Linking sight and sound: fMRI evidence of primary auditory cortex activation during visual word recognition.

We describe two studies that used repetition priming paradigms to investigate brain activity during the reading of single words. Functional magnetic resonance images were collected during a visual lexical decision task in which nonword stimuli were manipulated with regard to phonological properties and compared to genuine English words. We observed a region in left-hemisphere primary auditory cortex linked to a repetition priming effect. The priming effect activity was observed only for stimuli that sound like known words; moreover, this region was sensitive to strategic task differences. Thus, a brain region involved in the most basic aspects of auditory processing appears to be engaged in reading even when there is no environmental oral or auditory component.

A confrontational naming task produces congruent increases and decreases in PET and fMRI.

This work uses the well-established (by PET) confrontation naming task to compare PET and fMRI in a cognitive activation experiment. The signal changes from this task are much less than the changes caused by visual or motor activation tasks used in previous comparisons. ANOVA methods adjusted for multiple comparisons were used to determine significant changes in signal between confrontation naming and figure size discrimination tasks. All 17 significantly increased regions (confrontation naming signal greater) seen on one modality were increased on both modalities. Ten of 13 regions that were significantly decreased on one modality were decreased on the other. Three mismatched regions showed a significant decrease on one modality and a nonsignificant increase on the other. This study could not detect a consistent difference in activation site location between PET and fMRI.

Repetitive relationship themes in waking narratives and dreams.

The aims of the study were to see whether the core conflictual relationship theme (CCRT) measure can be reliably applied to dreams and to evaluate the degree to which the main components of the CCRT are present in both dreams and waking narratives in psychotherapy. For 13 psychoanalytic cases, the reliability of the CCRT was found to be good. Dreams and narratives were found to contain significant degrees of similarity in their CCRT components and similar and high level of negativity in both dreams and waking narratives. The results support the concept of a central relationship pattern that can be expressed in common in both waking narratives and dreams.

Radiographic evaluation of instability in spondylolisthesis.

STUDY DESIGN: The amount of intervertebral motion seen during dynamic radiography when imaged with the patient in the standing position was compared with that obtained with the patient in the lateral decubitus position. SUMMARY OF BACKGROUND DATA: Regarding analysis of spondylolisthesis, whether flexion/extension radiographs should be obtained with the patient in the lateral decubitus or standing position has been anecdotal. METHODS: Fifty consecutive adult patients with spondylolisthesis underwent flexion/extension lumbar spine radiographs in both positions. Abnormal motion was considered above 12 degrees dynamic angulation or 8% translation. RESULTS: Thirty-one of 50 patients displayed abnormal translation. Of these, 18 had abnormal motion only when they were examined in the lateral decubitus position and not when standing. Nine displayed excessive motion in both positions. Only four displayed more translation while standing. There was no statistical difference in the evaluation of dynamic angulation based on patient position. Neither age, degree of slip, listhetic level, nor type of spondylolisthesis correlated with abnormal motion. CONCLUSIONS: When spondylolisthesis is being analyzed, to maximize motion, flexion/extension radiographs should be obtained in the lateral decubitus position.

An electron-electron double-resonance study of interactions between [14N]- and [15N]stearic acid spin-label pairs: lateral diffusion and vertical fluctuations in dimyristoylphosphatidylcholine.

Vertical fluctuations of the terminal methyl groups of stearic acid acyl chains toward the surface of dimyristoylphosphatidylcholine (DMPC) bilayers have been investigated by using spin-label electron-electron double-resonance ( ELDOR ) methodology. Spin-label pairs consisting of two populations of stearic acid spin-labels were employed, each at 0.25 mol% concentration, where the nitroxides of the first population were 15N substituted and the nitroxides of the second contained 14N. Various combinations of labels with the nitroxide moieties located at carbons 5, 12, or 16 (C5, C12, C16) were used. ELDOR permits measurement of collision frequencies between the two constituents of the pair, for example, between 15N spin-labels at C5 and 14N labels at C16. Intramolecular contributions to the ELDOR effect including nitrogen nuclear relaxation are eliminated by the use of spin-label pairs. Above the main phase transition temperature, bimolecular collisions between C5 and C16 occur with about half the frequency of C16:C16 collisions. It is concluded that vertical fluctuations are very pronounced. A dependence of these fluctuations on temperature and pH has been observed. Lateral diffusion constants calculated from the bimolecular collision frequencies of C16:C16 pairs are 4.56 X 10(-8), 5.77 X 10(-8), and 8.09 X 10(-8) cm2/s at 27, 37, and 47 degrees C. These values are in good agreement with previous measurements of lipid diffusion in DMPC.

Electron-electron double resonance and saturation-recovery studies of nitroxide electron and nuclear spin-lattice relaxation times and Heisenberg exchange rates: lateral diffusion in dimyristoyl phosphatidylcholine.

Lateral diffusion constants of the stearic acid nitroxide radical spin label 2-(14-carboxytetradecyl)-2-ethyl-4,4-dimethyl-3-oxazolindinyl oxide in dispersions of dimyristoyl phosphatidylcholine have been measured. Electron-electron double resonance methods were used to determine the product of the bimolecular collision frequency and T1e, the electron spin-lattice relaxation time. T1e in turn was measured by the technique of saturation recovery. The theoretical model of Träuble and Sackmann was then used to relate the bimolecular collision frequencies to the diffusion constants. Results are in agreement with other methods. Lower spin-label concentrations than were used in previous electron paramagnetic resonance studies are needed (label-to-lipid ratio less than 0.5 mol%). Analysis of the data also yields values of the nitrogen nuclear spin-lattice relaxation time of the nitroxide moiety. These values are indicative of membrane fluidity.