scholarly journals Motor–sensory convergence in object localization: a comparative study in rats and humans

2011 ◽  
Vol 366 (1581) ◽  
pp. 3070-3076 ◽  
Author(s):  
Guy Horev ◽  
Avraham Saig ◽  
Per Magne Knutsen ◽  
Maciej Pietr ◽  
Chunxiu Yu ◽  
...  
Keyword(s):  
Comparative Study ◽  
Human Subjects ◽  
Tactile Perception ◽  
Object Localization ◽  
Object Location ◽  
Sensory Inputs ◽  
Spatial Alignment ◽  
Sensory Convergence ◽  
Temporal And Spatial ◽  
Sensory Process

In order to identify basic aspects in the process of tactile perception, we trained rats and humans in similar object localization tasks and compared the strategies used by the two species. We found that rats integrated temporally related sensory inputs (‘temporal inputs’) from early whisk cycles with spatially related inputs (‘spatial inputs’) to align their whiskers with the objects; their perceptual reports appeared to be based primarily on this spatial alignment. In a similar manner, human subjects also integrated temporal and spatial inputs, but relied mainly on temporal inputs for object localization. These results suggest that during tactile object localization, an iterative motor–sensory process gradually converges on a stable percept of object location in both species.

Visual Cortex Alterations in Early and Late Blind Subjects During Tactile Perception

Perception ◽  
2021 ◽  
Vol 50 (3) ◽  
pp. 249-265
Author(s):  
A. Ankeeta ◽  
S. Senthil Kumaran ◽  
Rohit Saxena ◽  
Sada N. Dwivedi ◽  
Naranamangalam R. Jagannathan
Keyword(s):  
Visual Cortex ◽  
Children And Adolescents ◽  
Age Of Onset ◽  
Human Subjects ◽  
Functional Results ◽  
Blood Oxygen Level Dependent ◽  
Tactile Perception ◽  
Blood Oxygen Level ◽  
Sensory Motor ◽  
Post Hoc

Involvement of visual cortex varies during tactile perception tasks in early blind (EB) and late blind (LB) human subjects. This study explored differences in sensory motor networks associated with tactile task in EB and LB subjects and between children and adolescents. A total of 40 EB subjects, 40 LB subjects, and 30 sighted controls were recruited in two subgroups: children (6–12 years) and adolescents (13–19 years). Data were acquired using a 3T MR scanner. Analyses of blood oxygen level dependent (BOLD), functional connectivity (FC), correlation, and post hoc test for multiple comparisons were carried out. Difference in BOLD activity was observed in EB and LB groups in visual cortex during tactile perception, with increased FC of visual with dorsal attention and sensory motor networks in EB. EB adolescents exhibited increased connectivity with default mode and salience networks when compared with LB. Functional results correlated with duration of training, suggestive of better performance in EB. Alteration in sensory and visual networks in EB and LB correlated with duration of tactile training. Age of onset of blindness has an effect in cross-modal reorganization of visual cortex in EB and multimodal in LB in children and adolescents.

Frames of Reference for Hand Orientation

1995 ◽  
Vol 7 (2) ◽  
pp. 182-195 ◽  
Author(s):  
Martha Flanders ◽  
John F. Soechting
Keyword(s):  
Reference Frame ◽  
Neural Control ◽  
Human Subjects ◽  
Object Orientation ◽  
Frame Of Reference ◽  
Object Location ◽  
Frames Of Reference ◽  
Spatial Reference ◽  
Hand Orientation ◽  
Spatial Reference Frame

In reaching and grasping movements, information about object location and object orientation is used to specify the appropriate proximal arm posture and the appropriate positions for the wrist and fingers. Since object orientation is ideally defined in a frame of reference fixed in space, this study tested whether the neural control of hand orientation is also best described as being in this spatial reference frame. With the proximal arm in various postures, human subjects used a handheld rod to approximate verbally defined spatial orientations. Subjects did quite well at indicating spatial vertical and spatial horizontal but made consistent errors in estimating 45° spatial slants. The errors were related to the proximal arm posture in a way that indicated that oblique hand orientations may be specified as a compromise between a reference frame fixed in space and a reference frame fixed to the arm. In another experiment, where subjects were explicitly requested to use a reference frame fixed to the arm, the performance was consistently biased toward a spatial reference frame. The results suggest that reaching and grasping movements may be implemented as an amalgam of two frames of reference, both neurally and behaviorally.

A COMPARATIVE STUDY OF VAGINAL AND CERVICAL CORNIFICATION IN HUMAN SUBJECTS

1948 ◽  
Vol 3 (3) ◽  
pp. 401-402
Author(s):  
J. E. AYRE ◽  
P. M. CHEVALIER ◽  
W. B. AYRE
Keyword(s):  
Comparative Study ◽  
Human Subjects

Role of Spatial and Temporal Coincidence in Depth Organization

Perception ◽  
1998 ◽  
Vol 27 (5) ◽  
pp. 541-552 ◽  
Author(s):  
Haruyuki Kojima ◽  
Randolph Blake
Keyword(s):  
Spatial Information ◽  
Space Perception ◽  
Video Monitor ◽  
Lateral Separation ◽  
Temporal Phase ◽  
Spatial Alignment ◽  
Uncrossed Disparity ◽  
Left And Right ◽  
Temporal And Spatial

The linking of spatial information is essential for coherent space perception. A study is reported of the contribution of temporal and spatial alignment for the linkage of spatial elements in terms of depth perception. Stereo half-images were generated on the left and right halves of a large-screen video monitor and viewed through a mirror stereoscope. The half-images portrayed a black vertically oriented bar with two brackets immediately flanking this bar and placed in crossed or uncrossed disparity relative to the bar. A pair of thin white ‘bridging lines' could appear on the black bar, always at zero disparity. Brackets and bridging lines could be flickered either in phase or out of phase. Observers judged whether the brackets appeared in front of or behind the black bar, with disparity varied. Compared to conditions when the bridging lines were absent, depth judgments were markedly biased toward “in front” when bridging lines and brackets flashed in temporal phase; this bias was much reduced when the bridging lines and brackets flashed out of phase. This biasing effect also depended on spatial offset of lines and brackets. However, perception was uninfluenced by the lateral separation between object and brackets.

A COMPARATIVE STUDY OF VAGINAL AND CERVICAL CORNIFICATION IN HUMAN SUBJECTS*

1947 ◽  
Vol 7 (11) ◽  
pp. 749-752 ◽  
Author(s):  
J. E. AYRE ◽  
P. M. CHEVALIER ◽  
W. B. AYRE
Keyword(s):  
Comparative Study ◽  
Human Subjects

scholarly journals A COMPARATIVE STUDY OF RED CELL VOLUMES IN HUMAN SUBJECTS WITH RADIOACTIVE PHOSPHORUS TAGGED RED CELLS AND T-1824 DYE 12

1950 ◽  
Vol 29 (2) ◽  
pp. 258-264 ◽  
Author(s):  
Herman M. Nachman ◽  
G. Watson James ◽  
John W. Moore ◽  
Everett Idris Evans ◽  
Evelyn Hayes ◽  
...  
Keyword(s):  
Comparative Study ◽  
Human Subjects ◽  
Red Cells ◽  
Red Cell ◽  
Radioactive Phosphorus ◽  
Cell Volumes

scholarly journals Taste, olfactory and food texture reward processing in the brain and the control of appetite

2012 ◽  
Vol 71 (4) ◽  
pp. 488-501 ◽  
Author(s):  
Edmund T. Rolls
Keyword(s):  
Food Reward ◽  
Functional Neuroimaging ◽  
Human Subjects ◽  
Reward Processing ◽  
Anterior Cingulate ◽  
Sensory Inputs ◽  
Word Level ◽  
Food Texture ◽  
Visual Inputs ◽  
Reward Value

Complementary neuronal recordings and functional neuroimaging in human subjects show that the primary taste cortex in the anterior insula provides separate and combined representations of the taste, temperature and texture (including fat texture) of food in the mouth independently of hunger and thus of reward value and pleasantness. One synapse on, in the orbitofrontal cortex (OFC), these sensory inputs are for some neurons combined by learning with olfactory and visual inputs, and these neurons encode food reward in that they only respond to food when hungry, and in that activations correlate with subjective pleasantness. Cognitive factors, including word-level descriptions, and attention modulate the representation of the reward value of food in the OFC and a region to which it projects, the anterior cingulate cortex. Further, there are individual differences in the representation of the reward value of food in the OFC. It is argued that over-eating and obesity are related in many cases to an increased reward value of the sensory inputs produced by foods, and their modulation by cognition and attention that over-ride existing satiety signals. It is proposed that control of all rather than one or several of these factors that influence food reward and eating may be important in the prevention and treatment of overeating and obesity.

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