Neglect:A Disorder of Spatial Attention Anjan Chatterjee produce subtle differences in deficits of these ptentmay meglect pants oftheiro bod are of A fferences themselve: tion and represen tions through the syndrome of parts of their environment,and even parts of scenes neglect is possible precisely because neglect is in their imagination.This clinical syndrome is pro- heterogeneous (Chatterjee,1998). duced by a lateralized disruption of spatial attention and representation and raises several questions of interest to cognitive neuroscientsts.How do humans Case Report represent space?How do humans direct spatial attention?How is attention related to perception? Neglect is How is attention related to action? with left brain d Spatial attention and representation can also be neglect following right brain damage.although similar studied in humans with functional neuroimaging deficits are seen sometimes following left brain damage. and with animal lesion and single-cell neurophysi- A 65-year-old woman presented to the hospital becaus She w ethargic Ior ological studies.Despite the unique methods and weakne approaches of these different disciplines,there is considerable convergence in our understanding of ber left hand was held in front of ber eves.she sug how the brain organizes and represents space.In that the limb belonged to the examiner.As her level of this chapter.I begin by describing the clinical syn- arousal improved.she continued to orient to her right.even drome of neglect.Following this description.I when approached and spoke outline the major theoretical approaches and bio- the foo ie of h logical correlates of the clinical phenomena.I then turn to prominent issues in recent neglect research Her speech was mildly dysarthric.She answered and to relevant data from human functional neuro questions correctly.but in a flat tone.Although her imaging and animal studies.Finally,I conclude with conversation was superficially appropriate.she seemed several issues that in my view warrant further unconcered about her condition or even about being in the hosp en why sh consideration As a prelude.it should be clear that neglect is When rofe to he .she neous disorder.Its manifestations vary would look at and lift her right arm.Over several days considerably across patients (Chatteriee.1998 after hearing from her physicians that she had had a stroke Halligan Marshall.1992.1998).This hete m if the s oal of PIst【o move er ler ged h arch v to establish nsive the clinical noted that she was pleasant and enga ng for short periods r when d de d the but not particularly motivated during therapy sessionsand e fatigued easily. oral heterogeneity y is actually critica nths after her ns use as eft-sike e.obvious signs attention, on,and sensation on the left.but after about 6 months she also damage to parts of these networks can experienced uncomfortable sensations both on the skin and"inside"her left arm.The patient continued to fatigueAnjan Chatterjee Unilateral spatial neglect is a fascinating clinical syndrome in which patients are unaware of entire sectors of space on the side opposite to their lesion. These patients may neglect parts of their own body, parts of their environment, and even parts of scenes in their imagination. This clinical syndrome is pro￾duced by a lateralized disruption of spatial attention and representation and raises several questions of interest to cognitive neuroscientsts. How do humans represent space? How do humans direct spatial attention? How is attention related to perception? How is attention related to action? Spatial attention and representation can also be studied in humans with functional neuroimaging and with animal lesion and single-cell neurophysi￾ological studies. Despite the unique methods and approaches of these different disciplines, there is considerable convergence in our understanding of how the brain organizes and represents space. In this chapter, I begin by describing the clinical syn￾drome of neglect. Following this description, I outline the major theoretical approaches and bio￾logical correlates of the clinical phenomena. I then turn to prominent issues in recent neglect research and to relevant data from human functional neuro￾imaging and animal studies. Finally, I conclude with several issues that in my view warrant further consideration. As a prelude, it should be clear that neglect is a heterogeneous disorder. Its manifestations vary considerably across patients (Chatterjee, 1998; Halligan & Marshall, 1992, 1998). This hetero￾geneity would be cause for alarm if the goal of neglect research were to establish a unified and comprehensive theory of the clinical syndrome. However, when neglect is used to understand the organization of spatial attention and representation, then the behavioral heterogeneity is actually critical to its use as an investigative tool. Distributed neuronal networks clearly mediate spatial attention, representation, and movement. Focal damage to parts of these networks can 1 Neglect: A Disorder of Spatial Attention produce subtle differences in deficits of these complex functions. These differences themselves are of interest. A careful study of spatial atten￾tion and representations through the syndrome of neglect is possible precisely because neglect is heterogeneous (Chatterjee, 1998). Case Report Neglect is more common and more severe with right than with left brain damage. I will refer mostly to left-sided neglect following right brain damage, although similar deficits are seen sometimes following left brain damage. A 65-year-old woman presented to the hospital because of left-sided weakness. She was lethargic for 2 days after admission. She tended to lie in bed at an angle, oriented to her right, and ignored the left side of her body. When her left hand was held in front of her eyes, she suggested that the limb belonged to the examiner. As her level of arousal improved, she continued to orient to her right, even when approached and spoken to from her left. She ate only the food on the right side of her hospital tray. Food some￾times collected in the left side of her mouth. Her speech was mildly dysarthric. She answered questions correctly, but in a flat tone. Although her conversation was superficially appropriate, she seemed unconcerned about her condition or even about being in the hospital. When asked why she was hospitalized, she reported feeling weak generally, but denied any specific problems. When referring to her general weakness, she would look at and lift her right arm. Over several days, after hearing from her physicians that she had had a stroke and having repeatedly been asked by her physical thera￾pist to move her left side, she acknowledged her left-sided weakness. However, her insight into the practical restric￾tions imposed by her weakness was limited. Her therapists noted that she was pleasant and engaging for short periods, but not particularly motivated during therapy sessions and fatigued easily. Three months after her initial stroke, obvious signs of left neglect abated. Her left-sided weakness also improved. She had slightly diminished somatosensory sensation on the left, but after about 6 months she also experienced uncomfortable sensations both on the skin and “inside” her left arm. The patient continued to fatigue