N-back exercise for training cognition

A computer-readable memory medium that stores program instructions for enhancing cognition in a participant, utilizing a computing device to present stimuli for training, and to record responses from the participant, wherein the program instructions are executable by a processor to perform:

• providing multiple first stimulus elements on a non-transitory computer-readable medium, wherein the multiple first stimulus elements are available for presentation to the participant;
• providing multiple second stimulus elements on a non-transitory computer-readable medium, wherein the multiple second stimulus elements are available for presentation to the participant, and wherein at least a portion of the second stimulus elements correspond to the first stimulus elements;
• presenting a temporal sequence of a plurality of the first stimulus elements through the computing device, including presenting each first stimulus element in the sequence for a specified computer-controlled duration separated by a specified computer-controlled interval;
• after a specified computer-controlled delay period, presenting a temporal sequence of groups of a plurality of the second stimulus elements through the computing device concurrently with said presenting the temporal sequence of the plurality of the first stimulus elements, wherein each group comprises a matching second stimulus element that matches a corresponding first stimulus element presented earlier by the specified computer-controlled delay period, wherein the specified computer-controlled duration plus the specified computer-controlled interval composes a specified stimulus onset asynchrony (SOA), wherein each group of second stimulus elements is presented for the duration of the SOA, wherein the computer-controlled delay period comprises the SOA times a specified value N, wherein the matching second stimulus element matches a corresponding first stimulus element presented N first stimulus elements back, and wherein N is a non-integer value;
• for each presented group of second stimulus elements, prompting the participant to respond through an input device to the computing device, including either indicating the matching second stimulus element, or indicating a second stimulus element in the group that does not match the corresponding first stimulus element;
• automatically determining, through the computing device, whether the participant responded correctly;
• automatically modifying the delay period based on said automatic determining;
• and
• repeating said presenting the temporal sequence of the plurality of the first stimulus elements, said presenting the temporal sequence of groups of the plurality of the second stimulus elements, said prompting, said automatically determining, and said automatically modifying one or more times in an iterative manner to improve the participant's cognition.