Dissociating Statistically Determined Normal Cognitive Abilities and Mild Cognitive Impairment Subtypes with DCTclock.

OBJECTIVE: To determine whether the DCTclock can detect differences across groups of patients seen in the memory clinic for suspected dementia. METHOD: Patients (n = 123) were classified into the following groups: cognitively normal (CN), subtle cognitive impairment (SbCI), amnestic cognitive impairment (aMCI), and mixed/dysexecutive cognitive impairment (mx/dysMCI). Nine outcome variables included a combined command/copy total score and four command and four copy indices measuring drawing efficiency, simple/complex motor operations, information processing speed, and spatial reasoning. RESULTS: Total combined command/copy score distinguished between groups in all comparisons with medium to large effects. The mx/dysMCI group had the lowest total combined command/copy scores out of all groups. The mx/dysMCI group scored lower than the CN group on all command indices (p < .050, all analyses); and lower than the SbCI group on drawing efficiency (p = .011). The aMCI group scored lower than the CN group on spatial reasoning (p = .019). Smaller effect sizes were obtained for the four copy indices. CONCLUSIONS: These results suggest that DCTclock command/copy parameters can dissociate CN, SbCI, and MCI subtypes. The larger effect sizes for command clock indices suggest these metrics are sensitive in detecting early cognitive decline. Additional research with a larger sample is warranted.

Cognitive differences between adults with traumatic brain injury and specific learning disorder.

Background: Impaired working memory, attention, and processing speed are common in individuals with traumatic brain injury (TBI) and specific learning disorder (SLD). Yet, there is a paucity of research that has examined cognitive differences between these groups.Objective: The current study examined potential group differences between individuals with TBI and SLD on performance-based tests of working memory, attention, and processing speed. Subsequently, the study examined whether just processing speed tests could discriminate persons with TBI versus SLD.Method: The authors analyzed archival data to assess differences between 39 adult participants with moderate-severe TBI versus 57 adult participants with SLD on the Trail Making Test Part A, Trail Making Test Part B, Digit Span test, and Symbol Search test.Results: 95% confidence intervals revealed that participants with TBI performed significantly worse on the Trail Making Test Part A and Symbol Search test. Logistic regression analysis procedures revealed that Trail Making Test Part A was the most sensitive discriminator.Conclusion: Diagnosis of moderate-severe TBI compared to SLD can be determined by poor performance on measures of visual scanning and processing speed. These findings may be used for diagnostic interpretation and treatment planning by clinicians.

Instrumental activities of daily living and mild cognitive impairment.

BACKGROUND: Functional impairments are a necessary requirement for the diagnosis of a dementia along with observed cognitive impairment. Comparatively, functional abilities are often relatively intact in those with mild cognitive impairment (MCI). OBJECTIVE: The current research examined the associations between memory clinic participants classified as cognitively intact, amnestic MCI, and mixed/dysexecutive MCI, using Jak-Bondi criteria, and Instrumental Activities of Daily Living - Compensation Scale (IADL-C) abilities, an informant-based questionnaire that quantifies functional abilities. The associations between functional abilities as assessed with the IADL-C and performance on neuropsychological tests were also investigated. METHODS: IADLC scores were obtained along with a comprehensive neuropsychological protocol on memory clinic participants (n = 100) classified as cognitively normal (CN), amnestic MCI (aMCI), or a combined mixed/dysexecutive (mixed/dys) MCI. Regression analyses were employed to determine how the IADLC related to neuropsychological test performance. RESULTS: On the IADLC, greater functional impairment was commonly observed in the mixed/dys MCI group compared to CN participants. Furthermore, the mixed/dys MCI group had lower scores on activities such as Money and Self-Management, Travel and Event Memory subscales compared to the CN group. Linear regression analyses found greater functional impairment in relation to lower scores on executive and episodic memory tests. CONCLUSIONS: Greater functional impairment as assessed with the IADL-C appears to be disproportionately associated with dysexecutive difficulty, and to a lesser degree, episodic memory.

Neurocognitive Constructs Underlying Executive Control in Statistically-Determined Mild Cognitive Impairment.

BACKGROUND: The model of executive attention proposes that temporal organization, i.e., the time necessary to bring novel tasks to fruition is an important construct that modulates executive control. Subordinate to temporal organization are the constructs of working memory, preparatory set, and inhibitory control. OBJECTIVE: The current research operationally-defined the constructs underlying the theory of executive attention using intra-component latencies (i.e., reaction times) from a 5-span backward digit test from patients with suspected mild cognitive impairment (MCI). METHODS: An iPad-version of the Backward Digit Span Test (BDT) was administered to memory clinic patients. Patients with (n = 22) and without (n = 36) MCI were classified. Outcome variables included intra-component latencies for all correct 5-span serial order responses. RESULTS: Average total time did not differ. A significant 2-group by 5-serial order latency interaction revealed the existence of distinct time epochs. Non-MCI patients produced slower latencies on initial (position 2-working memory/preparatory set) and latter (position 4-inhibitory control) correct serial order responses. By contrast, patients with MCI produced a slower latency for middle serial order responses (i.e., position 3-preparatory set). No group differences were obtained for incorrect 5-span test trials. CONCLUSION: The analysis of 5-span BDT serial order latencies found distinct epochs regarding how time was allocated in the context of successful test performance. Intra-component latencies obtained from tests assessing mental re-ordering may constitute useful neurocognitive biomarkers for emergent neurodegenerative illness.

Normative References for Graphomotor and Latency Digital Clock Drawing Metrics for Adults Age 55 and Older: Operationalizing the Production of a Normal Appearing Clock.

BACKGROUND: Relative to the abundance of publications on dementia and clock drawing, there is limited literature operationalizing 'normal' clock production. OBJECTIVE: To operationalize subtle behavioral patterns seen in normal digital clock drawing to command and copy conditions. METHODS: From two research cohorts of cognitively-well participants age 55 plus who completed digital clock drawing to command and copy conditions (n = 430), we examined variables operationalizing clock face construction, digit placement, clock hand construction, and a variety of time-based, latency measures. Data are stratified by age, education, handedness, and number anchoring. RESULTS: Normative data are provided in supplementary tables. Typical errors reported in clock research with dementia were largely absent. Adults age 55 plus produce symmetric clock faces with one stroke, with minimal overshoot and digit misplacement, and hands with expected hour hand to minute hand ratio. Data suggest digitally acquired graphomotor and latency differences based on handedness, age, education, and anchoring. CONCLUSION: Data provide useful benchmarks from which to assess digital clock drawing performance in Alzheimer's disease and related dementias.

[Formula: see text]Survey research in neuropsychology: A systematic review.

Objective: This systematic review paper summarizes the research in neuropsychology using survey methodology, tallies key design features of published survey studies, and evaluates the degree to which the survey methods are disclosed in these publications.Method: We conducted a systematic review of neuropsychological studies that used survey methodology using PRISMA guidelines. We rated 89 surveys on the American Association for Public Opinion Research (AAPOR) required disclosure items and quality indicators.Results: Following the AAPOR guidelines for survey disclosure and quality, we found only fair to good compliance with disclosure requirements, with the average article reporting 73% of the required elements of method. Rates of disclosure of required items went up after the year 2000 but then dropped back somewhat after 2010. We also found a decrease in survey response rates over time.Conclusions: Most of the surveys published concern practice patterns and trends in the field. Response rates have gone down, as is common in other surveys. There is room for improvement in disclosure practices in survey articles in neuropsychology. We provide a rubric for evaluating disclosure of methods, to guide researchers who want to use surveys in their neuropsychological research, as well as guide consumers of survey research.

Visuospatial performance in patients with statistically-defined mild cognitive impairment.

Introduction: The Oblique Effect denotes superior performance for perceiving horizontal or vertical rather than diagonal or oblique stimuli. The current research investigated responding to oblique test stimuli in patients with mild cognitive impairment (MCI).Method: Four statistically-determined groups (n = 112) were studied; patients with little to no cognitive impairment (non-MCI, n = 39); subtle cognitive impairment (SCI, n = 15); amnestic MCI (aMCI, n = 28); and a combined mixed/dysexecutive MCI (mixed/dys MCI, n = 30). The ability to respond to oblique versus non-oblique test stimuli was assessed using the Judgment of Line Orientation Test (JOLO). Comprehensive neuropsychological assessment was also obtained. Between-group differences for JOLO oblique and non-oblique test stimuli were analyzed. Hierarchical linear regression models were constructed to identify relations between accuracy for oblique and non-oblique test items and neurocognitive domains.Results: The mixed/dys MCI group demonstrated lower accuracy for oblique test items compared to non-MCI patients. Accurate responding to oblique test items was associated with better performance on tests measuring executive control, processing speed, naming/lexical retrieval, and verbal concept formation. No between-group differences were seen for non-oblique items and these items were not associated with cognition.Conclusions:Significant impairment on oblique test items distinguished patients with multi-domain/dysexecutive MCI from non-MCI patients. Accurate responding to oblique test items was associated with a complex array of neuropsychological tests suggesting that multidimensional neuropsychological skills underlie the visuospatial reasoning abilities necessary for successful oblique line identification. Research associating responding to oblique versus non-oblique test stimuli using additional neuropsychological test paradigms, and MRI-defined neuroanatomical regions of interest may provide additional information about the brain-behavior relations that underlie MCI subtypes.

Visual and Verbal Serial List Learning in Patients with Statistically-Determined Mild Cognitive Impairment.

BACKGROUND AND OBJECTIVE: Prior research with patients with mild cognitive impairment (MCI) suggests that visual versus verbal episodic memory test performance may be more sensitive to emergent illness. However, little research has examined visual versus verbal episodic memory performance as related to MCI subtypes. RESEARCH DESIGN AND METHODS: Patients were diagnosed with non-MCI, amnestic MCI (aMCI), and combined mixed/dysexecutive MCI (mixed/dys MCI). Visual and verbal episodic memory were assessed with the Brief Visuospatial Memory Test-Revised (BVMT-R) and the 12-word Philadelphia (repeatable) Verbal Learning Test (P[r]VLT), respectively. RESULTS: BVMT-R and P(r)VLT scores yielded similar between-group patterns of performance. Non-MCI patients scored better than other groups on all parameters. aMCI and mixed/dys MCI did not differ on immediate or delayed free recall. Both delayed BVMT-R and P(r)VLT recognition test performance dissociated all three groups. Logistic regression analyses found that BVMT-R delayed free recall and delayed recognition scores correctly classified more patients with MCI (75.40%) than analogous P(r)VLT scores (66.20%). Visual versus verbal memory within-group analyses found no differences among non-MCI patients; P(r)VLT immediate free recall was worse among aMCI patients, but BVMT-R immediate free recall and delayed recognition were worse among mixed/dys MCI patients. DISCUSSION AND IMPLICATIONS: Between-group analyses found convergent patterns of performance such that both tests identified elements of amnesia. However, logistic and within-group analyses found differing performance patterns suggesting that impaired visual episodic memory performance may be specific to emergent illness in mixed/dys MCI. Complementary but divergent neurocognitive networks may underlie visual versus verbal episodic memory performance in some patients with MCI.