Preserved metamemorial ability in patients with mild Alzheimer’s disease: Shifting response bias

Abstract

Patients with mild Alzheimer's disease (AD) display a greater tendency to endorse unstudied items as 'old' on memory tests than healthy older adults. This liberal response bias may result in mistaken beliefs about the completion of common tasks. This research attempted to determine whether it was possible to shift the response bias of mild AD patients to be more conservative on a recognition memory test through behavioral intervention. Patients with mild AD and matched controls were evaluated with two almost identical paradigms, separated by about one week. For each session, 30 words were studied and 60 words (half studied, half novel) were shown at test. During one session participants were told that 30% of words were old, and at the other session that 70% were old. We found that both groups were able to shift their response bias between the two conditions. That patients with mild AD were able to successfully shift their response bias demonstrates that-despite their overall liberal response bias and poor memory relative to controls-one component of metamemorial ability is preserved in patients with mild AD. Keywords memory; Alzheimer' s disease; response bias; metamemory; discrimination Alzheimer's disease (AD) causes progressive memory impairment leading to lesser than normal levels of true recognition and greater than normal levels of false recognition (for review see Budson, Wolk, Chong, & Waring, 2006). Discrimination in recognition memory tests is often calculated by using a "corrected score" of hits minus false alarms. However, this corrected Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Discrimination is one important factor in memory performance. In the context of a recognition memory task, discrimination is expressed by the ability to distinguish items previously seen from those which were not seen during the prior study portion. Another factor impacting memory is response bias, which is the overall tendency to respond "old" to test items. Response bias may be liberal (responding "old" greater than 50% of the time) or conservative (responding "old" less than 50% of the time) (Snodgrass & Corwin, 1988;Macmillan & Creelman, 2005;Huh, Kramer, Gazzaley, & Delis, 2006). Although perfect discrimination is always accompanied by a neutral bias, as discrimination decreases the range of possible biases increases. Individuals with high rates of false recognition show an abnormally liberal bias; understanding this liberal bias may be important in understanding false memories. NIH Public AccessSeveral studies have explored the impact of aging upon response bias in ...

Response bias and response monitoring: Evidence from healthy older adults and patients with mild Alzheimer’s disease

“…Several studies examining meta-memory have found evidence that patients perform similar to healthy controls on tasks measuring meta-memory (Bäckman & Lipinska, 1993; Gallo, Cramer, Wong, & Bennett, 2012; Moulin, Perfect, & Jones, 2000; Schmitter-Edgecombe & Seelye, 2011). As reviewed previously, Waring et al (2008) found that patients could shift their response bias when given more detailed instructions about the memory test. However, in the current study, patients were not told to respond in any specific manner.…”

“…Given that many studies have found an abnormally liberal response bias in patients with AD despite different experimental stimuli and conditions (Beth, Budson, Waring, & Ally, 2009; Budson, Wolk, Chong, & Waring, 2006; Deason, Hussey, Ally, & Budson, 2012; Waring, Chong, Wolk, & Budson, 2008), one important question that arose was whether patients with mild AD were capable of altering their response bias. Waring and colleagues (2008) directly examined whether patients with mild AD could shift their response bias if provided with specific instructions.…”

“…Waring and colleagues (2008) directly examined whether patients with mild AD could shift their response bias if provided with specific instructions. In their experiment, participants were presented with a recognition memory test composed of 50% old and 50% new words, but participants were instructed that either 30% or 70% of the words were old.…”

Enhancing the Salience of Fluency Improves Recognition Memory Performance in Mild Alzheimer's Disease

“…Moreover, enhancing patients' reliance on fluency was often found to shift them to a more liberal response bias [5,32]. Although it remains unclear what determines the response bias adopted by AD patients, it seems that, in certain conditions, they are not biased towards "yes" answers or even show conservative criteria [44,53,54]. One such condition, relevant to the current study, is the frequency of verbal stimuli.…”

Using Mental Imagery to Improve Memory in Patients With Alzheimer Disease

“…A great deal of research has recently been focused on helping patients with mild cognitive impairment or very mild AD use novel techniques to enhance new learning 71,72 . These findings, in addition to work showing that patients can use metacognitive strategies to improve memory performance 73,74 , have led researchers to develop salubrious cognitive rehabilitation programs for these individuals 75 . As part of cognitive rehabilitation to improve memory, many investigators have used mental imagery, which has shown great improvement in healthy older adults 14 .…”