MICROSACCADE Meaning and
Definition
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Microsaccades are small, involuntary, and rapid eye movements that occur during periods of visual fixation. Typically lasting between 10 to 150 milliseconds, these tiny eye movements have amplitudes measuring less than one degree of visual angle. Microsaccades are commonly observed when a person is trying to maintain focus on a stationary object or when engaging in prolonged visual tasks.
These eye movements are thought to play an essential role in stabilizing gaze fixation and preventing sensory adaptation. Microsaccades help counteract neural adaptation by introducing slight shifts in retinal image positions, thus keeping the visual system constantly engaged and attentive. They contribute to maintaining a clear perception by regularly updating visual information received by the retina.
While microsaccades are generally involuntary, they can be influenced by factors such as attention, fatigue, and cognitive load. For instance, increased attention to a specific object or stimulus can decrease the frequency and amplitude of microsaccades, promoting a more stable fixation. Conversely, fatigue or cognitive load can lead to an increase in the occurrence of microsaccades.
The study of microsaccades is important in fields such as cognitive neuroscience, ophthalmology, and psychology. By analyzing microsaccadic patterns, researchers can gain insights into cognitive processes, visual attention, and ocular health.
Etymology of MICROSACCADE
The word "microsaccade" is a combination of two elements: "micro-" and "saccade".
1. The prefix "micro-" is derived from the Greek word "mikros", meaning small. It is often used in scientific and technical terms to indicate something extremely small or on a microscopic scale.
2. The word "saccade" comes from the French verb "saccader", which means to jerk or make a sudden movement. It is commonly used to describe rapid, small, and involuntary eye movements.
Combining these two elements, "microsaccade" refers to minuscule jerky movements of the eyes. The term is mainly used in ophthalmology and neurophysiology to describe tiny, rapid eye movements that occur even when fixating on a particular object.
