Publications

Abstract

The cognate effect refers to translation equivalents with similar form between languages—i.e., cognates, such as “band” (English) and “banda” (Spanish)—being processed faster than words with dissimilar forms—such as, “cloud” and “nube.” Substantive literature supports this claim, but is mostly based on orthographic similarity and tested in the visual modality. In a previous study, we found an inhibitory orthographic similarity effect in the auditory modality—i.e., greater orthographic similarity led to slower response times and reduced accuracy. The aim of the present study is to explain this effect. In doing so, we explore the role of the speaker's accent in auditory word recognition and whether native accents lead to a mismatch between the participants' phonological representation and the stimulus. Participants carried out a lexical decision task and a typing task in which they spelled out the word they heard. Words were produced by two speakers: one with a native English accent (Standard American) and the other with a non-native accent matching that of the participants (native Spanish speaker from Spain). We manipulated orthographic and phonological similarity orthogonally and found that accent did have some effect on both response time and accuracy as well as modulating the effects of similarity. Overall, the non-native accent improved performance, but it did not fully explain why high orthographic similarity items show an inhibitory effect in the auditory modality. Theoretical implications and future directions are discussed.

Abstract

Manatees live in shallow, frequently turbid
waters. The sensory means by which they navigate in these
conditions are unknown. Poor visual acuity, lack of echo-
location, and modest chemosensation suggest that other
modalities play an important role. Rich innervation of sen-
sory hairs that cover the entire body and enlarged soma-
tosensory areas of the brain suggest that tactile senses are
good candidates. Previous tests of detection of underwater
vibratory stimuli indicated that they use passive movement
of the hairs to detect particle displacements in the vicinity
of a micron or less for frequencies from 10 to 150 Hz. In
the current study, hydrodynamic stimuli were created by
a sinusoidally oscillating sphere that generated a dipole
field at frequencies from 5 to 150 Hz. Go/no-go tests of
manatee postcranial mechanoreception of hydrodynamic
stimuli indicated excellent sensitivity but about an order of
magnitude less than the facial region. When the vibrissae
were trimmed, detection thresholds were elevated, suggest-
ing that the vibrissae were an important means by which
detection occurred. Manatees were also highly accurate in two-choice directional discrimination: greater than 90%
correct at all frequencies tested. We hypothesize that mana-
tees utilize vibrissae as a three-dimensional array to detect
and localize low-frequency hydrodynamic stimuli

Abstract

There is increasing evidence that long-lasting morphologic and
functional consequences can be present in the human visual system
after repetitive mild traumatic brain injury (r-mTBI). The exact lo-
cation and extent of the damage in this condition are not well un-
derstood. Using a recently developed mouse model of r-mTBI, we
assessed the effects on the retina and optic nerve using histology and
immunohistochemistry, electroretinography (ERG), and spectral-
domain optical coherence tomography (SD-OCT) at 10 and 13 weeks
after injury. Control mice received repetitive anesthesia alone (r-sham).
We observed decreased optic nerve diameters and increased cellularity
and areas of demyelination in optic nerves in r-mTBI versus r-sham
mice. There were concomitant areas of decreased cellularity in the
retinal ganglion cell layer and approximately 67% decrease in brain-
specific homeobox/POU domain protein 3AYpositive retinal ganglion
cells in retinal flat mounts. Furthermore, SD-OCT demonstrated a de-
tectable thinning of the inner retina; ERG demonstrated a decrease in
the amplitude of the photopic negative response without any change in
a- or b-wave amplitude or timing. Thus, the ERG and SD-OCT data
correlated well with changes detected by morphometric, histologic,
and immunohistochemical methods, thereby supporting the use of
these noninvasive methods in the assessment of visual function and
morphology in clinical cases of mTBI.