Effect of electrical microstimulation of the anterior Superior Temporal Sulcus body patch on visual categorization tasks
-
1
Faculty of Medicine, KU Leuven, Belgium
fMRI studies in primates show patches in the temporal cortex that are more strongly activated by images of bodies compared to other visual categories (objects and faces). Single unit studies in macaques have shown that in at least two of these fMRI defined body patches neurons respond on average stronger to bodies, including bodies of humans, monkeys, and other four-legged mammals, compared to images of objects and faces (Popivanov et al., J.Neurosci., 2014; Kumar et al., Cerebral Cortex, 2017). The body patch spiking activity contains sufficient information to categorize bodies vs. objects (including faces). Here we examine the contribution to categorization behavior of the anterior Superior Temporal Sulcus body patch, ASB, which is located rostrally in the lower bank of the Superior Temporal Sulcus (Kumar et al., Cerebral Cortex, 2017). In a first experiment, we trained two monkeys to categorize a broad set of images of four-legged mammals versus images of human-made objects, with each object category being associated with a saccadic choice target and using saccades as operants. Images were shown centrally (maximum image extent 4 deg) and were partially occluded by white noise at various signal to noise ratios. In both animals, unilateral electrical microstimulation (EM; 150 uA) of ASB increased the overall proportion of mammal target responses without affecting the slope of the psychometric function. In one monkey, EM did not affect body categorization at another location (1mm further but still inside ASB), which may suggest a heterogeneity of ASB in its contribution to body categorization behavior. Both monkeys were tested on faces vs. objects categorization where faces were paired with the same choice target as for the mammals. EM of ASB increased also the overall proportion of face choices. To dissociate face from mammal targets and evaluate the stimulus selectivity of EM, we associated each of 4 categories, i.e., mammals, human faces, objects, and houses, with each of 4 saccadic choice targets. EM (50 uA) during the performance of this 4-alternative categorization task affected mammal and house category choices but not faces and objects. In one monkey, EM increased mammal choices, while in the second animal, the opposite effect was present. In each animal, this effect of EM was absent in a site of the STS that was not body category selective (3-5 mm away from ASB stimulation site). Subsequent pairwise testing of the mammal category with objects also showed increased or decreased mammal target choices, depending on the monkey, with EM of ASB. These data suggest that low current EM of a body patch affects choice biases during categorization of complex visual images.
Acknowledgements
FWO Vlaanderen
References
Kumar S, Popivanov I, Vogels R. Transformation of Visual Representations Across Ventral Stream Body-selective Patches. Cerebral Cortex. 2017;:1-15.
Popivanov I, Jastorff J, Vanduffel W, Vogels R. Heterogeneous Single-Unit Selectivity in an fMRI-Defined Body-Selective Patch. Journal of Neuroscience. 2013;34(1):95-111.
Keywords:
macaque,
microstimulation,
Categorization,
Inferotemporal cortex,
body patch
Conference:
Belgian Brain Congress 2018 — Belgian Brain Council, LIEGE, Belgium, 19 Oct - 19 Oct, 2018.
Presentation Type:
e-posters
Topic:
NOVEL STRATEGIES FOR NEUROLOGICAL AND MENTAL DISORDERS: SCIENTIFIC BASIS AND VALUE FOR PATIENT-CENTERED CARE
Citation:
Mergan
E,
Kumar
S and
Vogels
R
(2019). Effect of electrical microstimulation of the anterior Superior Temporal Sulcus body patch on visual categorization tasks.
Front. Neurosci.
Conference Abstract:
Belgian Brain Congress 2018 — Belgian Brain Council.
doi: 10.3389/conf.fnins.2018.95.00015
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
30 Jul 2018;
Published Online:
17 Jan 2019.
*
Correspondence:
Prof. Rufin Vogels, Faculty of Medicine, KU Leuven, Leuven, Belgium, rufin.vogels@kuleuven.be