Jason M. Watson, Ph.D.Departments of Psychology and Neurology

Center on AgingCenter for Alzheimer’s Care, Imaging, & Research

The Brain InstituteUniversity of Utah

Email: jason.watson@psych.utah.eduPhone: 801-581-5040

Individual Differences inIndividual Differences inControlled Cognition Controlled Cognition

Academic Interests As a Cognitive Scientist, my overarching research goal is to use scientific methods to investigate brain-behavior relations.

Given the inter-disciplinary nature of Cognitive Science, I employ a combination of methods from Cognitive Psychology, Neuropsychology, and Cognitive Neuroscience to investigate controlled cognition including:

measuring reaction times & accuracy measuring memory performance cross-population studies functional neuroimaging

What Is Cognitive Control?

One of the primary functions of working memory is cognitive control.

Cognitive control refers to how working memory is used to maintain task goals in the presence of interfering or distracting information.

Individual differences in working memory capacity will influence behavioral performance in cognitively challenging tasks where interference must be minimized.

The neural substrates of controlled cognition are in prefrontal cortex.

Kane & Engle (2002)

Kane & Engle (2002)

Watson, Bunting, Poole, & Conway (2005)

Cognitive Control and Distraction

Controlled Cognition and the Frontal Lobe

Inducing false memoriesvia semantic associates

bed

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pajamas Deese (1959)Roediger & McDermott (1995) Roediger, Balota, & Watson (2001)

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Roediger, Watson, McDermott, & Gallo (2001)

Two Factor Theory

Automatic Spreading of Activation

Controlled Monitoring

Additional Evidence for Two-Factor TheoryOf Associative Memory Illusions

Presentation Duration Aging & Dementia

Functional Neuroimaging

McDermott & Watson (2001)

Watson, Balota, & Sergent-Marshall (2001)

McDermott, Petersen, Watson, & Ojemann (2003)

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Individual Differences in Working Memory Capacity and Associative False Memories

Watson, Bunting, Poole, and Conway (2005; Experiment 2, JEP:LMC)

Tested 100 young adults with varying levels of WMC

25 subjects/cell in a between-subjects factorial crossing of WMC (high vs. low span) with a warning manipulation (present vs. absent) using the Deese-Roediger-McDermott or DRM false memory paradigm

All participants received 5 study/test trials (i.e., practice).

Prediction: All subjects were expected to benefit from practice but only high spans were expected to benefit from forewarning.

Watson, Bunting, Poole, & Conway (2005)

Watson, Bunting, Poole, & Conway (2005)

Conclusion: Low spans had difficulty actively maintain task goal (warnings) intended to reduce susceptibility to false memories. Repeated study-test trials (practice) afforded greater environmental support to suppress false memories.

Individual Differences in Working Memory Capacity and Associative False Memories

Warning Effects on False Recall

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Conway, Kane, Bunting, Hambrick, Wilhelm, & Engle (2005)

A Primer on Working Memory Capacity Tasks

Summary & Conclusions – Part I

Activation-monitoring theories can explain DRM false memories.

Individual differences in working memory capacity may reflect underlying variability in frontally-mediated cognitive control.

Low spans may be less able to control false recall in the DRM paradigm via forewarning manipulations (Watson et al., 2005).

However, low spans can use forewarnings to reduce memory illusions – so long as you are using episodic recognition tests.

Recognition memory tests may offer participants greater environmental support to compensate for cognitive control deficits.

Localizing Impairment in Executive Functionin Early Alzheimer’s Disease with Neuroimaging

Memory loss is the cardinal, clinical symptom of Alzheimer’s disease.

There is increasing evidence that executive function or working memory is also compromised early in the disease with a prominent role for prefrontal cortex in goal-directed, controlled cognition.

Change in executive function in Alzheimer’s disease (AD) can be documented with carefully designed experimental procedures.

GOAL: Use advances in neuroimaging technology in combination with neuropsychological testing to determine the neural mechanisms of cognitive change in early AD.

Localizing Impairment in Executive Functionin Early Alzheimer’s Disease with Neuroimaging

HYPOTHESIS: Functional magnetic resonance imaging (fMRI), diffusion tensor imaging (DTI), and neuropsychological testing will localize the breakdown in executive function in early AD to frontal cortex.

PREDICTIONS: (1) fMRI will reveal decreased neural activity in prefrontal cortex due to increased plaque burden in early AD.

(2) DTI will reveal impaired white matter functional connectivity with prefrontal cortex in early AD.

(3) Neuropsychological testing will reveal deficits in executive function mediated by prefrontal cortex in early AD.

Castel, Balota, et al. (2007)

Cognitive Control and Goal Maintenance in the Simon Task

Why is the Simon Task Optimal?

Healthy older adults and AD patients differ behaviorally on this task.

Castel, Balota, et al. (2007)

Simon Says AD Patients Lose Cognitive Set with Deficits in Executive Function

Why is the Simon Task Optimal?

Healthy older adults and AD patients differ behaviorally on this task.

The Simon task is a relatively process-pure measure of executive function with minimal memory demands.

The Simon task activates the executive function network including prefrontal cortex and anterior cingulate (Peterson et al., 2002).

The Simon task can be administered quickly (about 45 min.) and on two occasions to assess its reliability and validity.

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Summary & Conclusions – Part II

The Simon task is optimal for investigating individual differences in cognitive control and goal maintenance.

AD deficits in Simon task may be due to breakdowns in prefrontal cortex and erosion of executive functions/cognitive control.

Investigations of cognitive control and reaction time distributions in young adults may offer predictions for age- or dementia-related changes in executive function.

High span young adults may attempt to automate control functions, resulting in decreased tails of RT distributions and increased errors.

Reactive vs. proactive control AND relative degradation with age/AD.

Status Report and Future Directions

Enrolled 10 healthy older adults who have already completed neuropsychological testing. Scanning to commence in March.

Actively recruiting AD patients who have already completed neuropsychological testing as part of their routine clinical care.

Data analysis, data analysis, data analysis (spring/summer 2008).

Grant writing and submission (fall 2008) using pilot data obtained to justify application of protocol to patient populations who may be at risk for developing AD (e.g., Mild Cognitive Impairment).

Continued, parallel investigation of controlled cognition in young adults as a possible model for age- or dementia-related declines in cognitive function and to determine if RT distribution parameters can truly be wed to functional neuroanatomy.

Executive

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1. Inhibition2. Task Switching3. Manipulation4. Goal

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Individual Differences

ACC

A set of cognitive abilities that control and

regulate other abilities and behaviors.A “supervisory

attention system” that is engaged during conflicts

among task goals, external stimuli and well-learned

response schemas

“Span measures strongly predict a

very broad range of higher-order

cognitive capabilities,

including language comprehension,

reasoning and even general

intelligence”

Acknowledgements

Janelle Seegmiller Ann Lambert Eve Miller many CSL Research Assistants

Center on Aging Pilot Grant Program Center for Alzheimer’s Care, Imaging, & Research Drs. Norman Foster, Gordon Chelune, Jim Lee, Ed Hsu, & Sarang Joshi