Module Assessment – Coversheet
Module Name: Applications of Neuropsychology and Cognition
Module Code: PSYC10022
Assessment Title (Word Length): Essay (2000 words)
Word Length for your submission: 2162 words
Submission Date: 18/10/2019
, Visual agnosia and the complexity of visual perception
In everyday life, the ability to identify and categorise objects is a cognitive ability that
is taken for granted and implemented facilely and promptly. However, in some cases, this
essential aptitude is impaired even though the senses are unaffected. Agnosia is a rare
disorder whereby a patient is incapable of recognising and identifying objects, persons, or
sounds using one or more of their senses that is not associated with a deficit in general
intelligence. The capability of perceiving objects is never abolished completely; it is usually
restricted to specific sensory systems without affecting others. A patient with visual agnosia
is unable to recognise an object visually but can recognise it tactilely or auditorily (Goldberg,
1990). The human visual system is composed of two distinct pathways in the brain
originating from the visual cortex. The ventral stream is involved with object recognition.
The dorsal stream is involved with processing an object's spatial location (Goodale & Milner,
1992). Visual agnosia was first defined by Lissauer in 1890. He described two types of visual
agnosia, namely “apperceptive visual agnosia” and “associative visual agnosia”.
Apperceptive visual agnosia is a disorder of intricate visual perceptual processing.
Individuals cannot fully perceive what they are seeing due to difficulties in perceptual
grouping processes; the patients are thus unable to organise individual segments and edges to
form a whole picture of what they are seeing (Grossman, Galetta, Ding, Morrison,
D’Esposito, Robinson et al., 1996). Although patients with apperceptive visual agnosia do not
acquire brain damage in precisely the same area, damage in proximity to the occipital lobe is
fundamentally correlated with the symptoms of deficit seen in apperceptive visual agnosia
(Grossman, Galetta & D'Esposito, 1997; Shelton, Bowers, Duara & Heilman, 1994; Sparr,
2000). Associative visual agnosia occurs even though perception is normal. However,
individuals have a visual access impairment to semantic representations in order to recognise
the object that they are seeing (Fery & Morais, 2003). Associative visual agnosia is usually
Module Name: Applications of Neuropsychology and Cognition
Module Code: PSYC10022
Assessment Title (Word Length): Essay (2000 words)
Word Length for your submission: 2162 words
Submission Date: 18/10/2019
, Visual agnosia and the complexity of visual perception
In everyday life, the ability to identify and categorise objects is a cognitive ability that
is taken for granted and implemented facilely and promptly. However, in some cases, this
essential aptitude is impaired even though the senses are unaffected. Agnosia is a rare
disorder whereby a patient is incapable of recognising and identifying objects, persons, or
sounds using one or more of their senses that is not associated with a deficit in general
intelligence. The capability of perceiving objects is never abolished completely; it is usually
restricted to specific sensory systems without affecting others. A patient with visual agnosia
is unable to recognise an object visually but can recognise it tactilely or auditorily (Goldberg,
1990). The human visual system is composed of two distinct pathways in the brain
originating from the visual cortex. The ventral stream is involved with object recognition.
The dorsal stream is involved with processing an object's spatial location (Goodale & Milner,
1992). Visual agnosia was first defined by Lissauer in 1890. He described two types of visual
agnosia, namely “apperceptive visual agnosia” and “associative visual agnosia”.
Apperceptive visual agnosia is a disorder of intricate visual perceptual processing.
Individuals cannot fully perceive what they are seeing due to difficulties in perceptual
grouping processes; the patients are thus unable to organise individual segments and edges to
form a whole picture of what they are seeing (Grossman, Galetta, Ding, Morrison,
D’Esposito, Robinson et al., 1996). Although patients with apperceptive visual agnosia do not
acquire brain damage in precisely the same area, damage in proximity to the occipital lobe is
fundamentally correlated with the symptoms of deficit seen in apperceptive visual agnosia
(Grossman, Galetta & D'Esposito, 1997; Shelton, Bowers, Duara & Heilman, 1994; Sparr,
2000). Associative visual agnosia occurs even though perception is normal. However,
individuals have a visual access impairment to semantic representations in order to recognise
the object that they are seeing (Fery & Morais, 2003). Associative visual agnosia is usually
