Motion perception

Ventral-dorsal streams

Motion perception is the process of inferring the speed and direction of elements in a scene based on visual, vestibular, and proprioceptive inputs. It is a fundamental aspect of visual perception, allowing organisms to navigate their environments effectively, detect prey or predators, and interact with objects and individuals in their surroundings. Understanding motion perception involves exploring the underlying neuroscience, psychology, and physics that contribute to how motion is detected and interpreted by the brain.

Mechanisms of Motion Detection

Motion perception is primarily mediated by the visual system. The retina contains specialized cells, such as photoreceptors, which respond to changes in light intensity. These changes can be caused by objects moving across the visual field. The information is then processed by other retinal cells and transmitted to the brain via the optic nerve.

In the brain, the primary visual cortex (V1) receives and processes visual information, including aspects of motion. However, the dorsal stream, which extends from the primary visual cortex to the parietal lobes, is particularly important for motion perception. This pathway, sometimes referred to as the "where" pathway, is involved in processing the motion and spatial location of objects.

The middle temporal visual area (MT or V5) and the medial superior temporal area (MST) are two regions within the dorsal stream that play crucial roles in motion perception. Neurons in these areas are specifically tuned to detect motion in various directions and speeds.

Types of Motion Perception

Motion perception can be categorized into several types, including:

- First-order motion, also known as luminance-based motion, involves the detection of an object moving across a background with a contrasting color or brightness. - Second-order motion involves the perception of motion from changes in attributes other than luminance, such as texture, contrast, or flicker. - Optic flow refers to the pattern of apparent motion of objects, surfaces, and edges in a visual scene caused by the relative motion between an observer and the scene. - Biological motion pertains to the ability to detect motion in living beings, such as the gait of a human or the flight of a bird.

Factors Influencing Motion Perception

Several factors can influence how motion is perceived, including:

- Speed and direction: The velocity and trajectory of an object can affect how smoothly or abruptly its motion is perceived. - Background and context: The contrast between an object and its background, as well as the presence of other moving or stationary objects, can impact motion detection. - Attention and expectation: An observer's focus and prior knowledge or assumptions about what is being observed can influence motion perception.

Applications and Implications

Understanding motion perception has practical applications in various fields, such as robotics, where it informs the development of systems that can detect and respond to movement, and augmented reality (AR) and virtual reality (VR), where it helps create more immersive and realistic experiences. In medicine, insights into motion perception can aid in diagnosing and treating conditions that affect vision and movement, such as amblyopia or Parkinson's disease.

Conclusion

Motion perception is a complex process that involves the integration of visual, vestibular, and proprioceptive information. It is essential for navigating and interacting with the environment. Ongoing research in neuroscience, psychology, and related fields continues to uncover the mechanisms behind motion detection and how these processes can be applied in technology and medicine.

‎

---

Translate: - East Asian 中文, 日本, 한국어, South Asian हिन्दी, தமிழ், తెలుగు, Urdu, ಕನ್ನಡ, Southeast Asian Indonesian, Vietnamese, Thai, မြန်မာဘာသာ, বাংলা
European español, Deutsch, français, Greek, português do Brasil, polski, română, русский, Nederlands, norsk, svenska, suomi, Italian
Middle Eastern & African عربى, Turkish, Persian, Hebrew, Afrikaans, isiZulu, Kiswahili,
Other Bulgarian, Hungarian, Czech, Swedish, മലയാളം, मराठी, ਪੰਜਾਬੀ, ગુજરાતી, Portuguese, Ukrainian