Hickok & Poeppel 2007 - Nature

Hickok, G., & Poeppel, D. (2007). The cortical organization of speech processing. Nature Reviews Neuroscience, 8(5), 393–402. https://doi.org/10.1038/nrn2113

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Hickok & Poeppel 2007 - Nature

summary of their model:

• In this model, a ventral stream processes speech signals for comprehension, and a dorsal stream maps acoustic speech signals to frontal lobe articulatory networks. The model assumes that the ventral stream is largely bilaterally organized — although there are important computational differences between the left- and right-hemisphere systems — and that the dorsal stream is strongly left-hemisphere dominant.

history of Wernicke and STG:

• This position was challenged by two discoveries in the 1970s and 1980s. The first was that deficits in the ability to perceive speech sounds contributed minimally to the auditory comprehension deficit in Wernicke’s aphasia2–7. The second was that destruction of the left STG does not lead to deficits in the auditory comprehension of speech, but instead causes deficits in speech production8. These findings do not rule out a role for the left STG in speech perception, but make it clear that additional regions participate in the process.
  • dieses paper geht echt schön auf die Geschichte des auditory-language-streams ein. könnte ich eventuell auch drüber schreiben in ein paar Sätzen am Anfang → Kapitel 1

dorsal stream:

• The suggestion that the dorsal stream has an auditory–motor integration function differs from earlier arguments for a dorsal auditory ‘where’ system, but is consistent with recent conceptualisations of the dorsal visual stream (BOX 2) and has gained support in recent years
• We suggest that there are at least two levels of auditory–motor interaction — one involving speech segments and the other involving sequences of segments. Segmental-level processes would be involved in the acquisition and maintenance of basic articulatory phonetic skills. Auditory–motor processes at the level of sequences of segments would be involved in the acquisition of new vocabulary, and in the online guidance of speech sequences80. We propose that auditory–motor interactions in the acquisition of new vocabulary involve generating a sensory representation of the new word that codes the sequence of segments or syllables. This sensory representation can then be used to guide motor articulatory sequences.
• On the assumption that areas involved in integrating sensory and motor processes would have both sensoryand motor-response properties92,93 (BOX 2), the analyses focused on regions that were active during both the perceptual and motor-related phases of the trial. A network of regions was identified, including the posterior STS bilaterally, a left-dominant site in the Sylvian fissure at the boundary between the parietal and temporal lobes (area Spt), and left posterior frontal regions (FIG. 4)52,53. We propose that the posterior STS (bilaterally) supports sensory coding of speech, and that area Spt is involved in translation between those sensory codes and the motor system
• the dorsal stream circuit that we are proposing is strongly left dominant, and, within the left hemisphere, involves only a portion of the PT.

connection to IFG:

• the left-dominant organization of speech production; the fact that Spt and inferior frontal areas are more tightly correlated in their activation timecourse than STS and inferior frontal areas

speech in both pathways:

• We propose that speech perception tasks rely to a greater extent on dorsal stream circuitry, whereas speech recognition tasks rely more on ventral stream circuitry (with shared neural tissue in the left STG), thus explaining the observed double dissociations

lateralization of both streams:

• the ventral stream itself comprises parallel processing streams. This would explain the failure to find substantial speech recognition deficits following unilateral temporal lobe damage. The dorsal stream, however, is strongly left-dominant, which explains why production deficits are prominent sequelae of dorsal temporal and frontal lesions, and why left-hemisphere injury can substantially impair performance in speech perception tasks.
• we propose that neural mechanisms for integrating information over longer timescales are predominantly located in the right hemisphere, whereas mechanisms for integrating over shorter timescales might be represented more bilaterally. Thus, we are suggesting that the traditional view of the left hemisphere being uniquely specialized for processing fast temporal information is incorrect, or at most weakly supported by existing data.

Text to figure 1:

• Regions shaded blue represent the dorsal stream, which is strongly left dominant. The posterior region of the dorsal stream corresponds to an area in the Sylvian fissure at the parietotemporal boundary (area Spt), which is proposed to be a sensorimotor interface, whereas the more anterior locations in the frontal lobe, probably involving Broca’s region and a more dorsal premotor site, correspond to portions of the articulatory network. aITS, anterior inferior temporal sulcus; aMTG, anterior middle temporal gyrus; pIFG, posterior inferior frontal gyrus; PM, premotor cortex.
• listening to speech activates the STG bilaterally, including the dorsal STG and superior temporal sulcus (STS).

⇒ es gibt dazu MNI Daten, die unbedingt anschauen.

STS:

• Beyond the earliest stages of speech recognition, there is accumulating evidence and a convergence of opinion that portions of the STS are important for representing and/or processing phonological information6,16,26,42,51. The STS is activated by language tasks that require access to phonological information, including both the perception and production of speech51, and during active maintenance of phonemic information52,53. Portions of the STS seem to be relatively selective for acoustic signals that contain phonemic information when compared with complex non-speech signals (FIG. 3a). STS activation can be modulated by the manipulation of psycholinguistic variables that tap phonological networks54, such as phonological neighbourhood density (the number of words that sound similar to a target word) (FIG. 3b). Thus, a range of studies converge on the STS as a site that is crucial to phonological-level processes. Although many authors consider this system to be strongly left dominant, both lesion and imaging (FIG. 3) evidence suggest a bilateral organization with perhaps a mild leftward bias.
• A number of studies have found activation during speech processing in anterior portions of the STS13,27,29,30, leading to suggestions that these regions have an important and, according to some papers, exclusive role in ventral stream phonological processes

posterior STS:

• In addition, the claim that posterior STS regions are not part of the ventral stream is dubious given the extensive evidence that left posterior temporal lobe disruption leads to auditory comprehension deficits6,61,62. It is possible that the ventral projection pathways extend both posteriorly and anteriorly30. We suggest that the crucial portion of the STS that is involved in phonological-level processes is bounded anteriorly by the most anterolateral aspect of Heschl’s gyrus and posteriorly by the posterior-most extent of the Sylvian fissure. This corresponds to the distribution of activation for ‘phonological’ processing, depicted in FIG. 3.

• There is strong evidence that posterior middle temporal regions are involved in accessing lexical and semantic information.

• debate about whether other anterior temporal lobe (ATL) regions also participate in lexical and semantic processing, and whether they might contribute to grammatical or compositional aspects of speech processing.

• Data from direct cortical stimulation studies corroborate the involvement of the middle temporal gyrus in auditory comprehension, but also indicate a much broader network involving most of the superior temporal lobe (including anterior portions), and the inferior frontal lobe

lexical semantic processing:

• Functional imaging studies have also implicated posterior middle temporal regions in lexical semantic processing
• We suggested previously that posterior middle temporal regions supported lexical and semantic access in the form of a sound-tomeaning interface network

middle temporal gyrus network:

• Most of the evidence reviewed above indicates a leftdominant organization for this middle temporal gyrus network. However, the finding that the right hemisphere can comprehend words reasonably well suggests that there is some degree of bilateral capability in lexical and semantic access, but that there are perhaps some differences in the computations that are carried out in each hemisphere.
• ATL regions have been implicated in both lexical/semantic and sentence-level processing (syntactic and semantic integration processes). Patients with semantic dementia have atrophy involving the ATL bilaterally, along with deficits on lexical tasks such as naming, semantic association and singleword comprehension70 , which has been used to argue for a lexical or semantic function for the ATL

PT:

• One recent proposal is that the PT functions as a computational hub that takes input from the primary auditory cortex and performs a segregation and spectrotemporal patternmatching operation; this leads to the output of sound object information, which is processed further in lateral temporal lobe areas, and spatial position information, which is processed further in parietal structures.
• PT is probably not homogeneous. In fact, four different cytoarchitectonic fields have been observed in this region96. It is therefore conceivable that one region of the PT serves as a computational hub (or some other function) and another portion computes sensorimotor transformations. Within-subject experiments with multiple stimulus and task conditions are needed to sort out a possible parcellation of the PT.

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Created: 2025-11-15 15:08