Data from: Vestigial auriculomotor activity indicates the direction of auditory attention in humans

Unlike dogs and cats, people do not point their ears as they focus
attention on novel, salient, or task-relevant stimuli. Our species may
nevertheless have retained a vestigial pinna-orienting system that has
persisted as a ”neural fossil” within in the brain for about 25 million
years. Consistent with this hypothesis, we demonstrate that the direction
of auditory attention is reflected in sustained electrical activity of
muscles within the vestigial auriculomotor system. Surface electromyograms
(EMGs) were taken from muscles that either move the pinna or alter its
shape. To assess reflexive, stimulus-driven attention we presented novel
sounds from speakers at four different lateral locations while the
participants silently read a boring text in front of them. To test
voluntary, goal-directed attention we instructed participants to listen to
a short story coming from one of these speakers, while ignoring a
competing story from the corresponding speaker on the opposite side. In
both experiments, EMG recordings showed larger activity at the ear on the
side of the attended stimulus, but with slightly different patterns.
Upward movement (perking) differed according to the lateral focus of
attention only during voluntary orienting; rearward folding of the pinna’s
upper-lateral edge exhibited such differences only during reflexive
orienting. The existence of a pinna-orienting system in humans, one that
is experimentally accessible, offers opportunities for basic as well as
applied science.