The repeatedly noted absence of case-reports of individuals with schizophrenia and congenital/early developed blindness has led several authors to argue that the latter can confer protective effects against the former. In this work, we present a number of relevant case-reports from different syndromes that show comorbidity of congenital and early blindness with schizophrenia. On the basis of these reports, we argue that a distinction between different types of blindness in terms of the origin of the visual deficit, (...) cortical or peripheral, is crucial for understanding the observed patterns of comorbidity. We discuss the genetic underpinnings and the brain structures involved in schizophrenia and blindness, with insights from language processing, laying emphasis on the three structures that particularly stand out: the occipital cortex, the lateral geniculate nucleus and the pulvinar. Last, we build on previous literature on the nature of the protective effects in order to offer novel insights into the nature of the protection mechanism from the perspective of the brain structures involved in each type of blindness. (shrink)

Cortical color blindness, or cerebral achromatopsia, has been likened by some authors to ''blindsight'' for color or an instance of ''covert'' processing of color. Recently, it has been shown that, although such patients are unable to identify or discriminate hue differences, they nevertheless show a striking ability to process wavelength differences, which can result in preserved sensitivity to chromatic contrast and motion in equiluminant displays. Moreover, visually evoked cortical potentials can still be elicited in response to chromatic (...) stimuli. We suggest that these demonstrations reveal intact residual processes rather than the operation of covert processes, where proficient performance is accompanied by a denial of phenomenal awareness. We sought evidence for such covert processes by conducting appropriate tests on achromatopsic subject M.S. An ''indirect'' test entailing measurement of reaction times for letter identification failed to reveal covert color processes. In contrast, in a forced choice oddity task for color, M.S. was unable to verbally indicate the position of the different color, but was surprisingly adept at making an appropriate eye movement to its location. This ''direct'' test thus revealed the possible covert use of chromatic differences. (shrink)

If the sight of cortically blind people were restored, could they visually recognize a cube or a sphere? This is Molyneux’s question. I argue that the answer to this question depends on the specificities of the mental setup of these cortically blind people. Some cortically blind people have (sometimes quite vivid) visual imagery. Others don’t. The answer to Molyneux’s question depends on whether the blind subjects have had visual imagery before their sight was restored. If they did, the answer to (...) Molyneux’s question is yes, if they didn’t, the answer is no. There is no generic answer to Molyneux’s question. (shrink)

It is proposed that there are at least two categories of blindsight. One is present in visually guided behaviour in normals as well as in brain-damaged patients, while the other is present only following cortical lesions. It is also proposed that blindsight is blind because residual visual functions are banned from consciousness either when they are subserved by subcortical centres alone or when they are mediated by cortical areas that have never been exclusively associated with such functions before (...) brain injury. (shrink)

Blindsight is the term commonly used to describe visually guided behaviour elicited by a stimulus falling within the scotoma (blind area) caused by a lesion of the striate cortex. Such is normally held to be unconscious and to be mediated by subcortical pathways involving the superior colliculus. Blindsight is of considerable theoretical importance since it suggests that destriate man is more like destriate monkey than had been previously believed and also because it supports the classical notion of two visual systems. (...) It is also of potential clinical importance, since it has been claimed recently that systematic practice in blindsight can lead to the recovery of normal visual function in patients with cortical lesions. From a review of the literature it is concluded that all of the phenomena of blindsight can be attributed either to light scatter into unimpaired parts of the visual field or to residual vision resulting from spared striate cortex. The possible contribution f other factors is also considered. It is concluded that blindsight studies have generally failed to control for such nonblindsight interpretations partly because of poor methodology and partly because of difficulties in defining the term. (shrink)

The field of neurotechnology intervening on blindness is rapidly expanding with several visual neural prostheses currently in development (Lowery 2013; Niketeghad and Pouratian 2019; Ptito et al. 2...

Executive functions are of vital importance in the process of active cognition, which is thought to be associated with the dorsolateral prefrontal cortex. As a valid brain stimulation technology, high-definition transcranial direct current stimulation has been used to optimize cognitive function in healthy adults. Substantial evidence indicates that short-term or single anodal tDCS sessions over the left DLPFC will enhance the performance of executive functions. However, the changes in performance and cortical activation of executive functions after modulation by repeated (...) anodal HD-tDCS is as yet unexplored. This study aims to examine changes in three core components of executive functions produced by nine HD-tDCS sessions, and to use functional near-infrared spectroscopy to bilaterally record DLPFC neural activity. A total of 43 participants were divided randomly into two study groups to complete nine interventions. Our results demonstrate that the enhancement of cognitive flexibility in the anodal group was significantly better than that in the sham group. Additionally, a Stroop effect-related decrease in oxygenated hemoglobin concentration in the DLPFC was observed in the anodal group but not the sham group. In conclusion, our study found that repeated anodal HD-tDCS sessions can significantly promote cognitive flexibility, one of the core components of executive function, and that alterations in DLPFC activation can enhance our understanding of the neuroplastic modifications modulated by HD-tDCS. (shrink)

As many as two million people in the United Kingdom repeatedly see people, animals, and objects that have no objective reality. Hallucinations on the border of sleep, dementing illnesses, delirium, eye disease, and schizophrenia account for 90% of these. The remainder have rarer disorders. We review existing models of recurrent complex visual hallucinations (RCVH) in the awake person, including cortical irritation, cortical hyperexcitability and cortical release, top-down activation, misperception, dream intrusion, and interactive models. We provide evidence that (...) these can neither fully account for the phenomenology of RCVH, nor for variations in the frequency of RCVH in different disorders. We propose a novel Perception and Attention Deficit (PAD) model for RCVH. A combination of impaired attentional binding and poor sensory activation of a correct proto-object, in conjunction with a relatively intact scene representation, bias perception to allow the intrusion of a hallucinatory proto-object into a scene perception. Incorporation of this image into a context-specific hallucinatory scene representation accounts for repetitive hallucinations. We suggest that these impairments are underpinned by disturbances in a lateral frontal cortex–ventral visual stream system. We show how the frequency of RCVH in different diseases is related to the coexistence of attentional and visual perceptual impairments; how attentional and perceptual processes can account for their phenomenology; and that diseases and other states with high rates of RCVH have cholinergic dysfunction in both frontal cortex and the ventral visual stream. Several tests of the model are indicated, together with a number of treatment options that it generates. Key Words: Blindness; Charles Bonnet; cholinergic; cortical release; delirium; dementia; dream intrusion; hallucination; Perception and Attention Deficit (PAD) model; schizophrenia. (shrink)

Molyneux’s question famously asks about whether a newly sighted subject might immediately recognize, by sight alone, shapes that were already familiar to her from a tactile point of view. This paper addresses three crucial points concerning this puzzle. First, the presence of two different questions: the classic one concerning visual recognition and another one concerning vision-for-action. Second, the explicit distinction, reported in the literature, between ocular and cortical blindness. Third, the importance of making reference to our best neuroscientific (...) account on vision, ‘the two visual systems model’, in order to better address Molyneux’s problem. Then, by offering a new, deeper analysis of the relation between, and, this paper suggests that the subjects of Molyneux’s two different questions show the same visual impairment as brain-damaged subjects with different lesions of the visual cortex. In particular, the subject of the first question shows the same impairment in visual recognition as a visual agnosic subject, while the subject of the second question shows the same visual impairment in visuomotor processing as an optic ataxic subject. These impairments still hold even if ocular processing is restored. Therefore, I suggest the following. For the first classic question, the required experimental setting cannot be properly reached. By contrast, concerning the second question, based on the interpretation we select, either the answer is negative, or, as with the first question, the experimental setting cannot be properly reached. This proposal constitutes, with the other approaches offered in the literature, a further attempt to tackle the enormous complexity of Molyneux’s puzzle. (shrink)

This paper concentrates on the basic properties of ''consciousness'' that temporal coding is postulated to relate to. A description of phenomenal consciousness based on what introspection tells us about its contents is offered. This includes a consideration of the effect of various brain lesions that result in cortical blindness, apperceptive and associative agnosia, and blindsight, together with an account of the manner in which sight is regained after cortical injuries. I then discuss two therories of perception-Direct Realism (...) and the Representative Theory. This includes a discussion of the concept of the body-image, phantom limbs, the alleged projection of sensations, the ontological status of phenomenal space, the homunculus argument, the validity of topographic coding, the difference between the stimulus field and the visual field, and two theories of brain-mind relationship-the Identity Theory and the Bohr-Heisenberg theory of brain-mind complementarity. Finally I suggest that the binocular rivalry obtained in the case of the stroboscopic patterns that result from intermittent photic stimulation of one eye, when used in animal expeiments with unit recording, offers a good experimental method of investigating the binding problem. (shrink)

GY, an extensively studied human hemianope, is aware of salient visual events in his cortically blind field but does not call this ''vision.'' To learn whether he has low-level conscious visual sensations or whether instead he has gained conscious knowledge about, or access to, visual information that does not produce a conscious phenomenal sensation, we attempted to image process a stimulus s presented to the impaired field so that when the transformed stimulus T(s) was presented to the normal hemifield it (...) would cause a sensation similar to that caused by s in the impaired field. While degradation of contrast, spatio-temporal filtering, contrast reversal, and addition of smear and random blobs all failed to match the response to a flashed bar sf, moving textures of low contrast were accepted to match the response to a moving contrast-defined bar, sm. Orientation and motion direction discrimination of the perceptually matched stimuli [sm and T(sm)] was closely similar. We suggest that the existence of a satisfactory match indicates that GY has phenomenal vision. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Fetal Tissue ResearchMary Carrington Coutts (bio)I. IntroductionThe use of tissue from fetal remains for transplantation and biomedical research has become a controversial issue in recent years, involving scientists, doctors, patients, and the federal government. Fetal tissue is potentially useful in a wide range of treatments for a number of serious diseases, some of them affecting millions of people. Despite the promise, transplantation research using fetal tissue from induced abortion (...) slowed dramatically in the U.S. in 1988, when a moratorium was declared on federal funding for such research involving humans. That moratorium was lifted by President Clinton on January 21, 1993. Though the future of fetal tissue transplantation research is brighter, public debate on the issue is likely to continue, exacerbated by the "acrimonious abortion debate" (VI, Post 1991, p. 14).Using fetal tissue in biomedical research and in transplantation is not a new practice. As early as 1928 unsuccessful attempts were made to transplant fetal pancreas cells into diabetics (VII, Fichera 1928). Fetal tissue was used effectively in biomedical research during the 1950s, and was instrumental in the culture of the polio virus, which led to the development of the polio vaccine. Fetal tissue cultures were also essential in the development of the rubella vaccine, and continue to be used in virology research. Transplantation of fetal thymus cells into patients with DiGeorge Syndrome has been recognized as effective therapy since the late 1960s.Many of the therapeutic applications involving fetal tissue are still experimental, so it is difficult to pinpoint fetal tissue transplantation's therapeutic potential. One promising application is the transplantation of human fetal brain cells into the substantia nigra of patients with Parkinson's disease to restore motor function. Fetal neural transplants have also shown promise for patients suffering from Alzheimer's disease, spinal cord and other neural tissue injuries, and possibly some forms of cortical blindness. Fetal liver cells may be useful for treatment of some kinds of bone marrow disease seen in leukemia and aplastic anemia patients. [End Page 81] Fetal tissue transplantation may also help those suffering from blood clotting disorders, such as sickle cell anemia, thalassemia, and hemophilia. Fetal pancreatic tissue has potential applications in the treatment of diabetes, especially juvenile onset diabetes. Human gene therapy may also employ embryonic and early fetal cells.The Center for Biomedical Ethics at the University of Minnesota reports that more than 1,000 patients have received transplanted fetal tissue worldwide. Countries where fetal tissue transplantation has occurred include: Australia, Canada, China, the Commonwealth of Independent States (formerly the U.S.S.R.), Cuba, Czechoslovakia, Finland, France, Germany, Great Britain, Hungary, India, Italy, Mexico, Norway, Spain, Sweden, and Yugoslavia (IV, Vawter 1992, p. 2; I, Spain 1988; VII, Reinikainen 1989).Fetal tissue has unique characteristics that make it especially valuable in some treatments. Fetal cells develop much faster than adult cells, hastening the therapeutic effect—a potentially significant benefit for gravely ill patients. They are also less likely to be rejected by transplant recipients because they are less antigenic than adult cells. This reduces the need for the exact tissue matches that can be so difficult to obtain. Fetal tissue is also easier to culture and proliferates more readily than comparable adult tissue. Furthermore, fetal tissue is in greater supply, due to the number of elective abortions.Questions about the use of fetuses and fetal tissue in biomedical research were raised in the United States in the early 1970s. Between 1969 and 1973, all 50 states enacted the Uniform Anatomical Gift Act, allowing for the donation of all or part of the body of a dead fetus for research or therapeutic research. Prospects for the use of fetal tissue increased after the Supreme Court decision in Roe v. Wade legalized abortion. As the availability of fetal tissue increased so did the concern over the potential for controversial research on living, soon-to-be-aborted fetuses, and anxiety over maltreatment of dead abortuses. Vivid examples include Geoffrey Chamberlain's 1968 report of an experiment on a fetus of 26 weeks gestational age. Delivered by hysterotomy from a 14-year-old patient, the fetus was attached to an "artificial placenta" and kept alive for more than... (shrink)

In three macaque monkeys with unilateral removal of primary visual cortex and in one unoperated monkey, we measured reaction times to a visual target that was presented at a lateral eccentricity of 20o in the normal, left, visual hemifield. When an additional stimulus was presented at the corresponding position in the right hemifield (hemianopic in three of the monkeys), it significantly slowed the reaction time to the left target if it preceded it by delays from 100-500 msec. The most effective (...) delay depended on the particular experimental paradigm and perhaps on the experience of the monkey with the task. The results show that reaction times to seen targets in the normal hemifield of monkeys are influenced by the presentation of ''unseen'' targets in the anopic hemifield, as in some patients with cortically blind visual field defects. (shrink)

Blindsight, the ability to blindly discriminate wavelength and other aspects of stimuli in a blind field, sometimes occurs in people with lesions to striate (V1) cortex. There is currently no consensus on whether qualitative color information of the sort that is normally computed by double opponent cells in striate cortex is indeed computed in blindsight but doesn’t reach awareness, perhaps owing to abnormal neuron responsiveness in striate or extra-striate cortical areas, or is not computed at all. The existence of (...) primesight, the experience of colored afterimages in blindsight, has been taken to suggest that qualitative color information is computed either in pre-striate or striate cortical areas but is not broadcast to working memory. I argue here that a recent study in which color phosphenes were induced in a blindsighter using bilateral transcranial magnetic stimulation indicates that computations necessary for conscious color vision are lost in blindsight. Owing to this loss, the neural responsiveness in extrastriate cortical areas is abnormal and hence is unable to give rise to color awareness. Blindsight is thus degraded vision in which the computations necessary for conscious color vision have been lost. (shrink)

In this single-blind within-subject study, autonomic and EEG variables were compared during 10-min, order-balanced eyes-closed rest and Transcendental Meditation (TM) sessions. TM sessions were distinguished by (1) lower breath rates, (2) lower skin conductance levels, (3) higher respiratory sinus arrhythmia levels, and (4) higher alpha anterior-posterior and frontal EEG coherence. Alpha power was not significantly different between conditions. These results were seen in the first minute and were maintained throughout the 10-min sessions. TM practice appears to (1) lead to a (...) state fundamentally different than eyes-closed rest; (2) result in a cascade of events in the central and autonomic nervous systems, leading to a rapid change in state (within a minute) that was maintained throughout the TM session; and (3) be best distinguished from other conditions through autonomic and EEG alpha coherence patterns rather than alpha power. Two neural networks that may mediate these effects are suggested. The rapid shift in physiological functioning within the first minute might be mediated by a ''neural switch'' in prefrontal areas inhibiting activity in specific and nonspecific thalamocortical circuits. The resulting ''restfully alert'' state might be sustained by a basal ganglia-corticothalamic threshold regulation mechanism automatically maintaining lower levels of cortical excitability. (shrink)

Cranial electrotherapy stimulation is a neuromodulation tool used for treating several clinical disorders, including insomnia, anxiety, and depression. More recently, a limited number of studies have examined CES for altering affect, physiology, and behavior in healthy, non-clinical samples. The physiological, neurochemical, and metabolic mechanisms underlying CES effects are currently unknown. Computational modeling suggests that electrical current administered with CES at the earlobes can reach cortical and subcortical regions at very low intensities associated with subthreshold neuromodulatory effects, and studies using (...) electroencephalography and functional magnetic resonance imaging show some effects on alpha band EEG activity, and modulation of the default mode network during CES administration. One theory suggests that CES modulates brain stem, limbic, and cortical regions and increases relative parasympathetic to sympathetic drive in the autonomic nervous system. There is no direct evidence supporting this theory, but one of its assumptions is that CES may induce its effects by stimulating afferent projections of the vagus nerve, which provides parasympathetic signals to the cardiorespiratory and digestive systems. In our critical review of studies using CES in clinical and non-clinical populations, we found severe methodological concerns, including potential conflicts of interest, risk of methodological and analytic biases, issues with sham credibility, lack of blinding, and a severe heterogeneity of CES parameters selected and employed across scientists, laboratories, institutions, and studies. These limitations make it difficult to derive consistent or compelling insights from the extant literature, tempering enthusiasm for CES and its potential to alter nervous system activity or behavior in meaningful or reliable ways. The lack of compelling evidence also motivates well-designed and relatively high-powered experiments to assess how CES might modulate the physiological, affective, and cognitive responses to stress. Establishing reliable empirical links between CES administration and human performance is critical for supporting its prospective use during occupational training, operations, or recovery, ensuring reliability and robustness of effects, characterizing if, when, and in whom such effects might arise, and ensuring that any benefits of CES outweigh the risks of adverse events. (shrink)

BackgroundTranscranial direct current stimulation targeting the primary motor hand area may induce lasting shifts in corticospinal excitability, but after-effects show substantial inter-individual variability. Functional magnetic resonance imaging can probe after-effects of TDCS on regional neural activity on a whole-brain level.ObjectiveUsing a double-blinded cross-over design, we investigated whether the individual change in corticospinal excitability after TDCS of M1-HAND is associated with changes in task-related regional activity in cortical motor areas.MethodsSeventeen healthy volunteers received 20 min of real or sham TDCS on (...) separate days in randomized order. Real and sham TDCS used the classic bipolar set-up with the anode placed over right M1-HAND. Before and after each TDCS session, we recorded motor evoked potentials from the relaxed left first dorsal interosseus muscle after single-pulse transcranial magnetic stimulation of left M1-HAND and performed whole-brain fMRI at 3 Tesla while participants completed a visuomotor tracking task with their left hand. We also assessed the difference in MEP latency when applying anterior-posterior and latero-medial TMS pulses to the precentral hand knob.ResultsReal TDCS had no consistent aftereffects on mean MEP amplitude, task-related activity or motor performance. Individual changes in MEP amplitude, measured directly after real TDCS showed a positive linear relationship with individual changes in task-related activity in the supplementary motor area and AP-LM MEP latency.ConclusionFunctional aftereffects of classical bipolar anodal TDCS of M1-HAND on the motor system vary substantially across individuals. Physiological features upstream from the primary motor cortex may determine how anodal TDCS changes corticospinal excitability. (shrink)

The heterogeneity of transcranial direct current stimulation protocols and clinical profiles may explain variable results in modulating excitability in the motor cortex after stroke. However, the cortical electrical effects induced by different tDCS protocols remain unclear. Here, we aimed to compare rhythm changes in electroencephalography induced by three tDCS position protocols and the association between tDCS effects and clinical factors in stroke. Nineteen patients with chronic ischemic stroke underwent four experimental sessions with three tDCS protocols [anodal, cathodal, and bilateral (...) ] and a sham protocol, according to a single-blind randomized crossover design. Resting-state EEG was acquired before and after each protocol. First, a paired-sample t-test was used to examine the difference in spectral power between pre- and post-stimulation. Then, linear and quadratic regression models were used separately to describe the association between the clinical factors of stroke and changes in spectral power which was significantly different between pre- and post-tDCS. Finally, repeated measures analysis of variance with lesion hemisphere, stimulation protocol, and the location was performed to investigate the effects of tDCS over time. The induced effect of tDCS was mainly reflected in the alpha rhythms. The alpha power was increased by atDCS, especially low-alpha, in localized areas of the central and distant areas of the frontal and parietal lobes. Bi-tDCS also affected alpha power but in a smaller area that mainly focused on high-alpha rhythms. However, ctDCS and sham had no significant effects on any EEG rhythm. The clinical factors of time since stroke and motor impairment level were related to the change in high-alpha induced by atDCS and bi-tDCS following quadratic regression models. The above-mentioned modulation effect lasted for 20 min without attenuation. In conclusion, our findings provide evidence that the alpha rhythm of EEG is modulated differently by different tDCS protocols and that high alpha is affected by clinical characteristics such as post-stroke time and motor deficits, which is of great significance for understanding the modulation effect of different tDCS protocols on stroke and the guidance of protocols to promote motor recovery following stroke. (shrink)

Background We report a randomised controlled clinical trial of neurofeedback therapy intervention for ADHD/ADD in adults. We focus on internal mechanics of neurofeedback learning, to elucidate the primary role of cortical self-regulation in neurofeedback. We report initial results; more extensive analysis will follow. Methods Trial has two phases: intervention and follow-up. The intervention consisted of neurofeedback treatment, including intake and outtake measurements, using a waiting-list control group. Treatment involved $\sim$40 hour-long sessions 2-5 times per week. Training involved either theta/beta (...) or sensorimotor-rhythm regimes, adapted by adding a novel 'inverse-training' condition to promote self-regulation. Follow-up (ongoing) will consist of self-report and executive function tests. Setting Intake and outtake measurements were conducted at University of Helsinki. Treatment was administered at partner clinic Mental Capital Care, Helsinki. Randomisation We randomly allocated half the sample then adaptively allocated the remainder to minimise baseline differences in prognostic variables. Blinding Waiting-list control design meant trial was not blinded. Participants 54 adult Finnish participants (mean age 36 years; 29 females) were recruited after screening by psychiatric review. 44 had ADHD diagnoses, 10 had ADD. Measurements Symptoms were assessed by computerised attention test (T.O.V.A.) and self-report scales, at intake and outtake. Performance during neurofeedback trials was recorded. Results Participants were recruited and completed intake measurements during summer 2012, before assignment to treatment and control, September 2012. Outtake measurements ran April-August 2013. After dropouts, 23 treatment and 21 waiting-list participants remained for analysis. Initial analysis showed that, compared to waiting-list control, neurofeedback promoted improvement of self-reported ADHD symptoms, but did not show transfer of learning to T.O.V.A. Comprehensive analysis will be reported elsewhere. Trial Registration "Computer Enabled Neuroplasticity Treatment (CENT)", ISRCTN13915109. Partly funded by Finnish science agency TEKES, project #440078. (shrink)

It has been shown that visual awareness in the blind hemifield of hemianopic cats that have undergone unilateral ablations of visual cortex can be restored by sectioning the commissure of the superior colliculus or by destroying a portion of the substantia nigra contralateral to the cortical lesion (the Sprague effect). We propose that the visual awareness that is recovered is due to synchronized oscillatory activities in the superior colliculus ipsilateral to the cortical lesion. These oscillatory activities are normally (...) partially suppressed by the inhibitory, GABAergic contralateral nigrotectal projection, and the destruction of the substantia nigra, or the sectioning of the collicular commissure, disinhibits the collicular neurons, causing an increase in the extent of oscillatory activity and/or synchronization between activities at different sites. This increase in the oscillatory and synchronized character is sufficient for the activities to give rise to visual awareness. We argue that in rodents and lower vertebrates, normal visual awareness is partly due to synchronized oscillatory activities in the optic tectum and partly due to similar activities in visual cortex. It is only in carnivores and primates that visual awareness is wholly due to cortical activities. Based on von Baerian recapitulation theory, we propose that, even in humans, there is a period in early infancy when visual awareness is partially due to activities in the superior colliculus, but that this awareness gradually disappears as the nigrotectal projection matures. (shrink)

A few findings from our laboratory are provided as evidence favoring “isomrphism” in filling-in. One is the responsivity of macaque-cortical area V1 cells to a stimulus designed for surface filling-in at the blind spot. Another is a phenomenological observation of motion aftereffect confined within a filled-in surface at the blind spot. Our recent study on the monkey's perception of surface filling-in at a scotoma is also mentioned.

Researchers in post-war industrial laboratories such as Bell Labs and the Smith-Kettlewell Institute pioneered solutions to compensate for sensory loss through so-called sensory substitution systems, premised on an assumption of cortical and sensory plasticity. The article tracks early discussions of plasticity in psychology literature from William James, acknowledged by Wiener, but explicitly developed by Bach-y-Rita and his collaborators. After discussing the conceptual foundations of the principles of sensory substitution, two examples are discussed. First, ‘Project Felix’ was an experiment in (...) vibrotactile communication by means of ‘hearing gloves’ for the deaf at Norbert Wiener’s laboratory at Massachusetts Institute of Technology, demonstrated to Helen Keller in 1950. Second, the tactile-visual sensory substitution system for the blind pioneered by Paul Bach-y-Rita from 1968 onwards. Cumulatively, this article underlines the crucial yet occluded history of research on sensory impairments in the discovery of underlying neurophysiological processes of plasticity and the emergent discourse of neuroplastic subjectivity. (shrink)

Our prior research demonstrated that the right temporoparietal junction exerted a modulatory role in ingroup bias in emotional mimicry. In this study, two experiments were conducted to further explore whether the rTPJ is a neural region for emotional mimicry or for the modulation of emotional mimicry by group membership in a sham-controlled, double-blinded, between-subject design. Both experiments employed non-invasive transcranial direct current stimulation to temporarily change the cortical excitability over the rTPJ and facial electromyography to measure facial muscle activations (...) as an index of emotional mimicry. After the anodal or sham stimulation, participants in Experiment 1 passively viewed a series of happy clips, while participants in Experiment 2 viewed happy clips performed by ethnic ingroup and outgroup models. fEMG analyses revealed that participants in Experiment 1 showed the same degree of happy mimicry for both tDCS conditions and participants in Experiment 2 showed an ingroup bias in happy mimicry in the sham condition, which disappeared in the anodal condition. Taken together, the present study demonstrated that rTPJ plays a role in the modulation of emotional mimicry by group membership. (shrink)

ObjectivesSeveral studies have examined the effects of repetitive transcranial magnetic stimulation (rTMS) on associative memory (AM) but findings were inconsistent. Here, we aimed to test whether twice-daily rTMS could significantly improve AM.MethodsIn this single-blind, sham-controlled experiment, 40 participants were randomized to receive twice-daily sham or real rTMS sessions for five consecutive days (a total of 16,000 pulses). The stimulation target in left inferior parietal lobule (IPL) exhibiting peak functional connectivity to the left hippocampus was individually defined for each participant. Participants (...) completed both a picture-cued word association task and Stroop test at baseline and 1 day after the final real or sham rTMS session. Effects of twice-daily rTMS on AM and Stroop test performance were compared using two-way repeated measures analysis of variance with main factors Group (real vs. sham) and Time (baseline vs. post-rTMS).ResultsThere was a significant Group × Time interaction effect. AM score was significantly enhanced in the twice-daily real group after rTMS, but this difference could not survive the post hoc analysis after multiple comparison correction. Further, AM improvement in the twice-daily real group was not superior to a previously reported once-daily rTMS group receiving 8,000 pulses. Then, we combined the twice- and once-daily real groups, and found a significant Group × Time interaction effect. Post hoc analysis indicated that the AM score was significantly enhanced in the real group after multiple comparisons correction.ConclusionOur prospective experiment did not show significant rTMS effect on AM, but this effect may become significant if more participants could be recruited as revealed by our retrospective analysis. (shrink)

Ethical thought experiments such as the trolley dilemma have been investigated extensively in the past, showing that humans act in utilitarian ways, trying to cause as little overall damage as possible. These trolley dilemmas have gained renewed attention over the past few years, especially due to the necessity of implementing moral decisions in autonomous driving vehicles. We conducted a set of experiments in which participants experienced modified trolley dilemmas as drivers in virtual reality environments. Participants had to make decisions between (...) driving in one of two lanes where different obstacles came into view. Eventually, the participants had to decide which of the objects they would crash into. Obstacles included a variety of human-like avatars of different ages and group sizes. Furthermore, the influence of sidewalks as potential safe harbors and a condition implicating self-sacrifice were tested. Results showed that participants, in general, decided in a utilitarian manner, sparing the highest number of avatars possible with a limited influence by the other variables. Derived from these findings, which are in line with the utilitarian approach in moral decision making, it will be argued for an obligatory ethics setting implemented in ADVs. (shrink)

The current financial reporting environment, with its increasing use of accounting estimates, including fair value estimates, suggests that unethical accounting estimates may be a growing concern. This paper provides explanations and empirical evidence for why some types of accounting estimates in financial reporting may promote a form of ethical blindness. These types of ethical blindness can have an escalating effect that corrupts not only an individual or organization but also the accounting profession and the public interest it serves. (...) Ethical blindness in the standards of professional accountants may be a factor in the extent of misreporting, and may have taken on new urgency as a result of the proposals to change the conceptual framework for financial reporting using international standards. The social consequences for users of financial statements can be huge. The acquittal of former Nortel executives on fraud charges related to accounting manipulations is viewed by many as legitimizing accounting gamesmanship. This decision illustrates that the courts may not be the best place to deal with ethical reporting issues. The courts may be relied on for only the most egregious unethical conduct and, even then, the accounting profession is ill equipped to assist the legal system in prosecuting accounting fraud unless the standards have been clarified. We argue that the problem of unethical reporting should be addressed by the accounting profession itself, preferably as a key part of the conceptual framework that supports accounting and auditing standards, and the codes of ethical conduct that underpin the professionalism of accountants. (shrink)

ABSTRACTThose who take ‘All lives matter’ to oppose ‘Black lives matter’ take the latter to mean something like ‘Only black lives matter.’ Those who regard this exclusionary construal as mistaken hold the error to be due to an ideology of color-blindness. It has further been argued that the ideologically-motivated suppression of racial discourse has resulted in an epistemic injustice, blinding objectors to the fact that ‘Black lives matter’ really means ‘Black lives matter, too’. I will argue that attempts to (...) make sense of this interpretive response in terms of color-blindness are mistaken. As I will discuss, the interpretive debates surrounding the words ‘Black lives matter’ are reminiscent of those surrounding ‘Black Power,’ which unfolded long before color-blindness could be said to have been a prevailing ethos. Critical affirmations such as ‘Black Power’ and ‘Black lives matter’ have proved difficult for many interpreters to understand because of the way that they manifest resistance to white suprema... (shrink)

Interrogating received knowledge is constitutive to any critical project, and recently there has been a wave of scholarship which argues for locating the origin of racist-thinking prior to modern Europe—even prior to the Common Era—without any real consideration of the potential dangers accompanying such a seismic redefinition. By expanding “racism” to include potentially any pre-modern xenophobic or ethnicist atrocity, even well-meaning scholarship dilutes the peculiar injustice of modern Europe’s most successful epistemological weapon. As a result, we lose any criteria to (...) distinguish ubiquitous oppressive projects from specifically racist-projects of hegemony and domination. However laudable its intent, such scholarship falls prey to methodological, epistemological, and practical errors that hamstring the ameliorative impact of contemporary anti-racist work while ironically diminishing racism’s impact. For if every conflict is racist, then contemporary colorblindness is correct: if white supremacy isn’t particularly white, then racism is a distinction without a difference. (shrink)

Based on various stimuli, the findings for the inattentional blindness paradigm suggest that many observers do not perceive an unexpected object in a dynamic setting. In a first experiment, inattentional blindness was combined with eye tracking data from children. Observers who did not notice the unexpected object in the basketball game test by Simons and Chabris spent on average as much time looking at the unexpected object as those subjects who did perceive it. As such, individual differences that (...) are responsible for the recognition of unexpected objects have to be found as further indicators. In a second experiment, the expert-novice paradigm was used to show that the probability of seeing an unexpected object can be increased with specific previous experience. The results in the same task indicate significant differences between basketball experts and basketball novices. The ages of the subjects in both experiments are discussed in connection with the inattentional blindness paradigm. (shrink)

Experiments on scene perception and change blindness suggest that the visual system does not construct detailed internal models of a scene. These experiments therefore call into doubt the traditional view that vision is a process in which detailed representations of the environment must be constructed. The non-existence of such detailed representations, however, does not entail that we do not perceive the detailed environment. The “grand illusion hypothesis” that our visual world is an illusion rests on (1) a problematic “reconstructionist” (...) conception of vision, and (2) a misconception about the character of perceptual experience. (shrink)