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ERIC Number: EJ945406
Record Type: Journal
Publication Date: 2011-Nov
Pages: 10
Abstractor: As Provided
Reference Count: 0
ISSN: ISSN-0028-3932
About Turn: How Object Orientation Affects Categorisation and Mental Rotation
Milivojevic, Branka; Hamm, Jeff P.; Corballis, Michael C.
Neuropsychologia, v49 n13 p3758-3767 Nov 2011
High-density ERPs evoked by rotated alphanumeric characters were examined to determine how neural processing is affected by stimulus orientation during letter/digit classifications and during mirror/normal discriminations. The former task typically produces response times that are unaffected by stimulus orientation while the latter is thought to require mental rotation. Sensitivity to orientation was first observed around 100-140 ms and this effect was attributed to differences in low-level features between vertical and oblique orientations. Subsequently, character misorientation amplified the N170, a neural marker of object classification, between 160 and 220 ms. Top-down processing is reflected in the ERPs beginning at 280-320 ms and this time range may reflect binding of ventral and dorsal stream information. In the case of mirror-normal discrimination these top-down processes can lead to mental rotation between 340 and 700 ms. Therefore, although neural processing reflects object orientation, these effects do not translate into increases in reaction-times or impaired accuracy for categorisation, and precede those that do in the mental-rotation task. (Contains 3 tables and 3 figures.)
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A