title: Just thinking about targets can aggravate neglect on cancellation tests.
abstract: While many studies investigate how the visual features of targets influence cancellation performance in neglect, few, if any, even consider that thought processes, such as the use of an algorithm to identify targets, might similarly aggravate neglect. This single-case study of a patient with chronic neglect compared cancellation performance after manipulating (1) ease of visual target identification, (2) the use of an algorithm to identify targets, and (3) the material-specific nature of target cancellation. Neglect severity was defined by the number and location of target omissions. While each manipulation had a differential impact on neglect severity, the novel and interesting finding occurred during the second condition, when a math algorithm was used to identify targets. In this condition, target omissions increased relative to other tests and target cancellations were confined to the right half of the page. This is the first report, to our knowledge, that neglect on cancellation tests can be aggravated by an internal thought process, a math algorithm, as opposed to external manipulations of visual stimuli and procedural characteristics of cancellation tests. An important characteristic of the algorithm used in this study is that it appeared to activate the intact left cerebral hemisphere.
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, AL, USA. markmenn@uab.edu
authors.forename: M S
authors.initials: MS
authors.lastname: Mennemeier
authors.forename: M
authors.initials: M
authors.lastname: Morris
authors.forename: K M
authors.initials: KM
authors.lastname: Heilman
mesh_terms: D000368:Aged; D000465:Algorithms; D001288:Attention / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007062:Identification, Psychological; D008297:Male; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology; D010468:Perceptual Disorders / Q000503:physiopathology*; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time; D012016:Reference Values; D013028:Space Perception / Q000502:physiology; D013850:Thinking / Q000502:physiology*