THE MAXIMUM MIND® studies

Based on Alan Baddeley's three-minute grammatical reasoning test (Baddeley, 1968). Short sentences describing the relationship of two shapes and an image of the shapes are displayed on the screen. Participants must indicate whether the sentence correctly describes the pair of objects displayed on the screen. Participants have 90 seconds to solve as many problems as possible. The primary outcome measure is the number of problems solved correctly, minus the number of problems answered incorrectly.

They are often used for measuring the ability to manipulate objects spatially in the mind (Silverman et al., 2000). Two grids of colored squared are displayed to either side of the screen, with one of the grids rotated by a multiple of 90 degrees. When rotated, the grids are either identical or differ by the position of just one square. Participants must indicate whether or not the grids are identical. Participants have 90 seconds to solve as many problems as possible. The primary outcome measure is the overall score - the sum of the difficulties of all successfully answered problems, minus the sum of the difficulties of all incorrectly answered problems.

A variant on a task from the non-human primate literature (Inoue & Matsuzawa, 2007). Sets of numbered squares are displayed on the screen at random locations. After a variable interval of time, the numbers disappear, leaving just the blank squares, and participants must respond by clicking the squares in ascending numerical sequence. Difficulty is increased or decreased by one numbered box depending on whether the participant got the previous trial correct. After three errors, the task ends. Outcome measures are (i) maximum level completed (e.g., the problem with the highest number of boxes that the user successfully completed) and (ii) average score: the sum of the number of boxes in all successfully solved problems, divided by the number of successfully completed problems.

Based on a test that is used to measure strategy during search behaviors (Collins et al., 1998). Boxes are displayed in random locations. Participants must find a hidden "token" by clicking on the boxes one at a time. When the token is found, it is hidden within another box. The token will not appear within the same box twice. Thus, participants must search the boxes until the token has been found once in each box. If they search the same empty box twice or search a box in which the token has previously been found, this is an error, and the trial ends. Difficulty is increased or decreased by one box depending on whether the participant got the previous trial correct. After three errors, the task will end. Outcome measure is the maximum level completed (e.g., the problem with the most tokens that the user successfully completed).

A direct descendant of the "Tower of London" task, Spatial Planning is a classic neuropsychological test of planning (Shallice, 1982). When the test begins, numbered beads are positioned on a tree-shaped frame. Participants must reposition the beads, so they are configured in ascending numerical order, in as few moves as possible. Problems become progressively harder, and participants have three minutes to solve as many as possible. The primary outcome measure is the overall score, calculated by subtracting the number of moves made from twice the minimum number of moves required.

A variant on the verbal working memory component of the WAIS-R intelligent test (Weschler, 1981). A sequence of numbers will appear on the screen one after another. Once the sequence is complete, participants must repeat the sequence. Difficulty is increased or decreased by one number depending on whether the participant got the previous trial correct. After three errors, the task ends. The primary outcome measure is the maximum level (i.e., the problem with the highest number of digits) that the player successfully completed.

A variant on a paradigm that is commonly used to assess memory impairments in aging clinical populations (Gould et al., 2005). Boxes are displayed at random locations on the screen. The boxes are opened one after another to reveal an enclosed object. Subsequently, the objects are displayed in random order in the center of the screen, and participants must determine which box contains the presented object. Difficulty is increased or decreased by one box depending on whether the participant got the previous trial correct. After three errors, the task will end. Outcome measures are (i) maximum level completed (e.g., the problem with the most boxes that the user successfully completed) and (ii) Average score: the sum of the number of boxes in all successfully solved problems, divided by the number of successfully completed problems.

Based on a sub-set of problems from the Cattell Culture Fair Intelligence Test (Cattell, 1949). Nine patterns will appear on the screen. The features that make up the patterns are color, shape, and number and are related to each other according to a set of rules. Participants must deduce the rules related to the object features and select the pattern that does not correspond to those rules. Difficulty is increased or decreased depending on whether the participant got the previous trial correct. Participants have 3 minutes to solve as many problems as possible. The primary outcome measure is the number of correctly answered problems, minus the number of incorrectly answered problems.

A variant on the verbal working memory component of the WAIS-R intelligent test (Weschler, 1981). A sequence of numbers will appear on the screen one after another. Once the sequence is complete, participants must repeat the sequence. Difficulty is increased or decreased by one number depending on whether the participant got the previous trial correct. After three errors, the task ends. The primary outcome measure is the maximum level (i.e., the problem with the highest number of digits) that the player successfully completed.

Based on the Interlocking Pentagons Task, which is often used to assess age-related disorders (Folstein et al., 1975). A pair of overlapping polygons is displayed on one side of the screen. Participants must indicate whether a polygon displayed on the other side of the screen is identical to one of the interlocking polygons. Difficulty is increased by making the differences between the polygons more subtle or decreased by making the differences between the polygons more pronounced. Participants have 90 seconds to solve as many problems as possible. The primary outcome measure is the overall score - the sum of the difficulties of all successfully answered problems, minus the sum of the difficulties of all incorrectly answered.