On the meaning of numbers: flexibility in the structure and retrieval of memories for Arabic numerals

"We read symbolic representations of numbers like ""24"" across a multitude of contexts – as the name of a TV show, the answer to common arithmetic problems, a symbol for the linguistic expression ""twenty-four"", among others – and utilize multiple systems of memory in order to appropriately interpret them. This thesis examines how these meanings of Arabic numerals are flexibly accessed, retrieved, and evaluated by healthy college-age adults. In order to dissociate these rapidly occurring processes, event-related potentials (ERPs) were recorded while participants read common numerals in tasks that differed in the type and amount of numeral-associated information that would need to be recalled. The first two experiments specifically looked at the evaluation of Arabic numerals in arithmetic contexts, and examined how the two cerebral hemispheres approach reading equations and evaluating potential answers. These experiments revealed similarities in how the hemispheres respond to contextually congruous and incongruous answers but differences in how they evaluate other aspects of provided answers. Specifically, the right hemisphere (and not the left) is sensitive to mathematical relationships beyond whether an answer is right or wrong. The second two experiments assessed how relatively more automatic access of meaning during numeral reading is influenced by task goals (Experiment 3) or by item-level properties of numerals (Experiment 4). The results showed that the amount of meaning information that is relatively automatically accessed during numeral reading is similar (and small) across task, but that the information that can be deliberately or explicitly retrieved differs across item type depending on personalized ratings of familiarity. Additionally, the nature of what is automatically retrieved from semantics is at least somewhat malleable, because, whereas Experiment 4 obtained effects similar in important ways to those observed during semantic retrieval for words, Experiment 3 did not. Across all experiments, the results speak to a fluidity in the kind of information that can be brought to bear during numeral processing, depending on what sort of contextual support is provided and which types of evaluative processes are needed in order to perform the task at hand."

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Psychology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2016

Author dc:creator

• Dickson, Danielle

Contributors dc:contributor

• Federmeier, Kara D.
• Fabiani, Monica
• Hillman, Charles
• Hyde, Daniel
• Fisher, Cynthia

• numerals
• Mathematical cognition
• Event-related potentials (ERPs)
• N400
• Hemispheric differences

Statement dc:rights

• Copyright 2016 Danielle Dickson

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/93066

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/93066