Visual and Auditory Cortex

Function and associated substructures

Visual Cortex Location

• The Visual Cortex occupies the posterior Occipital Lobe and is connected to the eyes via the optic nerve.

Function

• The Primary Visual Cortex (PVC) is highly specialized for processing information about static and moving objects and is excellent in pattern recognition.

• The PVC contains a number of specialized regions that process such things as color, spatial information, depth, texture, and motion.

• We will cover this region in greater depth in our Sensation and Perception Unit.

Auditory Cortex Location

• The Primary Auditory Cortex (Brodmann Areas 41 & 42) in the Temporal Lobe along the Superior Temporal Gyrus.

Function

• The Primary Auditory Cortex (PAC) performs the basics of hearing; pitch and volume.

• It is important to remember that the perception of sound, as something that carries meaning (ie. Speech, music, car horn), does not take place in the PAC but through the processes of PAC in conjunction with other association areas.

Substructures and associated areas

• Primary Auditory Cortex – tonotopically organized, which means that certain cells in the auditory cortex are sensitive to specific frequencies. This is a fascinating function which has been preserved throughout most of the audition circuit. This area of the brain “is thought to identify the fundamental elements of music, such as pitch and loudness

• Secondary Auditory Cortex – has been indicated in the processing of “harmonic, melodic and rhythmic patterns

• Tertiary Auditory Cortex –an association area that integrates everything into the overall experience of music.

• The three areas are concentrically organized such that the PAC is in the center.

Substructures and associated areas

• Wernicke’s area - involved in the understanding of written and spoken language. It is traditionally considered to consist of the posterior section of the superior temporal gyrus in the dominant cerebral hemisphere (which is the left hemisphere in about 90% of people).

Substructures and associated areas

• Middle Temporal Gyrus - located between the superior temporal gyrus and inferior temporal gyrus. Its exact function is unknown, but it has been connected with processes as different as contemplating distance, recognition of known faces, and accessing word meaning while reading.

• Fusiform Gyrus - Some researchers believe that the fusiform gyrus may be related to the disorder known as prosopagnosia, or face blindness

Follow-up Question

• The Fusiform Gyrus, located within the medial/inferior temporal lobe, is adjacent to both the Tertiary Auditory Cortex and areas of the Third Visual Complex (V3) and seems to play a large role in face recognition.

• Explain the relationship between the location of the Fusiform Gyrus and its function.

• Would a rose by any other name really smell as sweet?