Psychophysics Lab Topics
studied in our lab include
- Auditory localization -
Lateralization
- Temporal order judgments
- Visual field asymmetry
- Attention
Ongoing Research:
Processing speed of temporal order judgment
in dyslexia: (Leah Fostick,
Harvey Babkoff)
Studies concerning the origin of dyslexia have focused either on the
question of whether dyslexia is a language-specific disorder or on
dysfunction manifested in deficits of temporal processing. No previous
work compared the speed of correct response between these groups. We
compared the speed of the correct response of normal adult readers and
dyslexics in addition to the accuracy of their responses in judging
temporal order of pure tones. The findings show that dyslexics are
slower, in addition to being less accurate in processing temporal
information of rapidly presented stimuli. We speculate that maybe the
slower reading speed in dyslexia may not be rooted only in neurological
or physiological deficits, but may result from attempts to reduce the
occurrences of errors. Supporting this line of reasoning is the lack of
speed-accuracy relationship for the normal readers who, not making
readings mistakes do not need to slow down reading speed to avoid them.
Recent studies using the global precedence paradigm, indicate that
dyslexics differ from normal readers in temporal processing of visual
information. Because reading mainly involves rapid processing of visual
information, the dyslexics’ slower speed in processing visual stimuli
may have a devastating effect on their reading capability.
Upper - Lower visual field
differences: (Avi
Goldstein,
Harvey Babkoff)
The upper and lower parts of the visual field are
represented in separate areas in visual cortex: the upper
field ventrally below the calcarine fissure and the lower
field dorsally above the fissure. Thus the UVF is located
closer to the ventral "what" pathway and the
LVF closer to the dorsal "where" pathway. In a
series of experiments we are investigating whether there
are significant functional differences as a result of the
anatomical separation.
We have found an UVF advantage for the processing of
lexical stimuli (words), that increases with associative
priming. The upper-lower asymmetry was strikingly similar
to the familiar right-left asymmetry.
In a follow-up study we are exploring
whether form and object-identification processing (ventral)
lead to UVF advantages while spatial processing (dorsal)
lead to LVF advantages.
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