Biomedical subjects

Julie A Suhr

Publications and source records attributed to Julie A Suhr.

13 recordsLinked to original sources

PubMed2006

The validity of the letter memory test as a measure of memory malingering: robustness to coaching.

The letter memory test (LMT) is a computerized forced-choice test of malingering detection including two face valid difficulty manipulations: increase in target stimulus length and increase of response foils. Prior research suggests the LMT shows promise as a malingering detection measure. In the present study, the utility of the LMT in the identification of malingering was further explored, using a counterbalanced design in a simulated malingering sample. Prior work was extended by assessing the robustness of the LMT to coaching and assessing the effectiveness of an additional scoring method, utilizing the face valid difficulty manipulations. Results were consistent with prior research on the LMT, with the standard cutoff score yielding high indices of accuracy. The LMT showed no order effects and was superior to the 15-item test in accuracy indices. Both the standard LMT score and the proposed score based on difficulty manipulations were relatively robust to coaching. Overall, findings indicate the LMT is a viable contender among measures of memory malingering.

Case-Control Studies↗

PubMed2006

An obsessive-compulsive subtype of schizotypy: evidence from a nonclinical sample.

Obsessive-compulsive (OC) and schizotypal symptoms are highly correlated in clinical samples. The current study investigated the presence of schizotypal and OC symptomatology in a large undergraduate sample using factor and cluster analysis and t test comparison of cluster groups. Separate clusters of individuals reporting high levels of schizotypal and OC symptoms versus purely schizotypal symptoms emerged and demonstrated different overall symptom profiles. Individuals with high levels of pure schizotypy symptoms demonstrated a prevalence of interpersonal symptoms, including restricted affect, and few close friends. In contrast, those with high levels of both schizotypy and OC symptoms demonstrated higher cognitive/perceptual symptoms, including ideas of reference and suspiciousness. Consistent with research in clinical populations, results suggest greater prevalence of positive symptoms in individuals experiencing both schizotypal and OC disorder symptoms.

Adolescent↗

PubMed2005

Further exploration of the effect of "diagnosis threat" on cognitive performance in individuals with mild head injury.

The present study further explored the phenomenon of "diagnosis threat" (Suhr & Gunstad, 2002), by examining the potential explanatory roles of anxiety, effort, and depression. Individuals with mild head injury history were randomly assigned to receive either neutral instructions (controls, N = 25) or to have attention called to their head injury history as a reason for invitation into the study (diagnosis threat, N = 28). Depression was measured at baseline. Following the neuropsychological battery, ratings of effort, test pressure, and state anxiety were completed. The diagnosis threat group performed worse than controls on attention/working memory, psychomotor speed, and memory tasks, but not on measures of executive functioning, post-test anxiety, or effort. Effort, anxiety and depression were not related to cognitive performance, nor did depression interact with expectations in explaining group differences in performance. Results provide further support for the "diagnosis threat" effect, but offer no support for effort, anxiety, or depression explanations for diminished performance.

Adolescent↗

PubMed2004

The relation of hydration status to cognitive performance in healthy older adults.

Little is known about the relation of hydration status to cognitive performance in older adults, who may be more vulnerable to poor hydration and cognitive impairment. We examined whether hydration status was related to cognitive functioning in 28 healthy community-dwelling older adults. Hierarchical regression models demonstrated that lower hydration status was related to slowed psychomotor processing speed and poorer attention/memory performance, after controlling for demographic variables and blood pressure.

Aged↗

PubMed2004

Cognitive factors in Postconcussion Syndrome symptom report.

Past studies suggest a variety of factors that influence the report of Postconcussion Syndrome (PCS) symptoms, including head injury, depression, pain, and subjective expectation. Participants included 190 undergraduates across 8 groups chosen to examine the relative contribution of these factors, as well as treatment-seeking behavior, in the report of both current and past PCS symptoms. Depressed persons, depressed persons receiving treatment, and headache sufferers receiving treatment reported elevated rates of PCS symptoms when compared to controls. Five of the eight groups reported experiencing more current than past symptoms. Head-injured persons and headache sufferers underestimated premorbid symptom rates relative to the baseline of controls. These findings are consistent with the growing number of studies that suggest non-neurologic factors may be more closely related to PCS symptom report than head injury status and raise further concern regarding use of self-reported PCS symptoms in the diagnosis of head injury.

Adolescent↗

PubMed2004

Neuropsychological impairment associated with symptoms of schizotypy: role of depressive and paranoid symptoms.

: Little is known about the role of depressive symptoms in cognitive impairment associated with schizotypy. We compared neuropsychological performance among people reporting high levels of both schizotypal symptomatology on the Schizotypal Personality Questionnaire (SPQ) and depressive symptoms on the Beck Depression Inventory-II (BDI-II), people with high SPQ and low BDI-II, and healthy controls (low SPQ and BDI-II). We hypothesized that the group with both depressive and schizotypal features would demonstrate the greatest impairment. However, that group demonstrated better verbal memory and cognitive set maintenance. Further examination revealed higher endorsement of paranoid/suspicious symptoms in the people with both depressive and schizotypal features. Results highlight the importance of distinguishing among subtype variations in schizotypal research.

Adolescent↗

PubMed2003

Neuropsychological impairment in fibromyalgia: relation to depression, fatigue, and pain.

OBJECTIVE: The present study assessed the relationship of depression, pain, and fatigue to subjective cognitive complaints and objective impairment in patients with fibromyalgia (FM), patients with other chronic pain disorders, and healthy controls. METHOD: Neuropsychological assessment was conducted on 28 FM patients, 27 chronic pain patients, and 21 healthy controls. Five FM patients and five chronic pain patients were excluded due to poor effort on cognitive tasks. Assessment included measures of depression, pain, fatigue, subjective cognitive complaints, memory, executive functioning, intellect, attention, and psychomotor speed. Analysis of covariance was used to assess group differences in cognitive complaints and cognitive test performance, after controlling for depression, pain, and fatigue. Hierarchical regression was used to assess whether objective test performance was related to subjective cognitive complaints, after controlling for depression, pain, and fatigue. RESULTS: FM patients had more memory complaints and reported more fatigue, pain, and depression than other groups. Groups were not different in cognitive performance, after controlling for fatigue, pain, and depression; depression was related to memory performance and fatigue was related to psychomotor speed. Neuropsychological test results did not add significantly to the variance accounted for in subjective cognitive complaints, after accounting for depression, pain, and fatigue. CONCLUSION: Psychological factors, particularly effort, depression, and fatigue, are important in understanding both subjective cognitive complaints and objective cognitive impairment in FM and other chronic pain disorders.

Adult↗

PubMed2002

Executive function deficits associated with symptoms of schizotypy and obsessive-compulsive disorder.

Research suggests that executive dysfunction is seen both in disorders of the schizophrenia constellation and in obsessive-compulsive disorder (OCD), but that the patterns of executive deficits may differ. While disorders of the schizophrenia spectrum reflect impairment of functions such as integration of cognitive activities, a tendency to perseverate, and a failure to notice details (e.g. impairment associated with the dorsolateral prefrontal cortex), OCD may involve problems of impulse control and regulation of behavior, and an inability to maintain cognitive set (e.g. impairment associated with the orbitofrontal cortex). The present study examined differences between high-scorers on a measure of schizotypy, high-scorers on a measure of OCD, high-scorers on both schizotypy and OCD and a control group in performance on executive function tests. As expected, the OCD group demonstrated relative deficits on measures thought to reflect orbitofrontal functioning. However, contrary to expectations, the schizotypal group did not demonstrate deficits on neuropsychological tests thought to reflect dorsolateral prefrontal cortex functioning, and the combined group showed no executive impairment.

Adolescent↗

PubMed2002

"Diagnosis Threat": the effect of negative expectations on cognitive performance in head injury.

The present study examined the effect of negative expectations on neuropsychological test performance. It was hypothesized that having attention called to a history of prior head injury and the potential effects of head injury on cognition would result in diminished neuropsychological test performance relative to individuals with a similar head injury history but who did not have their attention called to their head injury history ('diagnosis threat'). Of 36 participants with a history of mild head injury, 17 were randomly assigned to diagnosis threat and 19 to neutral test directions. The diagnosis threat group performed significantly worse on tests measuring general intellect and memory, but were not different from the neutral group in basic attention or psychomotor speed. The diagnosis threat group rated themselves as putting forth less effort on the neuropsychological battery, and self-rated effort correlated with test performance in that group. Overall, results serve as a reminder that neuropsychological tests are measures of behavior, and thus can be influenced by nonneurological factors.

Adolescent↗

PubMed2002

Postconcussive symptom report: the relative influence of head injury and depression.

The present study explored whether any subset of self-reported postconcussion (PCS) symptoms or specific PCS symptom is sensitive and/or specific to head injury in non-self-selected samples of individuals aged 18-21 with head injury and depression (n = 32), head injury without depression (n = 31), depression without head injury (n = 25), and controls (n = 50). All participants completed a self-report PCS symptom scale based on their current symptoms. Results showed that depression, not head-injury status, largely accounted for elevation in PCS symptom reports, including cognitive symptoms. Thus, report of cognitive PCS symptoms is not specific to head injury, raising concerns about using such items to screen for head injury in the general population.

Adolescent↗

PubMed2002

Perception of illness: nonspecificity of postconcussion syndrome symptom expectation.

A growing number of studies show postconcussion syndrome (PCS) symptom report is influenced by factors other than head injury, suggesting symptoms typically associated with PCS may not be specific to head injury. Given the role that symptom expectation has been hypothesized to play in PCS symptom etiology, a comparison of symptoms expected for various disorders seems overdue. The present study asked 82 undergraduates to report the symptoms they currently experience, and then to report the symptoms they would expect to experience if they had had suffered either a head injury, an orthopedic injury, posttraumatic stress, or depression. No current differences in overall symptoms or in symptom subscales emerged. Results showed individuals portraying head injury, posttraumatic stress, and depression expected an increase in total symptoms, though individuals portraying an orthopedic injury did not expect such an increase. Results also showed simulators of head injury, posttraumatic stress, and depression expected equivalent rates of overall symptoms, memory/cognitive complaints, somatic concerns, and distracter symptoms, though head-injured individuals reported fewer affective symptoms than those portraying psychological disorders. In all, these findings suggest that individuals have a relative lack of specificity in symptom expectation for various disorders, with the implication that symptom checklists for "PCS" may not be useful for diagnosis.

Accidents, Traffic↗

PubMed2002

Malingering, coaching, and the serial position effect.

The normal pattern of performance on list-learning tasks is to recall more words from the beginning (primacy) and end (recency) of the list. This pattern is also seen in patients with closed head injury, but malingerers tend to recall less words from the beginning of word lists, leading to a suppressed primacy effect. The present study examined this pattern on both learning trials and delayed recall of the Auditory Verbal Learning Test (AVLT) in 34 persons performing with normal effort, 38 naive malingerers, 33 warned malingerers, and 29 head-injured patients. Both malingering groups had lower scores on the primacy portion of the list during learning trials, while normals and head-injured patients had normal serial position curves. During delayed recall, normals and head-injured patients did better than the two malingering groups on middle and recency portions of the list. Findings suggest that the serial position effect during learning trials may be a useful pattern of performance to watch for when suspicious of malingering.

Journal Article↗

PubMedDate not supplied

The relationship between blood pressure and cognitive performance in the Third National Health and Nutrition Examination Survey (NHANES III).

OBJECTIVE: The present study examined the relationship between blood pressure and cognitive performance in 2727 healthy men and women between the ages of 20 and 59 years who participated in the Third National Health and Nutrition Examination Survey (NHANES III). METHODS: Participants were selected from a subsample of 5662 NHANES III respondents who completed an initial home interview, a medical examination, and a series of computerized cognitive tests of visuomotor reaction time, complex psychomotor speed (ie, symbol digit substitution), and verbal learning/attention (ie, serial digit learning). RESULTS: Hierarchical regressions tested the contribution of resting blood pressure to the prediction of performance on each of the cognitive tests. Results indicated that, after controlling for demographic variables (age, sex, race/ethnicity, education) and resting blood pressure, the interaction of systolic blood pressure by age was a significant predictor of performance on the test of verbal learning/attention. Follow-up analyses revealed that higher systolic blood pressure was associated with poorer performance in those younger than 40 years. CONCLUSIONS: Expanding on findings from previous epidemiological studies, the present study reports a small but significant relationship between resting blood pressure and cognitive performance that is particularly evident in younger healthy adults.

Adult↗