DOI: 10.5061/dryad.4mw6m909g
title: Imprinting on time-structured acoustic stimuli in ducklings

description: Filial imprinting is a dedicated learning process that lacks explicit
 reinforcement. The phenomenon itself is narrowly heritably canalized, but
 its content, the representation of the parental object, reflects the
 circumstances of the newborn. Imprinting has recently been shown to be
 even more subtle and complex than previously envisaged, since ducklings
 and chicks are now known to select and represent for later generalization
 abstract conceptual properties of the objects they perceive as neonates,
 including movement pattern, heterogeneity, and inter-component
 relationships of same or different. Here we investigate day-old Mallard
 (Anas platyrhynchos) ducklings’ bias towards imprinting on acoustic
 stimuli made from mallards’ vocalizations as opposed to white noise,
 whether they imprint on the temporal structure of brief acoustic stimuli
 of either kind, and whether they generalize timing information across the
 two sounds. Our data are consistent with a strong innate preference for
 natural sounds, but do not reliably establish sensitivity to temporal
 relations. This fits with the view that imprinting includes the
 establishment of representations of both primary percepts and selective
 abstract properties of their early perceptual input, meshing together
 genetically transmitted prior predispositions with active selection and
 processing of the perceptual input.
description: Video was recorded using Sony wireless 4K action cameras
 (FDR-X3000 R) at 30 Hz. A colour thresholding method was implemented using
 custom <i>Bonsai</i> code (Lopes
 et al., 2015) to track the position of the subjects and each
 speaker.
description: "ALLdata.mat" is a nested structure.
 [data] is divided into [.raw] or [.processed].
 [data.raw] contains all raw positions (x,y) of each stimuli and
 individual ducklings during tests. inside [data.raw]
 there is the following structure:
 raw.imprinting.[impringSoundType].[duration].[difficulty],
 with: [.impringSoundType] —&gt; artificial or
 natural [.duration] —&gt; short or long
 [.difficulty] —&gt; easy; int1_soundDIFF; int2_timeDIFF;
 hard Note: During the revision of the paper, we have
 changed the naming of the “difficulty” label to “test condition”, and
 categories “easy”, “int1”, “int2”, “hard”, to “sound&time”,
 “sound”, “time (imprint=target)” and “time (imprint≠target),
 respectively. [.raw] files are xyRED (position of the
 red stimulus), xyGREEN (position of the green stimulus), xyANIMAL for the
 entire testing time (rows) and individual animals (3rd
 dimension). In all cases, stimuli were marked with
 visual (red and/or green) tags (not visible to the animals) to facilitate
 tracking. For practical reasons, imprinting exposure
 stimuli is always RED for [short] groups and GREEN otherwise.
 Exceptions are for group
 '.natural.short.int1_soundDIFF' where GREEN marked the
 imprinting stimulus and for  '.natural.long.int1_soundDIFF' 
 where RED marked the imprinting stimulus [.processed]
 files are arrays of 600x40, with every 2 columns showing x,y position of
 each animal in a particular testing condition, rotated and
 normalized. Code for analysis can be found here:
 https://github.com/PTMonteiro/MonteiroHartKacelnik_2021.git