scholarly journals The role of efference copy in saccadic adaptation

2011 ◽  
Vol 11 (11) ◽  
pp. 496-496
Author(s):  
T. Collins ◽  
J. Wallman
Keyword(s):  
Efference Copy ◽  
Saccadic Adaptation

scholarly journals Effect of Saccadic Adaptation on Sequences of Saccades

2012 ◽  
Vol 5 (1) ◽  
Author(s):  
Muriel Panouillères ◽  
Roméo Salemme ◽  
Christian Urquizar ◽  
Denis Pélisson
Keyword(s):  
Daily Life ◽  
Saccadic Eye Movements ◽  
Neural Substrates ◽  
Efference Copy ◽  
Saccadic Adaptation ◽  
Adaptation Mechanisms ◽  
Before And After ◽  
Saccade Size ◽  
Voluntary Saccades ◽  
Rightward Saccade

Accuracy of saccadic eye movements is maintained thanks to adaptation mechanisms. The adaptive lengthening and shortening of reactive and voluntary saccades rely on partially separate neural substrates. Although in daily-life we mostly perform sequences of saccades, the effect of saccadic adaptation has been mainly evaluated on single saccades. Here, sequences of two saccades were recorded before and after adaptation of rightward saccades. In 4 separate sessions, reactive and voluntary saccades were adaptively shortened or lengthened. We found that the second saccade of the sequence always remained accurate and compensated for the adaptive changes of the first rightward saccade size. This finding suggests that adaptation loci are upstream of the site where the efference copy involved in sequence planning originates.

Differential cortical activation during saccadic adaptation

2012 ◽  
Vol 107 (6) ◽  
pp. 1738-1747 ◽  
Author(s):  
Steven P. Blurton ◽  
Markus Raabe ◽  
Mark W. Greenlee
Keyword(s):  
Target Location ◽  
Visual Stimulation ◽  
Signal Amplitude ◽  
Cortical Activation ◽  
Saccadic Adaptation ◽  
Before And After ◽  
Posterior Insula ◽  
Cortical Regions ◽  
Gain Adjustment

The human saccadic system can dynamically adjust its gain if errors occur after saccade execution. Although this ability has long been studied, the underlying neural mechanisms and its functional purpose remain as of yet unclear. Using functional magnetic resonance imaging coupled with gaze-contingent visual stimulation, we compared brain activation before and after subjects adapted to a gaze-contingent shift in the target location (inward step). This comparison suggests the existence of a predictive signal related to the gain adjustment of upcoming saccades to decrease saccadic gain. Contrary to previous studies, we were able to identify activation differences in the supplementary eye fields that vary with the amount of saccadic gain decrease. In addition to signal amplitude differences in saccade-related eye fields, we also found active cortical regions in the temporal lobe and the posterior insula, which have been functionally related to vestibular processing and to the representation of head position and head motion. The results might point to new directions for research on saccadic adaptation pointing to the functional role of this mechanism.

scholarly journals The role of the thalamus in conveying efference copy information

2004 ◽  
Vol 4 (8) ◽  
pp. 647-647
Author(s):  
C. Bellebaum ◽  
L. Lunenberger ◽  
B. Koch ◽  
I. Daum ◽  
M. Schwarz ◽  
...  
Keyword(s):  
Efference Copy

scholarly journals Encoding of 3D Head Orienting Movements in Primary Visual Cortex

2020 ◽  
Author(s):  
Grigori Guitchounts ◽  
Javier Masis ◽  
Steffen BE Wolff ◽  
David Cox
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Processing ◽  
Efference Copy ◽  
Three Dimensions ◽  
Movement Direction ◽  
Sensory Stimuli ◽  
Cortical Dynamics ◽  
Specific Manner

AbstractAnimals actively sample from the sensory world by generating complex patterns of movement that evolve in three dimensions. At least some of these movements have been shown to influence neural codes in sensory areas. For example, in primary visual cortex (V1), locomotion-related neural activity influences sensory gain, encodes running speed, and predicts the direction of visual flow. As most experiments exploring movement-related modulation of V1 have been performed in head-fixed animals, it remains unclear whether or how the naturalistic movements used to interact with sensory stimuli– like head orienting–influence visual processing. Here we show that 3D head orienting movements modulate V1 neuronal activity in a direction-specific manner that also depends on the presence or absence of light. We identify two largely independent populations of movement-direction-tuned neurons that support this modulation, one of which is direction-tuned in the dark and the other in the light. Finally, we demonstrate that V1 gains access to a motor efference copy related to orientation from secondary motor cortex, which has been shown to control head orienting movements. These results suggest a mechanism through which sensory signals generated by purposeful movement can be distinguished from those arising in the outside world, and reveal a pervasive role of 3D movement in shaping sensory cortical dynamics.

The role of “prespecification” in an embodied cognition

2004 ◽  
Vol 27 (3) ◽  
pp. 408-409 ◽  
Author(s):  
J. Scott Jordan
Keyword(s):  
Embodied Cognition ◽  
Efference Copy ◽  
Original Formulation

Grush makes extensive use of von Holst and Mittelstaedt's (1950) efference copy hypothesis. Although his embellishment of the model is admirably more sophisticated than that of its progenitors, I argue that it still suffers from the same conceptual limitations as entailed in its original formulation.

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