Selection of GENTasks per (sub)cortical area

Considering the fascicle terminations in each parcel, the GENTasks can be adapted to the area to be resected; hence the idea to use tasks most relevant for the underlying language fascicles. Since syntactic functions are particularly confined to the frontal lobe, resections of frontal lesions should be monitored with verb generation/action naming and sentence production.

The GENTask with four drawn objects and one written subject requires the production of a sentence with a (transitive) verb, connecting the subject and object. On the other hand, parieto-temporal lesion resections are better monitored with auditory input, provided by the "speaking slide," where the (intransitive) verb is presented audibly at the start of the task trigger.

Schematically, a functional-to-anatomical relationship can be proposed:

• Verb Generation (Syntax): (superior) frontal parcels

• Auditory, spoken verb & repetition (Phonological tasks): superior-temporal & parietal parcels

• Correlation (Semantics): mid- & inferior temporal parcels

• Memory: anterior temporal parcels

Or an anatomical-to-functional relation:

• Frontal: Syntax > Phonology > Semantics

• Parietal: Phonology >> Semantics

• Temporal: Semantics > Phonology

Proposed Scheme:

• Frontal: 4 Objects, 1 Subject (written or spoken), Verb to generate

• Parieto-Temporal: 4 Objects, 1 Subject (written), 1 Verb (spoken)

• Temporal: 4 Objects, 1 Verb (written or spoken)

The purpose is to obtain from the patient the construction of a short, grammatically and semantically correct sentence. The written and depicted items must be linked with a verb, proposed or generated by the patient. Besides pictures of objects, living or not, famous faces, numbers, colors, or geometrical shapes can also be presented.

Instead of verbs, sounds of living (e.g., animals) or daily life objects (natural phenomena) are available. The verbs are preferably transitive to allow a direct object or intransitive, lowering syntactic complexity. Simultaneous evaluation of the visual fields is achieved by presenting the four objects in the four corners of the screen: the correct item is best projected in the corner opposite to the lesion (left corner for right-sided lesions and vice-versa, superior corner for inferior lesions and vice-versa).

Manual indication of the correct response on the touch screen by the patient, using the index finger opposite to the lesional side, offers the simultaneous possibility to evaluate mobility.

Another advantage is the possibility to evaluate illiterate or non-native patients through visual presentation of the four objects with auditory input of a subject or verb. An interpreter is necessary to evaluate the response accurately.

In case of error, spontaneous speech is elicited to verify if a steady state is reached before restarting the mapping tasks.