Human sensory stimulation and deprivation: positron emission
tomographic results and strategies
Source: Ann Neurol
1984;15 Suppl:S50-S60.
Author: Mazziotta JC;Phelps ME PubMed ID: 6611127
Abstract:
Fluorine-18-labeled fluorodeoxyglucose was used to measure local
cerebral glucose metabolism by means of positron emission tomography
(PET) in patients and in normal subjects. Various states of audiovisual
stimulation and deprivation were explored. Our experience in performing
neurobehavioral PET studies in over 145 normal right-handed individuals
is described. In normal subjects metabolic left-right symmetry was found
in states of partial sensory deprivation (eyes patched or ears plugged).
Metabolic asymmetries (right less than left) were observed in subjects
with more complete sensory deprivation (eyes patched and ears plugged).
Auditory stimulation studies in normal subjects demonstrated metabolic
evidence of cerebral lateralization. No correlation between site of
metabolic response and side of stimulation was observed. Both the site
and the side (left versus right) of maximal metabolic response
correlated with the type (verbal versus nonverbal) and content of the
stimulus as well as with the strategy used by the subject to solve the
listening task. Visual stimuli of increasing complexity produced
symmetrical increases in metabolic rate for the primary and secondary
visual cortices. Focal stimulation of the central portion of the retina
produced focal responses limited to the occipital poles, while full-
field visual stimulation produced increased metabolic activity
throughout the entire extent of the primary visual cortex. Patients with
lesions of the visual pathway that spared the visual cortex itself
demonstrated abnormalities in visual cortical metabolic rate that
correlated with clinical symptoms. The refinement of neurobehavioral PET
studies is discussed in terms of the limitations presently induced by
spatial resolution, temporal resolution, anatomical localization
accuracy, experimental neuropsychological paradigm design, and data
analysis techniques. These limitations, as well as future prospects for
using PET to study human brain function in both normal and pathological
states, are discussed