scholarly journals Fixation Preference for Visual and Auditory Targets in Monkeys with Strabismus

2020 ◽  
Vol 61 (11) ◽  
pp. 24
Author(s):  
Santoshi Ramachandran ◽  
Vallabh E. Das
Keyword(s):  
Fixation Preference

scholarly journals Fixation Preference and Visual Acuity Testing in a Population-based Cohort of Preschool Children with Amblyopia Risk Factors

Ophthalmology ◽  
2009 ◽  
Vol 116 (1) ◽  
pp. 145-153 ◽  
Author(s):  
Susan A. Cotter ◽  
Kristina Tarczy-Hornoch ◽  
Erin Song ◽  
Jesse Lin ◽  
Mark Borchert ◽  
...  
Keyword(s):  
Risk Factors ◽  
Visual Acuity ◽  
Preschool Children ◽  
Population Based ◽  
Visual Acuity Testing ◽  
Fixation Preference

Visual Recognition of Mother by Young Infants: Facilitation by Speech

Perception ◽  
1993 ◽  
Vol 22 (10) ◽  
pp. 1133-1153 ◽  
Author(s):  
Denis Burnham
Keyword(s):  
Visual Recognition ◽  
Visual Fixation ◽  
Facial Cues ◽  
Young Infants ◽  
Series Of Experiments ◽  
Fixation Preference ◽  
Mother’S Voice ◽  
Speech Information ◽  
The Voice ◽  
Relative Salience

Infants recognise their mother's voice at birth but appear not to recognise visual-only presentations of her face until around 3 months. In a series of experiments visual discrimination by infants aged 1, 3, and 5 months of their mother's and a female stranger's face was investigated in visual-only and visual-plus-speech conditions. In the first experiment these infants' discrimination of mother's and female stranger's faces was measured by their visual-fixation-preference scores. Discrimination was found to be facilitated by the addition of speech information. In experiment 2 naive adults viewed silent videotapes of infants from experiment 1 and judged whether the mother had been presented on the infants' left or right. This added further information to the fixation-preference results of experiment 1: it was found that 1-month-olds discriminate mother's and stranger's face only in the presence of speech information, whereas 3-month-olds also do so in visual-only conditions. In experiments 3 and 4 the relative salience of lip movements and voice information in visual recognition of mother's face was investigated. In experiment 3, no significant differences in infants' visual-fixation-preference scores were obtained. However, in experiment 4 adults' ‘where is mother?’ judgments of videotapes from experiment 3 were found to be more accurate in the voice than in the lip-movements conditions, especially for the 3-month-olds and more accurate when mother rather than stranger was talking. It is concluded that young infants' visual recognition of mother is facilitated by addition of speech information, that it is primarily the voice component of speech that causes this facilitation, and that social discrimination is best indexed by a dependent variable which is sensitive to a range of facial cues provided by infants.

scholarly journals Contrasting effects of strabismic amblyopia on metabolic activity in superficial and deep layers of striate cortex

2015 ◽  
Vol 113 (9) ◽  
pp. 3337-3344 ◽  
Author(s):  
Daniel L. Adams ◽  
John R. Economides ◽  
Jonathan C. Horton
Keyword(s):  
Metabolic Activity ◽  
Striate Cortex ◽  
Optokinetic Nystagmus ◽  
Rectus Muscle ◽  
Visually Guided ◽  
Experimental Intervention ◽  
Deep Layers ◽  
Unusual Occurrence ◽  
Fixation Preference ◽  
The Right

To probe the mechanism of visual suppression, we have raised macaques with strabismus by disinserting the medial rectus muscle in each eye at 1 mo of age. Typically, this operation produces a comitant, alternating exotropia with normal acuity in each eye. Here we describe an unusual occurrence: the development of severe amblyopia in one eye of a monkey after induction of exotropia. Shortly after surgery, the animal demonstrated a strong fixation preference for the left eye, with apparent suppression of the right eye. Later, behavioral testing showed inability to track or to saccade to targets with the right eye. With the left eye occluded, the animal demonstrated no visually guided behavior. Optokinetic nystagmus was absent in the right eye. Metabolic activity in striate cortex was assessed by processing the tissue for cytochrome oxidase (CO). Amblyopia caused loss of CO in one eye's rows of patches, presumably those serving the blind eye. Layers 4A and 4B showed columns of reduced CO, in register with pale rows of patches in layer 2/3. Layers 4C, 5, and 6 also showed columns of CO activity, but remarkably, comparison with more superficial layers showed a reversal in contrast. In other words, pale CO staining in layers 2/3, 4A, and 4B was aligned with dark CO staining in layers 4C, 5, and 6. No experimental intervention or deprivation paradigm has been reported previously to produce opposite effects on metabolic activity in layers 2/3, 4A, and 4B vs. layers 4C, 5, and 6 within a given eye's columns.

Tests of Fixation Preference for Amblyopia

2005 ◽  
Vol 55 (1) ◽  
pp. 76-81 ◽  
Author(s):  
David K. Wallace
Keyword(s):  
Fixation Preference

The Effect of Hearing Loss on the Perception of Infant- and Adult-Directed Speech

2013 ◽  
Vol 56 (4) ◽  
pp. 1108-1119 ◽  
Author(s):  
Susie Robertson ◽  
Deborah von Hapsburg ◽  
Jessica S. Hay
Keyword(s):  
Hearing Loss ◽  
Language Learning ◽  
Hearing Impairment ◽  
Speech Signal ◽  
Developmentally Appropriate ◽  
Normal Hearing ◽  
Chronological Age ◽  
Fixation Preference ◽  
Central Fixation

Purpose Infant-directed speech (IDS) facilitates language learning in infants with normal hearing, compared to adult-directed speech (ADS). It is well established that infants with normal hearing prefer to listen to IDS over ADS. The purpose of this study was to determine whether infants with hearing impairment (HI), like their NH peers, show a listening preference for IDS over ADS. Method A total of 36 infants—9 HI infants (mean chronological age of 19.1 with mean listening age of 7.7 months), 9 NH infants with similar average listening age (7.8 months), and 9 NH infants with similar average chronological age (18.6 months)—were tested on their listening preference for IDS compared with ADS using the central fixation preference procedure. Results Infants with HI significantly preferred listening to IDS over ADS. The preference for IDS was also seen in the younger NH infants, but not older NH controls. Additionally, HI infants showed shorter overall looking times as compared to either NH group. Conclusion Although infants with hearing loss displayed a shorter looking time to speech compared to NH controls, HI infants nonetheless appear to have sufficient access to the speech signal to display a developmentally appropriate preference for IDS over ADS.

Atypical Fixation Preference with Anisometropia

2007 ◽  
Vol 84 (9) ◽  
pp. E848-E851 ◽  
Author(s):  
ROBERT P. RUTSTEIN ◽  
MARK W. SWANSON
Keyword(s):  
Fixation Preference

The Effect of Fixation Target on Fixation Preference Testing

1999 ◽  
Vol 49 (1) ◽  
pp. 105-110 ◽  
Author(s):  
Nancy Fischer ◽  
Steven E. Brooks
Keyword(s):  
Fixation Target ◽  
Preference Testing ◽  
Fixation Preference
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