How do Hemispatial Neglect patients react when told of their disability? Hemispatial Neglect patients are known to have Anosognosia meaning they don't recognize their disability. These patients neglect either their left or right field of vision entirely, as if they couldn't see anything on that side of their body.

How do these patients react when directly confronted with the fact of their disability? Hemispatial Neglect can be treated as it is an issue of attention not lack of sensation. Are these patients able to focus on the neglected area (before treatment) if explicitly told to do so? 

Wikipedia notes a delusional form of the disorder:


  Neglect may also present as a delusional form, where the patient denies ownership of a limb or an entire side of the body. Since this delusion often occurs alone without the accompaniment of other delusions, it is often labeled as a monothematic delusion.


So some patients may outright deny that the neglected side of their body exist, but this does not seem to exist in all cases of the disorder.
It’s probably best to ask clinicians since papers usually don’t go into very specific details about patient interactions, but in general this is what I can conclude based on a bit of research. Neglect often co-occurs with other impairments as there can be a range of causes (such as stroke) arising from damage to various brain structures; so it should be considered “as a cluster of deficits characterised by lateralised spatial bias” (Manly, 2002). Besides severity of neglect, these co-occuring impairments would also affect the type of reactions neglect patients may show.

Patients with neglect due to right-hemisphere damage show hypoarousal, flattened affect, and emotional indifference (Heilman et al., 1978) which may explain why many are unconcerned about their disorder (anosodiaphoria) and act indifferent toward their disorder (Denes et al., 1982). Similar to emotional impairment, there is also a strong associated lack of awareness of their disorder (anosognosia)  among neglect patients (Eslinger et al., 2002; Buxbaum et al., 2004). Sometimes, even after improvement due to therapy and training, patients may still not acknowledge their impairment (Manly, 2002). Patients that are unaware of the disorder usually react with denial (Bisiach, 2007; Berti &amp; Rizzolatti 1992). In one study, which uses mirrors to flip objects in the left visual to the right, patients “behave as if the object were behind, or in, the mirror — as if the left side of their world did not ‘exist’” (Turnbull, 1997). Neglect is more likely associated with right-hemisphere damage compared to left, and both anosodiaphoria and anosognosia occur at higher rates in neglect patients with right-hemisphere damage compared to left (Stone et al. 1993).