Based on the technique of pressure blinding of the eye, two types of after-image were identified. A physicalist or mind/brain identity explanation was established for a negative a AI produced by moderately intense stimuli. These AI's were shown to be located in the neurons of the retina. An illusory AI of double a grating's spatial frequency was also produced in the same structure and was both prevented from being established and abolished after establishment by pressure blinding, thus showing that (...) the location was not more central. The illusory AI was predicted from the known non-linearity in the retina and this is the first case of a clear cut type-type identity of a sensation and a neural process. Some implications for the concepts of the explanatory gap between neurology and consciousness and multiple neural realizations of conscious states and topic neutrality are discussed. (shrink)

Russell and others have argued that the real nature of colour is transparentto us in colour vision. It's nature is fully revealed to us and no further knowledgeis theoretically possible. This is the doctrine of revelation. Two-dimensionalFourier analyses of coloured checkerboards have shown that apparently simple,monadic, colours can be based on quite different physical mechanisms. Experimentswith the McCollough effect on different types of checkerboards have shown thatidentical colours can have energy at the quite different orientations of Fourierharmonic components but no (...) energy at the edges of the checkerboards, thusrefuting revelation. It is concluded that this effect is not explained by a superveniencedispositional account of colour as proposed by McGinn . It was argued that theMcCollough effect in checkerboards was an example of a local mind/body reduction, by which the different characteristics of identical colours falsifies revelation. This reduction being based on both physical and neurological mechanisms led to a clear explanation of the perceive phenomenal effects and thus laid a small bridge over the explanatory gap. (shrink)

Cortical stimulation has been used for brain mapping for over a century, and a standard assumption is that stimulation interferes with task execution due to local effects at the stimulation site. Stimulation can however produce afterdischarges which interfere with functional localization and can lead to unwanted seizures. We previously showed that cognitive effort can terminate these afterdischarges, when termination thus occurs, there are electrocorticography changes throughout the cortex, not just at sites with afterdischarges or sites thought functionally important for (...) the cognitive task used, and thresholds for afterdischarges and functional responses can change among stimulation trials. We here show that afterdischarge termination can occur prior to overt performance of the cognitive tasks used to terminate them. These findings, taken together, demonstrate that task-related brain changes are not limited to one or a group of functional regions or a specific network, and not limited to the time directly surrounding overt task execution. Discrete locations, networks and times importantly underpin clinical behaviors. However, brain activity that is diffuse in location and extended in time also affect task execution and can affect brain mapping. This may in part reflect fluctuating levels of attention, engagement, or motivation during testing. (shrink)

Successful surgical treatment of patients with focal drug-resistant epilepsy remains challenging, especially in cases for which it is difficult to define the area of cortex from which seizures originate, the seizure onset zone. Various diagnostic methods are needed to select surgical candidates and determine the extent of resection. Interictal magnetoencephalography with source imaging has proven to be useful for presurgical evaluation, but the use of ictal MEG data remains limited. The purpose of the present study was to determine whether pre-ictal (...) variations of spectral properties of neural activity from ictal MEG recordings are predictive of SOZ location.We performed a 4 h overnight MEG recording in an 8-year-old child with drug-resistant focal epilepsy of suspected right fronto-temporal origin and captured one ~45-s seizure. The patient underwent a right temporal resection from the anterior temporal neocortex and amygdala to the mid-posterior temporal neocortex, sparing the hippocampus proper. She remains seizure-free 21 months postoperatively. The histopathological assessment confirmed frank focal cortical dysplasia type IIa in the MEG-defined SOZ, which was based on source imaging of averaged ictal spikes at seizure onset. We investigated temporal changes together with spatial differences in spectral parameters of background brain activity, namely the aperiodic broadband offset and slope, and assessed how they confounded the interpretation of apparent variations of signal power in typical electrophysiological bands. Our data show that the SOZ was associated with a higher aperiodic offset and exponent during the seizure compared to control regions. Both parameters increased in all regions from 2 min before the seizure onwards. Regions anatomically closer to the SOZ also expressed higher values compared to contralateral regions, potentially indicating ictal spread. We also show that narrow-band power changes were caused by these fluctuations in the aperiodic component of ongoing brain activity. Our results indicate that the broadband aperiodic component of ongoing brain activity cannot be reduced to background noise of no physiological interest, and rather may be indicative of the neuropathophysiology of the SOZ. We believe these findings will inspire future studies of ictal MEG cases and confirm their significance. (shrink)

This book critically examines the case for and against the belief in personal survival of bodily death. It discusses key philosophical questions. How could a discarnate individual be identified as a person who was once alive? What is the relationship between minds and their brains? Is a 'next world' conceivable? The book also examines classic arguments for the immortality of the soul, and focuses on types of prima facie evidence of survival: near-death experiences, apparitions, mediumistic communications, and ostensible reincarnation cases.

Nerve cells - neurons - are arguably the most complex of all cells. From the action of these cells comes movement, thought and consciousness. It is a challenging task to understand what molecules direct the various diverse aspects of their function. This has produced an ever-increasing amount of molecular information about neurons, and only in Molecular Biology of the Neuron can a large part of this information be found in one source. In this book, a non-specialist can learn about the (...) molecules that control information flow in the brain or the progress of brain disease in an approachable format, while the expert has access to a wealth of detailed information from a wide range of topics impacting on his or her field of endeavour. The text is designed to achieve a balance of accessibility and broad coverage with up-to-date molecular detail. In the six years since the first edition of Molecular Biology of the Neuron there has been an explosion in the molecular information about neurons that has been discovered, and this information is incorporated into this second edition. Entirely new chapters have been introduced where recent advances have made a new aspect of neuronal function more comprehensible at the molecular level. Written by leading researchers in the field, the book provides an essential overview of the molecular structure and function of neurons, and will be an invaluable tool to students and researchers alike. (shrink)

How is technology changing the way people remember? This book explores the interplay of memory stored in the brain and outside of the brain, providing a thorough interdisciplinary review of the current literature, including relevant theoretical frameworks from across a variety of disciplines in the sciences, arts, and humanities. It also presents the findings of a rich and novel empirical data set, based on a comprehensive survey on the shifting interplay of internal and external memory in the 21st (...) century. Results reveal a growing symbiosis between the two forms of memory in our everyday lives. The book presents a new theoretical framework for understanding the interplay of internal and external memory, and their complementary strengths. It concludes with a guide to important dimensions, questions, and methods for future research. Memory and Technology will be of interest to researchers, professors, and students across the disciplines of psychology, philosophy, library and information science, human factors, media and cultural studies, anthropology and archaeology, photography, and cognitive rehabilitation, as well as anyone interested in how technology is affecting human memory. _____ "This is a novel book, with interesting and valuable data on an important, meaningful topic, as well as a gathering of multidisciplinary and interdisciplinary ideas...The research is accurately represented and inclusive. As a teaching tool, I can envision graduate seminars in different disciplines drawing on the material as the basis for teaching and discussions." Dr. Linda A. Henkel, Fairfield University "This book documents the achievements of a vibrant scientific project – you feel the enthusiasm of the authors for their research. The organization of the manuscript introduces the reader into a comparatively new field the same way as pioneering authors have approached it." Prof. Dr. Wolfgang Schönpflug, Freie Universität Berlin. (shrink)

The three introductory questions posed by Hobson et al. point toward further investigations of cellular, circuit, and systems mechanisms involved in cognitive function that include the effect of CNS-state related modulatory systems on these mechanisms. [Hobson et al.].

Discrimination of forms defined solely by color and discrimination of hue are dissociated in cerebral achromatopsia. Both must be based on potentially explicit information derived from differentially color-sensitive photoreceptors, yet only one gives rise to phenomenal experience of color. By analogy, visual information may be used to form explicit representations for action without giving rise to any phenomenal experience other than that of making the action.

Studies have shown that as MRI T2 relaxation time lengthens there is a shift toward more unbound or “free-water” and less partitioning of the protein/lipid molecules per unit volume. A shift toward less water partitioning or lengthened MRI T2 relaxation time is linearly related to reduced high frequency EEG amplitude, reduced short distance EEG coherence, increased long distance EEG coherence, and reduced cognitive functioning (Thatcher et al. 1998a; 1998b).

The present study applies a new method for investigating dynamic unconscious processes. The method consists of selection of words from patient interview and test protocols that in the clinicians' judgments capture the patients' conscious symptom experience and the hypothetical unconscious conflict related to the symptom, subliminal and supraliminal presentation of these words, signal analysis of event-related potentials obtained to the word presentations. Eight phobics and three patients suffering from pathological grief reactions served as subjects. A time-frequency ERP analysis revealed that (...) subjects' ERPs classified the unconscious conflict words better subliminally than supraliminally, while the reverse was true for the conscious symptom words = 2.82, p = .011). The relationship between frequency and latency revealed a similar mirror image pattern for the unconscious conflict and conscious symptom words . This method demonstrated that objective, brain-based evidence for unconscious conflict can be obtained. (shrink)

A photoaffinity analog of cGMP has been used to biochemically identify a new ligand-binding subunit of the retinal rod cGMP-activated ion channel, as well as amino acids in contact with cGMP in the original subunit. Covalent tethering of this probe to channels in excised menbrane patches has revealed a functional heteogeneity in the ligand-binding sites that may arise from the two biochemically identified subunits.

One new tradition that has emerged from early research on autonomous robots is embodied cognitive science. This paper describes the relationship between embodied cognitive science and a related tradition, synthetic psychology. It is argued that while both are synthetic, embodied cognitive science is antirepresentational while synthetic psychology still appeals to representations. It is further argued that modern connectionism offers a medium for conducting synthetic psychology, provided that researchers analyze the internal representations that their networks develop. The paper then provides a (...) detailed example of the synthetic approach by showing how the construction of a connectionist network can be used to contribute to a theory of how humans solve Piaget's classic balance scale task. (shrink)

Transplantation of vital organs has been premised ethically and legally on "the dead donor rule" (DDR)—the requirement that donors are determined to be dead before these organs are procured. Nevertheless, scholars have argued cogently that donors of vital organs, including those diagnosed as "brain dead" and those declared dead according to cardiopulmonary criteria, are not in fact dead at the time that vital organs are being procured. In this article, we challenge the normative rationale for the DDR by rejecting (...) the underlying premise that it is necessarily wrong for physicians to cause the death of patients and the claim that abandoning this rule would exploit vulnerable patients. We contend that it is ethical to procure vital organs from living patients sustained on life support prior to treatment withdrawal, provided that there is valid consent for both withdrawing treatment and organ donation. However, the conservatism of medical ethics and practical concerns make it doubtful that the DDR will be abandoned in the near future. This leaves the current practice of organ transplantation based on the "moral fiction" that donors are dead when vital organs are procured. (shrink)

Activity anorexia illustrates selection of behavior at the biological, behavioral, and neural levels. Based on evolutionary history, food depletion increases the reinforcement value of physical activity that, in turn, decreases the reinforcement effectiveness of eating – resulting in activity anorexia. Neural opiates participate in the selection of physical activity during periods of food depletion.

Seeking parallels among disciplines can have both risks and benefits. Finding parallels may be a vacuous exercise in categorization, generating no new insights. And pointing to analogous functions may cause us to treat them as homologous. Hull et al. have provided a basis for the generation of insights in different selectionist areas, without confusing analogy with homology.

Awareness is a personal experience, which is only accessible to the rest of world through interpretation. We set out to identify a neural correlate of visual awareness, using brief subliminal and supraliminal verbal stimuli while measuring cerebral blood flow distribution with H215O PET. Awareness of visual verbal stimuli differentially activated medial parietal association cortex (precuneus), which is a polymodal sensory cortex, and dorsolateral prefrontal cortex, which is thought to be primarily executive. Our results suggest participation of these higher order perceptual (...) and executive cortical structures in visual verbal awareness. (shrink)