**Subjects** We will run 30 participants recruited from the University of Illinois at Urbana-Champaign course credit subject pool. **Apparatus** View distance: 57 cm, with subjects stabilized on a chinrest Monitor: BenQ XL2420TX (1920 x 1080, max refresh rate of 100 Hz running at 60 Hz) **Stimuli** The experiment was programmed using the Psychopy library for Python. Positions are given in degrees visual angle and are relative to the center of the screen; (0, 0) is in the center, negative values are down and left, and positive values are up and right. After an instruction screen, subjects are presented with the trial stimuli. The play area is a 15.53 by 15.53 degree square on a white background. On the left and right edges of the play area are light gray (211, 211, 211) "sidewalks," each subtending 2.66 by 15.53 degrees visual angle, while a dark gray "road" (128, 128, 128) subtending 10.21 by 15.53 degrees visual angle lies between the sidewalks. The avatar under the control of the subject is a .82 by .82 degree purple (128, 0, 128) square. The square sits at a fixed vertical position of -1.94 degrees, but moves left and right at a rate of 3.7 degrees per second when the left and right arrow keys are pressed. At the beginning of each block, its position is in the middle of the left sidewalk (-6.43, -1.94). During the trial, two sets of objects stream continuously through the display. One set, "pedestrians," consists of blue (0, 0, 255) equilateral triangles (base of .82 degrees) that move at a rate of 1.23 degrees per second, either from the bottom of the display to the top, or from the top to the bottom, chosen randomly at each spawn. They are confined to the sidewalks on either side, spawning at a fixed vertical distance that hides them outside the play area (y = -8.59 for upward-moving pedestrians and y = 8.59 for downward-moving pedestrians) and at a random X position in the range of the left sidewalk (between -5.1 and -7.77) or the right sidewalk (between 5.1 and 7.77). A pedestrian spawns every 900 ms, and there can be up to 10 onscreen at one time. They do not interact with the player avatar in any way, but will occlude the player if the avatar crosses their path. The other set of objects is the "cars." Cars are red (255, 0, 0) circles (.51 degree radius) that always move top to bottom in the display at a randomly chosen rate of 2.47, 3.70, 4.93, 6.16, 7.40, 8.63, 9.86, or 11.09 degrees per second. Cars spawn randomly on the road (y = -8.28, x = between -7.77 and 7.77) every 400 ms. There can be up to 15 cars onscreen at once. Cars have a circular hitbox that has a radius 85% the size of their total radius (.44 degrees); if the edges of the player's avatar overlap with this hitbox, it is registered as a "collision" and on the next refresh the player is returned to the middle of whichever sidewalk they began crossing from ((-6.43, -1.94) if the crossing started on the left, (6.43, -1.94) if it started on the right). Probes also appear periodically throughout the trial. These are green (0, 128, 0) diamonds (1.03 degree width, 1.03 degree height). There are two types of probes: static probes, which appear at a random position within a cell in an invisible grid covering the play area, and dynamic probes, which spawn randomly positioned inside a "lane" along the top, bottom, left, and right of the play area. Dynamic probes start offscreen and move to the opposite side of the display at a rate of 3.70 degrees per second, meaning they are onscreen for a total of 4.2 seconds. Static probes are onscreen for the same length of time, appearing suddenly and disappearing suddenly. On top of the play area is a score counter that updates each time a crossing is completed and a timer counting down the time left in the block. **Procedure** On the initial block of the experiment, subjects are presented with an instruction screen explaining the game they will be playing. They are informed that they gain points by successfully completing a road crossing, and should try to maximize their score during the block. They are also told that the objects in the road will send them back to the sidewalk, forcing them to start over, but that the objects on the sidewalks won't affect them. They are also instructed that green probes will periodically appear, and that they are to press the space bar when they notice them. Once the subject presses a key, the 10 minute block begins. Objects spawn and move continuously as the player moves back and forth. The timer counts down by seconds, and the score counter increases by 25 points each time a successful crossing is made. There are 80 probes total. These appear every 5 to 7 seconds, and the probe sequence is shuffled on each trial. The position of the probes is randomly jittered within each probe's slot. There are 44 dynamic probes, 11 on each side of the display in 2.66 degree "lanes", and 36 static probes, each one confined to a 2.66 by 2.66 degree cell in an invisible 6 x 6 grid. Probe presentations are timed independently of a subject's reaction time, and all probes are presented during each block. Data is recorded on a probe-by-probe basis. For each probe, the following information is recorded: * the probe type (static or dynamic) * whether or not the probe was detected * the reaction time for response to the probe * the probe's x and y position at time of detection * the player's x and y position at time of detection * the Euclidean distance from the probe to the player at the time of detection * the time, relative to the start of the trial, when the probe was deployed * the x and y position the probe spawned at * the vertical and horizontal direction of the probe's movement * the block number When the block ends, subjects are shown a screen displaying their final score and the number of times they crossed. Subjects complete 3 blocks total.