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AliceD
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Two areas in the visual cortex are associated with the perception of velocity, namely:

  1. The primary visual cortex (V1) and
  2. The middle temporal area (MT or V5).

Both V1 and MT contain neurons that respond strongly to motion in a particular direction and also have selective responses to a particular speed. Direction and speed together define the velocity vector, i.e., these V1 and MT neurons are velocity-tuned. The velocity tuned neurons in V1 typically project to velocity tuned cells in MT. While V1 harbors maroundcontains approximately 25% velocity-tuned neurons, those in the MT neurons are nearly all velocity-tuned (Bradley & Goyal, 2008).

Now this is all bottom-up processing. You basically ask as well whether top-down issues play a role. I do not think so. The visual system is basically split in a dorsal 'what' and a ventral 'where' stream (Fig. 1). The 'what' system identifies a target and the 'where' system (containing MT) determines location and velocity. As far as I know, there is no feedback from the dorsal stream onto the ventral one to affect velocity processing.

streams
Fig. 1. Dorsal (parietal) and ventral (temporal) streams. source: Lehky & Sereno (2007)

References
- Bradley & Goyal, &Nature Rev Neurosci (2008); 9: 686-95
- Lehky & Sereno, *J Neurophysiol (2007); 97(1): 307-19

Two areas in the visual cortex are associated with the perception of velocity, namely:

  1. The primary visual cortex (V1) and
  2. The middle temporal area (MT or V5).

Both V1 and MT contain neurons that respond strongly to motion in a particular direction and also have selective responses to a particular speed. Direction and speed together define the velocity vector, i.e., these V1 and MT neurons are velocity-tuned. The velocity tuned neurons in V1 typically project to velocity tuned cells in MT. While V1 harbors maround 25% velocity-tuned neurons, those in the MT neurons are nearly all velocity-tuned (Bradley & Goyal, 2008).

Now this is all bottom-up processing. You basically ask as well whether top-down issues play a role. I do not think so. The visual system is basically split in a dorsal 'what' and a ventral 'where' stream (Fig. 1). The 'what' system identifies a target and the 'where' system (containing MT) determines location and velocity. As far as I know, there is no feedback from the dorsal stream onto the ventral one to affect velocity processing.

streams
Fig. 1. Dorsal (parietal) and ventral (temporal) streams. source: Lehky & Sereno (2007)

References
- Bradley & Goyal, &Nature Rev Neurosci (2008); 9: 686-95
- Lehky & Sereno, *J Neurophysiol (2007); 97(1): 307-19

Two areas in the visual cortex are associated with the perception of velocity, namely:

  1. The primary visual cortex (V1) and
  2. The middle temporal area (MT or V5).

Both V1 and MT contain neurons that respond strongly to motion in a particular direction and also have selective responses to a particular speed. Direction and speed together define the velocity vector, i.e., these V1 and MT neurons are velocity-tuned. The velocity tuned neurons in V1 typically project to velocity tuned cells in MT. While V1 contains approximately 25% velocity-tuned neurons, those in the MT neurons are nearly all velocity-tuned (Bradley & Goyal, 2008).

Now this is all bottom-up processing. You basically ask as well whether top-down issues play a role. I do not think so. The visual system is basically split in a dorsal 'what' and a ventral 'where' stream (Fig. 1). The 'what' system identifies a target and the 'where' system (containing MT) determines location and velocity. As far as I know, there is no feedback from the dorsal stream onto the ventral one to affect velocity processing.

streams
Fig. 1. Dorsal (parietal) and ventral (temporal) streams. source: Lehky & Sereno (2007)

References
- Bradley & Goyal, &Nature Rev Neurosci (2008); 9: 686-95
- Lehky & Sereno, *J Neurophysiol (2007); 97(1): 307-19

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AliceD
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Two areas in the visual cortex are associated witwith the perception of velocity., namely:

  1. The primary visual cortex (V1) and
  2. The middle temporal area (MT or V5).

Both V1 and MT contain neurons that respond strongly to motion in a particular direction and also have selective responses to a particular speed. Direction and speed together define the velocity vector, i.e., these V1 and MT neurons are velocity-tuned. The velocity tuned neurons in V1 typically project to velocity tuned cells in MT. While V1 harbors maround 25% velocity-tuned neurons, those in the MT neurons are nearly all velocity-tuned (Bradley & Goyal, 2008).

Now this is all bottom-up processing. You basically ask as well whether top-down issues play a role. I do not think so. The visual system is basically split in a dorsal 'what' and a ventral 'where' stream (Fig. 1). The 'what' system identifies a target and the 'where' system (containing MT) determines location and velocity. As far as I know, there is no feedback from the dorsal stream onto the ventral one to affect velocity processing.

streams
Fig. 1. Dorsal (parietal) and ventral (temporal) streams. source: Lehky & Sereno (2007)

References
- Bradley & Goyal, &Nature Rev Neurosci (2008); 9: 686-95
- Lehky & Sereno, *J Neurophysiol (2007); 97(1): 307-19

Two areas in the visual cortex are associated wit the perception of velocity.

  1. The primary visual cortex (V1) and
  2. The middle temporal area (MT or V5).

Both V1 and MT contain neurons that respond strongly to motion in a particular direction and also have selective responses to a particular speed. Direction and speed together define the velocity vector, i.e., these V1 and MT neurons are velocity-tuned. The velocity tuned neurons in V1 typically project to velocity tuned cells in MT. While V1 harbors maround 25% velocity-tuned neurons, those in the MT neurons are nearly all velocity-tuned (Bradley & Goyal, 2008).

Now this is all bottom-up processing. You basically ask as well whether top-down issues play a role. I do not think so. The visual system is basically split in a dorsal 'what' and a ventral 'where' stream (Fig. 1). The 'what' system identifies a target and the 'where' system (containing MT) determines location and velocity. As far as I know, there is no feedback from the dorsal stream onto the ventral one to affect velocity processing.

streams
Fig. 1. Dorsal (parietal) and ventral (temporal) streams. source: Lehky & Sereno (2007)

References
- Bradley & Goyal, &Nature Rev Neurosci (2008); 9: 686-95
- Lehky & Sereno, *J Neurophysiol (2007); 97(1): 307-19

Two areas in the visual cortex are associated with the perception of velocity, namely:

  1. The primary visual cortex (V1) and
  2. The middle temporal area (MT or V5).

Both V1 and MT contain neurons that respond strongly to motion in a particular direction and also have selective responses to a particular speed. Direction and speed together define the velocity vector, i.e., these V1 and MT neurons are velocity-tuned. The velocity tuned neurons in V1 typically project to velocity tuned cells in MT. While V1 harbors maround 25% velocity-tuned neurons, those in the MT neurons are nearly all velocity-tuned (Bradley & Goyal, 2008).

Now this is all bottom-up processing. You basically ask as well whether top-down issues play a role. I do not think so. The visual system is basically split in a dorsal 'what' and a ventral 'where' stream (Fig. 1). The 'what' system identifies a target and the 'where' system (containing MT) determines location and velocity. As far as I know, there is no feedback from the dorsal stream onto the ventral one to affect velocity processing.

streams
Fig. 1. Dorsal (parietal) and ventral (temporal) streams. source: Lehky & Sereno (2007)

References
- Bradley & Goyal, &Nature Rev Neurosci (2008); 9: 686-95
- Lehky & Sereno, *J Neurophysiol (2007); 97(1): 307-19

Source Link
AliceD
  • 20.8k
  • 8
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  • 142

Two areas in the visual cortex are associated wit the perception of velocity.

  1. The primary visual cortex (V1) and
  2. The middle temporal area (MT or V5).

Both V1 and MT contain neurons that respond strongly to motion in a particular direction and also have selective responses to a particular speed. Direction and speed together define the velocity vector, i.e., these V1 and MT neurons are velocity-tuned. The velocity tuned neurons in V1 typically project to velocity tuned cells in MT. While V1 harbors maround 25% velocity-tuned neurons, those in the MT neurons are nearly all velocity-tuned (Bradley & Goyal, 2008).

Now this is all bottom-up processing. You basically ask as well whether top-down issues play a role. I do not think so. The visual system is basically split in a dorsal 'what' and a ventral 'where' stream (Fig. 1). The 'what' system identifies a target and the 'where' system (containing MT) determines location and velocity. As far as I know, there is no feedback from the dorsal stream onto the ventral one to affect velocity processing.

streams
Fig. 1. Dorsal (parietal) and ventral (temporal) streams. source: Lehky & Sereno (2007)

References
- Bradley & Goyal, &Nature Rev Neurosci (2008); 9: 686-95
- Lehky & Sereno, *J Neurophysiol (2007); 97(1): 307-19