The overall goal of this procedure is to test the usability of a tablet, computer-based application in investigating the effects of age on cognitive functions across the lifespan, this is accomplished by first developing an application which contains seven neuropsychological tests of learning and memory, attention and concentration, executive functions, and processing speed. The second step of the procedure is to recruit a large sample of subjects spanning a wide age range. Next, the subjects are invited and the neuropsychological tests are conducted on the tablet-based application.
The final step is to analyze the results and to assess the effects of age on cognitive performance. Ultimately, the emo cog meter is used to show that a tablet, computer-based application has great clinical and practical potential for detection and monitoring of cognitive dysfunction. The main advantage of the iPad application over existing methods like pencil and paper tests or computer based tests on working stations is that the app requires no prior computer knowledge and enhances motivation and compliance, especially in all the subjects Before using the assessments as described in this protocol.
First, obtain approval from your institution's review board, as well as written informed consent from the subject to be tested. Then introduce the subject to the tablet and the format of the tests that will be run here. The emo cogni will be used, which is an iPad based application, including seven neuropsychological tests that were developed to investigate cognitive functions in several domains prior to each test.
A short introduction and demonstration is displayed on the screen. Note that in the version scene here, assessments are displayed in German. Note that there should be no verbal instruction or feedback from the experimenter during the assessments.
Subjects should need approximately 25 to 30 minutes to complete the testing session as described in this protocol. The first assessment for learning and memory is a memory span test. For this task, present the participant with a series of digits and instruct them to input the numbers immediately afterwards.
First, start with two digits. Then if the participant is successful, provide a longer list of numbers. End the task after five minutes or earlier.
If the subject successfully recalls nine digits. Working memory can also be tested for this task, have the participant view sequences of positive, negative and neutral words and instruct them to respond if a word is the same as one presented two trials before. End the working memory task after five minutes, and be sure to record the number of correct responses or hits false responses as well as the mean latency of responses.
To test for selective attention, apply a variant of the stroop task and ask the subject to respond if the written color name corresponds to the color in which it is displayed on the screen. End this task after three minutes, and again, record the number of correct responses, false responses, missed responses, as well as the mean latency of responses. To test for sustained attention, use a task that includes a small working memory component.
Present a circle consisting of small, blue and yellow circles as seen here that are illuminated in a pseudorandom order. In the center of the screen, instruct the subject to detect and respond when sequences of blue, yellow, yellow are seen and the task after four minutes and record the number of correct false and missed responses. The trail making test B can be used to test for executive functions.
More specifically, this task assesses the ability for task switching. Instruct the subject to sequentially and alternatively connect 13 numbers and 12 letters that appear on the screen. Do not display the connection if the subject made an error and do not continue the task before the correct connection is selected and the task after 90 seconds if it has not been successfully completed at that time, and record the total time required to complete the task.
Another executive function assessment is the Tower of Hanoi task, which assesses planning and the ability to achieve a goal through a series of intermediate steps. Use aversion with three rods and four discs of subsequently smaller size. Inform the subject to move the entire stack of discs to another rod by obeying the following rules.
One, only one disc may be moved at a time.Two. Each move consists of taking the upper disc from one of the rods and sliding it onto another rod on top of the other discs that may already be present on that rod. And three, no disc may be placed on top of a smaller disc and the test if the subject fails to reach the goal after four minutes, record the time needed to solve the task and the number of moves required to find a solution.
To assess processing speed in subjects, use the symbol letter modalities. Test for this assessment. Present subjects with nine letters along with corresponding geometric symbols in the upper part of the screen.
Also, display rows of letters in the lower section of the tablet screen. Instruct the subject to move the corresponding symbol under each of the letters as fast as possible. Once again, record the number of correct responses or hits false responses, missed responses, and the mean latency of responses within the allowed time of 90 seconds for the tests probing, working memory, selective attention and sustained attention and accuracy ratio can be defined as the number of hits, minus the number of false responses divided by the number of targets multiplied by 100.
Data can be analyzed using multi-variate analyses of variants with the between subjects, factors of age, group and gender. Greenhouse geiser corrections should be applied where appropriate. If multi-variate analyses reveal significant main or interaction effects, further statistical analyses can then be conducted.
Using T-test comparisons for the digit span test, there was a main effective age with lower digit span in old compared to young, as well as to middle-aged subjects for working memory. There was a main effective age on accuracy with significantly lower accuracy in old compared to young, as well as to middle-aged subjects. Regardless of stimulus valence, post hoc T tests revealed a continuous increase in reaction times across the lifespan only in women with significantly longer reaction times in middle aged compared to young and old compared to middle aged subjects in men.
Middle-aged subjects had shorter reaction times than young and also than old subjects. Analysis of selective attention showed that age had a significant main effect on accuracy with a decline between middle and old age, and for sustained attention. There was a main effect of age on accuracy with a continuous decline from young to middle and middle to old age.
For the trial making B test, the Inova showed a significant main effect of age on the time required to complete the task, which continuously increased across the lifespan. The Tower of Hanoi tests indicated a main effect of age on the time needed to solve the task. Post hoc T tests showed that solution time continuously increased across the lifespan.
Finally, in the processing speed symbol letter modalities test age had a significant main effect on the number of letters correctly matched with geometric forms, which continuously decreased across the lifespan. Once mastered, this technique can be done in 25 minutes if it is performed properly.
