Story reading with incidental comprehension and memory: left hemisphere dominance

ABSTRACT Background: There are no studies on adults with unilateral brain lesions regarding story reading with incidental/implicit comprehension and memory, in which memory is only assessed through delayed recall. There is a need for validation of cerebral laterality in this type of verbal recall, which includes spontaneous performance (free or uncued condition (UC)), and induced-through-question performance regarding the forgotten units (cued condition (CC)). Objectives: To explore the effects of unilateral brain lesions, of oral reading with expression (RE) and comprehension (RC) on delayed recall of a story, as either UC or CC; and to validate the ability of UC and CC to discriminate the side of brain injury. Methods: Data were obtained from 200 right-handed volunteers, among whom 42 had left-hemisphere injury (LHI), 49 had right-hemisphere injury (RHI) and 109 were demographically-matched healthy participants (HP). Patients who were unable to read, understand or speak were excluded. Results: LHI individuals presented impairment of both UC and CC, in relation to the other two groups (non-LHI) with sensitivity and specificity above 70%. LHI and RHI individuals were not significantly different in RE and RC, but they were both different from HP in all the assessments except CC, in which RHI individuals resembled HP. Despite this lack of abnormality in RHI individuals during CC, about half of this group showed impairment in UC. Additionally, whereas RE had a significant effect on UC, the moral of the story (RC) had a significant effect on both UC and CC. Conclusions: The left hemisphere was dominant for this memory task involving implicit processing.

Effects of Mouthpiece Noninvasive Ventilation on Speech in Men With Muscular Dystrophy: A Pilot Study

Purpose The use of noninvasive ventilation (NIV) is on the rise as an alternative to tracheostomy for individuals with neuromuscular disorders with life-prolonging and quality-of-life benefits. This pilot study was designed to determine if mouthpiece NIV (M-NIV) alters speech in individuals with muscular dystrophy (MD). Method Eight men (23–44 years), seven with Duchenne MD and one with Becker MD, who used daytime M-NIV, were asked to sustain phonation, count, and read under three conditions: (a) Uncued (no instructions), (b) With M-NIV (cued to use M-NIV with all speaking breaths), and (c) Without M-NIV (as tolerated). Breath group and inspiratory durations, syllables/breath group, and relative sound pressure level were determined from audio and video recordings. Results Uncued condition: Participants used the ventilator for all inspirations that preceded sustained phonation and counting. During reading, four participants used M-NIV for all inspirations, one never used it, and three used it for some (19%–41%) inspirations. With- versus Without-M-NIV conditions: Breath group duration was significantly longer across all tasks, syllables per breath group were significantly greater during reading, and inspiratory pause duration during reading was significantly longer with M-NIV than without. Sound pressure level was significantly higher during the first second of sustained phonation with M-NIV (though not for counting and reading). Two participants were unable to complete the reading task audibly without using their M-NIV. Conclusions Speech may be better with M-NIV than without because it is possible to produce longer breath groups and some people with severe respiratory muscle weakness may not be able to speak at all without ventilator-supplied air. Nevertheless, the longer inspiratory pauses that accompany M-NIV may interrupt the flow of speech. Future research is needed to determine the most effective way to use M-NIV for speaking and whether training participants in its use can bring even greater speech benefits.

Influence of Predictive Information on Responses of Tonically Active Neurons in the Monkey Striatum

Apicella, Paul, Sabrina Ravel, Pierangelo Sardo, and Eric Legallet. Influence of predictive information on responses of tonically active neurons in the monkey striatum. J. Neurophysiol. 80: 3341–3344, 1998. We investigated how the expectation of a signal of behavioral significance influences the activity of tonically active neurons in the striatum of two monkeys performing a simple reaction time task under two conditions, an uncued condition in which the trigger stimulus occurred randomly in time and a cued condition in which the same trigger was preceded by an instruction stimulus serving as a predictive signal for the forthcoming signal eliciting an immediate behavioral reaction. Both monkeys benefited from the presence of the instruction stimulus to reduce their reaction time, suggesting an increased ability to predict the trigger onset during cued trials compared with uncued trials. A majority of neurons (199/272, 73%) showed a phasic reduction in activity after the onset of the trigger stimulus in the uncued condition, whereas only 38% responded to the same stimulus when it was preceded by the instruction. Furthermore, magnitudes of trigger responses in the uncued condition were significantly higher than in the cued condition. Fifty-seven percent of the neurons responded to the instruction stimulus, and one-half of the neurons losing their response to the trigger in the cued condition responded to the instruction stimulus. These findings suggest that responses of tonic striatal neurons to a trigger stimulus for movement were influenced by predictive information.

Effects of Locus of Control and Relevance on Intentional and Incidental Memory for Passages

On the basis of a median split of their scores on Rotter's locus of control scale, 34 undergraduates were classified as internals and 36 as externals. All subjects read six passages representing three levels of relevance for lives of students under one of three sets of instructions. In the cued condition, subjects were informed that a memory test would follow four days later; in the uncued condition subjects rated the relevance of the passages; and in the pure uncued condition subjects summarized the passages Material of low relevance was remembered more poorly than those in the two higher levels, but internal and external students performed similarly in. all conditions. These results cast further doubt on the prediction from social learning theory that internal persons would be selectively superior to external ones on more relevant material in the uncued conditions.