Effects of episodic familiarity and statistical regularity On intentional forgetting

Intentional forgetting of unwanted information is an essential cognitive function often studied using the item-method directed forgetting (DF) procedure, whereby cuing some study materials with a Forget instruction impairs their memory compared to cuing with a Remember (R) instruction. Across seven experiments, this investigation examined how episodic familiarity and statistical regularity influence intentional forgetting using verbal and pictorial stimuli. In Experiment 1-4, some stimuli were familiarized by a preview phase before the DF phase, and memory was later assessed using an old/new recognition test. Experiment 1 used words, Experiment 2 used fractal images, Experiment 3 included both meaningful and meaningless object images, and Experiment 4 compared words and nonwords. Previewed items showed reduced DF compared to non-previewed items, regardless of the nature of the information, and meaningless stimuli are challenging to intentionally forget regardless of their degrees of familiarization unless they are meaningless verbal material. Experiment 5 and 6 used complex scene images that varied in statistical regularity. Experiment 5 had no preview phase, whereas Experiment 6 introduced episodic familiarity through a preview phase. Experiment 7 assessed the perceived meaningfulness of previewed and non-previewed images and examined how those ratings related to DF magnitudes from Experiment 5 and 6. Experiment 5 showed that statistically regular scenes were more susceptible to DF than statistical irregular scenes. Notably, meaningfulness emerged as a key factor influencing DF across all experiments. More meaningful materials were more susceptible to intentional forgetting. Additionally, when previewing enhanced the meaningfulness of statistically irregular images (as seen in Experiments 5, 6, and 7), it also increased their susceptibility to DF. Together, the results showed that materials associated with higher memory performance are not always harder to intentionally forget and are determined by multiple factors.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Psychology

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Lo, Yi-Pei

Contributors dc:contributor

• Sahakyan, Lili
• Beck, Diane
• Benjamin, Aaron
• Federmeier, Kara
• Montag, Jessica

• memory
• intentional forgetting
• directed forgetting
• episodic memory
• memory control
• statistical regularity

Statement dc:rights

• Copyright 2025 Yi-Pei Lo

Language dc:language

en

Handle dc:identifier

https://hdl.handle.net/2142/132556

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/132556