Answer: Also called the “dual-stream model,” the Hickok-Poeppel model, is a neurolinguistic theory of speech perception.
The Hickok-Poeppel theory is a model for explaining how the human brain experiences and perceives speech stimuli. It is named after the two neurolinguistic who first proposed the theory in 2007, Gregory Hickok and David Poeppel. It goes against some of the similar speech perception theories that existed in the field previously, namely that of Broca and Wernicke.
According to Hickok and Poeppel, speech perception and responding is similar to the visual system. They suggest that there are two streams of information that are processed simultaneously after speech is perceived by the auditory system. Just like in the visual system, the Hickok-Poeppel model describes a dorsal stream and a ventral stream. According to their hypothesis, the ventral stream plays an important role in understanding or recognizing the inputs, while the dorsal stream serves as the means with which the person is able to respond using their motor system. The ventral streams therefore play very similar roles in both the visual system and the speech perception system.
After a linguistic stimulus enters through the ears and into the brain, the information gets passed through the superior temporal gyrus. According to the Hickok-Poeppel model, this processing is important in both streams. The ventral stream is when that information passes into the posterior middle temporal gyrus.
In the ventral stream of processing, the individual sounds are turned into something with phonetic meaning. In this way, it is similar to the ventral stream of visual processing that is sometimes also called the “what” pathway.
Auditory information enters through the ears and is processed by the superior temporal gyrus. From here, the dorsal stream begins, when the left Sylvian parietal-temporal then functions. From here, information moves into the articulatory network, which is essentially the motor system for speech production.
According to the model, damage to the dorsal stream may result in conduction aphasia, characterized by a difficulty with repetition of speech with no impairment to the recognition of speech.