The lateral intraparietal cortex (area LIP) is found in the
intraparietal sulcus of the brain.
This area is most likely involved in eye movement, as electrical stimulation evokes
saccade
In vision science, a saccade ( ; ; ) is a quick, simultaneous movement of both Eye movement (sensory), eyes between two or more phases of focal points in the same direction. In contrast, in Smooth pursuit, smooth-pursuit movements, the eyes mov ...
s (quick movements) of the eyes. It is also thought to contribute to
working memory
Working memory is a cognitive system with a limited capacity that can Memory, hold information temporarily. It is important for reasoning and the guidance of decision-making and behavior. Working memory is often used synonymously with short-term m ...
associated with guiding eye movement, examined using a delayed saccade task described below:
[Pesaran, B., Pezaris, J. S., Sahani, M., Mitra, P. P., & Andersen, R. A. (2002). Temporal structure in neuronal activity during working memory in macaque parietal cortex. Nature neuroscience, 5(8), 805-811.]
#A subject focuses on a fixation point at the center of a computer screen.
#A target (for instance a shape) is presented at a peripheral location on the screen.
#The target is removed and followed by a variable-length delay period.
#The initial focus point in the middle of the screen is removed.
#The subject's task is to make a saccade to the location of the target.
Neurons in area LIP have been shown to start responding with the initial presentation of the stimulus. The neurons keep responding through the delay period until the saccadic eye movement starts and the animal soon focuses on the exact location of the previously shown target. There is also evidence for neurons firing for saccadic responses in the
two-alternative forced choice task.
The conclusion of this task experiment is that neurons in area LIP store information (the location of the target) useful for guiding the saccadic movement; that is, this area of the cortex shows
modality
Modality may refer to:
Humanities
* Modality (theology), the organization and structure of the church, as distinct from sodality or parachurch organizations
* Modality (music), in music, the subject concerning certain diatonic scales
* Modalit ...
-specific working memory.
Areas showing specificity for other modalities have been located.
References
Neuroscience of memory
Cerebrum
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