alpha model). Although the model imitates (as does the lambda model) spring-like properties of motor performance, it nevertheless is inconsistent with a substantial data base on intact motor control. An analysis of alpha models, including their treatment of motor performance in deafferented animals, reveals that they suffer from grave shortcomings. It is concluded that parameterization of the stretch reflex is a basis for intact motor control. Muscle deafferentation impairs this graceful mechanism though it does not remove the possibility of movement.     

Rethinking the gender identity crossover hypothesis: A test of a new model

Both self-report and projective assessment techniques were used to examine whether there exists a gender identity crossover at midlife such that men develop a communal or affiliative orientation and women become more interested in agency and power. A sample of 150 predominantly Caucasian men and women ages 24–84 were divided into three age groups for comparison: (1) young (ages 20–39); (2) middle-aged (ages 40–65); and (3) old (ages 66–84). Measures included six pictures from the Thematic Apperception Test, which were coded for achievement, power, intimacy, and affiliation needs, and the Goldberg 50-Bipolar, from which items were selected to derive agency and communion scales. Middle-aged men were lower in the need for power and higher in the need for affiliation than were younger men; there were no age differences in self attributions of agency and communion. Results are discussed in terms of the traditionality of the men and the nontraditionality of the women with respect to work and family roles.This research was supported in part by grants to Margie Lachman from the John D. and Catherine T. MacArthur Foundation Research Network on Successful Midlife Development and the National Institute on Aging (AG06038).     

Item-specific adaptation and the conflict-monitoring hypothesis: a computational model

M. M. Botvinick, T. S. Braver, D. M. Barch, C. S. Carter, and J. D. Cohen (2001) implemented their conflict-monitoring hypothesis of cognitive control in a series of computational models. The authors of the current article first demonstrate that M. M. Botvinick et al.'s (2001) conflict-monitoring Stroop model fails to simulate L. L. Jacoby, D. S. Lindsay, and S. Hessels's (2003) report of an item-specific proportion-congruent (ISPC) effect in the Stroop task. The authors then implement a variant of M. M. Botvinick et al.'s model based on the assumption that control must be able to operate at the item level. This model successfully simulates the ISPC effect. In addition, the model provides an alternative to M. M. Botvinick et al.'s explanation of the list-level proportion-congruent effect in terms of an ISPC effect. Implications of the present modeling effort are discussed.     

An evaluation of a computational model of lexical access: comment on Dell et al. (1997)

The computational model of lexical access proposed by G. S. Dell, M. F. Schwartz, N. Martin, E. M. Saffran, and D. A. Gagnon (1997) is evaluated. They argued that fits of their model to naming data obtained from normal and brain-damaged patients support assumptions regarding interactivity in the lexicon, global damage in aphasia, and continuity between normal and aphasic naming behavior. Additional analysis reveals that the model fits the empirical data poorly and that the claims Dell et al. made on the basis of the model's performance would not follow even if the model were accurate. Although use of a novel automatic regression procedure improved the model's fit, it cannot account for 5 of Dell et al.'s 21 patients (24%), and its limitations were found to be inherent in its design. It is argued that claims such as those made by Dell et al. can only be addressed by considering evidence from multiple related tasks and by comparing multiple computational models.     

Sometimes-competing retrieval (SOCR): a formalization of the comparator hypothesis

Cue competition is one of the most studied phenomena in associative learning. However, a theoretical disagreement has long stood over whether it reflects a learning or performance deficit. The comparator hypothesis, a model of expression of Pavlovian associations, posits that learning is not subject to competition but that performance reflects a complex interaction of encoded associative strengths. That is, subjects respond to a cue to the degree that it signals a change in the likelihood or magnitude of reinforcement relative to that in the cue's absence. Initially, this performance-focused view was supported by studies showing that posttraining revaluation of a competing cue often influences responding to the target cue. However, recently developed learning-focused accounts of retrospective revaluation have revitalized the debate concerning cue competition. Further complicating the picture are phenomena of cue facilitation, which have been addressed less frequently than cue competition by formal models of conditioning of either class. The authors present a formalization and extension of the comparator hypothesis, which results in sharpened differentiation between it and the new learning-focused models.     

A note on the equivalence of the graded response model and the sequential model

This paper concerns items that consist of several item steps to be responded to sequentially. The item scoreX is defined as the number of correct responses until the first failure. Samejima's graded response model states that each steph=1,...,m is characterized by a parameterb _h , and, for a subject with ability, Pr(Xh; )=F(–b _h ). Tutz's general sequential model associates with each step a parameterdh, and it states that Pr(Xh;)= _r ^=1h G(–d _r ). Tutz's (1991, 1997) conjectures that the models are equivalent if and only ifF(x)=G(x) is an extreme value distribution. This paper presents a proof for this conjecture.     

Decision making and memory: a critique of Juslin and Olsson's (1997) sampling model of sensory discrimination.

P. Juslin and H. Olsson's (1997) distinction between Thurstonian and Brunswikian uncertainty is examined and their sampling model of sensory discrimination analyzed as a representative of the class of memoryless decision processes. The separate characteristics and combined behavior of 4 main components of the model are explored: (a) the basic decision process, (b) the assumption of deadline responding, (c) the moving window model of memory, and (d) the hypothesized basis for confidence. It is argued that grafting a moving window memory onto a memoryless decision process has several undesirable consequences. Moreover, the suggested basis for confidence leads to predictions that are counterintuitive and unsupported by empirical evidence. It is concluded that the window-sampling model is a maladapted combination of inappropriate elements, which is implausible as a model of decision making, memory, or confidence, in sensory discrimination.     

A note on keats' generalization of the rasch model

An alternative derivation is given for a simple test model which incorporates anability parameter for the subject anddifficulty level andguessing parameters for the problem. The probability of a correct response to the problem is a projective transformation of the problem difficulty. The ability and difficulty parameters separate into additive components.     

A note on a cognitive probability model incorporating the serial position effect

A generalization of a cognitive probability model is proposed utilizing the serial position effect to account for decay in probability of recall. The general nature of the model permits the incorporation of almost any of the recent free-recall serial position curve results. Two examples, hypothesizing different serial position curves, are given.     

A criterion-shift model for enhanced discriminability in perceptual identification: A note on the counter model

The original version of the counter model for perceptual identification (Ratcliff & McKoon, 1997) assumed that word frequency and prior study act solely to bias the identification process (i.e., subjects have a tendency to prefer high-frequency and studied low-frequency words, irrespective of the presented word). In a recent study, using a two-alternative forced-choice paradigm, we showed an enhanced discriminability effect for high-frequency and studied low-frequency words (Wagenmakers, Zeelenberg, & Raaijmakers, 2000). These results have led to a fundamental modification of the counter model: Prior study and high frequency not only result in bias, but presumably also result in a higher rate of feature extraction (i.e., better perception). We demonstrate that a criterion-shift model, assuming limited perceptual information extracted from the flash as well as a reduced distance to an identification threshold for high-frequency and studied low-frequency words, can also account for enhanced discriminability.