Categories in the pigeon brain: A reverse engineering approach

Pigeons are well known for their visual capabilities as well as their ability to categorize visual stimuli at both the basic and superordinate level. We adopt a reverse engineering approach to study categorization learning: Instead of training pigeons on predefined categories, we simply present stimuli and analyze neural output in search of categorical clustering on a solely neural level. We presented artificial stimuli, pictorial and grating stimuli, to pigeons without the need of any differential behavioral responding while recording from the nidopallium frontolaterale (NFL), a higher visual area in the avian brain. The pictorial stimuli differed in color and shape; the gratings differed in spatial frequency and amplitude. We computed representational dissimilarity matrices to reveal categorical clustering based on both neural data and pecking behavior. Based on neural output of the NFL, pictorial and grating stimuli were differentially represented in the brain. Pecking behavior showed a similar pattern, but to a lesser extent. A further subclustering within pictorial stimuli according to color and shape, and within gratings according to frequency and amplitude, was not present. Our study gives proof‐of‐concept that this reverse engineering approach—namely reading out categorical information from neural data—can be quite helpful in understanding the neural underpinnings of categorization learning.     

A Machine That Knows Its Own Code

We construct a machine that knows its own code, at the price of not knowing its own factivity.     

Ecumenism in the 21st Century

This article explores the challenges facing the ecumenical movement at the beginning of the 21st century: global demographic trends and a shift in the centre of gravity of Christianity toward the global South; the need for ecumenical structures and institutions to change in response to new realities; the need to widen the ecumenical fellowship so that Roman Catholics, Pentecostals, and evangelicals who have not played a part in the WCC may participate more fully; the urgency of inter‐religious dialogue; and the need to discover a “spirituality of engagement” in interaction with the world and its people.     

Imaginative Transportation

Actors, undercover investigators, and readers of fiction sometimes report ‘losing themselves’ in the characters they imitate or read about. They speak of ‘taking on’ or ‘assuming’ the beliefs, thoughts, and feelings of someone else. I offer an account of this strange but familiar phenomenon—what I call imaginative transportation.     

The Influence of an Acute Bout of Whole Body Vibration on Human Postural Control Responses

The use of vibrating platforms has become increasingly available, and popular at sports and rehabilitation institutes. Given the discrepancies in the literature regarding whole body vibration (WBV) and human reflexive responses, the purpose of this study was to examine the acute effects of WBV on postural response latencies, as well as associated electromyography measures of the lower extremities during balance perturbations. Reflexive responses during backward and forward balance perturbations were examined before, after, and 10 min after a bout of WBV. The findings suggest that following an acute bout of whole body vibration, muscle activity of the lower extremities is decreased during a reflexive response to an unexpected perturbation, and may be associated with faster reaction time.     

The Quantificational Domain of <Emphasis Type="BoldItalic">dou</Emphasis>: An Experimental Study

Which NP does all associate with in e.g. “The pandas, the children all saw”—the pandas, the children, or both? The intuition of adult Mandarin Chinese native speakers regarding the interpretation of the adverbial quantifier dou ‘all’ remains unclear and controversial, and various incommensurate theories of domain selection have been proposed. These studies may have failed to yield clear results because they used testing materials in which the interpretation of dou is confounded with other principles of NP interpretation (e.g. zhexie xiaohai ‘these children’ is truth-functionally synonymous with ‘all these children’). To address these concerns, we present the first set of experimental studies on adult knowledge and use of syntactic constraints on the quantifier domain of dou. The results support the hypothesis that dou can take one and only one c-commanding NP as its domain, but falsify interesting theoretical accounts that assume a strict locality constraint on dou quantification.     

Longitudinal evaluation of anhedonia as a mediator of fear of positive evaluation and other depressive symptoms

ABSTRACT

Fear of positive evaluation (FPE) is experiencing dread during real or potential praise. FPE is associated with social anxiety, but its relation to depressive symptoms is unclear. Anhedonia is a core symptom of depression related to symptoms of anxiety in cross-sectional research. The current study investigated the indirect effect of FPE on depressive symptoms via anhedonia over time. One-hundred ninety-six participants completed three waves of questionnaires over a total timespan of approximately four months via Amazon’s Mechanical Turk, including measures of FPE, depressive symptoms, and anticipatory and consummatory anhedonia. Findings indicated that anticipatory anhedonia at Time 2 mediated the relationship between FPE at Time 1 and depressive symptoms at Time 3. Consummatory anhedonia, however, did not. Each model was contextualised by accounting for prospective covarying relationships, such as depressive symptoms predicting the same symptoms at later waves. The constellation of findings is considered within a reward devaluation framework.     

Is Shepherd's pen mightier than Berkeley's word?

In 1827, Lady Mary Shepherd published Essays on the Perception of an External Universe, which offers both an argument for the existence of a world of external bodies existing outside our minds and a criticism of Berkeley's argument for idealism in A Treatise Concerning the Principles of Human Knowledge. In this paper, I evaluate Margaret Atherton's criticisms of Shepherd's case against Berkeley, and provide reasons for thinking that, although Shepherd's particular criticisms of Berkeley do not succeed, she correctly identifies an important problem to which Berkeley's reasoning is subject.