Limits...
Computation of linear acceleration through an internal model in the macaque cerebellum.

Laurens J, Meng H, Angelaki DE - Nat. Neurosci. (2013)

Bottom Line: Although the cerebellum has been proposed as a candidate for implementation of internal models, concrete evidence from neural responses is lacking.Using unnatural motion stimuli, which induce incorrect self-motion perception and eye movements, we explored the neural correlates of an internal model that has been proposed to compensate for Einstein's equivalence principle and generate neural estimates of linear acceleration and gravity.We found that caudal cerebellar vermis Purkinje cells and cerebellar nuclei neurons selective for actual linear acceleration also encoded erroneous linear acceleration, as would be expected from the internal model hypothesis, even when no actual linear acceleration occurred.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, USA.

ABSTRACT
A combination of theory and behavioral findings support a role for internal models in the resolution of sensory ambiguities and sensorimotor processing. Although the cerebellum has been proposed as a candidate for implementation of internal models, concrete evidence from neural responses is lacking. Using unnatural motion stimuli, which induce incorrect self-motion perception and eye movements, we explored the neural correlates of an internal model that has been proposed to compensate for Einstein's equivalence principle and generate neural estimates of linear acceleration and gravity. We found that caudal cerebellar vermis Purkinje cells and cerebellar nuclei neurons selective for actual linear acceleration also encoded erroneous linear acceleration, as would be expected from the internal model hypothesis, even when no actual linear acceleration occurred. These findings provide strong evidence that the cerebellum might be involved in the implementation of internal models that mimic physical principles to interpret sensory signals, as previously hypothesized.

Show MeSH

Related in: MedlinePlus

Population responses, eye movements and model simulations during steady-state TWR(a) Average changes in firing rate (lines) and confidence interval (bands) following tilt in PD (red) or anti-PD (blue) (n = 21, 20 and 17 cells in animals V,T and K at 45°/s, n = 11 in animal T at 120°/s). Superimposed black lines show the simulated estimate of translational acceleration induced by TWR. Neural responses are shown in spikes per s and simulated translation is shown in units of m.s−2 (left and right ordinate, respectively). Peak responses in each animal have approximately the same amplitude, ~1.5 m.s−2, which matches the slope of the regression line shown in Fig. 5a (as both represent a decoded acceleration signal). (b) Horizontal eye velocity that reflects the induced erroneous translation signal5. (c) Actual tilt aVOR (green) and induced (cyan) vertical aVOR. The confidence intervals are too narrow to be visible. Superimposed black lines show the simulated estimate of the induced tilt signal (scaled by a factor of 0.8 to be compared with the induced aVOR). The tVOR (b) and aVOR (c) were evaluated using 219, 780 and 1018 trials in animals V,T and K at 45°/s, and 495 in animal T at 120°/s.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3818145&req=5

Figure 6: Population responses, eye movements and model simulations during steady-state TWR(a) Average changes in firing rate (lines) and confidence interval (bands) following tilt in PD (red) or anti-PD (blue) (n = 21, 20 and 17 cells in animals V,T and K at 45°/s, n = 11 in animal T at 120°/s). Superimposed black lines show the simulated estimate of translational acceleration induced by TWR. Neural responses are shown in spikes per s and simulated translation is shown in units of m.s−2 (left and right ordinate, respectively). Peak responses in each animal have approximately the same amplitude, ~1.5 m.s−2, which matches the slope of the regression line shown in Fig. 5a (as both represent a decoded acceleration signal). (b) Horizontal eye velocity that reflects the induced erroneous translation signal5. (c) Actual tilt aVOR (green) and induced (cyan) vertical aVOR. The confidence intervals are too narrow to be visible. Superimposed black lines show the simulated estimate of the induced tilt signal (scaled by a factor of 0.8 to be compared with the induced aVOR). The tVOR (b) and aVOR (c) were evaluated using 219, 780 and 1018 trials in animals V,T and K at 45°/s, and 495 in animal T at 120°/s.

Mentions: We also analyzed the time course of the population response to steady-state TWR (Fig. 6a). The population activity decayed with a time constant of 4 s (animal V), 2.2 s (animal T) and 1.3 s (animal K). The anti-PD population responses were weaker, as is often the case for cerebellar neurons42, and not significant in animals T and K.


Computation of linear acceleration through an internal model in the macaque cerebellum.

Laurens J, Meng H, Angelaki DE - Nat. Neurosci. (2013)

Population responses, eye movements and model simulations during steady-state TWR(a) Average changes in firing rate (lines) and confidence interval (bands) following tilt in PD (red) or anti-PD (blue) (n = 21, 20 and 17 cells in animals V,T and K at 45°/s, n = 11 in animal T at 120°/s). Superimposed black lines show the simulated estimate of translational acceleration induced by TWR. Neural responses are shown in spikes per s and simulated translation is shown in units of m.s−2 (left and right ordinate, respectively). Peak responses in each animal have approximately the same amplitude, ~1.5 m.s−2, which matches the slope of the regression line shown in Fig. 5a (as both represent a decoded acceleration signal). (b) Horizontal eye velocity that reflects the induced erroneous translation signal5. (c) Actual tilt aVOR (green) and induced (cyan) vertical aVOR. The confidence intervals are too narrow to be visible. Superimposed black lines show the simulated estimate of the induced tilt signal (scaled by a factor of 0.8 to be compared with the induced aVOR). The tVOR (b) and aVOR (c) were evaluated using 219, 780 and 1018 trials in animals V,T and K at 45°/s, and 495 in animal T at 120°/s.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3818145&req=5

Figure 6: Population responses, eye movements and model simulations during steady-state TWR(a) Average changes in firing rate (lines) and confidence interval (bands) following tilt in PD (red) or anti-PD (blue) (n = 21, 20 and 17 cells in animals V,T and K at 45°/s, n = 11 in animal T at 120°/s). Superimposed black lines show the simulated estimate of translational acceleration induced by TWR. Neural responses are shown in spikes per s and simulated translation is shown in units of m.s−2 (left and right ordinate, respectively). Peak responses in each animal have approximately the same amplitude, ~1.5 m.s−2, which matches the slope of the regression line shown in Fig. 5a (as both represent a decoded acceleration signal). (b) Horizontal eye velocity that reflects the induced erroneous translation signal5. (c) Actual tilt aVOR (green) and induced (cyan) vertical aVOR. The confidence intervals are too narrow to be visible. Superimposed black lines show the simulated estimate of the induced tilt signal (scaled by a factor of 0.8 to be compared with the induced aVOR). The tVOR (b) and aVOR (c) were evaluated using 219, 780 and 1018 trials in animals V,T and K at 45°/s, and 495 in animal T at 120°/s.
Mentions: We also analyzed the time course of the population response to steady-state TWR (Fig. 6a). The population activity decayed with a time constant of 4 s (animal V), 2.2 s (animal T) and 1.3 s (animal K). The anti-PD population responses were weaker, as is often the case for cerebellar neurons42, and not significant in animals T and K.

Bottom Line: Although the cerebellum has been proposed as a candidate for implementation of internal models, concrete evidence from neural responses is lacking.Using unnatural motion stimuli, which induce incorrect self-motion perception and eye movements, we explored the neural correlates of an internal model that has been proposed to compensate for Einstein's equivalence principle and generate neural estimates of linear acceleration and gravity.We found that caudal cerebellar vermis Purkinje cells and cerebellar nuclei neurons selective for actual linear acceleration also encoded erroneous linear acceleration, as would be expected from the internal model hypothesis, even when no actual linear acceleration occurred.

View Article: PubMed Central - PubMed

Affiliation: Department of Otolaryngology, Washington University School of Medicine, St. Louis, Missouri, USA.

ABSTRACT
A combination of theory and behavioral findings support a role for internal models in the resolution of sensory ambiguities and sensorimotor processing. Although the cerebellum has been proposed as a candidate for implementation of internal models, concrete evidence from neural responses is lacking. Using unnatural motion stimuli, which induce incorrect self-motion perception and eye movements, we explored the neural correlates of an internal model that has been proposed to compensate for Einstein's equivalence principle and generate neural estimates of linear acceleration and gravity. We found that caudal cerebellar vermis Purkinje cells and cerebellar nuclei neurons selective for actual linear acceleration also encoded erroneous linear acceleration, as would be expected from the internal model hypothesis, even when no actual linear acceleration occurred. These findings provide strong evidence that the cerebellum might be involved in the implementation of internal models that mimic physical principles to interpret sensory signals, as previously hypothesized.

Show MeSH
Related in: MedlinePlus