Drawing deficits in brain-damaged patients' freehand pictures

Semantic and perceptual errors in aphasics' freehand category drawing.

“…The difference between the two sets of studies may be due in part to the use of colored pictures and photographs in the latter studies, compared with black-and-white line drawings in earlier studies. The data presented in this report indicate that the drawings of aphasics are generally more recognizable than the drawings of patients with damage to the right hemisphere, who are known to be compromised at the level of expressing specific perceptual information, such as color or shape (Grossman, 1988). These findings suggest that impairments on the category drawing task cannot be fully explained by a deficit in the ability to express perceptual characteristics or by a constructional apraxia.…”

Semantic and perceptual errors in aphasics' freehand category drawing.

“…The difference between the two sets of studies may be due in part to the use of colored pictures and photographs in the latter studies, compared with black-and-white line drawings in earlier studies. The data presented in this report indicate that the drawings of aphasics are generally more recognizable than the drawings of patients with damage to the right hemisphere, who are known to be compromised at the level of expressing specific perceptual information, such as color or shape (Grossman, 1988). These findings suggest that impairments on the category drawing task cannot be fully explained by a deficit in the ability to express perceptual characteristics or by a constructional apraxia.…”

Object Recognition Difficulty in Visual Apperceptive Agnosia

“…These visual perceptual processing devices have been dissociated in lesion studies and functional neuroimaging studies of healthy adults, demonstrating the independence of processes for visual shape (Corbetta, Miezin, Dobmeyer, Shulman, & Petersen, 1990, 1991Desimone, Schein, Moran, & Ungerleider, 1985) and color (Martin, Haxby, Lalonde, Wiggs, & Ungerleider, 1995;Lueck, Zeki, Friston, Deiber, Cope, Cunningham, Lammertsma, Kennard, & Frackowiak, 1989;Zeki, 1973;Livingstone & Hubel, 1984;Pearlman, Birch, & Meadows, 1979;Meadows, 1974). We hypothesize that the object recognition difficulty of apperceptive agnosia is due in part to difficulty appreciating multiple perceptual characteristics that contribute to an object's visual features, especially difficulty processing shape (Warrington & James, 1986;1988;Humphreys & Riddoch, 1984). Our data do not investigate color appreciation in as much detail as shape and letter appreciation, and in fact shape generally appeared to be more difficult for these patients to appreciate than color.…”

Development of Scoring Criteria for the Clock Drawing Task in Alzheimer's Disease

“…The drawing of a clock without a model requires reconstructing, to a verbal command, the memory of a clock into a graphic image 21 – 22 . This “constructional praxis” involves visuoperceptual analysis but is also affected by motor execution, attention, language comprehension, and numerical knowledge.…”

“…This “constructional praxis” involves visuoperceptual analysis but is also affected by motor execution, attention, language comprehension, and numerical knowledge. Focal right‐hemisphere lesions may result in abnormal clock drawings solely from impaired visuoperceptual analysis 2 , 21 , 23 . Left‐hemisphere lesions may disturb this task by an executive motor defect, 24 – 26 deficient language comprehension, 23 , 24 or a disturbed mental image of the clock 22 .…”

“…Left‐hemisphere lesions may disturb this task by an executive motor defect, 24 – 26 deficient language comprehension, 23 , 24 or a disturbed mental image of the clock 22 . Visual attentional disturbances or frontal executive disorders can also disrupt the clock‐drawing task 21 . The drawings of AD and other dementia patients may include all of these elements.…”

Semantic and perceptual errors in aphasics' freehand category drawing.

“…The difference between the two sets of studies may be due in part to the use of colored pictures and photographs in the latter studies, compared with black-and-white line drawings in earlier studies. The data presented in this report indicate that the drawings of aphasics are generally more recognizable than the drawings of patients with damage to the right hemisphere, who are known to be compromised at the level of expressing specific perceptual information, such as color or shape (Grossman, 1988). These findings suggest that impairments on the category drawing task cannot be fully explained by a deficit in the ability to express perceptual characteristics or by a constructional apraxia.…”

Object Recognition Difficulty in Visual Apperceptive Agnosia

“…These visual perceptual processing devices have been dissociated in lesion studies and functional neuroimaging studies of healthy adults, demonstrating the independence of processes for visual shape (Corbetta, Miezin, Dobmeyer, Shulman, & Petersen, 1990, 1991Desimone, Schein, Moran, & Ungerleider, 1985) and color (Martin, Haxby, Lalonde, Wiggs, & Ungerleider, 1995;Lueck, Zeki, Friston, Deiber, Cope, Cunningham, Lammertsma, Kennard, & Frackowiak, 1989;Zeki, 1973;Livingstone & Hubel, 1984;Pearlman, Birch, & Meadows, 1979;Meadows, 1974). We hypothesize that the object recognition difficulty of apperceptive agnosia is due in part to difficulty appreciating multiple perceptual characteristics that contribute to an object's visual features, especially difficulty processing shape (Warrington & James, 1986;1988;Humphreys & Riddoch, 1984). Our data do not investigate color appreciation in as much detail as shape and letter appreciation, and in fact shape generally appeared to be more difficult for these patients to appreciate than color.…”

Development of Scoring Criteria for the Clock Drawing Task in Alzheimer's Disease

“…The drawing of a clock without a model requires reconstructing, to a verbal command, the memory of a clock into a graphic image 21 – 22 . This “constructional praxis” involves visuoperceptual analysis but is also affected by motor execution, attention, language comprehension, and numerical knowledge.…”

“…This “constructional praxis” involves visuoperceptual analysis but is also affected by motor execution, attention, language comprehension, and numerical knowledge. Focal right‐hemisphere lesions may result in abnormal clock drawings solely from impaired visuoperceptual analysis 2 , 21 , 23 . Left‐hemisphere lesions may disturb this task by an executive motor defect, 24 – 26 deficient language comprehension, 23 , 24 or a disturbed mental image of the clock 22 .…”

“…Left‐hemisphere lesions may disturb this task by an executive motor defect, 24 – 26 deficient language comprehension, 23 , 24 or a disturbed mental image of the clock 22 . Visual attentional disturbances or frontal executive disorders can also disrupt the clock‐drawing task 21 . The drawings of AD and other dementia patients may include all of these elements.…”

Semantic and perceptual errors in aphasics' freehand category drawing.

“…The difference between the two sets of studies may be due in part to the use of colored pictures and photographs in the latter studies, compared with black-and-white line drawings in earlier studies. The data presented in this report indicate that the drawings of aphasics are generally more recognizable than the drawings of patients with damage to the right hemisphere, who are known to be compromised at the level of expressing specific perceptual information, such as color or shape (Grossman, 1988). These findings suggest that impairments on the category drawing task cannot be fully explained by a deficit in the ability to express perceptual characteristics or by a constructional apraxia.…”

Object Recognition Difficulty in Visual Apperceptive Agnosia

“…These visual perceptual processing devices have been dissociated in lesion studies and functional neuroimaging studies of healthy adults, demonstrating the independence of processes for visual shape (Corbetta, Miezin, Dobmeyer, Shulman, & Petersen, 1990, 1991Desimone, Schein, Moran, & Ungerleider, 1985) and color (Martin, Haxby, Lalonde, Wiggs, & Ungerleider, 1995;Lueck, Zeki, Friston, Deiber, Cope, Cunningham, Lammertsma, Kennard, & Frackowiak, 1989;Zeki, 1973;Livingstone & Hubel, 1984;Pearlman, Birch, & Meadows, 1979;Meadows, 1974). We hypothesize that the object recognition difficulty of apperceptive agnosia is due in part to difficulty appreciating multiple perceptual characteristics that contribute to an object's visual features, especially difficulty processing shape (Warrington & James, 1986;1988;Humphreys & Riddoch, 1984). Our data do not investigate color appreciation in as much detail as shape and letter appreciation, and in fact shape generally appeared to be more difficult for these patients to appreciate than color.…”

Development of Scoring Criteria for the Clock Drawing Task in Alzheimer's Disease

“…The drawing of a clock without a model requires reconstructing, to a verbal command, the memory of a clock into a graphic image 21 – 22 . This “constructional praxis” involves visuoperceptual analysis but is also affected by motor execution, attention, language comprehension, and numerical knowledge.…”

“…This “constructional praxis” involves visuoperceptual analysis but is also affected by motor execution, attention, language comprehension, and numerical knowledge. Focal right‐hemisphere lesions may result in abnormal clock drawings solely from impaired visuoperceptual analysis 2 , 21 , 23 . Left‐hemisphere lesions may disturb this task by an executive motor defect, 24 – 26 deficient language comprehension, 23 , 24 or a disturbed mental image of the clock 22 .…”

“…Left‐hemisphere lesions may disturb this task by an executive motor defect, 24 – 26 deficient language comprehension, 23 , 24 or a disturbed mental image of the clock 22 . Visual attentional disturbances or frontal executive disorders can also disrupt the clock‐drawing task 21 . The drawings of AD and other dementia patients may include all of these elements.…”