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====Body awareness disorders====
Disorders in body awareness can arise at different levels. First, being aware of a physical deficit such as a paralysis can be disturbed. Different gradations exist, patients with [[anosognosia]] for hemiplegia reject the idea of physical impairment, while other patients admit the existence of their deficit but underestimate the severity and the implications of their physical impairment '''(anosodiaphoria)'''. Anosognosia can exist for both motor and somatosensory impairments. The first is related to lesions to the posterior insula (Karnath et al., 2005), the second is a consequence of lesions to the basal ganglia (i.e. putamen) (Pia et al., 2014). Anosognosia for hemiplegia is relatively common with 18% of the first-ever stroke patients and 32% of the right hemisphere stroke patients suffering from this disorder (Appelros et al., 2002; Vocat et al., 2010).
A second group of disorders concerns impairments in awareness about (part) of the body itself. Patients with '''asomatognosia''' experience that a body part is ‘missing’ or has disappeared from corporal awareness, for example the loss of awareness of one body-half (which may or may not be paralyzed). Another disorder related to disturbances in body ownership is '''somatoparaphrenia''' in which patients suffer from asomatognosia plus extensive delusions, misidentifications, and confabulations regarding the limb. For example, patients might give an alternative explanation for the limb disownership, for example by believing that the affected limb belongs to someone else, that is an animal or that it is part of a rotting corpse. A reverse interpretation has been observed as well, with patients identifying body parts of another person as their own (Garcin et al. 1938, Gerstmann 1942). Different theories on the etiology of asomatognosia and somatoparaphrenia exist, also because patients often suffer from other neuropsychological impairments. Therefore, hemispatial neglect, hemianesthesia, prioprioceptive and attentional impairments have been commonly associated with asomatognosia and somatoparaphrenia (Feinberg et al. 2010, Gandola et al. 2012, Vallar & Ronchi. 2009). Furthermore, it has been suggested that multisensory integration and building a spatial representation of the body is hampered (Vallar & Ronchi. 2009). Interestingly, these problems are only present for a first-person perspective, but diminishes when a patients views him or herself in the mirror (Fotopoulou et al. 2011). The duration of symptoms of asomatognosia and somatoparaphrenia varies from minutes to months. Interestingly, providing evidence to the patient that contradicts the delusion only temporarily reduces the denial, after which the asomatognosia or somatoparaphrenia returns. '''Misoplegia''' is a more affective form of body awareness disorder and can be defined as a hatred for the affected limb, with offensive behaviours toward the limb as a result. 
With respect to the underlying neural substrate, disorders of body awareness and ownership are often a consequence of large right hemispheric lesions, involving premotor, parietal and posterior insular areas (for review see Vallar & Ronchi, 2009). In addition, cases have been described in which somatoparaphrenic symptoms were induced through vestibular stimulation suggesting that body awareness disorders might be a consequence of functional rather that structural deficits (Ronchi et al. 2013). 
Problems concerning body ownership and awareness can also occur when a limb is no longer a physical part of the body, as in the case of [[phantom touch|phantom limb phenomenon]]. This can be defined as “the persistent experience of the postural and motor aspects of a limb after its physical loss” (Brugger 2006). Phantom limb experiences a present in approximately 95% of patients who undergo amputation of a limb (Melzack 1990). [[Image:CTD_phantom limb patient.jpg|thumb|400px|right|F5| An example of the phantom limb phenomenon. A patient experiences a phantom hand but no forearm after amputation. <small>''From: Wright Halligan and Kew, Wellcome SciArt Project 1997''</small>]]. 
A similar phenomenon (i.e. experience of a limb that is not physically present) can also occur after brain damage, but is less frequently observed. This is referred to as '''supernumerary phantom limb (SPL)''', and is defined as “the awareness of having an "extra limb" in addition to the regular set of two arms and two legs.” Multimodal experience of the extra limb has been reported including tactile (feel objects with their phantom arm), visual (visually perceive their phantom limb) and motor components (generate action). Neural representations of this extra limb have been reported in the brain areas that represent these modalities, particularly in the left hemisphere (Khateb 2009), although the phenomenon has been described after right-sided lesions as well (Miyazawa 2004). 
Except for anosognosia, disorders of body awareness after brain damage appear to occur relatively infrequently, although it’s prevalence so far has not been well-documented. They also tend to recover over time. These disorders are nevertheless of great interest as they can further our understanding of the functional and neural mechanisms underlying bodily awareness, body ownership and self-other distinctions.