Publications by authors named "Amra Hodzic"

3 Publications

  • Page 1 of 1

Distinct cortical networks for the detection and identification of human body.

Neuroimage 2009 May 6;45(4):1264-71. Epub 2009 Feb 6.

Department of Neurophysiology, Max Planck Institute for Brain Research, Deutschordenstr. 46, D-60528 Frankfurt am Main, Germany.

In the human brain information about bodies and faces is processed in specialized cortical regions named EBA and FBA (extrastriate and fusiform body area) and OFA and FFA (occipital and fusiform face area), respectively. Here we investigate with functional magnetic resonance imaging (fMRI) the cortical areas responsible for the identification of individual bodies and the distinction between 'self' and 'others'. To this end we presented subjects with images of unfamiliar and familiar bodies and their own body. We identified separate coactivation networks for body-detection (processing body related information), body-identification (processing of information relating to individual bodies) and self-identification (distinction of self from others). Body detection involves the EBA in both hemispheres, and in the right hemisphere: the FBA and areas in the IPL (inferior parietal lobe). Body identification involves areas in the inferior frontal gyrus (IFG) of both hemispheres and in the right hemisphere areas in the medial frontal gyrus (MFG), in the cingulate gyrus (CG), in the central (CS) and the post-central sulcus (PCS), in the inferior parietal lobe (IPL) and the FBA. When the recognition of one's own body is contrasted to the identification of familiar bodies, differential activation is observed in areas of the inferior parietal lobe (IPL) and inferior parietal sulcus (IPS) of the right hemisphere, and in the posterior orbital gyrus (pOrbG) and in the lateral occipital gyrus (LOG) of the left hemisphere. Thus, identification of individual bodies and self-other distinction involve in addition to the classical occipito-parietal network a parieto-frontal network. Interestingly, the EBA shows no differential activation for distinctions between familiar or unfamiliar bodies or recognition of one's own body.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.neuroimage.2009.01.027DOI Listing
May 2009

Cortical responses to self and others.

Hum Brain Mapp 2009 Mar;30(3):951-62

Department of Neurophysiology, Max Planck Institute for Brain Research, Frankfurt am Main, Germany.

The extrastriate body area (EBA) is one among the multiple, functionally specialized regions of the human visual cortex exhibiting modulation by body-related stimuli. Here we investigate whether activation patterns differ for the perception of one's own body and the bodies of others. We used functional magnetic resonance imaging to identify body-related brain areas and to see how these areas differentiate between images of one's own body and those of others in the absence of facial or motion cues. Whole brain explorative group-level analysis identified body-related blood oxygen level dependent (BOLD) signal enhancement in five regions of the right and in one region of the left hemisphere (right: in the extrastriate visual and parietal cortex and in the precentral gyrus, left: in the extrastriate visual cortex). General linear model group-level random effects analysis of the self-other contrast revealed self-related responses in the extrastriate and parietal regions in the right hemisphere but also in the right middle frontal gyrus. These results suggest the existence of a cortical network for the extraction of body-related information and another cortical network for the extraction of self-related body information. The two networks partially overlap in the right superior and inferior parietal cortices, but are clearly segregated in the extrastriate visual cortex and in the middle frontal gyrus. In addition, we report that the classical EBA is only involved in the analysis of body-related information but not in the assignment of body identity. The latter appears to be accomplished by a network in right hemisphere comprising the fusiform body area, regions of the superior parietal lobe, the inferior parietal cortex, and the middle frontal gyrus.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/hbm.20558DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6870742PMC
March 2009

Improvement and decline in tactile discrimination behavior after cortical plasticity induced by passive tactile coactivation.

J Neurosci 2004 Jan;24(2):442-6

Institute of Medical Psychology and Behavioral Neurobiology, University of T├╝bingen, D-72074 T├╝bingen, Germany.

Perceptual learning can be induced by passive tactile coactivation without attention or reinforcement. We used functional MRI (fMRI) and psychophysics to investigate in detail the specificity of this type of learning for different tactile discrimination tasks and the underlying cortical reorganization. We found that a few hours of Hebbian coactivation evoked a significant increase of primary (SI) and secondary (SII) somatosensory cortical areas representing the stimulated body parts. The amount of plastic changes was strongly correlated with improvement in spatial discrimination performance. However, in the same subjects, frequency discrimination was impaired after coactivation, indicating that even maladaptive processes can be induced by intense passive sensory stimulation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1523/JNEUROSCI.3731-03.2004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6730006PMC
January 2004
-->