| Inferior frontal (IFG) |
Pars opercularis (pop) |
Phonological processing & articulatory control |
- Intraoperative stimulation†: Anomia & phonological paraphasias
- Excision / infarct ‡: Reduced (phonemic) fluency; ‘Broca’s aphasia’
|
| Pars triangularis (ptr) |
Semantic executive control, esp. under high demands |
- Intraoperative stimulation: Anomia
- Excision / infarct: Disrupted speech and perhaps comprehension; (Semantic) errors during naming or reading
|
| Pars orbitalis (por) |
Controlled semantic retrieval |
- Intraoperatively: Most likely no behavioral change
- Excision / infarct: Sentence comprehension; semantic errors in reading
|
| Ventral premotor cortex |
Speech output / articulation |
- Intraoperatively: Dys/anarthria
- Excision: Speech production deficits
|
| Middle frontal (MFG) |
Mid-to-posterior, including inferior frontal junction |
Semantic processing; task & language switching |
- Intraoperatively†: semantic errors & paraphasias; anomia
- Excision / infarct: transient deficits
|
| “Area 55b”; junction with precentral gyrus |
Articulation, fluency; integration of phonological & semantic processing |
- Intraoperatively: Speech arrest, semantic paraphasias, anomia
- Excision / infarct: apraxia of speech
|
| “Exner’s”; junction of SFS and precentral gyrus |
Graphemic representations / control |
- Intraoperatively: Agraphia (writing arrest/errors)
- Excision / infarct: Agraphia
|
| Superior frontal (SFG) |
pre-Supplementary Motor Area (SMA) |
Initiation and sequencing of spontaneous speech |
- Intraoperatively: Speech slowing / arrest, naming/fluency errors
- Excision: Ataxic speech
|
| Insula |
Insula |
Complex articulatory control |
- Intraoperatively: Speech arrest/anarthria, anomia
- Excision / infarct: (persistent) aphasia, reduced fluency
|
| Inferior Parietal Lobe; TemporoParietal junction (IPL/ TPJ) |
General region |
Cognitive processes required for writing |
- Intraoperatively: Writing errors/agraphia
- Excision / infarct: Pure or apraxic agraphia
|
| Supramarginal gyrus (SMG) |
Phonological processing with sub-regions (e.g., for concept integration) |
- Intraoperatively: Anomia, phonological paraphasias / articulation errors
- Excision / infarct: “Broca’s aphasia”
|
| Angular gyrus |
Multimodal executive semantic processing & integration with subdivisions |
- Intraoperatively: anomia, sometimes reading errors
- Excision / infarct: anomic aphasia, Agraphia / dystypia / alexia, Sentence /auditory comprehension deficits
|
| Lateral temporal lobe |
Posterior superior temporal gyrus (STG) / sulcus (STS) (lateral to planum temporale) |
Phonological processing incl. auditory short-term memory and feedback monitoring |
- Intraoperatively: Anomia, Phonological paraphasias / repetition errors, Comprehension deficits, Semantic paraphasias
- Excision / ischemia: Wernicke’s aphasia, Repetition errors, Broca’s aphasia, Naming errors, Syntactic difficulties
|
| Middle STG/STS (lateral to Heschl’s gyrus) |
Acoustic processing of attended / perceived meaningful word sounds |
- Intraoperatively: Anomia, phonological errors, Semantic paraphasias, Sentence / word comprehension deficits
- Excision / ischemia: Comprehension deficits, especially sentence-level
|
| Posterior middle temporal gyrus (MTG) |
Multimodal semantic processing & integration
(Lexical-semantic & Semantic-phonological) |
- Intraoperatively: Anomia/dysnomia, Semantic, phonological, reading errors
- Excision / ischemia: Comprehension, naming errors, Semantic / phonological paraphasias/ errors
|
| Middle MTG |
Word-level semantic processing |
- Intraoperatively: Semantic and phonemic paraphasias; Auditory single word comprehension
- Excision / ischemia: Auditory comprehension, naming errors
|
| Posterior) lateral ITG |
Lexical access for words; integrating word sound & meaning |
- Intraoperatively: Anomia and alexia
- Excision / ischemia: Naming errors and (long-term) alexia (if white matter involved)
|
| Temporal pole (ant. STG + MTG) |
Semantic combinations / judgements for complex sentence structure |
- Intraoperatively: Naming / sentence comprehension errors
- Excision / ischemia: Word finding difficulties, esp. visual naming, Word and sentence comprehension deficits
|
| Medial inferior temporal |
Ventral occipitotemporal cortex (VOTC) (mid- post. fusiform) |
Orthographic processing with subdivisions (visual categorization vs integration) |
- Intraoperatively: Reading errors /disruption esp. meaning-based (morphogram) reading
- Excision / ischemia: Impaired reading
|
| Basal temporal language area (BTLA) (ant. fusiform, between pole & VOTC) |
Multimodal semantic processing; orthographic-semantic integration |
- Intraoperatively: Various errors, most consistently in naming
- Excision / ischemia: Persistent naming decline
|