System and method for computerized stimulus presentation and behavioral interaction measurement

1 . A computerized behavioral measurement system comprising:

a display;

one or more input devices;

at least one processor; and a memory storing instructions that, when executed by the at least one processor, cause the system to:

present, via the display, a sequence of visual stimuli, wherein each visual stimulus in the sequence of visual stimuli is associated with a stimulus identifier and a stimulus category,

wherein the sequence of visual stimuli include a sequence of photographs of human subjects,

wherein the stimulus identifier comprises race or ethnicity of the human subjects,

wherein the stimulus category comprises a level of threat associated with the human subjects;

enforce, for each visual stimulus in the sequence of visual stimuli, at least one of (i) a presentation interval and (ii) a response window;

receive, via the one or more input devices and during the response window, one or more participant response, wherein the one or more participant response is associated with the stimulus identifier;

measure, during presentation of each visual stimulus in the sequence of visual stimuli, an interaction metric comprising a dwell-time metric associated with at least one of (a) each visual stimulus in the sequence of visual stimuli or (b) a region-of-interest of each visual stimulus in the sequence of visual stimuli;

generate, from the one or more participant response and the interaction metric, a machine-readable output record comprising one or more category-segmented response metric for a participant;

normalize the one or more category-segmented response metric to generate an ipsative metric for the participant,

wherein generating the ipsative metric for the participant comprises computing a deviation of the one or more category-segmented response metric from an aggregate metric across the stimulus categories for the visual stimuli for the participant; and

store the machine-readable output record in a non-transitory storage medium.

2 . The computerized behavioral measurement system of claim 1 , wherein measuring the dwell-time metric comprises measuring, without expressly prompting the participant to provide the dwell-time metric, an elapsed time corresponding to participant attention to each visual stimulus in the sequence of visual stimuli based on event data captured by the system.

3 . The computerized behavioral measurement system of claim 2 , wherein the event data comprises at least one of cursor-position events, pointer-movement events, click events, keystroke events, scrolling events, viewport-focus events, window-focus events, or touch-input events.

4 . The computerized behavioral measurement system of claim 1 , wherein the region-of-interest is defined by region metadata stored in association with the stimulus identifier.

5 . The computerized behavioral measurement system of claim 1 , wherein enforcing the presentation interval and/or the response window comprises disabling at least one of (i) stimulus skipping, (ii) stimulus replay, (iii) stimulus backtracking, or (iv) response submission outside the response window.

6 . The computerized behavioral measurement system of claim 1 , wherein presenting the sequence of visual stimuli comprises selecting the sequence according to a session policy that enforces a minimum quantity of stimuli per stimulus category.

7 . The computerized behavioral measurement system of claim 1 , wherein the one or more category-segmented response metric comprises at least one of per-category accuracy, per-category error rate, per-category response-distribution statistics, per-category dwell-time statistics, or per-category response-time statistics.

8 . The computerized behavioral measurement system of claim 1 , wherein measuring the dwell-time metric comprises accumulating elapsed time while event data indicates a participant focus within the region-of-interest.

9 . A computer-implemented method comprising:

presenting, on a display, a sequence of visual stimuli, wherein each visual stimulus in the sequence of visual stimuli is associated with a stimulus identifier and a stimulus category,

wherein the sequence of visual stimuli includes a sequence of photographs of human subjects,

wherein the stimulus identifier comprises race or ethnicity of the human subjects,

wherein the stimulus category comprises a level of threat associated with the human subjects;

for each visual stimulus in the sequence of visual stimuli, enforcing a presentation interval and a response window;

capturing one or more participant response associated with the stimulus identifier during the response window;

measuring, during the presentation of each visual stimulus in the sequence of visual stimuli, an interaction metric comprising a dwell-time metric associated with at least one of each visual stimulus in the sequence of visual stimuli or a region-of-interest of each visual stimulus in the sequence of visual stimuli;

generating, based on the one or more participant response and the interaction metric, one or more category-segmented response metric for a participant;

normalizing the one or more category-segmented response metric to generate an ipsative metric for the participant,

wherein generating the ipsative metric for the participant comprises computing a deviation of the one or more category-segmented response metric from an aggregate metric across the stimulus categories for the visual stimuli for the participant; and

outputting and storing a machine-readable output record comprising the one or more category-segmented response metric.

10 . The computer-implemented method of claim 9 , wherein normalizing comprises scaling at least one category-segmented response metric in the one or more category-segmented response metric for the participant using at least one of z-score normalization, min-max scaling, rank-order normalization, or vector normalization.

11 . The computer-implemented method of claim 9 , wherein measuring the dwell-time metric comprises computing the dwell-time metric from event data without expressly requesting the dwell-time metric from the participant.

12 . The computer-implemented method of claim 9 , wherein generating the one or more category-segmented response metric comprises generating at least one of an under-classification rate, an over-classification rate, or a confusion matrix based on the one or more participant response mapped to a set of allowed response classes.

13 . The computer-implemented method of claim 9 , wherein the enforcing comprises disabling at least one of stimulus backtracking, stimulus replay, or response entry outside the response window.

14 . The computer-implemented method of claim 9 , further comprising storing, in association with the machine-readable output record, session metadata comprising at least one of device identifiers, display parameters, timing parameters, or an ordering of the presented stimuli.

15 . A computerized behavioral testing system comprising:

a display;

one or more input devices;

at least one processor; and

a memory storing instructions that, when executed by the at least one processor, cause the system to:

execute a first task module that presents scenario-based visual stimuli and captures participant classification responses under enforced response windows,

wherein the scenario-based visual stimuli comprise photographs of human subjects including predetermined characteristics comprising (1) race or ethnicity and (2) facial expression;

execute a second task module that presents lexical stimuli comprising letter strings and captures participant lexical-decision responses indicating whether each letter string is a word or a non-word under the enforced response windows;

compute, for the first task module, at least one category-segmented visual-task metric;

compute, for the second task module, at least one lexical-task metric comprising a lexical error rate; and

generate and store a unified machine-readable output record comprising the at least one category-segmented visual-task metric and the at least one lexical-task metric for a participant.

16 . The computerized behavioral testing system of claim 15 , wherein the first task module further measures an interaction metric comprising a dwell-time metric associated with at least one visual stimulus of the scenario-based visual stimuli or a region-of-interest of the at least one visual stimulus of the scenario-based visual stimuli.

17 . The computerized behavioral testing system of claim 15 , wherein the lexical stimuli comprise at least two lexical stimulus sets selected from a static word set, an emotive word set, and a nonsense letter-string set.

18 . The computerized behavioral testing system of claim 15 , wherein the system further comprises a session orchestrator configured to interleave the first task module and the second task module according to a session policy that enforces at least one of randomized ordering, counterbalanced ordering, or minimum counts per task module.

19 . The computerized behavioral testing system of claim 15 , wherein generating the unified machine-readable output record comprises generating a participant-specific output vector comprising at least (i) the at least one category-segmented visual-task metric, (ii) the lexical error rate, and (iii) at least one timing-derived metric.

20 . The computerized behavioral testing system of claim 15 , wherein the system is configured to export the unified machine-readable output record in a structured format comprising at least one of JSON, XML, or a tabular file format for downstream processing by an external computing system.