The electrophysiology of tactile extinction: ERP correlates of unconscious somatosensory processing

Early sensory processing in right hemispheric stroke patients with and without extinction

“…These results suggest that early sensory processing of single contralesional stimuli is impaired in extinction patients. This is also supported by the results of a study performed by Eimer et al (2002) who found that early somatosensory evoked potentials elicited by unilateral tactile stimuli were reduced for contralesional tactile stimuli compared to ipsilesional tactile stimuli in a single patient suffering from tactile extinction, but not in two age-matched healthy subjects. However, as these studies by Deouell et al (2000) and Eimer et al (2002) did not assess brain damaged patients without extinction, it is currently unclear whether these results suggesting that, compared to early sensory processing in neurologically healthy subjects, early contralesional sensory processing is impaired in extinction patients, are truly specific to extinction patients or instead a general consequence of right hemispheric brain damage.…”

“…The aim of the study was to investigate whether the observation from previous studies that extinction patients demonstrate early sensory impairments in their contralesional hemifield (Deouell et al, 2000;Eimer et al, 2002) is truly specific to extinction patients or instead a general consequence of unilateral brain damage. We used a masked visuo-motor response priming paradigm to study the influence of both contralesional and ipsilesional peripheral subliminal prime stimuli on central target performance, allowing us to compare the strength of the early sensory processing associated with these prime stimuli between neurological patients with extinction, neurological patients without extinction and healthy elderly subjects Schlaghecken and Eimer, 2000).…”

Visuotactile Representation of Peripersonal Space: A Neural Network Study

“…Many studies have focused on how these various sensory cues may be combined and integrated to achieve perception of limb location and representation of the space immediately around the body (i.e., peripersonal space). Numerous findings have been accumulated by using different methodologies: single-cell recordings in animals (Hyvarinen, 1981;Rizzolatti, Scandolara, Matelli, & Gentilucci, 1981;Fogassi et al, 1996;Graziano, Hu, & Gross, 1997;Duhamel, Colby, & Goldberg, 1998;Avillac, Ben, & Duhamel, 2007), neuropsychological studies in brain-damaged patients (see Làdavas, 2002;Holmes & Spence, 2004, for a review), and psychophysical and neuroimaging investigation in healthy and brain-damaged subjects (Tipper et al, 1998;Macaluso, Frith, & Driver, 2000;Marzi, Girelli, Natale, & Miniussi, 2001;Kennett, Taylor-Clarke, & Haggard, 2001;Eimer, Maravita, van Velzen, Husain, & Driver, 2002;TaylorClarke, Kennett, & Haggard, 2002;Sarri, Blankenburg, & Driver, 2006).…”

Effects of somatosensory stimulation and attention on human somatosensory cortex: An fMRI study

“…Previous EEG studies have shown that P100 and N140 components of somatosensory evoked potentials (P = positivity, N = negativity, peak latency in milliseconds) increased in amplitude during active attention (typically counting stimuli), thus reflecting selective attention-related enhancement of information processing in somatosensory and associative cortices (Desmedt and Robertson, 1977;Desmedt and Tomberg, 1989;Michie et al, 1987;García-Larrea et al, 1995;Kekoni et al, 1996;Eimer and Driver, 2000;Eimer et al, 2001Eimer et al, , 2002Eimer and Forster, 2003;Valeriani et al, 2003;Kida et al, 2003Kida et al, , 2004Tamura et al, 2004). Amplitude of P100 and N140 was also observed to increase for isolated somatosensory stimuli when compared to the same stimuli inserted among frequent stimuli (Kida et al, 2006), thus unveiling attentional effects related to the passive shifts of attention to sensory stimuli presented suddenly against a silent background (i.e.…”