Metamorphopsia and letter recognition

Metamorphopsia and letter recognition.

Acuity is the most commonly used measure of visual function, and reductions in acuity are associated with most eye diseases. Metamorphopsia--a perceived distortion of visual space--is another common symptom of visual impairment and is currently assessed qualitatively using Amsler (1953) charts. In order to quantify the impact of metamorphopsia on acuity, we measured the effect of physical spati...

Spoken Letter Recognition

Through the use of neural network classifiers and careful feature selection, we have achieved high-accuracy speaker-independent spoken letter recognition. For isolated letters, a broad-category segmentation is performed Location of segment boundaries allows us to measure features at specific locations in the signal such as vowel onset, where important information resides. Letter classification ...

Addressing issues in letter recognition.

The present research strategy utilizes factorial designs, functional measurement, testing of mathematical models and strong inference in the study of letter perception. To test the viability of this framework, subjects judged a number of ambiguous letters, varying between Q and G, in both a rating and discrete choice task. The letters were created by varying features of openness in the oval and...

Isolated English Letter Speech Recognition

Neural specialization for letter recognition.

Functional magnetic resonance imaging (fMRI) was used to estimate neural activity while subjects viewed strings of consonants, digits, and shapes. An area on or near the left fusiform gyrus was found that responded significantly more to letters than digits. Similar results were obtained when consonants were used whose visual features were matched with the digits and when an active matching task...