Comparison of cognitive performance between patients with Parkinson’s disease and dystonia using an intraoperative recognition memory test

Neuroscientific studies on the function of the basal ganglia often examine the behavioral performance of patients with movement disorders, such as Parkinson’s disease (PD) and dystonia (DT), while simultaneously examining the underlying electrophysiological activity during deep brain stimulation surgery. Nevertheless, to date, there have been no studies comparing the cognitive performance of PD and DT patients during surgery. In this study, we assessed the memory function of PD and DT patients with the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE). We also tested their cognitive performance during the surgery using a continuous recognition memory test. The results of the MoCA and MMSE failed to reveal significant differences between the PD and DT patients. Additionally, no significant difference was detected by the intraoperative memory test between the PD and DT patients. The intraoperative memory test scores were highly correlated with the MMSE scores and MoCA scores. Our data suggest that DT patients perform similarly to PD patients in cognitive tests during surgery, and intraoperative memory tests can be used as a quick memory assessment tool during surgery.

The fear factor : effects of implicit and explicit processing on the emotional enhancement of memory

This thesis examines whether implicit and explicit processing of emotional facial expressions affects the emotional enhancement of memory (EEM). On the basis that explicit processing is associated with relative reductions in amygdala activation and arousal, I predicted that fearful faces, in particular, would lead to a robust EEM effect following encoding with implicit, but not explicit processing. Participants were shown a series of facial expressions (happy, fearful, angry, and neutral) in an "indirect" and a "direct" task designed to elicit implicit and explicit processing, respectively. Later they underwent a recognition memory test using the Remember-Know paradigm. Fearful faces exhibited a unique pattern whereby indirect encoding led to an enhanced subjective sense of recollection, whereas direct encoding prevented an increase in recollection that was observed for all other emotions. These findings may reflect interactions among amygdalar/arousal thresholds and levels of processing (LOP) effects on recognition memory.

The fear factor : effects of implicit and explicit processing on the emotional enhancement of memory

This thesis examines whether implicit and explicit processing of emotional facial expressions affects the emotional enhancement of memory (EEM). On the basis that explicit processing is associated with relative reductions in amygdala activation and arousal, I predicted that fearful faces, in particular, would lead to a robust EEM effect following encoding with implicit, but not explicit processing. Participants were shown a series of facial expressions (happy, fearful, angry, and neutral) in an "indirect" and a "direct" task designed to elicit implicit and explicit processing, respectively. Later they underwent a recognition memory test using the Remember-Know paradigm. Fearful faces exhibited a unique pattern whereby indirect encoding led to an enhanced subjective sense of recollection, whereas direct encoding prevented an increase in recollection that was observed for all other emotions. These findings may reflect interactions among amygdalar/arousal thresholds and levels of processing (LOP) effects on recognition memory.

Metamemory for pictures of naturalistic scenes: Assessment of accuracy and cue utilization

Memory for naturalistic pictures is exceptionally good. However, little is known about people’s ability to monitor the memorability of naturalistic pictures. We report the first systematic investigation into the accuracy and basis of metamemory in this domain. People studied pictures of naturalistic scenes, predicted their chances of recognizing each picture at a later test (judgment of learning, JOL), and completed a recognition memory test. Across three experiments, JOLs revealed substantial accuracy. This was due to people basing their JOLs on multiple cues, most of which predicted recognition memory. Identified cues include intrinsic picture attributes (e.g., peacefulness of scenes; scenes with or without persons) and extrinsic aspects of the study situation (e.g., presentation frequency; semantic distinctiveness of scenes with respect to the context). This work provides a better understanding of metamemory for pictures and it demonstrates close parallels between metamemory for naturalistic scenes and verbal materials.

A-215 The Utility of the First Ten Items of the Warrington Recognition Memory Test as a Performance Validity Test

Objective Performance validity tests (PVTs) are widely used in neuropsychological evaluations but are often lengthy and time-consuming. Therefore, development of more efficient PVTs is critical. The current study evaluated the utility of the first 10 items of the Warrington Recognition Memory Test (RMT) as an indicator of performance validity. Methods This study utilized archival data from 134 veterans presenting for a clinical neuropsychological evaluation at a southeastern Veterans Affairs hospital. Patients were deemed “credible” if they failed less than two unrelated PVT measures, had a FSIQ > 70, and did not carry a diagnosis of dementia. This resulted in 103 patients in the credible group [Mage = 49.76(11.67); Meducation = 14.09(2.88); 77.67% Male]. The 31 patients in the non-credible group met Slick et al. (1999) criteria[Mage = 45.13(11.18); Meducation = 12.77(2.53); 87.10% Male]. Frequency counts were run to determine sensitivity and specificity values at established cut-offs and to create new cut-offs for the first 10 items. Results Using established cut-off scores, the RMT total score had adequate specificity (91%) with a corresponding sensitivity of 84%, and the RMT time score had adequate specificity (93%) with a corresponding sensitivity of 34%. When examining the first 10 items on the RMT, a score of < 8 resulted in 96% specificity and 61% sensitivity. Conclusions The established cutoffs for the RMT performed well in this patient sample. Additionally, using a cutoff score of ≤ 8 on the first 10 items of the RMT may be a useful indicator of probable failure on the RMT, significantly reducing test administration time.

The impact of sleep on eyewitness identifications

Sleep aids the consolidation of recently acquired memories. Evidence strongly indicates that sleep yields substantial improvements on recognition memory tasks relative to an equivalent period of wake. Despite the known benefits that sleep has on memory, researchers have not yet investigated the impact of sleep on eyewitness identifications. Eyewitnesses to crimes are often presented with a line-up (which is a type of recognition memory test) that contains the suspect (who is innocent or guilty) and fillers (who are known to be innocent). Sleep may enhance the ability to identify the guilty suspect and not identify the innocent suspect (i.e. discriminability). Sleep may also impact reliability (i.e. the likelihood that the identified suspect is guilty). In the current study, we manipulated the presence or the absence of sleep in a forensically relevant memory task. Participants witnessed a video of a mock crime, made an identification or rejected the line-up, and rated their confidence. Critically, some participants slept between witnessing the crime and making a line-up decision, while others remained awake. The prediction that participants in the sleep condition would have greater discriminability compared to participants in the wake condition was not supported. There were also no differences in reliability.

Young and Older Adults May Utilize Different Cognitive Abilities When Performing a Spatial Recognition Memory Test With Varying Levels of Similarity

We used signal detection theory to evaluate spatial recognition memory utilizing a behavioral test hypothesized to tax pattern separation. Correlations with standardized neuropsychological tests also were examined. Healthy young ( n = 40) and older ( n = 30) adults completed a spatial recognition memory test involving high- and low-similarity conditions. Using d’ as the dependent variable, we found that older adults were significantly impaired relative to young adults on the high- and low-similarity conditions ( ps < .05). Both groups performed significantly better in the low-similarity condition compared to the high-similarity condition ( p < .05), with young adults exhibiting greater improvement relative to older adults. We also found that young adults may rely on spatial attention abilities when performing our test, while older adults might rely on memory and executive function abilities. These findings indicate that young and older adults may utilize different cognitive abilities when performing certain spatial memory tests.