Erratum to: Italian neuropsychology in the second half of the twentieth century

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Bisecting Real and Fake Body Parts: Effects of Prism Adaptation After Right Brain Damage

The representation of body parts holds a special status in the brain, due to their prototypical shape and the contribution of multisensory (visual and somatosensory-proprioceptive) information. In a previous study (Sposito et al., 2010), we showed that patients with left unilateral spatial neglect exhibit a rightward bias in setting the midpoint of their left forearm, which becomes larger when bisecting a cylindrical object comparable in size. This body part advantage, found also in control participants, suggests partly different processes for computing the extent of body parts and objects. In this study we tested 16 right-brain-damaged patients, and 10 unimpaired participants, on a manual bisection task of their own (real) left forearm, or a size-matched fake forearm. We then explored the effects of adaptation to rightward displacing prism exposure, which brings about leftward aftereffects. We found that all participants showed prism adaptation (PA) and aftereffects, with right-brain-damaged patients exhibiting a reduction of the rightward bias for both real and fake forearm, with no overall differences between them. Second, correlation analyses highlighted the role of visual and proprioceptive information for the metrics of body parts. Third, single-patient analyses showed dissociations between real and fake forearm bisections, and the effects of PA, as well as a more frequent impairment with fake body parts. In sum, the rightward bias shown by right-brain-damaged patients in bisecting body parts is reduced by prism exposure, as other components of the neglect syndrome; discrete spatial representations for real and fake body parts, for which visual and proprioceptive codes play different roles, are likely to exist. Multisensory information seems to render self bodily segments more resistant to the disruption brought about by right-hemisphere injury

Sharing Social Touch in the Primary Somatosensory Cortex

SummaryTouch has an emotional and communicative meaning, and it plays a crucial role in social perception and empathy. The intuitive link between others’ somatosensations and our sense of touch becomes ostensible in mirror-touch synesthesia, a condition in which the view of a touch on another person’s body elicits conscious tactile sensations on the observer’s own body [1]. This peculiar phenomenon may implicate normal social mirror mechanisms [2]. Here, we show that mirror-touch interference effects, synesthesia-like sensations, and even phantom touches can be induced in nonsynesthetes by priming the primary somatosensory cortex (SI) directly or indirectly via the posterior parietal cortex. These results were obtained by means of facilitatory paired-pulse transcranial magnetic stimulation (ppTMS) contingent upon the observation of touch. For these vicarious effects, the SI is engaged at 150 ms from the onset of the visual touch. Intriguingly, individual differences in empathic abilities, assessed with the Interpersonal Reactivity Index [3], drive the activity of the SI when nonsynesthetes witness others’ tactile sensations. This evidence implies that, under normal conditions, touch observation activates the SI below the threshold for perceptual awareness [4]; through the visual-dependent tuning of SI activity by ppTMS, what is seen becomes felt, namely, mirror-touch synesthesia. On a broader perspective, the visual responsivity of the SI may allow an automatic and unconscious transference of the sensation that another person is experiencing onto oneself, and, in turn, the empathic sharing of somatosensations [2]

Rivermead assessment of somatosensory performance: Italian normative data

The Rivermead assessment of somatosensory performance (RASP) provides a quantitative assessment of somatosensory processing, suitable for brain-damaged patients suffering from stroke. It consists of seven subcomponents: Subtest 1 (sharp/dull discrimination), Subtest 2 (surface pressure touch), Subtest 3 (surface localization), Subtest 4 (sensory extinction), Subtest 5 (2- point discrimination), Subtest 6 (temperature discrimination), and Subtest 7 (proprioception). Overall, the RASP assesses 5 bilateral body regions: face (cheek), hand (palm and back), and foot (sole and back). This study aimed at providing normative data and cut-off scores for RASP subtests, for each body region, in a large Italian population sample. We present results from 300 healthy Italian individuals aged 19 to 98 years. Data represent a comprehensive set of norms that cover each subtest and each body region tested. Performance in Subtests 1, 5, and 6 decreased, for some body regions, with increasing age. Based on these results, norms were stratified for age (seven groups), with the pathological/non-pathological cut-off coinciding with the 5th percentile. Conversely, other results were not influenced by age; in such cases, a single error, in each body region, has to be considered indicative of pathological performance. This independent investigation of all subcomponents of the somatosensory system, for each body region, further confirms RASP’s potential in clinical practice, for neurological assessment, as well as in research settings

Neuroimaging the consciousness of self: Review, and conceptual-methodological framework

We review neuroimaging research investigating self-referential processing (SRP), that is, how we respond to stimuli that reference ourselves, prefaced by a lexical-thematic analysis of words indicative of “self-feelings”. We consider SRP as occurring verbally (V-SRP) and non-verbally (NV-SRP), both in the controlled, “top-down” form of introspective and interoceptive tasks, respectively, as well as in the “bottom-up” spontaneous or automatic form of “mind wandering” and “body wandering” that occurs during resting state. Our review leads us to outline a conceptual and methodological framework for future SRP research that we briefly apply toward understanding certain psychological and neurological disorders symptomatically associated with abnormal SRP. Our discussion is partly guided by William James’ original writings on the consciousness of self

Chapter 1 \u2013 The history of the neurophysiology and neurology of the parietal lobe

The development and change of knowledge on the function of the parietal lobe from the second half of the 19th century to the early 1970s are reviewed. Motor and somatosensory functions were initially localized in a broad frontoparietal region. At the beginning of the 20th century the motor cortex was restricted to the posterior frontal lobe. The separate attribution of somatosensory functions to the parietal lobe was initially based on anatomic considerations, but mostly on localized bodily sensations elicited by electric stimulation in awake patients. Patients and nonhuman primates with anterior parietal damage showed deficits in somatic sensation (tactile discrimination and position sense, less markedly pain and thermal sensitivity). Somatosensory evoked potentials demonstrated in all mammals that the body is orderly and multiply represented in the anterior parietal cortex. The parietal lobe was divided into an anterior and a posterior cortex (PPC). The PPC is particularly developed in primates, where it includes a superior and an inferior parietal lobule. The PPC was initially thought to be a higher-order region for somatosensory information processing, but its functional specialization proved soon to be greater and more complex. PPC damage in humans gives rise to a variety of neuropsychologic disorders: pain asymbolia, sensory extinction, spatial neglect, optic ataxia and limb apraxia, alexia and agraphia. Single-neuron recordings in freely behaving monkeys furnished the complementary information that the PPC is involved in body-environment interactions, for visual exploration and hand use as a sensor and a tool. The PPC is now believed to underpin higher-order processes of sensory inputs, multisensory and sensorimotor integration, spatial attention, intention, and the conjoint representation of external space and the body. The symptoms in which disorders of these processes manifest after PPC damage are considerably different in humans and nonhuman primates

Anosognosia for motor and sensory deficits after unilateral brain damage: a review

PURPOSE: The syndrome of unawareness (anosognosia) for sensory and motor neurological deficits (hemiplegia, hemianaesthesia, and hemianopia), contralateral to the side of a hemispheric lesion, is reviewed. CONTENT: Main topics include: basic historical facts; the types of patient's interview and specific questions used to reveal the deficits; the clinical patterns of presentation; the associations and dissociations of the different anosognosic manifestations, and their relationships with associated disorders of sensory, memory, and executive-intellectual functions; the hemispheric asymmetry of anosognosia, that, as the syndrome of unilateral spatial neglect, is more frequent and severe after damage to the right cerebral hemisphere; the relationships between spatial neglect and the anosognosias, and their neural correlates; the effects of lateralized sensory stimulations on defective awareness of neurological impairments. CONCLUSIONS: The argument is made that anosognosia for sensory and motor neurological deficits should be considered as a multi-component syndrome, including a number of specific disorders that are due to the impairment of discrete monitoring systems, specific for the different supervised functions. The putative causal role of associated deficits of other parts of the sensory-motor or cognitive (e.g., memory, general intelligence) system is critically discussed. These specific control processes may be physically implemented in brain areas anatomically (and functionally) close to those subserving the monitored function

Somatoparaphrenia: a body delusion. A review of the neuropsychological literature

A review of published brain-damaged patients showing delusional beliefs concerning the contralesional side of the body (somatoparaphrenia) is presented. Somatoparaphrenia has been reported, with a few exceptions, in right-brain-damaged patients, with motor and somatosensory deficits, and the syndrome of unilateral spatial neglect. Somatoparaphrenia, most often characterized by a delusion of disownership of left-sided body parts, may however occur without associated anosognosia for motor deficits, and personal neglect. Also somatosensory deficits may not be a core pathological mechanism of somatoparaphrenia, and visual field disorders may be absent. Deficits of proprioception, however, may play a relevant role. Somatoparaphrenia is often brought about by extensive right-sided lesions, but patients with posterior (parietal-temporal), and insular damage are on record, as well as a few patients with subcortical lesions. Possible pathological factors include a deranged representation of the body concerned with ownership, mainly right-hemisphere-based, and deficits of multisensory integration. Finally, the rubber hand illusion, that brings about a bodily misattribution in neurologically unimpaired participants, as somatoparaphrenia does in brain-damaged patients, is briefly discussed

Brain Stimulation and behavioural cognitive rehabilitation: a new tool for neurorehabilitation? A foreword

2This special issue of Neuropsychological Rehabilitation aims to present new knowledge about a recent and innovative approach that can possibly ameliorate the outcome of the rehabilitation of cognitive deficits, namely: non-invasive brain stimulation (NIBS). The issue includes a series of papers on NIBS and combined rehabilitation studies (reviews and some original contributions), highlighting the challenges, as well as the power, of this novel approach. The old and time-honoured concept that the brain structure becomes immutable after childhood has been abandoned, based on the evidence that all areas of the brain remain plastic in adulthood and during physiological ageing, with even some evidence for neurogenesis (Berlucchi, this issue).reservedmixedC. Miniussi; G. VallarMiniussi, Carlo; G., Valla

Unilateral Spatial Neglect

Unilateral spatial neglect is a neuropsychological syndrome, more frequent after damage to the right cerebral hemisphere, featuring an impaired ability to orient toward the contralateral left side of space and the body, and the inability to detect and report events from that side, of which patients are not aware. In addition to these defective manifestations, patients may show gratuitous behaviors, which include additional productions, unrelated to the task's demand, such as drawings and repeated marks (perseveration) in exploratory target cancellation tasks. Neglect is a multi-component deficit, whose diverse manifestations share a divide between the attended ipsilateral and the neglected contralateral sides of space. Different pathological mechanisms contribute to neglect, including perceptual and premotor impairments, that may be specific to sensory modality, sector of space, and mental images. Neglect may manifest in different coordinate frames with reference to the body and body parts, and objects (egocentric and allocentric neglect). Spatial neglect is a severely disabling disorder, which interferes with functional recovery from stroke. The neural correlates of neglect include cerebral cortical regions surrounding the sylvian fissure: the posterior inferior-parietal cortex, the temporo-parietal junction, the posterior-superior temporal and the frontal premotor cortices, subcortical gray nuclei and white matter fiber tracts connecting these regions. Neglect is independent of, and cannot be traced back to, sensory and motor deficits, and may be interpreted as a derangement of multiple networks, primarily based in the right hemisphere, supporting spatial attention and representation of space and objects in it