The Effects of Presentation and Processing on Explicit Memory in Older AdultsFelicia Oropeza M. A.

California State University, Sacramento

“It is a mistake to regard age as a downhill grade toward dissolution. The reverse is true. As one grows older, one climbs with surprising strides.” George Sand (1804 - 1876)

Overview

• Memory Tasks and Processes• Research on Cognitive Aging• Operational Definitions• Hypotheses• Methods• Results• Limitations• Discussion • Future Directions

Memory Tasks and Processes

• Memory Tasks• Explicit• Implicit

• Memory Processes• Supraliminal• Subliminal

Which tasks use more conscious thought?

Implicit Memory

Explicit Memory

Free Recall

Direct Recollection

Conscious Awareness

Priming

No Conscious Recollection

Research on Cognitive Aging

•Mild dementia => Short term memory lapses

•Moderate and severe cases => Long term memory lapses

Is it Truly Memory Loss?

• Reasons for Inability to remember • High Glucose intake• Lower oxygen and respiratory capacity• Heightened Anxiety

• Limited social circles• Discrimination• Limited mobility • Declines in physical and mental health

Age Effects on Memory

• Worst fear of the aging population• More than 20% of seniors 85+ suffer from dementia

• Urgent call for intervention to slow or reverse early stages of dementia‒ Cognition‒ Behavioral Science‒ Educational Technology

Age Effects on Memory (cont’d)• Age effects on memory tests

• Explicit • Not on implicit tests

• Category exemplar tests are the exception! • Differential age effects on memory tasks blur

Relationship between levels of processing, associative neural networks and compensatory strategies• Classical study of levels of processing (Craik

and Lockhart)• Connection between thematic relatedness

and associative neural networks activated by deep levels of processing

• Compensatory strategy seen more commonly in older adult memory test performance

The Aging Brain

Compensatory Neural Networks

Levels of Processing

Presentation of Visual Stimuli

Why is thematic relatedness a more appropriate variable for studying levels of processing in aging populations?

• Significant age differences in effortful processing tasks when presented with atypical and related stimuli

• Captures effects of:• Meaning based processes• Depth of encoding• Strengthened neural networks• Parallel and distributed memory processes

Independent VariablesOrder of

Presentation

Video Code 1

Video Code 2

Video Code 3

Video Code 4

Relatedness

Thematic

Non-thematic

Presentation

Supraliminal

Subliminal

RelatednessT

hem

atic

: Z

oo A

nim

als

• 1 Phase per video

• A total of two randomly sorted lists of 10 words each

The

mat

ic :

Veg

etab

les

• 1 Phase per video

• A total of two randomly sorted lists of 10 words each

Non

-The

mat

ic

• 2 Phases per Video: 1 Supraliminal and 1 Subliminal

• The phases contain a randomly sorted list of 10 words each

Presentation

Supraliminal10 words presented for 2 seconds at a time per

phase

Two phases of supraliminal conditions per video

20 supraliminal words used in sum

Subliminal10 words presented for .04 seconds at a time per

phase

Two phases of subliminal conditions per video

20 subliminal words used in sum

Presentation

Dependent Variables

Hits• The number of correctly

remembered words

False Alarms

• The number of words written on the exam that were not presented during the testing phase

Hypotheses: Main Effects

Presentation

Supraliminal

Subliminal

Relatedness

Thematic

Non-Thematic

Hypotheses: Interactions

Supraliminal Thematic

Supraliminal Non Thematic

Will the compound effect of thematic relatedness and supraliminal presentation of stimuli yield

higher explicit memory test performance results in older adults?

Methods• Received approval from the CSUS IRB with

minimal risk• Random assignment of 48 older adults to one of

four video conditions• Four phases

• supraliminal-thematic• supraliminal-nonthematic• subliminal-thematic• subliminal-nonthematic.

• Used a partial counterbalancing Latin Square procedure

Results• Hits

(Modified by Interaction)

• False Alarms

Presentation

• Hits only (Modified by Interaction)

Relatedness

Order of Presentation

No Main Effect or Interaction!

Main Effects Modified by One-Way Interaction

Supraliminal Thematic

Supraliminal Non-Thematic

Findings• Higher recall for words presented for 2

seconds than for words presented for .04 seconds

• Higher recall for words in thematic than in non-thematic conditions

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.504.10

1.15

0.150.00

Supraliminal

Subliminal

Nu

mb

er

of

Co

rre

ctl

y

Gu

es

se

d W

ord

s (

Hit

s)

Significant Interaction of Presentation by Relatedness for

Hits

Discussion

• Combined effect of supraliminal presentation and thematic relatedness => role of deeply processed content

• Younger adults may not use categories to the same degree as older adults to assist in memory test performance

• The contribution of associations between related words to the engagement of conscious processes during completion of memory tasks

Limitations of study

Limited Power

Sampling Method

Type II Error

Small Sample

Size

Limitations of study (cont’d)

Screening tool for

cognitive functioning

• Comparing anomalies to normative performance

Future Directions

• Development of web-based media and curricula specifically geared for the aging population

• Design of senior centers using assistive devices that present engaging reading material for longer periods of time facilitating better reading comprehension

• Leads the way for more work in applied behavior labs specializing in disability research

• May pave the way for interventions that could slow the effects of mild cognitive impairment or even reverse the onset of dementia in genetically predisposed populations

Conclusion• Positive outlook for aging population with

modern cognitive aging research• The enhanced neural network mirrors the

complex interplay of meaning and consciousness as it forever shapes our human experience and survival.

Thank you!

• Special thanks to the Psychology Department at California State University, Sacramento• Thesis Chair: Dr. Kelly Cotter, Ph.D.• Thesis Advisor: Dr. Emily Wickelgren, Ph.D.• Thesis Advisor: Dr. John Schaeuble, Ph.D.

• Many thanks to the Adult Education Research Conference at the University of Missouri at St. Louis for allowing me to present.

• My contact info is: feliciapsychresearcher@gmail.com