Inferior parietal lobule

From Psy3241

The inferior parietal lobule (IPL) is the multi-model assimilation area of the parital lobe and is concerned with multiple aspects of sensory processing and sensorimotor integration. This area is located below the horizontal portion of the intraparietal sulcus and behind the lower part of the postcentral sulcus. It contains the angular sulcus which is a lobule bypassing the ascending posterior segment and the supramarginal gyri which is an arched lobule surrounding the end of the lateral fissure.

The IPL is considered to be a multimodal sensory association area because a single inferior parietal neuron receives input from areas associated with visual, auditory, movement, and somesthetic. This is why the IPL is important for organization, labeling and multiple categorization of sensory-motor and conceptual events. This is how we are able to label an object simultaneously as not only a word, but a visual object and other aspects. The IPL is also known to be involved in oculomotor and attentional mechanisms, the establishment of maps of extrapersonal space, and the adaptive recalibration of eye-hand coordination. The left IPL becomes activated when reading during semantic processing and when generating words or making syllable judgments. The IPL seems to become activated during short-term memory and word retrieval and becomes highly active when retrieving the meaning of words during semantic processing and semnatic decision tasks.

Damage to the Inferior parietal lobule

Damage to this area can lead to anomia, which is a condition of having difficulty with naming and describing objects or pictures. Also, pure blindness can occur if damage occurs between the fiber pathways linking the left inferior parietal lobule with the visual cortex. Another possibility due to IPL damage is aphasia because this region transfers information from Wernickes area to Broca's area. Deficits in spatial perception can also be a result of damage.

Of all the cortical regions, the IPL is one of the last to mature functionally and anatomically.

References

[1] [2] [3]