THREE COGNITIVE DOMAINS
In addition to the critical domain of memory, the complex cognitive (“executive”) functions of various symbol fluency and information processing speeds (simple and complex) are predictive of dementia.
Predictive memory measurement methods (category-guided memory acquisition, immediate and delayed free and guided recall) were selected and combined to create the most reliable and longitudinally valid composite memory score.
Impairments in multiple cognitive domains are predictive of MCI-to-AD progression, even among MCI patients diagnosed with single-domain amnestic MCI,. Word and symbol fluency abilities are associated with greater risk of progression to AD dementia than are isolated memory deficits. .
PROCESSING SPEED/EXECUTIVE FUNCTIONS
Attentional speed along with several dimensions of attention flexibility all add to the robust predictive capacity and reliability of the CANS-MCI Executive Function factor score.
8 SELF-ADMINISTERED TESTS
The assessment of cognition includes measures of free and guided recall, delayed free and guided recognition, primed picture naming, word-to-picture matching, design matching, clock hand placement and the Stroop Test
Presents progressively more difficult tests of general reaction time. (Contributes to the executive function factor score.)
Presents sets of four pictures with a word that describes one of the four. The patient is instructed to touch the picture that goes with the word. (Contributes to the symbol fluency factor score.)
FREE AND GUIDED RECALL – IMMEDIATE
The patient learns 5 sets of four different pictures by touching ones that fit into categories. The same items are displayed for free recall, shown along with two incorrect items from other categories. Incorrect answers are tested for category-guided recall and items are re-learned before a new free recall trial. (Contributes to the memory factor score.)
Presents 8 designs, paired with letters in non-alphabetical order, and a set of buttons with the letters in alphabetical order. One of the designs is presented and the patient is instructed to touch its paired letter. Complexity of the required attention-switching is increased by design similarity. (Contributes to the executive factor score.)
CLOCK HAND PLACEMENT
Ten blank clock faces are presented with a digital time. The patient is instructed to touch the appropriate hour-hand position and then the appropriate minute-hand position on an analog clock face. (Contributes to the symbol fluency factor score.)
The patient is instructed to touch buttons matching the ink color, not the word name, of the words “red”, “blue”, or “green”, which are shown one at a time in either red, blue or green ink. (Contributes to the executive function factor score.)
Pictures in multiple categories are shown, each with one correct, and three incorrect, 2-letter ‘word beginnings’ (e.g., Ro….. for a picture of a Rose). The patient is instructed to touch the most likely word beginning. (Recognition latency scores contribute to the executive function factor score.)
FREE AND GUIDED RECALL – DELAYED
Presents a delayed trial of the Free And Guided Recall tests. (Contributes to the memory factor score.)
To determine how close the patient’s cognitive abilities are to a sub-group with similar educational backgrounds, the patient’s abilities are measured in eight ways. These results are then compared against the distribution of test results for others having similar education.
In addition, if they have previously taken Screen’s tests, the patient’s past test results are compared to the latest results and plotted over time (longitudinally) so the earliest important cognitive changes can be detected in each of the three cognitive domains. By using longitudinal analyses with scalable test scores, even if the patient’s current test results are within the “normal” range, cognitive declines within that range can be detected—providing early warnings of active decline in high functioning patients.
STATISTICAL VALIDATION OF THE CANS-MCI
Screen’s Test Battery vs. Gold Standard for 2 Education Sub-groups: ROC Analysis
|Education||Area Under Curve||% Sensitivity||% Specificity|
|Less Than 13 Years||1.0||100||100|
|13 or More Years||.96||100||84.8|
Over the last two years, the CANS-MCI has been consistently referenced by major journals in articles that covered computer-directed neuropsychological tests. In 2008, in a study that systematically reviewed the top 11 computer-based test batteries that are used to detect cognitive decline in aging populations, independent researchers gave Screen’s CANS-MCI test battery the top overall score in all categories assessed.
Jane B. Tornatore, PhD Emory Hill, PhD Jo Anne Laboff, MSW, “Self-Administered Screening for Mild Cognitive Impairment: Initial Validation of a Computerized Test Battery,” Journal of Neuropsychiatry and Clinical Neurosciences, Volume 17, No. 1, 98-105, Winter, 2005.
Jane B. Tornatore, PhD, Emory Hill, PhD, Jo Anne Laboff, MSW The CANS-MCI: Self-administered Screening for Mild Cognitive Impairment. Alzheimer’s and Dementia, 1, Suppl 1, 104, 2005. (Abstract)
Wild K, Howieson D, Webbe F, Seelye A, Kaye J. Status of computerized cognitive testing in aging: a systematic review. Alzheimers Dementia. 2008; 4(6):428–437. Each test battery was rated on the availability of normative data, level of evidence for test validity & reliability, comprehensiveness and usability.