DOI: 10.5061/dryad.fttdz091d
title: Spiking activity in the ventral visual pathway under delayed match-to-sample task

description: The hierarchical view of the ventral object recognition pathway is
 primarily based on feedforward mechanisms, starting from a fixed basis set
 of object primitives and ending on a representation of whole objects in
 the inferotemporal cortex. Here we provide a different view. Rather than
 being a fixed “labeled line” for a specific feature, neurons are
 continually changing their stimulus selectivities on a moment-to-moment
 basis, as dictated by top-down influences of object expectation and
 perceptual task. Here we also derive the selectivity for stimulus features
 from an ethologically curated stimulus set, based on a delayed
 match-to-sample task, that finds components that are informative for
 object recognition.
description: We implanted microelectrode arrays (Blackrock) in different parts
 of the ventral visual pathway in the left hemisphere. In animal MJ we
 implanted four arrays, three 6 x 6 and one 4 x 5, for a total of 128
 electrodes with 400 µm spacing between electrodes. All electrodes were 1
 mm long. One 6 x 6 array was implanted in opercular V1 representing 2°
 eccentricity in a lower visual field quadrant; the others were implanted
 at three positions along the prelunate gyrus. Animal MR was implanted with
 three arrays: one 6 x 8 array in opercular V1 representing 2° eccentricity
 in the lower visual field quadrant, and two 5 x 8 arrays in the prelunate
 gyrus. With the arrays we were able to record single unit and multiunit
 action potentials and local field potentials. Multiunit activity was
 manually sorted offline with SpikeSort software (Plexon). Sorted spikes
 are binned in 1ms bins. The animals were given an
 initial cue or sample consisting of a full object for 500 msec, a mask
 consisting of a jumbled image between 400 and 800 msec, and a target
 consisting of a full object or object component for 500 msec. The
 components consisted of cropped parts of the object images. We collected
 data on how successful each animal was in recognizing whether the first
 image (cue) and second image (target) corresponded to the same
 object.
description: [https://doi.org/10.5061/dryad.fttdz091d](https://doi.org/10.5061/dryad.fttdz091d) ## Description of the data and file structure Each file represents one dataset. The .mat file is openable with Matlab. The file name represents the acquisition date (YYMMDD) followed by the anima's identification (either J or R). Each row on the dataset represents a trial. Columns represent the electrode number, unit (electrodes can record more than one cell, which we sorted manually), cue stimulus, cue presentation time (msec) , target stimulus, target presentation time (msec), behavior (1 for correct answer, 0 for incorrect answer and -1 for time out), and the time series of spike count (1ms bins). The images named in the file are available on Zenodo, which has the cue images, scrambled imaged and target images. The sequence of the trial is cue followed by scrambled followed by target. The trials all have different lengths, so it is important that all trials be aligned according to the portion you wish to analyze, keeping in mind that cue, distractor and target might have been presented at slightly different times. Zenodo  image file names, in .png format, match the visual stimulus presented. File names with five numeric characters (00000) are stimuli presented to animal J, filenames with six numeric characters (000000) are stimuli presented to animal R.