Prof. Stefan Heim | If so few are "many" how many are "few"? The neurocogntion of quantifier processing
Guest Lecture
- Date: Feb 14, 2019
- Time: 11:00 AM - 12:00 PM (Local Time Germany)
- Speaker: Prof. Stefan Heim
- Department of Psychiatry, Psychotherapy, and Psychosomatics, Medical School, RWTH Aachen University, Germany
- Location: MPI for Human Cognitive and Brain Sciences
- Room: Wilhelm Wundt Room (A400)
The processing of quantifiers such as "many" or "few" is a complex
operation involving the estimation of the numerosities of objects, their
comparison to a reference amount, and semantic evaluation of that
comparison. This series of processing steps is supported by a
fronto-parietal network predominantly in the left hemisphere. The
criterion that defines a number of objects as e.g. "many" depends on the
context (many pandas vs. many ants) and on personal experience ("many
miles" for a long-distance runner vs. a person using crutches with a
broken leg). We found that this internal criterion can be modified in
the course of a learning paradigm in which healthy young subjects can be
trained to adapt their judgement of "many" from 60% to 40% of all
circles. Most interestingly, changing the criterion for the quantifier
"many" also leads to a change in the criterion for the untrained
quantifier "few", i.e. this change in meaning carries over to the
respective polar opposite. Next, we showed that the source of this
effect was located in Broca's region in the left inferior frontal
cortex, a region known to be relevant for semantic operations in other
paradigms. This finding was further corroborated in two experiments with
patients suffering from atrophy in the frontal cortex, who had
unreliable direct learning and failed to show any carry-over effects to
the untrained quantifier. In contrast, in patients with schizophrenia
who are notorious for their disordered thought, we did not observe any
difficulties in quantifier processing except for general slowing. Poster