TY - JOUR
T1 - Structural similarity and category-specificity
T2 - a refined account
AU - Gerlach, Christian
AU - Law, Ian
AU - Paulson, Olaf B
PY - 2004
Y1 - 2004
N2 - It has been suggested that category-specific recognition disorders for natural objects may reflect that natural objects are more structurally (visually) similar than artefacts and therefore more difficult to recognize following brain damage. On this account one might expect a positive relationship between blood flow and structural similarity in areas involved in visual object recognition. Contrary to this expectation we report a negative relationship in that identification of articles of clothing cause more extensive activation than identification of vegetables/fruit and animals even though items from the categories of animals and vegetables/fruit are rated as more structurally similar than items from the category of articles of clothing. Given that this pattern cannot be explained in terms of a tradeoff between activation and accuracy, we interpret these findings within a model where the matching of visual forms to memory incorporates two operations: (i) the integration of stored object features into whole object representations (integral units), and (ii) the competition between activated integral units for selection (i.e. identification). In addition, we suggest that these operations are differentially affected by structural similarity in that high structural similarity may be beneficial for the integration of stored features into integral units, thus explaining the greater activation found with articles of clothing, whereas it may be harmful for the selection process proper because a greater range of candidate integral units will be activated and compete for selection, thus explaining the higher error rate associated with animals. We evaluate the model based on previous evidence from both normal subjects and patients with category-specific disorders and argue that this model can help reconcile otherwise conflicting data.
AB - It has been suggested that category-specific recognition disorders for natural objects may reflect that natural objects are more structurally (visually) similar than artefacts and therefore more difficult to recognize following brain damage. On this account one might expect a positive relationship between blood flow and structural similarity in areas involved in visual object recognition. Contrary to this expectation we report a negative relationship in that identification of articles of clothing cause more extensive activation than identification of vegetables/fruit and animals even though items from the categories of animals and vegetables/fruit are rated as more structurally similar than items from the category of articles of clothing. Given that this pattern cannot be explained in terms of a tradeoff between activation and accuracy, we interpret these findings within a model where the matching of visual forms to memory incorporates two operations: (i) the integration of stored object features into whole object representations (integral units), and (ii) the competition between activated integral units for selection (i.e. identification). In addition, we suggest that these operations are differentially affected by structural similarity in that high structural similarity may be beneficial for the integration of stored features into integral units, thus explaining the greater activation found with articles of clothing, whereas it may be harmful for the selection process proper because a greater range of candidate integral units will be activated and compete for selection, thus explaining the higher error rate associated with animals. We evaluate the model based on previous evidence from both normal subjects and patients with category-specific disorders and argue that this model can help reconcile otherwise conflicting data.
KW - Adult
KW - Association Learning/physiology
KW - Attention/physiology
KW - Brain Mapping
KW - Cerebral Cortex/physiology
KW - Concept Formation/physiology
KW - Decision Making/physiology
KW - Discrimination Learning/physiology
KW - Female
KW - Humans
KW - Image Processing, Computer-Assisted
KW - Magnetic Resonance Imaging
KW - Male
KW - Pattern Recognition, Visual/physiology
KW - Reaction Time/physiology
KW - Reference Values
KW - Regional Blood Flow/physiology
KW - Software
KW - Temporal Lobe/physiology
KW - Tomography, Emission-Computed
U2 - 10.1016/j.neuropsychologia.2004.03.004
DO - 10.1016/j.neuropsychologia.2004.03.004
M3 - Journal article
C2 - 15246291
SN - 0028-3932
VL - 42
SP - 1543
EP - 1553
JO - Neuropsychologia
JF - Neuropsychologia
IS - 11
ER -