Figure 1. Natural image change detection task with familiar and novel images.

(A) Schematic of stimulus presentation during the task. Images are presented for 250 ms followed by 500 ms of gray screen. (B) Trial structure. Colors represent different images. On go trials, the image identity changes and mice must lick within the 750 ms response window to receive a water reward. On catch trials no image change occurs and the behavioral response is measured to quantify guessing behavior. (C) Example lick raster, aligned to the image change time. Purple dots indicate rewards and green ticks are reward consumption licks. Red ticks indicate incorrect licking responses outside the response window. (D) Example behavior performance over four minutes of one session, separated into one-minute epochs. Colored vertical bars indicate stimulus presentations (different colors are different images). Green tick marks indicate licks, purple triangles indicate rewards. 5% of all non-change image flashes are omitted, visible as a gap in the otherwise regular stimulus sequence. (E) Training stages. Mice are initially trained with gratings of 2 orientations, first with no intervening gray screen (stage 1), then with a 500 ms inter-stimulus delay (stage 2). Next, mice perform change detection with eight natural scene images (stage 3, image set A). During the 2-photon imaging portion of the experiment, mice are tested with image set A as well as three novel image sets (B, C, D) on subsequent days. (F) The four sets of 8 natural images. Image set A is the familiar training set, and image sets B, C and D were the novel sets shown for the first time during 2-photon imaging. (G) Example training time course of one mouse. (H) Number of sessions spent in each stage across mice. Mean ± 95% confidence intervals in color, individual mice in gray. (I) Response rates for go and catch trials are similar across image sets. Individual behavior sessions are shown in gray and average ± 95% confidence intervals across sessions for each image set are shown in color. (J) Reaction times, measured as latency to first lick, are not significantly different across image sets. Mean ± 95% confidence intervals in color, individual sessions in gray.

Figure 1—figure supplement 1. Behavior is similar across image sets.

(A) Number of sessions in each training stage for all mice in the study. Slc17a7+ mice are shown in green and VIP+ mice are shown in purple. Inset shows color legend for training stages. (B) Average running speed is similar across image sets (p>0.05 for all image set comparisons, Welch’s t-test used for all statistical comparisons, see Materials and methods for additional details). Mean running speed is computed for each stimulus presentation within a session then averaged across the session. Gray lines indicate session average running speed for each mouse, colors indicate average across mice with 95% confidence intervals. (C) Average change triggered running speed is similar across image sets. Right panel shows slowing of running behavior following a stimulus change, with median lick latency (values from Figure 1J) for each image set indicated by arrows and dotted lines. (D) Mean d-prime is similar across image sets (p>0.05 for all image set pairs except A-B, where p=0.002). (E) Average licking response rate (± SEM) measured for image change trials, catch trials, all non-change stimulus presentations, stimulus omissions, and for the stimulus presentation immediately following an omitted stimulus. (F) Pattern of mouse licking behavior around the time of stimulus omission is similar across image sets. Gray bars show histogram of lick counts in each time bin pooled over all mice (left y-axis). Colored lines show kernel density estimate of lick distribution over time for each image set (right y-axis).