Paired associative stimulation at the spinal cord has been shown to increase muscle force and dexterity by strengthening the corticomuscular connection, through spike timing dependent plasticity. Typically, transcranial magnetic stimulation and transcutaneous peripheral nerve electrical stimulation are often used in spinal PAS. PNS targets superficial nerve branches, by which the number of applicable muscles is limited. Alternatively, a muscle can be activated by positioning the stimulation electrode on the “motor point”, which is the most sensitive location of a (...) muscle to electrical stimulation. Although this can increase the number of applicable muscles for spinal PAS, nobody has tested whether MPS can be used for the spinal PAS to date. Here we investigated the feasibility of using MPS instead of PNS for spinal PAS. Ten healthy male individuals received spinal PAS on two separate days with different stimulation timings expected to induce facilitation of corticospinal excitability or no effect on the soleus. The motor evoked potentials response curve in the soleus was measured prior to the spinal PAS, immediately after and at 10, 20, 30 min post-intervention as a measure of corticospinal excitability. The post-intervention MEP response curve areas were larger in the REAL condition than the CONTROL conditions. Further, the post-intervention MEP response curve areas were significantly larger than pre-intervention in the REAL condition but not in the CONTROL condition. We conclude that MPS can facilitate corticospinal excitability through spinal PAS. (shrink)

Functional electrical stimulation (FES), a method for inducing muscle contraction, has been successfully used in gait rehabilitation for patients with deficits after neurological disorders and several clinical studies have found that it can improve gait function after stroke and spinal cord injury. However, FES gait training is not suitable for patients with walking difficulty, such as those with severe motor paralysis of the lower limbs. We have previously shown that action observation combined with motor imagery (AO + MI) of (...) walking induces walking-related cortical activity. Therefore, we combined FES, which alternately generates dorsiflexion and plantar flexion, with AO + MI as an alternative to gait training. The present study investigates the transient effects of 20-min of FES simultaneously with and without AO + MI of walking on corticospinal and spinal reflex excitability in able-bodied participants. We measured motor evoked potentials and Hoffmann-reflexes to assess corticospinal and spinal reflex excitability at rest before and after the 20-min FES with and without the AO + MI. Our results show that FES without AO + MI did not change excitability (p > 0.05), while FES with AO + MI facilitated corticospinal excitability (p < 0.05). This facilitation likely occurred due to the synchronization of sensory inputs from FES and cortical activity during AO + MI. Facilitation was observed only in the dorsiflexor but not the plantar flexor muscle (p < 0.05), suggesting muscle specificity of the facilitation. These results demonstrate the effectiveness of combining FES with AO + MI and pave the way for novel neurorehabilitation strategies for patients with neurological gait deficits. (shrink)

This study investigated the neuromodulatory effects of transspinal stimulation on soleus H-reflex excitability and electromyographic activity during stepping in humans with and without spinal cord injury. Thirteen able-bodied adults and 5 individuals with SCI participated in the study. EMG activity from both legs was determined for steps without, during, and after a single-pulse or pulse train transspinal stimulation delivered during stepping randomly at different phases of the step cycle. The soleus H-reflex was recorded in both subject groups under (...) control conditions and following single-pulse transspinal stimulation at an individualized exactly similar positive and negative conditioning-test interval. The EMG activity was decreased in both subject groups at the steps during transspinal stimulation, while intralimb and interlimb coordination were altered only in SCI subjects. At the steps immediately after transspinal stimulation, the physiological phase-dependent EMG modulation pattern remained unaffected in able-bodied subjects. The conditioned soleus H-reflex was depressed throughout the step cycle in both subject groups. Transspinal stimulation modulated depolarization of motoneurons over multiple segments, limb coordination, and soleus H-reflex excitability during assisted stepping. The soleus H-reflex depression may be the result of complex spinal inhibitory interneuronal circuits activated by transspinal stimulation and collision between orthodromic and antidromic volleys in the peripheral mixed nerve. The soleus H-reflex depression by transspinal stimulation suggests a potential application for normalization of spinal reflex excitability after SCI. (shrink)

There is a growing interest in non-invasive stimulation interventions as treatment strategies to improve functional outcomes and recovery after spinal cord injury. Repetitive transcranial magnetic stimulation is a neuromodulatory intervention which has the potential to reinforce the residual spinal and supraspinal pathways and induce plasticity. Recent reviews have highlighted the therapeutic potential and the beneficial effects of rTMS on motor function, spasticity, and corticospinal excitability modulation in SCI individuals. For this scoping review, we focus on the stimulation (...) parameters used in 20 rTMS protocols. We extracted the rTMS parameters from 16 published rTMS studies involving SCI individuals and were able to infer preliminary associations between specific parameters and the effects observed. Future investigations will need to consider timing, intervention duration and dosage that may depend on the stage, the level, and the severity of the injury. There is a need for more real vs. sham rTMS studies, reporting similar designs with sufficient information for replication, to achieve a significant level of evidence regarding the use of rTMS in SCI. (shrink)

The use of upper limb vibration during exercise and rehabilitation continues to gain popularity as a modality to improve function and performance. Currently, a lack of knowledge of the pathways being altered during ULV limits its effective implementation. Therefore, the aim of this study was to investigate whether indirect ULV modulates transmission along spinal and corticospinal pathways that control the human forearm. All measures were assessed under CONTROL and ULV conditions while participants maintained a small contraction of the right (...) flexor carpi radialis muscle. To assess spinal pathways, Hoffmann reflexes elicited by stimulation of the median nerve were recorded from FCR with motor response amplitudes matched between conditions. An H-reflex conditioning paradigm was also used to assess changes in presynaptic inhibition by stimulating the superficial radial nerve 37 ms prior to median nerve stimulation. Cutaneous reflexes in FCR elicited by stimulation of the SR nerve at the wrist were also recorded. To assess corticospinal pathways, motor evoked potentials elicited by transcranial magnetic stimulation of the contralateral motor cortex were recorded from the right FCR and biceps brachii. ULV significantly reduced H-reflex amplitude by 15.7% for both conditioned and unconditioned reflexes. Therefore, ULV inhibits cutaneous and H-reflex transmission without influencing corticospinal excitability of the forearm flexors suggesting increased presynaptic inhibition of afferent transmission as a likely mechanism. A general increase in inhibition of spinal pathways with ULV may have important implications for improving rehabilitation for individuals with spasticity. (shrink)

In action theory, emotional actions are standardly treated as exceptions—cases where the “normal” springs of action are not functioning properly. My aim here is to argue that this is not so. We have plenty of evidence—beautifully brought together in the present special issue—that emotions play a crucial and often constitutive role in all the important phases of action preparation and initiation. Most of our actions are less stupid than, say, Zidane’s head-butt, but all of our actions have emotional components. Actions (...) can be more or less emotional, but they are never completely nonemotional. (shrink)

The Hoffmann reflex (H-wave) is produced by alpha-motoneuron activation in the spinal cord. A feature of this electromyography response is that it exhibits fluctuations in amplitude even during repetitive stimulation with the same intensity of current. We herein explore the hypothesis that physical training induces plastic changes in the motor system. Such changes are evaluated with the fractal dimension (FD) analysis of the H-wave amplitude-fluctuations (H-wave FD) and the cross-covariance (CCV) between the bilateral H-wave amplitudes. The aim of this (...) study was to compare the H-wave FD as well as the CCV before and after track training in sedentary individuals and athletes. The training modality in all subjects consisted of running three times per week (for 13 weeks) in a concrete road of 5 km. Given the different physical condition of sedentary vs. athletes, the running time between sedentary and athletes was different. After training, the FD was significantly increased in sedentary individuals but significantly reduced in athletes, although there were no changes in spinal excitability in either group of subjects. Moreover, the CCV between bilateral H-waves exhibited a significant increase in athletes but not in sedentary individuals. These differential changes in the FD and CCV indicate that the plastic changes in the complexity of the H-wave amplitude fluctuations as well as the synaptic inputs to the Ia-motoneuron systems of both legs were correlated to the previous fitness history of the subjects. Furthermore, these findings demonstrate that the FD and CCV can be employed as indexes to study plastic changes in the human motor system. (shrink)

Pains that persist long after damaged tissue hasrecovered remain a perplexing phenomenon. Theseso-called chronic pains serve no useful function foran organism and, given its disabling effects, mighteven be considered maladaptive. However, a remarkablesimilarity exists between the neural bases thatunderlie the hallmark symptoms of chronic pain andthose that subserve learning and memory. Bothphenomena, wind-up in the pain literature andlong-term potentiation (LTP) in the learning andmemory literature, are forms of neuroplasticity inwhich increased neural activity leads to a longlasting increase in the (...) class='Hi'>excitability of neuronsthrough structural modifications at pre- andpost-synaptic sites. Moreover, the synapticmodifications of wind-up and LTP share a commonmechanism: a glutamate N -methyl-D-aspartate(NMDA) receptor interaction that initiates a calciummediated biochemical cascade that ultimately enhancessignal processing at the -amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid (AMPA) receptor. This paper arguesthat chronic pain, which has no adaptive value, canbe accounted for in terms of the highly adaptivephenomenon of activity-dependent neural plasticity;hence, some cases of chronic pain can beconceptualized as a memory trace in spinal neurons. (shrink)

Starting from macroscopic and microscopic facts of cerebellar histology, we propose a new functional interpretation that may elucidate the role of the cerebellum in movement control. The idea is that the cerebellum is a large collection of individual lines (Eccles's : Eccles et al. 1967a) that respond specifically to certain sequences of events in the input and in turn produce sequences of signals in the output. We believe that the sequence-in/sequence-out mode of operation is as typical for the cerebellar cortex (...) as the transformation of sets into sets of active neurons is typical for the cerebral cortex, and that both the histological differences between the two and their reciprocal functional interactions become understandable in the light of this dichotomy. The response of Purkinje cells to sequences of stimuli in the mossy fiber system was shown experimentally by Heck on surviving slices of rat and guinea pig cerebellum. Sequential activation of a row of eleven stimulating electrodes in the granular layer, imitating a of the stimuli along the folium, produces a powerful volley in the parallel fibers that strongly excites Purkinje cells, as evidenced by intracellular recording. The volley, or has maximal amplitude when the stimulus moves toward the recording site at the speed of conduction in parallel fibers, and much smaller amplitudes for lower or higher The succession of stimuli has no effect when they in the opposite direction. Synchronous activation of the stimulus electrodes also had hardly any effect. We believe that the sequences of mossy fiber activation that normally produce this effect in the intact cerebellum are a combination of motor planning relayed to the cerebellum by the cerebral cortex, and information about ongoing movement, reaching the cerebellum from the spinal cord. The output elicited by the specific sequence to which a is tuned may well be a succession of well timed inhibitory volleys the motor sequences so as to adapt them to the complicated requirements of the physics of a multijointed system. (shrink)

We report that upon excitation by a single pulse, a classical harmonic oscillator immersed in the classical electromagnetic zero-point radiation exhibits a discrete harmonic spectrum in agreement with that of its quantum counterpart. This result is interesting in view of the fact that the vacuum field is needed in the classical calculation to obtain the agreement.

Radial excitations of hadrons carrying zero instanton number are investigated. The mass relations among relevant non-strange and strange mesons and baryons have been derived consistently with the observed data.

To commemorate 40 years since the founding of the Journal of Business Ethics, the editors-in-chief of the journal have invited the editors to provide commentaries on the future of business ethics. This essay comprises a selection of commentaries aimed at creating dialog around the theme Bringing Excitement to Empirical Business Ethics Research (inspired by the title of the commentary by Babalola and van Gils). These editors, considering the diversity of empirical approaches in business ethics, envisage a future in which quantitative (...) business ethics research is more bold and innovative, as well as reflexive about its techniques, and dialog between quantitative and qualitative research nourishes the enrichment of both. In their commentary, Babalola and van Gils argue that leadership research has stagnated with the use of too narrow a range of perspectives and methods and too many overlapping concepts. They propose that novel insights could be achieved by investigating the lived experience of leadership (through interviews, document analysis, archival data); by focusing on topics of concern to society; by employing different personal, philosophical, or cultural perspectives; and by turning the lens on the heroic leader (through “dark-side” and follower studies). Taking a provocative stance, Bal and Garcia-Lorenzo argue that we need radical voices in current times to enable a better understanding of the psychology underlying ethical transformations. Psychology can support business ethics by not shying away from grander ideas, going beyond the margins of “unethical behaviors harming the organization” and expanding the range of lenses used to studying behavior in context. In the arena of finance and business ethics, Guedhami, Liang, and Shailer emphasize novel data sets and innovative methods. Significantly, they stress that an understanding the intersection of finance and ethics is central to business ethics; financial equality and inclusion are persistent socio-economic and political concerns that are not always framed as ethics issues, yet relevant business policies and practices manifest ethical values. Finally, Charles Cho offers his opinion on the blurry line between the “ethical” versus “social” or “critical” aspects of accounting papers. The Journal of Business Ethics provides fertile ground for innovative, even radical, approaches to quantitative methods (see Zyphur and Pierides in J Bus Ethics 143(1):1–16, https://doi.org/10.1007/s10551-017-3549-8, 2017), as part of a broad goal of ethically reflecting on empirical research. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Excited DeliriumFalsifiability, Causality, and the Importance of AdvocacyArjun Byju, MD (bio) and Phoebe Friesen, PhD (bio)We want to begin by thanking both Kathryn Petrozzo and Paul B. Lieberman for taking the time to read and respond to our article, “Making Up Monsters, Redirecting Blame: An Examination of Excited Delirium,” so thoughtfully. They each offered us an opportunity to consider dimensions of excited delirium that we had not encountered as (...) of yet and encouraged us to think more carefully about them. In our response, we consider each of their commentaries in turn, given that, as a philosopher and a psychiatrist, they each speak to different aspects of our argument.First, we turn to Kathryn Petrozzo’s commentary “Excited Delirium: The Self-Fulfilling Prophecy of Police Brutality.” We are grateful for her generous comments and careful engagement with our arguments. While much of the commentary is supportive of our piece, Petrozzo makes three critical and insightful points that we hope to respond to here.The first point Petrozzo makes is that our assertion that excited delirium is non-falsifiable is not supported. She suggests that those “seeking to exonerate the police/first responders responsible for these deaths, are not accepting this evidence leading them to reject the excited delirium diagnosis, but rather, are crafting an incorrect causal narrative. This is deeply problematic, but it does not necessarily render excited delirium as nonfalsifiable.”Although we are intrigued by this challenge, we would like to hear more about what it would look like to falsify the phenomenon of excited delirium. The way that the causal theories related to it are structured are such that if one causal factor is not present (e.g., drug use), then another causal factor can be located (e.g., mental health), and if that is not found, another may be simply made up (e.g., genetic predisposition), making excited delirium multiply realizable in a seemingly endless fashion. This is precisely what took place in the case of Anthany Dawson, who was initially said to have been experiencing a mental health crisis, but was later said to have died from excited delirium related to a genetic condition never identified before (Hon, 2004; Razack, 2015). [End Page 361]In practice, confirmations of excited delirium are found on the basis of various unrelated factors, such that after a death involving police force, there is almost always the option to reach for excited delirium as an explanation/exoneration. According to proponents, there is no factor that could be present that could rule out the diagnosis of excited delirium as it is currently constructed. Indeed, even in the presence of video evidence showing police officers choking an individual until they stop breathing, these deaths are still attributed to excited delirium. This seems like a clear instance of non-falsifiability.Although Petrozzo might maintain that this is simply “an incorrect causal narrative,” it is a causal narrative that aligns with the current theoretical scaffolding surrounding excited delirium.The second point Petrozzo makes is regarding widespread criticisms of Popper’s demarcation criterion of falsifiability. Indeed, this criterion has been called too inclusive, in that any empirical claim can be called falsifiable in principle—even if it refers to a future apocalypse or a UFO landing. It has also been criticized for being too exclusive, in that it ignores the “remarkable tenacity of scientific theories,” as Lakatos puts it (2009, p. 516). In practice, scientists do not merely abandon a theory if it is not supported by facts; they tend to find other explanations (e.g., the measurement was faulty) rather than accept an instance of falsification.Despite this, we believe it is still worth discussing falsifiability in the context of excited delirium for two reasons. First, while falsifiability may not be successful as a criterion that draws a line between science and pseudoscience, in this case, we argue, it still works well as a signifier of pseudoscience. Recently, many interested in the demarcation question have turned towards pluralism as a way to identify pseudoscientific practices (Pigliucci & Boudry, 2013). And excited delirium offers an excellent example of a phenomenon that bumps up against many of the features that might indicate a pseudoscientific practice... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Excited DeliriumThe Self-Fulfilling Prophecy of Police BrutalityKathryn Petrozzo (bio)In their timely and pressing piece, Arjun Byju and Phoebe Friesen explore the contentious diagnosis of excited delirium; a syndrome characterized by erratic, aggressive, and “delusional” behavior (2023). Overwhelmingly, this term is used when individuals come in contact with police and/or first responders. Although much attention has been given to debating whether or not this is a “real” diagnosis, the authors (...) want to shift the focus to examining the work that excited delirium is doing in the world, as well as the underlying beliefs guiding it that are perpetuating substantial harm. Drawing significantly on the work of Ian Hacking (1998, 2006) and Sherene Razack (2015), Byju and Friesen explore what kinds of people are being made up by the label of “excited delirium” and the subsequent dehumanization that perpetuates violence towards those in this grouping.Despite the lack of an agreed upon definition, excited delirium tends to frequently group together young Black men and other marginalized people of color, who have a psychiatric history, and those who have taken or are suspected to have taken drugs (Byju & Friezen, 2023). As this is “observed” when individuals come into contact with law enforcement and/or first responders, those who are presumed to be suffering from excited delirium are typically met with physical restraints (chokeholds, hogties, etc.), forced injections of sedatives, and/or taser guns. The violent reactions are often justified not only by this “diagnosis,” but the employment of racial stereotypes; notably, the notion that Black bodies as being less susceptible to pain. As the authors aptly put it:This kind of symptom language helps make up the novel category of a person who suffers from excited delirium: a crazed and inhumane monster, a golem that must be met with unrelenting and superordinate force, who is fated, regardless of interventions, to die a spontaneous death. This paradox, that those with excited delirium are supposedly both too strong and too weak, is at the core of the illness narrative.(2023)It is evident that this label is reinforcing the combination of two harmful stereotypes: the notion that those suffering from severe mental illness occupy a space that is “less than fully human,” and racist stereotyping of Black bodies “superseding human strength.” This perpetuates total dehumanization of the individual, where it is then justified to invoke brutal tactics, as well as signal [End Page 357] to the greater community this is how individuals with mental illnesses and/or belonging to a particular racial group (chiefly, Black men), should be treated. This is despite the fact that those suffering from mental illnesses are significantly more likely to be victims of violent crimes, Black Americans are 3.2 times more likely to be murdered by police, and convergence of these factors (being Black and living with a mental illness) increases likelihood of such fatal interactions (Schwartz & Jahn 2020; Shadravan, Edwards, & Vinson 2021; Stuart, 2003).Although I am in wholehearted support of their account, I take issue with the authors’ conceptualization of excited delirium as non-falsifiable, as well as the notion that diseases, generally, are falsifiable. In an attempt to further criticize the utilization of excited delirium, Byju and Friesen call upon Karl Popper’s falsifiability criterion as a measure for what constitutes as scientific; arguing that excited delirium is not a legitimate scientific concept as it is impossible to falsify. First, I am not convinced that excited delirium is in principle non-falsifiable; as the way in which it’s conceptualized actually appears to be falsifiable. The authors point out that external factors, such as tasing and violent restraints, are clearly the causal explanation, which should in fact, lead one to reject the hypothesis of an excited delirium diagnosis. However, in practice, those who are seeking to exonerate the police/first responders responsible for these deaths, are not accepting this evidence leading them to reject the excited delirium diagnosis, but rather, are crafting an incorrect causal narrative. This is deeply problematic, but it does not necessarily render excited delirium as non-falsifiable. More broadly, I am concerned with the reliance on the falsifiability criterion, which has been widely criticized in the... (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Excited DeliriumWhat’s Psychiatry Got to do With It?Paul B. Lieberman, MDIf in life we are surrounded by death, so too in the health of our intellect by madness.—WittgensteinDelirium is a medical syndrome defined as “a relatively acute decline in cognition that fluctuates over hours or days” whose primary manifestation is a deficit of attention. It is common, estimated to occur in 10% to more than 50% of hospitalized patients, (...) with higher prevalence rates among people in nursing homes and at the end of life. It is often fatal, with a mortality rate in the hospital estimated to be 25% to 33%. Caused by a wide variety of conditions and frequently difficult to diagnose, it lacks characteristic postmortem pathology (Josephson & Miller 2018)‘Excited delirium,’ as Byju and Friesen forcefully argue (Byju & Friesen, 2023), is, if nothing else, an excuse. The ‘diagnosis’ has not been empirically validated and remains controversial (American Psychiatric Association, 2020). And while delirium is usually treated by internists and emergency medicine physicians, psychiatrists should also be concerned about the misuse of a putative medical diagnosis and join actively in discussion about it. For one thing, patients mis-diagnosed with this condition, as Byju and Friesen’s examples suggest, may actually have another psychiatric condition and, so, be people for whose safety we should advocate. Moreover, the kinds of police interventions which Byju and Friesen document as involving excited delirium also befall patients with other psychiatric problems in whom the issue of delirium does not arise.There are at least two broad ways in which psychiatrists are qualified and obligated to engage with this issue. As physicians, we should join our medical colleagues in carefully but persistently telling the scientific, medical truth. As psychiatrists, we should bring psychiatric knowledge into the discussion, for example, by explaining what can happen when people who do not, apparently, have a diagnosable mental disorder interact under stress with other people who, apparently, do.Delirium is a clinical diagnosis, made when characteristic signs and symptoms are present which should not be made ‘by exclusion’ when, as may happen, other causes are not found. There is no evidence of delirium in any of the three clinical descriptions Byju and Friesen provide. Perhaps such evidence exists which is not in their brief reports, but these three people appear to have had, either, another psychiatric condition, such as psychosis or drug intoxication, or perhaps no [End Page 353] diagnosis at all. Psychiatrists are particularly wellpositioned to make this point since patients with mental health problems are often misdiagnosed when they seek medical attention and are told, and treated as if, “it’s all (“just”!) psychological.”Excited delirium, if it exists, is fatal in 10% of cases (Gonin, Beysard, Hersin, & Carron, 2018) and, although this is lower than the rate for delirium in general, it is still high. Medical personnel must be available to evaluate and ensure the safety of patients in custody.The potential conflict between protecting the patient and protecting the public should not be overstated. Although physical trauma and excessive administration of medications, including ketamine 500 mg IV (Orhurhu, Vashicht, Claus, & Cohen, 2023) can be lethal, mechanical restraint by itself is not (Chieze et al., 2019; Gleerup et al., 2019): something else is necessary, such as asphyxiation (Evans, Wood, & Lambert, 2003). Nor is restraint necessary in many cases in which ‘de-escalation’ techniques can be equally effective (Garriga et al., 2016; Fernández-Costa, 2020). Perhaps these points are best made by law enforcement leaders—and they have been—but psychiatrists can add that safe management of potential violence can be provided for agitated people with psychiatric conditions.Although it is not clear what kind of strength ‘superhuman’ strength might be (certainly not medical), relative imperviousness to pain is clinically described. Its locus classicus is Beecher’s observation, during World War II, that injured soldiers awaiting return home from the front, required lower than usual doses of analgesics (Beecher, 1946). And it’s a common experience, scientifically confirmed, that physical trauma may not become painful until sometime after the injury (Melzack, Wall, & Ty, 1982). But pain is a warning. Its absence is not a license, but a caution... (shrink)

Previous studies on body ownership illusions have shown that under certain multimodal conditions, healthy people can experience artificial body-parts as if they were part of their own body, with direct physiological consequences for the real limb that gets ‘substituted’. In this study we wanted to assess (a) whether healthy people can experience ‘missing’ a body-part through illusory ownership of an amputated virtual body, and (b) whether this would cause corticospinal excitability changes in muscles associated with the ‘missing’ body-part. Forty (...) right-handed participants saw a virtual body from a first person perspective but for half of them the virtual body was missing a part of its right arm. Single pulse transcranial magnetic stimulation was applied before and after the experiment to left and right motor cortices. Motor evoked potentials (MEPs) were recorded from the first dorsal interosseous (FDI) and the extensor digitorum communis (EDC) of each hand. We found that the stronger the illusion of amputation and arm ownership, the more the reduction of MEP amplitudes of the EDC muscle for the contralateral sensorimotor cortex. In contrast, no association was found for the EDC amplitudes in the ipsilateral cortex and for the FDI amplitudes in both contralateral and ipsilateral cortices. Our study provides evidence that a short-term illusory perception of missing a body-part can trigger inhibitory effects on corticospinal pathways and importantly in the absence of any limb deafferentation or disuse. (shrink)

IntroductionPrevious transcranial magnetic stimulation studies have revealed that the activity of the primary motor cortex ipsilateral to an active hand plays an important role in motor control. The aim of this study was to investigate whether the ipsi-M1 excitability would be influenced by goal-directed movement and laterality during unilateral finger movements.MethodTen healthy right-handed subjects performed four finger tapping tasks with the index finger: simple tapping task, Real-word task, Pseudoword task, and Visually guided tapping task. In the Tap task, the (...) subject performed self-paced simple tapping on a touch screen. In the real-word task, the subject tapped letters displayed on the screen one by one to create a Real-word. Because the action had a specific purpose, this task was considered to be goal-directed as compared to the Tap task. In the Pseudoword task, the subject tapped the letters to create a pseudoword in the same manner as in the Real-word task; however, the word was less meaningful. In the VT task, the subject was required to touch a series of illuminated buttons. This task was considered to be less goal-directed than the Pseudoword task. The tasks were performed with the right and left hand, and a rest condition was added as control. Single- and paired-pulse TMS were applied to the ipsi-M1 to measure corticospinal excitability and short- and long-interval intracortical inhibition in the resting first dorsal interosseous muscle.ResultsWe found the smaller SICI in the ipsi-M1 during the VT task compared with the resting condition. Further, both SICI and LICI were smaller in the right than in the left M1, regardless of the task conditions.DiscussionWe found that SICI in the ipsi-M1 is smaller during visual illumination-guided finger movement than during the resting condition. Our finding provides basic data for designing a rehabilitation program that modulates the M1 ipsilateral to the moving limb, for example, for post-stroke patients with severe hemiparesis. (shrink)

“Excited Delirium Syndrome” (ExDS) is a controversial diagnosis. The supposed syndrome is sometimes considered to be a potential cause of death. However, it has been argued that its sole purpose is to cover up excessive police violence because it is mainly used to explain deaths of individuals in custody. In this paper, we examine the epistemic conditions giving rise to the controversial diagnosis by discussing the relation between causal hypotheses, evidence, and data in forensic medicine. We argue that the practitioners’ (...) social context affects causal inquiry through background assumptions that enter inquiry at multiple stages. This analysis serves to better understand the wide usage of the controversial diagnosis of ExDS. (shrink)

Résumé Les liens psyché-soma retiennent toute l’attention au cours des premiers mois de la vie. Le bébé, placé sous la dépendance étroite de ses parents, bénéficie de soins et d’une attention la plupart du temps adaptés, mais il faut pouvoir prendre en compte le travail psychique que réalisent les parents pour parer à ses états de tension et d’excitation. Ainsi, pour le bébé dont l’organisation psychique est en cours de développement, le système pare-excitation maternel et plus largement parental joue un (...) rôle central dans le développement psychosomatique. La présentation d’une situation clinique permet d’illustrer les propos de l’auteur, de mesurer l’importance du système pare-excitation parental durant les premiers mois de la vie et ses effets, au sein des régulations précoces, en cas de défaillance. (shrink)

Here we elucidate a paradox: how a single chemoattractant‐receptor system in two individuals is used for communication despite the seeming inevitability of self‐excitation. In the filamentous fungus Neurospora crassa, genetically identical cells that produce the same chemoattractant fuse via the homing of individual cell protrusions toward each other. This is achieved via a recently described “ping‐pong” pulsatile communication. Using a generic activator‐inhibitor model of excitable behavior, we demonstrate that the pulse exchange can be fully understood in terms of two excitable (...) systems locked into a stable oscillatory pattern of mutual excitation. The most puzzling properties of this communication are the sudden onset of oscillations with final amplitude, and the absence of seemingly inevitable self‐excitation. We show that these properties result directly from both the excitability threshold and refractory period characteristic of excitable systems. Our model suggests possible molecular mechanisms for the ping‐pong communication. (shrink)

With the same intellectual courage with which she addressed issues of gender, Judith Butler turns her attention to speech and conduct in contemporary political life, looking at several efforts to target speech as conduct that has become subject to political debate and regulation. Reviewing hate speech regulations, anti-pornography arguments, and recent controversies about gay self-declaration in the military, Judith Butler asks whether and how language acts in each of these cultural sites.

One of the most oft-cited parts of Francis Hutcheson’s Illustrations upon the Moral Sense (1728) is his discussion of “exciting reasons.” In this paper I address the question: What is the function of that discussion? In particular, what is its relation to Hutcheson’s attempt to show that the rationalists’ normative thesis ultimately implies, contrary to their moral epistemology, that moral ideas spring from a sense? Despite first appearances, Hutcheson’s discussion of exciting reasons is not part of that attempt. Mainly, it (...) is part of Hutcheson’s comeback to Gilbert Burnet’s objections to Hutcheson’s Inquiry into the Original of Our Ideas of Beauty and Virtue (1725). (shrink)

The historical continuity of spinal catastrophism, traced across multiform encounters between philosophy, psychology, biology, and geology. Drawing on cryptic intimations in the work of J. G. Ballard, Georges Bataille, William Burroughs, Andre Leroi-Gourhan, Elaine Morgan, and Friedrich Nietzsche, in the late twentieth century Daniel Barker formulated the axioms of spinal catastrophism: If human morphology, upright posture, and the possibility of language are the ramified accidents of natural history, then psychic ailments are ultimately afflictions of the spine, which itself (...) is a scale model of biogenetic trauma, a portable map of the catastrophic events that shaped that atrocity exhibition of evolutionary traumata, the sick orthograde talking mammal. Tracing its provenance through the biological notions of phylogeny and "organic memory" that fueled early psychoanalysis, back into idealism, nature philosophy, and romanticism, and across multiform encounters between philosophy, psychology, biology, and geology, Thomas Moynihan reveals the historical continuity of spinal catastrophism. From psychoanalysis and myth to geology and neuroanatomy, from bioanalysis to chronopathy, from spinal colonies of proto-minds to the retroparasitism of the CNS, from "railway spine" to Elizabeth Taylor's lost gill-slits, this extravagantly comprehensive philosophical adventure uses the spinal cord as a guiding thread to rediscover forgotten pathways in modern thought. Moynihan demonstrates that, far from being an fanciful notion rendered obsolete by advances in biology, spinal catastrophism dramatizes fundamental philosophical problematics of time, identity, continuity, and the transcendental that remain central to any attempt to reconcile human experience with natural history. (shrink)

In a recent article, L. Angel ([2001]) argues that if we do not implement Newtonian physics adding to it a certain usual type of boundary condition, then this leads to the rejection of what he calls the P principle: ‘the composition of contact interactions does not create a noncontact interaction.’ Here I shall demonstrate that this conclusion does not follow. However, as will be made clear, this in no way diminishes the interest or importance of the model introduced by Angel (...) in his paper.1Introduction2The ‘impact without contact’ argument3Taking self‐excitations seriously4Some interesting implications. (shrink)

In Pérez Laraudogoitia (1996), I introduced a simple example of a supertask that involved the possibility of spontaneous self-excitation and, therefore, of a particularly interesting form of indeterminism in classical dynamics. Alper and Bridger (1998) criticised (among other things) this result. In the present article, I answer their criticisms. In what follows I assume familiarity both with Pérez Laraudogoitia (1996) and Alper and Bridger’s subsequent article.

Objectives: The objective of this post hoc exploratory analysis was to examine the relationship between age and measures of cortical excitability and inhibition. Methods: Forty-six participants (24 with major depressive disorder and 22 healthy controls) completed MT, SICI, ICF, and CSP testing in a cross-sectional protocol. Of these 46 participants, 33 completed LICI testing. Multiple linear robust regression and Spearman partial correlation coefficient were used to examine the relationship between age and the TMS measures. Results: In the overall sample (...) of 46 participants, age had a significant negative relationship with motor threshold in both the right (rs = -0.49, adjusted p =.007; β= -0.08, adjusted p=.001) and left (rs = -0.42, adjusted p =.029; β= -0.05, adjusted p=.004) hemispheres. This significant negative relationship of age with motor threshold was also observed in the sample of depressed youth in both the right (rs = -0.70, adjusted p =.002; β= -0.09, adjusted p=.001) and left (rs = -0.54, adjusted p =.034; β= -0.05, adjusted p=.017) hemispheres, but not in healthy controls. In the sample of the 33 participants who completed LICI testing, age had a significant negative relationship with LICI (200 millisecond interval) in both the right (rs = -0.48, adjusted p =.05; β= -0.24, adjusted p=.007) and left (rs = -0.64, adjusted p =.002; β= -0.23, adjusted p=.001) hemispheres. This negative relationship between age and LICI (200 millisecond interval) was also observed in depressed youth in both the right (rs = -0.76, adjusted p =.034; β= -0.35, adjusted p=.004) and left (rs = -0.92, adjusted p =.002; β= -0.25, adjusted p=.001) hemispheres. Conclusion: These findings suggest that younger children have higher motor thresholds. This is more pronounced in depressed youth than healthy controls. LICI inhibition may also increase with age in youth. (shrink)

Inherited disorders of ion‐channels are associated with paroxysmal dysfunction of excitable tissues and manifest as diseases of the brain, heart and skeletal muscle. These so‐called channelopathies have now been described for most of the major categories of voltage‐dependent ion‐channels including those selectively permeable to sodium. Sodium channelopathies affecting the heart and brain are reviewed in this essay. They show striking differences and similarities including, for example, their responsiveness to changes in body temperature and sleep state. They represent a paradigm for (...) efforts to trace disturbed behaviour of physiological systems back to its molecular origins and understanding their molecular basis may provide clues to important health issues such as cardiac side effects of drugs and response to medication used to treat epilepsy. BioEssays 25:981–993, 2003. © 2003 Wiley Periodicals, Inc. (shrink)