Fig. 1
From: Encoding of long-term associations through neural unitization in the human medial temporal lobe
Exemplary multi-responsive unit. a Responses of a unit in the left hippocampus. For each stimulus, the raster plot (blue lines represent the appearance of a spike and each row is associated to a trial; first trial is at the top and time zero is the stimulus onset), instantaneous firing rate, and spike shapes in the response period (between 100 and 800 ms after stimulus onset), are shown. Stimulus numbers appear at the top of the stimulus pictures. The unit responded to the picture of a Boeing, the interior of a cabin airplane, and the actor Leslie Nielsen (who had a major role in the 1980 movie “Airplane!”). The association scores for this unit (Methods) were ASR–R = 0.3 and ASRN–R = −0.06, indicating a strong association between the response-eliciting stimuli. Note that the spike shapes are the same for all responses, indicating that they come for the same neuron. b Surrogate distributions of strength difference for each response-eliciting pair in this unit. Vertical dashed lines represent the actual strength difference for each pair. All three pairs showed no significant difference (stimuli 10–18, p = 0.27; stimuli 10–15, p = 0.61; stimuli 15–18, p = 0.63). c Confusion matrix based on the single trial spike count of the response-eliciting stimuli (the color code represents the percentage of trials where stimulus i was presented and the decoder labeled it as stimulus j). Stimulus numbers are the same as in a. The decoding performance was 14%, not significantly different from chance (p = 0.92). Due to copyright issues, the images presented here are similar to the ones actually presented to the subjects. Copyright notes: Picture 6 is a self-portrait from Dr Antonio Valentin (co-author of the paper). Picture 10 was cropped from “Leslie Nielsen” by Alan Light, licensed under CC BY 2.0. Picture 8 was cropped from “Spider2007-09-03” by Trounce, licensed under CC BY-SA 3.0. Picture 18 was cropped from “Airplane Cabin 1 2017-06-18” by FASTILY, licensed under CC BY-SA 4.0. Picture 15 was cropped from “Front view of B787 Approaching at Oshkosh 2011” by H. Michael Miley, licensed under CC BY-SA 2.0
