Computer system having a fractal cognitive computing node configured to perform computational operations for learning procedures, the fractal cognitive computing node comprising: - a first input, configured to receive a first input signal from another fractal cognitive computing node or from a remote sensor or actuator, said first input signal comprising a set of pairs <key, value>, wherein the key representing an identifier and the value representing a magnitude of the first input signal; - a first output, configured to provide a first output signal, said first output signal comprising a set of pairs <key, value>, wherein the key representing an identifier and the value representing a magnitude of the first output signal; - a second input, configured to receive a second input signal, said second input signal being a first output signal of another fractal cognitive computing node and comprising a set of pairs <key, value> wherein the key representing an identifier and the value representing a magnitude of the second input signal; - a third input, configured to receive a spatial attention parameter comprising a single dimension value; - a memory, configured to store a collection of items, each item having a set of tuples <key, value>, and each item representing a previously stored input from at least one of said first or second input signals; and - a processing unit, configured to implement a computational function that: - compares the first input signal or the second input signal or a combination of said first and second input signals to some or all of the stored collection of items; and - calculates a similarity measure for each compared item; wherein said first output signal outputted via said first output being calculated as a selection of the compared items having a similarity measure greater than said spatial attention parameter; wherein if the selection of compared items is empty, a new item is added to said memory and the set of tuples <key, value> of the new item and the first output signal are set according to the first input signal, to the second input signal or to a combination of the first and second input signals; and wherein if the selection of compared items is not empty, the first output signal is set to said selection. - a first input, configured to receive a first input signal from another fractal cognitive computing node or from a remote sensor or actuator, said first input signal comprising a set of pairs <key, value>, wherein the key representing an identifier and the value representing a magnitude of the first input signal; - a first output, configured to provide a first output signal, said first output signal comprising a set of pairs <key, value>, wherein the key representing an identifier and the value representing a magnitude of the first output signal; - a second input, configured to receive a second input signal, said second input signal being a first output signal of another fractal cognitive computing node and comprising a set of pairs <key, value> wherein the key representing an identifier and the value representing a magnitude of the second input signal; - a third input, configured to receive a spatial attention parameter comprising a single dimension value; - a memory, configured to store a collection of items, each item having a set of tuples <key, value>, and each item representing a previously stored input from at least one of said first or second input signals; and - a processing unit, configured to implement a computational function that: - compares the first input signal or the second input signal or a combination of said first and second input signals to some or all of the stored collection of items; and - calculates a similarity measure for each compared item; - compares the first input signal or the second input signal or a combination of said first and second input signals to some or all of the stored collection of items; and - calculates a similarity measure for each compared item; wherein said first output signal outputted via said first output being calculated as a selection of the compared items having a similarity measure greater than said spatial attention parameter; wherein if the selection of compared items is empty, a new item is added to said memory and the set of tuples <key, value> of the new item and the first output signal are set according to the first input signal, to the second input signal or to a combination of the first and second input signals; and wherein if the selection of compared items is not empty, the first output signal is set to said selection.