LGN-single-unit-recordings-of-awake-fixating-macaques
Single unit data isolated from linear multielectrode arrays while recording in awake fixating monkeys and gratings drifted on the screen
Here are important definitions of the variables stored in each file:
Onsets: stimulus onset times from photodiode
offsets: stimulus offset times from photodiode
trstart: trial onset time
trend: trial end time
presnum: stimulus presentation number
trial: trial number
tilt: grating orientation
sf: stimulus spatial frequency
contrast: contrast in dominant eye
fixedc: contrast non dominant eye
diameter: stimulus diameter
eye: dominant eye
oridist: orientation difference of stimuli between eyes
phase: grating phase at stim onset
temporal_freq: grating drifting speed in cyc/sec
xpos: horizontal eye position
ypos: vertical eye position
photo_on: photodiode onset time
trg_photo: 0
refresh: monitor refresh rate
measured_refresh: empirical monitor refresh rate
paradigm: paradigm name
sdftr_chan: convolved single unit activity
spk_bin_chan: binary data
wf: waveforms
clust: cluster label from kilosort
norm_autocorr: discretized data
chan: channel label
Methods:
All procedures complied with the regulations by the Association for the Assessment and Accreditation of Laboratory Animal Care (AAALAC), Vanderbilt University’s Institutional Animal Care and Use Committee (IACUC) and National Institutes of Health (NIH) guidelines.
Paradigm:
For each session, data were collected while animals performed visual tasks that rewarded passive fixation while drifting sine-wave gratings of varying contrast were presented to one or both eyes. The gratings had a spatial frequency of 1 cyc/deg and drifted at a temporal frequency of 4 Hz while the animal fixated within a 1-2 deg radius around the fixation cue (0.5 deg) at the center of the screen. Within each recording epoch, gratings maintained a constant orientation with orientation tilts in the range of -45°, 0°, 45°, 60°, 90°, 135°, 180°, and grating size varied from 2° to 8° . The interstimulus interval varied between a median duration of 1.3 s and 2.1 s across sessions, with an overall median duration of 1.7 s. The stimulus appeared from 250 to 500 ms after the fixation cross appeared on the screen. If the monkey fixated on the cross throughout the whole duration of a trial, it received a juice reward.
Single units were isolated using Kilosort (1).
References:
1. Pachitariu M, Steinmetz N, Kadir S, Carandini M, and Harris KD. Kilosort: realtime spike-sorting for extracellular electrophysiology with hundreds of channels. bioRxiv 061481, 2016, 10.1101/061481.)
