Deep brain stimulation of the subthalamic nucleus is a clinically effective tool for treating medically refractory Parkinson’s disease, but its neural mechanisms remain debated. Previous work has demonstrated that STN DBS results in evoked potentials in the primary motor cortex, suggesting that modulation of cortical physiology may be involved in its therapeutic effects. Due to technical challenges presented by high-amplitude DBS artifacts, these EPs are often measured in response to low-frequency stimulation, which is generally ineffective at PD symptom management. This (...) study aims to characterize STN-to-cortex EPs seen during clinically relevant high-frequency STN DBS for PD. Intraoperatively, we applied STN DBS to 6 PD patients while recording electrocorticography from an electrode strip over the ipsilateral central sulcus. Using recently published techniques, we removed large stimulation artifacts to enable quantification of STN-to-cortex EPs. Two cortical EPs were observed – one synchronized with DBS onset and persisting during ongoing stimulation, and one immediately following DBS offset, here termed the “start” and the “end” EPs respectively. The start EP is, to our knowledge, the first long-latency cortical EP reported during ongoing high-frequency DBS. The start and end EPs differ in magnitude and latency, and the end, but not the start, EP magnitude has a significant relationship to ongoing high gamma power during the EP. These contrasts may suggest mechanistic or circuit differences in EP production during the two time periods. This represents a potential framework for relating DBS clinical efficacy to the effects of a variety of stimulation parameters on EPs. (shrink)

The paper challenges Joseph Salerno’s recent revisionist account in “The Place of Human Action in the Development of Economic Thought” of the relationship between Friedrich von Wieser and F.A. Hayek and of their views on equilibrium theory. The paper argues, contra Salerno, that Wieser was not a proponent of general equilibrium theory, so could not have influenced Hayek in the manner Salerno suggests; that there was not a concerted effort by Schumpeter, Wieser, Mayer, and Hayek to advocate general equilibrium theory (...) in the prewar and inter-war years among the Austrians; and finally, that Hayek’s early attraction to what he called “equilibrium analysis” had causes independent of those alleged by Salerno.Cet article récuse l’interprétation révisionniste récente de Joseph Salerno dans son article “The Place of Human Action in the Development of Economic Thought” à propos des relations entre Friedrich von Wieser et Friedrich Hayek, et de leurs visions au sujet de l’équilibre. S’inscrivant en cela en opposition avec ce qu’avance Salerno, cet article suggère que Wieser n’était pas un partisan de la théorie de l’équilibre général et, en conséquence, ne peut avoir influencé Hayek comme le suggère Salerno ; qu’il n’y a eu aucun effort concerté entre Schumpeter, Wieser, Mayer et Hayek pour promouvoir la théorie de l’équilibre général parmi les autrichiens durant les années d’avant-guerre et celles de l’entre-deux guerres ; et enfin, que l’intérêt du jeune Hayek dans ce qu’il appelait “l’analyse de l’équilibre” avait des causes autres que celles évoquées par Salerno. (shrink)

Providing an original and systematic treatment of foundational issues in philosophy of religion, J. L. Schellenberg's new book addresses the structure of..

J.L. Ackrill's work on Plato and Aristotle has had a considerable influence upon ancient philosophical studies in the late twentieth century. This volume collects the best of Ackrill's essays on the two greatest philosophers of antiquity. With philosophical acuity and philological expertise he examines a wide range of texts and topics--from ethics and logic to epistemology and metaphysics--that continue to be in the focus of debate.

Seit dem 2. nachchristlichen Jahrhundert werden die Schriften von Aristoteles kommentiert. Diese Ausgabe enthält griechische Kommentare zu seinem Werk vom 3. bis 8. Jahrhundert n. Chr., u. a. von Alexander von Aphrodiensias, Themistios, Joh. Philoponus, Simplicius in griechischer Sprache.

Originally published in Proceedings of the British Academy 60 (1974), 339-359.

J. L. Ackrill; VIII*—Aristotle's Definitions of Psuche, Proceedings of the Aristotelian Society, Volume 73, Issue 1, 1 June 1973, Pages 119–134, https://doi.org.

A comprehensive one-year graduate (or advanced undergraduate) course in mathematical logic and foundations of mathematics. No previous knowledge of logic is required; the book is suitable for self-study. Many exercises (with hints) are included.

J. L. Ackrill; VIII*—Aristotle's Definitions of Psuche, Proceedings of the Aristotelian Society, Volume 73, Issue 1, 1 June 1973, Pages 119–134, https://doi.org.

The traditional verbal/nonverbal dichotomy is inadequate for completely describing cerebral lateralization. Musical functions are not necessarily mediated by the right hemisphere; evidence for a specialist left-hemisphere mechanism dedicated to the encoded speech signal is weakening, and the right hemisphere possesses considerable comprehensional powers. Right-hemisphere processing is often said to be characterized by holistic or gestalt apprehension, and face recognition may be mediated by this hemisphere partly because of these powers, partly because of the right hemisphere's involvement in emotional affect, and (...) possibly through the hypothesized existence of a specialist face processor or processors in the right. The latter hypothesis may, however, suffer the same fate as the one relating to a specialist encodedness processor for speech in the left. Verbal processing is largely the province of the left because of this hemisphere's possession of sequential, analytic, time-dependent mechanisms. Other distinctions are special cases of an analytic/holistic dichotomy. More fundamentally, however, the left hemisphere is characterized by its mediation of discriminations involving duration, temporal order, sequencing, and rhythm, at thesensory level, and especially at themotorlevel. Spatial aspects characterize the right, the mapping of exteroceptive body space, and the positions of fingers, limbs, and perhaps articulators, with respect to actual and target positions. Thus there is a continuum of function between the hemispheres, rather than a rigid dichotomy, the differences being quantitative rather than qualitative, of degree rather than of kind. (shrink)

_The Foundations of Arithmetic_ is undoubtedly the best introduction to Frege's thought; it is here that Frege expounds the central notions of his philosophy, subjecting the views of his predecessors and contemporaries to devastating analysis. The book represents the first philosophically sound discussion of the concept of number in Western civilization. It profoundly influenced developments in the philosophy of mathematics and in general ontology.

Aristotle is widely regarded as the greatest of all philosophers; indeed, he is traditionally referred to simply as `the philosopher'. Today, after more than two millennia, his arguments and ideas continue to stimulate philosophers and provoke them to controversy. In this book J.L. Ackrill conveys the force and excitement of Aristotle's philosophical investigations, thereby showing why contemporary philosophers still draw from him and return to him. He quotes extensively from Aristotle's works in his own notably clear English translation, and a (...) picture emerges of a lucid, lively, subtle and tough-minded thinker of astonishing range and penetration. Professor Ackrill identifies many striking connections between Aristotle's ideas and ideas in recent philosophy; he also raises philosophical questions of his own, and exemplifies the way in which Aristotle can still be argued with and learned from. (shrink)

In a single volume intended for philosophy students of all levels as well as their teachers, this reader provides modern, accurate translations of the texts necessary for a careful study of most aspects of Aristotle's philosophy. Professor Ackrill has drawn on his broad experience of teaching graduate classes in selecting the texts, and his choice reflects issues of current philosophical interest as well as the perennial themes. Only recent translations which achieve a high level of accuracy have been chosen: the (...) aim is to place the reader without Greek, as nearly as possible, in the position of a reader of Greek. As an aid to study, a valuable guide to the key topics covered is also suppied, giving references to works or passages contained in the reader, an indication of their interrelation, and a currnet bibliography. (shrink)