Shannon McGillivray

Brain Atrophy in Long-Term Abstinent Alcoholics Who Demonstrate Impairment on a Simulated Gambling Task

We recently demonstrated impairment on the Simulated Gambling Task (SGT) in long-term abstinent alcoholics (AbsAlc). Brain regions that have been shown to be necessary for intact SGT performance are the ventromedial prefrontal cortex (VMPFC) and the amygdala; patients with VMPFC or amygdalar damage demonstrate SGT impairments similar to those of substance abusing populations. We examined these brain regions, using T1-weighted MRIs, in the 101 participants from our previous study using voxel-based morphometry (VBM). VBM was performed using a modification we developed [Fein, G., Landman, B., Tran, H., Barakos, J., Moon, K., Di Sclafani, V., Shumway, R., 2006. Statistical parametric mapping of brain morphology: sensitivity is dramatically increased by using brain-extracted images as inputs. Neuroimage] of Barons procedure, [], in which we use skull-stripped images as input. We also restricted the analysis to a ROI consisting of the amygdala and VMPFC as defined by the Talairach Daemon resource. Compared to the controls, the AbsAlc participants had significant foci of reduced gray matter density within the amygdala. Thus, SGT decision-making deficits are associated with reduced gray matter in the amygdala, a brain region previously implicated in similar decision-making impairments in neurological samples. This structurally based abnormality may be the result of long-term alcohol abuse or dependence, or it may reflect a pre-existing factor that predisposes one to severe alcoholism. From an image analysis perspective, this work demonstrates the increased sensitivity that results from using skull-stripped inputs and from restricting the analysis to a ROI. Without both of these methodological advances, no statistically significant finding would have been forthcoming from this work.

Selecting Valuable Information to Remember: Age-Related Differences and Similarities in Self-Regulated Learning

It is often necessary to selectively attend to important information, at the expense of less important information, especially if you know you cannot remember large amounts of information. The present study examined how younger and older adults select valuable information to study, when given unrestricted choices about how to allocate study time. Participants were shown a display of point values ranging from 1-30. Participants could choose which values to study, and the associated word was then shown. Study time, and the choice to restudy words, was under the participants control during the 2-minute study session. Overall, both age groups selected high value words to study and studied these more than the lower value words. However, older adults allocated a disproportionately greater amount of study time to the higher-value words, and age-differences in recall were reduced or eliminated for the highest value words. In addition, older adults capitalized on recency effects in a strategic manner, by studying high-value items often but also immediately before the test. A multilevel mediation analysis indicated that participants strategically remembered items with higher point value, and older adults showed similar or even stronger strategic process that may help to compensate for poorer memory. These results demonstrate efficient (and different) metacognitive control operations in younger and older adults, which can allow for strategic regulation of study choices and allocation of study time when remembering important information. The findings are interpreted in terms of life span models of agenda-based regulation and discussed in terms of practical applications.

Monitoring One's Own Forgetting in Younger and Older Adults

The present study examined whether there are age-related differences in the ability to accurately monitor forgetting. Young and older adults studied a mixed list of categorized words, and later recalled items when cued with each category. They then estimated the number of additional items that they did not recall-a form of monitoring ones forgetting. Older adults exhibited impaired memory performance compared with young adults, but also accurately estimated they forgot more information than young adults. Both age groups were fairly accurate in predicting forgetting in terms of resolution, indicating that aging does not impair the ability to monitor forgetting.

Mismatch Negativity: No Difference Between Treatment Naïve Alcoholics and Controls

BACKGROUND Several studies have examined the mismatch negativity (MMN) evoked potential as a measure of a brain inhibitory deficit in alcoholics or those at risk for alcoholism. This study examined MMN in actively drinking treatment-naive alcohol-dependent individuals. This study examined the association of MMN with risk factors for alcoholism, postalcohol withdrawal hyperexcitability, and alcohol use variables. METHODS Electroencephalograms were gathered on 84 subjects (42 controls and 42 treatment-naive alcohol-dependent individuals) during a nonattending MMN experiment. Alcoholism family history density, the number of externalizing disorder symptoms, and psychological indices of deviance proneness served as measures of risk factors associated with the vulnerability to alcoholism. Alcohol use variables were used as measures of alcoholism severity. RESULTS There were no differences in the MMN integral, amplitude, or latency between control and treatment-naive alcohol-dependent subjects. There also were no significant associations of MMN measures with any of the measures of alcoholism vulnerability, with any of the alcohol use variables, or with the prevalence or severity of symptoms of postalcohol withdrawal hyperexcitability. CONCLUSIONS Although there is a strong association between alcohol abuse and symptoms of disinhibition and deviance proneness, the MMN response does not offer any direct physiological evidence of this phenomenon.

Memory for Allergies and Health Foods: How Younger and Older Adults Strategically Remember Critical Health Information

OBJECTIVES While older adults often display memory deficits, with practice, they can sometimes selectively remember valuable information at the expense of less value information. We examined age-related differences and similarities in memory for health-related information under conditions where some information was critical to remember. METHOD In Experiment 1, participants studied 3 lists of allergens, ranging in severity from 0 (not a health risk) to 10 (potentially fatal), with the instruction that it was particularly important to remember items to which a fictional relative was most severely allergic. After each list, participants received feedback regarding their recall of the high-value allergens. Experiment 2 examined memory for health benefits, presenting foods that were potentially beneficial to the relatives immune system. RESULTS While younger adults exhibited better overall memory for the allergens, both age groups in Experiment 1 developed improved selectivity across the lists, with no evident age differences in severe allergen recall by List 2. Selectivity also developed in Experiment 2, although age differences for items of high health benefit were present. DISCUSSION The results have implications for models of selective memory in older age, and for how aging influences the ability to strategically remember important information within health-related contexts.

Memory for medication side effects in younger and older adults: The role of subjective and objective importance

Older adults often experience memory impairments, but sometimes they can use selective processing and schematic support to remember important information. In the present experiments, we investigated the degrees to which younger and healthy older adults remembered medication side effects that were subjectively or objectively important to remember. Participants studied a list of common side effects and rated how negative these effects would be if they were to experience them, and they were then given a free recall test. In Experiment 1, the severity of the side effects ranged from mild (e.g., itching) to severe (e.g., stroke), and in Experiment 2, certain side effects were indicated as being critical to remember (i.e., “contact your doctor if you experience this”). We observed no age differences in terms of free recall of the side effects, and older adults remembered more severe side effects than mild effects. However, older adults were less likely to recognize the critical side effects on a later recognition test, relative to younger adults. These findings suggest that older adults can selectively remember medication side effects but have difficulty identifying familiar but potentially critical side effects, and this has implications for monitoring medication use in older age.

I owe you: age-related similarities and differences in associative memory for gains and losses

ABSTRACT Older adults often experience associative memory impairments but can sometimes remember important information. The current experiments investigate potential age-related similarities and differences associate memory for gains and losses. Younger and older participants were presented with faces and associated dollar amounts, which indicated how much money the person “owed” the participant, and were later given a cued recall test for the dollar amount. Experiment 1 examined face-dollar amount pairs while Experiment 2 included negative dollar amounts to examine both gains and losses. While younger adults recalled more information relative to older adults, both groups were more accurate in recalling the correct value associated with high-value faces compared to lower-value faces and remembered gist-information about the values. However, negative values (losses) did not have a strong impact on recall among older adults versus younger adults, illustrating important associative memory differences between younger and older adults.

Gist-based memory for prices and “better buys” in younger and older adults

ABSTRACT Ageing typically leads to various memory deficits which results in older adults’ tendency to remember more general information and rely on gist memory. The current study examined if younger and older adults could remember which of two comparable grocery items (e.g., two similar but different jams) was paired with a lower price (the “better buy”). Participants studied lists of grocery items and their prices, in which the two items in each category were presented consecutively (Experiment 1), or separated by intervening items (Experiment 2). At test, participants were asked to identify the “better buy” and recall the price of both items. There were negligible age-related differences for the “better buy” in Experiment 1, but age-related differences were present in Experiment 2 when there were greater memory demands involved in comparing the two items. Together, these findings suggest that when price information of two items can be evaluated and compared within a short period of time, older adults can form stable gist-based memory for prices, but that this is impaired with longer delays. We relate the findings to age-related changes in the use of gist and verbatim memory when remembering prices, as well as the associative deficit account of cognitive ageing.

OLDER AND YOUNGER ADULTS’ STRATEGIC CONTROL OF METACOGNITIVE MONITORING: THE ROLE OF CONSEQUENCES, TASK EXPERIENCE, AND PRIOR KNOWLEDGE

Background/Study Context: Although explicit memory abilities decline during older adulthood, there is evidence that suggests that metacognitive capabilities are relatively well preserved. However, it is unclear what effect aging, consequences of forgetting, prior knowledge, and task experience have on the strategic control and use of one’s metacognitive capabilities. Methods: In the current study, older and younger adults were presented with six unique lists of words (Experiment 1), related and unrelated word pairs (Experiment 2), or items within specific scenarios (e.g., items to bring on a picnic; Experiment 3). For each item, participants assigned it a point value (from 0 to 10) that was akin to “betting” on the likelihood the item would be remembered. If the item was recalled (free recall in Experiments 1 and 3, cued recall in Experiment 2), participants received the points they had assigned to it, but if the item was forgotten they lost those points. Participants were told to maximize their point score and were told their score at the end of each list. Results: Although younger adults remembered more words in Experiment 1, older and younger adults were equally able to remember items assigned higher values, and accuracy of predictions and point scores increased with task experience. In Experiments 2 and 3, when participants were able to rely on semantic knowledge, age-related differences in memory performance were eliminated. Conclusion: The results suggest that both younger and older adults achieve accurate metacognitive insight and are able to use this knowledge strategically in order to maximize goal-related memory outcomes and performance.