Animal Cognition - November 2018

**Hennefield, L., Hwang, H. G., Weston, S. J., & Povinelli,**
D. J. (2018). Meta-analytic techniques reveal that corvid causal reasoning in
the Aesop’s Fable paradigm is driven by trial-and-error learning. *Animal*
Cognition*,* 21*(6), 735–748. https://doi.org/10.1007/s10071-018-1206-y'*

A meta-analysis of studies looking at corvids ability to drop
objects into a water-filled tube to reach a floating worm. The authors looked
at whether the data from these studies provided clear evidence for causal
reasoning versus trial-and-error problem solving techniques. A previous
meta-analysis looked at studies on a trial by trial basis: reporting corvid’s
success due to initial preferences for successful objects (i.e. large over
small stones or sinking over floating objects) and learning across trials. But
in this analysis, the authors looked at each individual drop of an object
within trials instead of the overall trial. Here, there was little evidence for
an initial preference of successful objects or tubes containing either water or
sand and there was some evidence for significant rates of learning across
object insertions. For example, birds were more likely to return to a tube
filled with water after dropping something in it, but this learning effect was
not present for tubes filled with sand. Overall, the subjects were learning
from successful, but not unsuccessful actions. Finally, they did not find a transfer
of learning from one task to subsequent tasks (the rate of learning did not
increase with experience). Overall, the studies investigated in this analysis
are unable to distinguish between trial-and-error and causal reasoning based on
their results.

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**Xiong, W., Yi, L.-C., Tang, Z., Zhao, X., & Fu, S.-J.**
(2018). Quantity discrimination in fish species: fish use non-numerical
continuous quantity traits to select shoals. *Animal Cognition*, *21*(6),
813–820. https://doi.org/10.1007/s10071-018-1214-y

Several species of fish discriminate/select shoals by a
non-numerical continuous trait (cumulative surface area of shoal) and not by
discrete cues (number of members at shoal).

**Humphrey, B., Helton, W. S., Bedoya, C., Dolev, Y., &**
Nelson, X. J. (2018). Psychophysical investigation of vigilance decrement in
jumping spiders: overstimulation or understimulation? *Animal Cognition*, *21*(6),
787–794. https://doi.org/10.1007/s10071-018-1210-2

This study looked at whether there was a decrease in vigilance
in jumping spiders dependent on the difficulty of the given task. Spiders were
shown stimuli on 2 monitors and given a little ball to hold on to (which I
personally think is adorable) as a way for the experimenters to measure their
movements towards a moving stimulus on the screens. Stimuli were either
presented as high or low clutter as well as high or low contrast. Spiders were
tested in either a hungry or sated state. There was a weak evidence that hunger
and the amount of clutter impacted spiders’ vigilance, and that the effect of stimulus
salience (contrast) was more consistent. There was a steeper decrement in vigilance
in the ‘harder’ task (low contrast, high clutter), consistent with human
studies that more demanding tasks make it more difficult to sustain
attention/vigilance.

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**Zoratto, F., Cordeschi, G., Grignani, G., Bonanni, R.,**
Alleva, E., Nascetti, G., … Carere, C. (2018). Variability in the “stereotyped”
prey capture sequence of male cuttlefish (Sepia officinalis) could relate to
personality differences. *Animal Cognition*, *21*(6), 773–785.
https://doi.org/10.1007/s10071-018-1209-8

For anyone who might be interested in personality/individual
differences. This one looked at differences in a prey capture technique (a
relatively consistent behavior) in male cuttlefish and whether these
differences were associated with personality differences.

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**Stuebing, S. L., Marshall, A. T., Triplett, A., &**
Kirkpatrick, K. (2018). Females in the forefront: time-based intervention
effects on impulsive choice and interval timing in female rats. *Animal*
Cognition*,* 21*(6), 759–772. https://doi.org/10.1007/s10071-018-1208-9'*

Here is a paper coming from the lab Travis is now at!
Looking at how a temporal intervention mitigates impulsive choice behavior.
Previous research had shown that these interventions attenuated impulsive choice
in male rats and this paper was investigating the effect in female rats. The
impulsive choice task required rats to choose between a smaller sooner (SS) and
larger later (LL) reward. The temporal intervention consisted of trials in
which a pellet was delivered after a 10s delay on the SS lever or a 30s delay
on the LL lever (the equivalent of forced-choice trials from the choice task
and no free-choice or peak trials). After the intervention the rats were given
the impulsive choice task again. The intervention improved timing accuracy but
not timing precision and increased long responses at the shorter durations. Overall,
impulsive choice behaviors can be reduced via temporal interventions in both
male and female rats.