The name is absent

30

between parts of the LOC and MT+ (Kourtzi, et al. 2002). This raises the question of
whether the tactile MST responses observed in our study correspond to LOtv or
represent a distinct focus of tactile activity. To answer this question, brain activity was
measured as subjects viewed photographs and scrambled photographs. Cortex
preferring real to scrambled photographs (the LOC) covered a large portion of lateral
and ventral occipitotemporal lobes (Fig. ЗА). An overlap map was created to show the
relationship between LOC and other regions of interest (Fig. 36). Superior portions of
the LOC overlapped with inferior portions of MT. Tactile responses were observed in
posterior and anterior portions of the LOC, corresponding to the previous descriptions
of LOtv (Amedi, et al. 2∞2; Amedi, et al. 2001). In the single-subject and group maps
(Fig. 3), the more anterior portion of LOtv was near the inferior border of MT. Therefore,
the relatively few nodes in MT with a significant response to tactile stimulation likely
share membership with LOtv. Tactile responses in MST were anterior and superior to
Lotvandconstitutedadistinctfocusofactivity.

Figure 3. Relationship between tactile responses in MST and LOC (A, B, single subject; C, D, group
data). A, Brain regions, in red, showing greater response to real pictures compared with scrambled
controls in a single-subject left hemisphere. Dashed white line shows the fundus of the ascending
limb of the posterior inferior temporal sulcus. B, Enlarged view of posterior lateral cortex (black
region outlined in A). Shown is a composite map of LOC (outlined in purple), MST (blue), and MT
(green) overlaid on tactile responses (orange). Portions of LOC, labeled as LOtv and outlined in
yellow, responded to tactile stimulation. C, Group composite map showing identified visual areas
overlaid on tactile activation in the left hemisphere (anterior is left). D, Group composite map of
right hemisphere (anterior is right).

<<   38   39   40   41   42   43   44   >>

More intriguing information