Wm. Drew Gouvier

The relationships of working memory, secondary memory, and general fluid intelligence: working memory is special.

Recent efforts have been made to elucidate the commonly observed link between working memory and reasoning ability. The results have been inconsistent, with some work suggesting that the emphasis placed on retrieval from secondary memory by working memory tests is the driving force behind this association (Mogle, Lovett, Stawski, & Sliwinski, 2008), whereas other research suggests retrieval from secondary memory is only partly responsible for the observed link between working memory and reasoning (Unsworth & Engle, 2006, 2007). In the present study, we investigated the relationship between processing speed, working memory, secondary memory, primary memory, and fluid intelligence. Although our findings show that all constructs are significantly correlated with fluid intelligence, working memory-but not secondary memory-accounts for significant unique variance in fluid intelligence. Our data support predictions made by Unsworth and Engle (2006, 2007) and suggest that the combined need for maintenance and retrieval processes present in working memory tests makes them special in their prediction of higher order cognition.

Effects of sophistication and motivation on the detection of malingered memory performance using a computerized forced-choice task.

The present study employed a computerized forced-choice recognition memory task, the Multi-Digit Memory Test (MDMT), to examine the effects of instructional set (i.e., dissimulation information provided subjects) and motivation (i.e., monetary incentive) on simulated malingering behavior in a group of 119 university undergraduate students and 33 patients sustaining varying severity of closed-head injury. For the nonpatient groups, a significant effect of instructional set was revealed. Motivational incentive, however, did not affect forced-choice performance. Overall, significant performance differences emerged between all groups with nonmalingering students performing nearly perfectly, the brain-injured patients performing well above chance levels, sophisticated student malingers performing at chance, and naive student malingers performing well below chance levels. These results suggest the MDMT may offer a clinically useful and convenient addition to a neuropsychological assessment when there is suspicion of feigned memory problems. These data also support the use of naive and sophisticated malingering subjects in further analog studies addressing this topic.

Stress as a diagnostic challenge for postconcussive symptoms: sequelae of mild traumatic brain injury or physiological stress response.

There is considerable controversy regarding whether persistent postconcussive symptoms (PCS) are injury-specific, in a subgroup of individuals after mild traumatic brain injury (TBI). The following findings have contributed to this controversy: (1) The base rate of PCS in mild TBI is comparable to uninjured controls; and (2) The severity of PCS covary with daily stress levels (Gouvier, Cubic, Jones, Brantley, Cutlip, 1992). We examined this relationship further by evaluating the effects of experimental conditions of stress or relaxation on individuals with TBI and uninjured control subjects, with low and high PCS endorsement. We evaluated psychophysiological parameters, neuropsychological performance, and changes in PCS and stress perception. In our study, subjects with TBI increased PCS after engaging in cognitively challenging tasks, and demonstrated significant autonomic changes in the stress condition. Symptomatic TBI subjects exposed to high stress had increases in PCS complaints, decreased speed of information processing, and subtle memory deficits. Our results suggest that PCS are injury-specific and that individuals with a history of TBI are susceptible to the effects of stress. Relaxation training including breathing retraining may be an effective means of decreasing PCS and cognitive complaints in subjects with mild TBI.

Prospective remembering in younger and older adults: Role of the prospective cue

In these studies, adult age differences in event-based prospective memory were examined using an adapted version of G.O. Einstein and M.A. McDaniels (1990) task. In Experiments 13, we varied prospective cue specificity by assigning a specific target word or an unspecified word drawn from a given taxonomic category. In Experiment 3, we manipulated cue typicality by presenting low or high typicality target words. Results yielded positive effects of cue specificity on prospective performance. Age effects occurred when high typicality target words served as prospective cues (Exps. 1 and 3), but younger and older adults performed comparably with moderate and low typicality words (Exps. 2 and 3). Hierarchical regression analyses indicated that age accounted for a small but significant amount of variance in prospective memory, although the contribution of age was substantially reduced after statistically controlling for recognition memory. Implications of these data for current views on prospective remembering are discussed.

“Why Is This So Hard?” A Review of Detection of Malingered ADHD in College Students

Objective: The purpose of this article is to review studies that have investigated malingered ADHD in college students and offer recommendations for assessing effort in clinical evaluations of ADHD in college students. Method: This article identified and summarized nineteen peer-reviewed, empirical studies published between 2002 and 2011 that investigated malingered ADHD in college students. Results: Few of the measures examined proved useful for detecting malingered ADHD. Most self-report questionnaires were not sensitive to malingering. While there is some variability in the usefulness of neuropsychological test failure, profiles between malingerers and individuals with ADHD are too similar to confidently detect malingered ADHD. Failure of three or more symptom validity tests proved most useful at detecting malingered ADHD. Conclusion: This review suggests that there is substantial need for measures designed specifically for detecting malingered ADHD simulators are able to produce plausible profiles on most tools used to diagnose ADHD.

Wheelchair obstacle course performance in right cerebral vascular accident victims.

The initial experiment of this paper investigated the role of hemispatial neglect in wheelchair-related accidents of right-hemisphere stroke victims. Twelve subjects with and 12 subjects without neglect of left space drove their wheelchairs through an obstacle course. Two types of obstacle course errors were evaluated: direct hits and sideswipes. The neglecting group made significantly more direct hits but there were no significant differences between groups in sideswipe errors. In Experiment 2, the nonneglecting groups data were compared with a left-hemisphere stroke group without neglect and three motor control groups to investigate if their errors resulted from motor deficits. The right-hemisphere stroke group made significantly more left-sided errors and errors in contralateral space than any other group. In Experiment 3, 13 subjects with neglect were taught to scan to the left which resulted in significant decreases in direct hits but not in sideswipes on the obstacle course. These results suggest that obstacle course performance is sensitive to more than hemispatial neglect.

Differential Vulnerability between Postconcussion Self-Report and Objective Malingering Tests in Identifying Simulated Mild Head Injury

The present study examined the ability of analog malingerers to feign postconcussion symptoms and neuropsychological performance patterns seen in mild head-injured patients. Experimental subjects were randomly assigned to either a control condition, asked to feign deficits consistent with mild head injury without task specific instruction, or feign deficits while given task-specific instruction. A separate group of mild head-injured patients served as a clinical comparison group. Analog malingering groups accurately simulated levels of postconcussive symptoms seen in the mild head-injured patients. However, poorer performance was displayed by the analog malingerers on the objective malingering tests. Coaching did not facilitate realistic patterns of performance for analog malingerers. The results of this study indicate that analog malingerers accurately replicated self-reported postconcussive symptoms, but were less able to simulate objective clinical malingering test performance. These results suggest that self-report measures of postconcussive symptoms and clinical tests are differentially vulnerable to simulation attempts.

Influence of Social Context on Reported Attitudes of Nondisabled Students toward Students with Disabilities.

The Attitudes Toward Disabled Persons scale was completed by groups of university students with a disability and their nondisabled peers in the presence of either another student with a disability or a nondisabled student. Results showed that the presence of a person with disabilities improved the reported attitudes of individuals without disabilities.

Assessment and rehabilitation of acquired visuospatial and proprioceptive deficits associated with visuospatial neglect

Visuoperceptual disruptions are among the most common, and most debilitating, of the aftereffects following stroke or head injury. Visuospatial neglect in particular, which frequently occurs as a result of insult to the right cerebral hemisphere, has a variety of implications for patient welfare and outcome. And while there exists a great deal of useful information in the area of visual neglect, it is spread out amongst near-countless journal articles, book chapters, and workshop summaries. Thus, it is the purpose of this paper to provide an overview of various topics relating to visuospatial disturbances. Areas covered include theories on sequelae and neuropathology, common direct and indirect complications, rates and types of recovery, past and current trends in assessment and rehabilitation techniques, and thoughts on directions for future research.

Stability of postconcussion symptomatology differs between high and low responders and by gender but not by mild head injury status.

A large sample of undergraduates (N = 2,326) were screened for general health. The screen discretely included items assessing postconcussion symptomatology and neurologic history. A subsample of experiment-blind participants whose self-reported postconcussion symptom levels were >0.5 SD below the screening sample mean (low symptomatic; n = 45) or >0.5 SD above the screening sample mean (high symptomatic; n = 53) were re-evaluated for postconcussion symptomatology 3 to 90 days later. The sample included 50 participants who reported history of mild head injury (MHI) and 48 controls. MHI was defined as loss of consciousness of < or =20 minutes within the past 10 years, but no more recent than 3 months. Persons with history of >1 head injury or with other neurologic history were not included in the study. The stability of postconcussion symptoms differed by high symptomatic versus low symptomatic presentation (high symptomatic presentation was more variable) and by gender (females were more variable), but not by actual history of MHI. Sex differences in self-reported postconcussion symptomatology are consistent with gender-related differences in reporting of other physical and psychological symptoms. In addition to demonstrating differences in the stability of self-reported postconcussion symptomatology, the current study provides normative test-retest data for the Postconcussion Symptom Checklist for extreme responders by gender and MHI status.