2b. Cogmed Working Memory Training: adaptive vs. non-adaptive
Working memory (WM) is the ability to hold information in mind, in the face of distraction, and manipulate that information to produce a response in the short term. The maximum amount of information that a person can retain in WM is their WM capacity. Cogmed Working Memory Training keeps the user training close to their WM capacity by using an adaptive staircase method that adjusts task difficulty on a trial-by-trial basis. Task difficulty is adjusted by increasing/decreasing the number of items that the user has to remember and by increasing/decreasing the difficultly of the item sequences.
For example, if the user views a 4 x 4 grid of dots on the computer screen and 3 of the dots light up in red, the user must hold in mind the order in which the dots lit up and then repeat back the sequence by clicking on the dots at the end of the stimuli presentation. If they are correct, they may be presented with 3 more dots to remember, but in a more complicated arrangement. If they correctly remember this series, they may be presented with 4 dots to remember. If they correctly remember this series, they may be presented with 4 more dots to remember but in a more complicated series and so on. However, if they incorrectly remember the sequence, they will prompted to remember only 3 items in the next trial. It is in this manner that Cogmed Working Memory Training adapts on an individualized basis to challenge each user’s particular WM capacity.
The unique presentation of stimuli in adaptive training demands that the user actively maintain the items and thus, prevents automation. The user must simultaneously maintain increasingly longer/shorter and more/less difficult sequences of stimuli, hold the stimuli representation in mind during a short delay before responding and must continue this process repeatedly. When the user can no longer hold in mind a certain number of items in a certain sequence, they have reached their WM capacity. With repeated practice of trials, following the standard protocol for training with Cogmed (30-40 minutes per day, 5 days per week for 5 weeks) – the user engages in sustained and rigorous working memory training. Processes called upon during this training include attentional control, gating the flow of information, resisting distraction and rapid shifting between encoding and retrieval demands.
If Cogmed were not adaptive, one might expect the user to become increasingly faster and better practiced at responding to the stimuli – simply repeating the same number of items over and over – but, WM capacity would not be challenged. This is precisely the concept behind the placebo version of Cogmed. Placebo (or low-dose/sham/non-adaptive) Cogmed involves the same number and type of working memory exercises as the standard (adaptive) Cogmed program. A placebo user will train the same amount of time as the standard Cogmed protocol (30-40 minutes per day, 5 days per week for 5 weeks) requires, they will have the same level of coach support, they will receive the same verbal and text reinforcement from the program and they will receive the same rewards for completion of training. The only difference between the typical Cogmed user and a placebo Cogmed user is that the placebo Cogmed user does non-adaptive training.
It is in comparing adaptive to non-adaptive training that researchers studying the effectiveness of Cogmed in different populations can parse out the effect of the training from the impact of other variables that occur in the environment: altering one’s behavior in response to being watched or studied (Hawthorne effect), motivation, test familiarity, performance anxiety, expectations etc. The placebo version of Cogmed is used solely for research purposes and these randomized, double-blinded, placebo controlled Cogmed trials are considered the most rigorous investigations of Cogmed’s efficacy.