There is evidence from neuropsychological and psychophysical measurements that conscious sensory information is processed in discrete time segments. The segmentation process may be described as neuronal activity at a frequency of 40 Hz. Stimulus-induced neuronal activities of this frequency are found in the middle latency range of the auditory evoked potential . First, we have studied the effects of different general anesthetics on MLAEP and auditory evoked 40-Hz activity. Second, we investigated MLAEP and explicit and implicit memory for information presented (...) during cardiac anesthesia. In the awake patients peak latencies of the MLAEP were in the normal range. An auditory evoked 40-Hz activity was present 20–100 ms poststimulus. Under nonspecific anesthetics MLAEP and the 40-Hz activity were suppressed, and under receptor-specific agents MLAEP and the 40-Hz activity were partly preserved. None of the cardiac patients had conscious explicit recall of the intraoperative events, whereas some patients showed unconscious implicit memory for an intraoperative tape message. The implicit memory could be related to midlatency auditory evoked potentials. No implicit memory was detectable when MLAEP and the primary cortical processing of the auditory stimuli and 40-Hz activity were blocked. Implicit memory could be detected in more than 50% of the cases when MLAEP, a 30-Hz activity, and the primary cortical stimulus processing were preserved. In conclusion, our observations support the view that a high frequency oscillatory mechanisms, recorded as a grouped neuronal activity in the MLAEP, may be part of a basic neuronal program for conscious sensory information processing. (shrink)
In seinem Buch Illusion freier Wille? verfolgt Sven Walter zwei Hauptziele. Das erste besteht in dem detaillierten Nachweis, dass die in den letzten beiden Jahrzehnten öffentlichkeitswirksam vorgetragene kognitions- und neurowissenschaftlich begründete Freiheitsskepsis durch die empirischen Befunde nicht gedeckt sei. Das zweite Hauptziel ist, aufzuzeigen, dass Willensfreiheit bzw. „unsere intuitive Freiheitsgewissheit“ durchaus empirisch erforschbaren Beeinträchtigungen unterliegt, aber anderen als von den Wortführern der neurobiologischen Freiheitskritik angeführten: „Unbewusste situationale Einflüsse“ auf unsere Willens- und Entscheidungsbildung seien zwar nicht per se, wohl aber (...) dann freiheitsbedrohend, „wenn sie dazu führen, dass sich unser Wille nicht mehr unserem rückhaltlosen Urteil darüber fügt, was zu tun richtig wäre“. [...]. (shrink)
Sven Bernecker’s contribution to the ongoing revival in the philosophy of memory offers a consistent vision and analysis of propositional remembering, and covers a range of topics in analytic metaphysics and epistemology. Bernecker defends a methodological externalism, by which memory ‘must be analyzed from a third-person point of view’ (34): so even though conceptual analysis remains the primary method, the ‘linguistic intuitions’ that guide it ‘are not a priori but empirical working hypotheses’ (31). Given the central role of such (...) intuitions in Bernecker’s treatment of many briefly described thought experiments throughout the book, it is strange that he does not defend their use more explicitly in this early section on method, instead leaving it to a later footnote (147, n. 11) to say that ‘trying to defend the use of intuitions in the philosophy of memory would . . . take us too far afield’. Bernecker’s subtitle signals a restricted target audience: this is a book for those analytic philosophers who will enjoy long exegeses on Twin Earth, slow switching or quasi-memory. Psychological results on memory are cited, but only piecemeal, and interactive dialogue with scientific theory is not Bernecker’s aim. (shrink)
This comment on Sven Ove Hansson's article on the history of the journal Theoria elaborates and corrects Hansson's characterisation of the political standpoint of the Finnish philosopher Eino Kaila as "sympathetic towards the German regime". Although not an easy question, particularly considering Kaila's unfortunate publications during the Second World War, it is argued that the characterisation is plainly wrong if it refers to the mid-1930s.
The book under review is a collection of thirteen essays on the nature phenomenal concepts and the ways in which phenomenal concepts figure in debates over physicalism. Phenomenal concepts are of special interest in a number of ways. First, they refer to phenomenal experiences, and the qualitative character of those experiences whose metaphysical status is hotly debated. There are recent arguments, originating in Descartes’ famous conceivability argument, that purport to show that phenomenal experience is irreducibly non-physical. Second, phenomenal concepts are (...) widely thought to be special and unique among concepts. Both the anti-physicalist arguments and physicalist replies to these arguments turn on views about the nature of phenomenal concepts. In this review I survey the many ways in which the essays in this volume are engaged with anti-physicalist arguments and the role phenomenal concepts play in these arguments. (shrink)