Learning and development of embodied numerosity

Recent empirical evidence indicates that seemingly abstract numerical cognitions are rooted in sensory and bodily experiences. In particular in finger counting finger-based representations reflect a specific case of embodied cognition, we termed embodied numerosity. Furthermore, we suggest that finger-based representations should be considered a distinct representation of number (magnitude) and argue that this representation is activated automatically whenever we encounter a number. We discuss in what way such a theoretical framework can account for the associations of fingers and numbers observed so far. In the final part, we evaluate whether the concept of embodied numerosity should be generalized beyond finger-based representations with particular focus on whether bodily-sensory experiences (such as moving the whole body along the mental number line) may corroborate numerical capabilities. In a series of intervention studies, we consistently observed more pronounced training effects for our embodied numerosity trainings for different age groups, different digital media, different number ranges, and different control conditions. Taken together, we conclude that embodied representations of number (magnitude) exist, are not limited to finger-based representations, and influence number processing in a systematic and functional way that can be used to foster the efficiency of numerical trainings.     

Decomposing the interaction between retention interval and study/test practice: the role of retrievability

Even without feedback, test practice enhances delayed performance compared to study practice, but the size of the effect is variable across studies. We investigated the benefit of testing, separating initially retrievable items from initially nonretrievable items. In two experiments, an initial test determined item retrievability. Retrievable or nonretrievable items were subsequently presented for repeated study or test practice. Collapsing across items, in Experiment 1, we obtained the typical cross-over interaction between retention interval and practice type. For retrievable items, however, the cross-over interaction was quantitatively different, with a small study benefit for an immediate test and a larger testing benefit after a delay. For nonretrievable items, there was a large study benefit for an immediate test, but one week later there was no difference between the study and test practice conditions. In Experiment 2, initially nonretrievable items were given additional study followed by either an immediate test or even more additional study, and one week later performance did not differ between the two conditions. These results indicate that the effect size of study/test practice is due to the relative contribution of retrievable and nonretrievable items.     

The Effectiveness of Cognitive Processing Therapy for PTSD With Refugees in a Community Setting

Opinions vary on the generalizability of empirically supported treatments to diverse populations in naturalistic settings and on the relative merits of delivering treatments through interpreters. The authors present statistical analyses of outcome data from a community mental health program that served foreign-born refugees resettled in the U.S. The program used a manualized, empirically supported treatment, Cognitive Processing Therapy, to address symptoms of PTSD in this population. Participants received psychological treatment in native languages either with a therapist who spoke their language or with a therapist who used an interpreter. Results demonstrated that treatment of PTSD was highly effective whether delivered directly or through an interpreter.     

Short-term limb immobilization affects motor performance

C. Ghez, J. Gordon, and M. R Ghilardi (1995; J. Gordon, M. R Ghilardi, & C. Ghez, 1995; R. L. Sainburg, M. R Ghilardi, H. Poizner, & C. Ghez, 1995) have found that proprio-ceptive deafferentation impairs feedforward and feedback mechanisms that control reaching movements. In the present study, the authors found immobilization-induced changes in limb kinematics, including joint motion, in 32 healthy participants who performed out-and-back movements before and after 0, 6, or 12 hr of immobilization of the left arm. Control participants did not undergo the arm immobilization procedure. Immobilization for 12 hr, but not 6 hr, caused trajectories with increased hand-path areas and altered interjoint coordination. The abnormalities were smaller in amplitude but similar in quality to those reported in deafferented patients (R. L. Sainburg et al.). In addition, movement onset point significantly drifted after immobilization. Thus, short-term limb disuse can affect interjoint coordination by acting on feedforward mechanisms. These behavioral alterations are potentially related to cortical plastic changes.     

Assessing theories,Bayes style

The problem addressed in this paper is “the main epistemic problem concerning science”, viz. “the explication of how we compare and evaluate theories [...] in the light of the available evidence” (van Fraassen, BC, 1983, Theory comparison and relevant Evidence. In J. Earman (Ed.), Testing scientific theories (pp. 27–42). Minneapolis: University of Minnesota Press). Sections 1– 3 contain the general plausibility-informativeness theory of theory assessment. In a nutshell, the message is (1) that there are two values a theory should exhibit: truth and informativeness—measured respectively by a truth indicator and a strength indicator; (2) that these two values are conflicting in the sense that the former is a decreasing and the latter an increasing function of the logical strength of the theory to be assessed; and (3) that in assessing a given theory by the available data one should weigh between these two conflicting aspects in such a way that any surplus in informativeness succeeds, if the shortfall in plausibility is small enough. Particular accounts of this general theory arise by inserting particular strength indicators and truth indicators. In Section 4 the theory is spelt out for the Bayesian paradigm of subjective probabilities. It is then compared to incremental Bayesian confirmation theory. Section 4 closes by asking whether it is likely to be lovely. Section 5 discusses a few problems of confirmation theory in the light of the present approach. In particular, it is briefly indicated how the present account gives rise to a new analysis of Hempel’s conditions of adequacy for any relation of confirmation (Hempel, CG, 1945, Studies in the logic of comfirmation. Mind, 54, 1–26, 97–121.), differing from the one Carnap gave in § 87 of his Logical foundations of probability (1962, Chicago: University of Chicago Press). Section 6 adresses the question of justification any theory of theory assessment has to face: why should one stick to theories given high assessment values rather than to any other theories? The answer given by the Bayesian version of the account presented in section 4 is that one should accept theories given high assessment values, because, in the medium run, theory assessment almost surely takes one to the most informative among all true theories when presented separating data. The concluding section 7 continues the comparison between the present account and incremental Bayesian confirmation theory.     

Prime diagnosticity in short-term repetition priming: is primed evidence discounted, even when it reliably indicates the correct answer?

The authors conducted 4 repetition priming experiments that manipulated prime duration and prime diagnosticity in a visual forced-choice perceptual identification task. The strength and direction of prime diagnosticity produced marked effects on identification accuracy, but those effects were resistant to subsequent changes of diagnosticity. Participants learned to associate different diagnosticities with primes of different durations but not with primes presented in different colors. Regardless of prime diagnosticity, preference for a primed alternative covaried negatively with prime duration, suggesting that even for diagnostic primes, evidence discounting remains an important factor. A computational model, with the assumption that adaptation to the statistics of the experiment modulates the level of evidence discounting, accounted for these results.     

Reference dependence in iterative choices

Valuation of goods often proceeds from a series of hypothetical pairwise choices. We examine reference dependence on the outcome of such evaluations in a large-scale study in which respondents make a series of choices between areas that differ on cost of living and the quality of lakes and rivers. We uncover three substantial reference effects. First, we find that respondents’ choices are altered by being told the national value of water quality. For these people, consistent with prospect theory, changes in water quality below the 65% referenced national standard are treated as losses and given more weight while identical changes above 65% are treated as gains and given less weight. Second, we find that the sequence of iterative choices matters in a surprising way. The iterations proceed by encouraging switching either by degrading the chosen alternative or improving the item chosen. We show that improving the item not chosen produces the greatest switching, a result consistent with prospect theory, but only if the item changed in the iteration becomes the reference alternative. Finally, we find a strong starting reference effect. That is, we show that the trade-off in the first choice reflected in the change in cost of living divided by the change in water quality has a substantial impact on the final valuation. We assess the relative impact of these three reference effects and suggest ways of dealing with them for valuation of non-market goods.     

Lateralized cognition: asymmetrical and complementary strategies of pigeons during discrimination of the "human concept"

This study was aimed at revealing which cognitive processes are lateralized in visual categorizations of "humans" by pigeons. To this end, pigeons were trained to categorize pictures of humans and then tested binocularly or monocularly (left or right eye) on the learned categorization and for transfer to novel exemplars (Experiment 1). Subsequent tests examined whether they relied on memorized features or on a conceptual strategy, using stimuli composed of new combinations of familiar and novel humans and backgrounds (Experiment 2), whether the hemispheres processed global or local information, using pictures with different levels of scrambling (Experiment 3), and whether they attended to configuration, using distorted human figures (Experiment 4). The results suggest that the left hemisphere employs a category strategy and concentrates on local features, while the right hemisphere uses an exemplar strategy and relies on configuration. These cognitive dichotomies of the cerebral hemispheres are largely shared by humans, suggesting that lateralized cognitive systems already defined the neural architecture of the common ancestor of birds and mammals.     

The Logic of Theory Assessment

This paper starts by indicating the analysis of Hempel’s conditions of adequacy for any relation of confirmation (Hempel, 1945) as presented in Huber (submitted). There I argue contra Carnap (1962, Section 87) that Hempel felt the need for two concepts of confirmation: one aiming at plausible theories and another aiming at informative theories. However, he also realized that these two concepts are conflicting, and he gave up the concept of confirmation aiming at informative theories. The main part of the paper consists in working out the claim that one can have Hempel’s cake and eat it too — in the sense that there is a logic of theory assessment that takes into account both of the two conflicting aspects of plausibility and informativeness. According to the semantics of this logic, α is an acceptable theory for evidence β if and only if α is both sufficiently plausible given β and sufficiently informative about β. This is spelt out in terms of ranking functions (Spohn, 1988) and shown to represent the syntactically specified notion of an assessment relation. The paper then compares these acceptability relations to explanatory and confirmatory consequence relations (Flach, 2000) as well as to nonmonotonic consequence relations (Kraus et al., 1990). It concludes by relating the plausibility-informativeness approach to Carnap’s positive relevance account, thereby shedding new light on Carnap’s analysis as well as solving another problem of confirmation theory. A precursor of this paper has appeared as “The Logic of Confirmation and Theory Assessment” in L. Běhounek & M. Bílková (eds.), The Logica Yearbook 2004, Prague: Filosofia, 2005, 161–176.