Robert's mother is usually meticulous in her presentation. When picking her up for a family dinner, he noticed that her make-up was only applied to the right side of her face. Her hair was also brushed on the right side, but on the left it was matted and uncombed. He immediately took her to the hospital after she was unaware of any problems. She was diagnosed with __________, which is evidenced by damage to the association areas of the right hemisphere.