Increased reading speed for stories presented during general anesthesia.
BACKGROUND: In the absence of explicit memories such as the recall and recognition of intraoperative events, memory of auditory information played during general anesthesia has been demonstrated with several tests of implicit memory. In contrast to explicit memory, which requires conscious recollection, implicit memory does not require recollection of previous experiences and is evidenced by a priming effect on task performance. The authors evaluated the effect of a standardized anesthetic technique on implicit memory, first using a word stem completion task, and then a reading speed task in a subsequent study. METHODS: While undergoing lumbar disc surgery, 60 patients were exposed to auditory materials via headphones in two successive experiments. A balanced intravenous technique with propofol and alfentanil infusions and a nitrous oxide-oxygen mixture was used to maintain adequate anesthesia. In the first experiment, 30 patients were exposed randomly to one of the two lists of 34 repeated German nouns; in the second experiment, 30 patients were exposed to one of two tapes containing two short stories. Thirty control patients for each experiment heard the tapes without receiving anesthesia. All patients were tested for implicit memory 6-8 h later: A word stem completion task for the words and a reading speed task for the stories were used as measures of implicit memory. RESULTS: The control group completed the word stems significantly more often with the words that they had heard previously, but no such effect was found in the anesthetized group. However, both the control and patient groups showed a decreased reading time of about 40 ms per word for the previously presented stories compared with the new stories. The patients had no explicit memory of intraoperative events. CONCLUSIONS: Implicit memory was demonstrated after anesthesia by the reading speed task but not by the word stem completion task. Some methodologic aspects, such as using low frequency words or varying study and test modalities, may account for the negative results of the word stem completion task. Another explanation is that anesthesia with propofol, alfentanil, and nitrous oxide suppressed the word priming but not the reading speed measure of implicit memory. The reading speed paradigm seems to provide a stable and reliable measurement of implicit memory. (+info)
Readability of patient information leaflets on antiepileptic drugs in the UK.
The Audit Commission in the UK recommends that patient information leaflets (PILs) should be audited by health professionals using a formal readability test. However, no such study on antiepileptic drugs (AEDs) has been identified in a Medline search. The aim of this study was to audit the readability of PILs prepared for marketed proprietary AEDs in the UK. Twelve PILs were compared with six antiepileptic drug articles from medical journals and six headline articles from UK newspapers. The Gunning Fog index and the Flesch Reading Ease index were calculated for each PIL and article. The results of the Gunning Fog index and the Flesch Reading Ease score were compared using the Kruskal-Wallis non-parametric test. PILs were shown to have a statistically significant lower mean reading age than the medical articles and newspapers (P < 0.001). The Gunning Fog index and Flesch Reading Ease score showed that PILs had a mean reading age of 8.8 and mean readability score of 69, respectively. In conclusion, the PILs prepared for proprietary antiepileptic drugs in the UK are suitable for the reading age of the general adult population. (+info)
Characteristics of discrepancies between self-reported visual function and measured reading speed. Salisbury Eye Evaluation Project Team.
PURPOSE: Visual impairment is a risk factor for morbidity in the elderly and is often screened for by self-report. This study evaluates whether there are subsets for whom there is a discrepancy between self-reported and measured function. METHODS: The prevalence of a discrepancy between self-reported difficulty reading a newspaper and measured reading speed was determined in 2520 community-based men and women, aged 65 to 84 years, and the discrepant group characterized by polychotomous regression. RESULTS: Of subjects who reported minimal difficulty reading a newspaper, 10.8% (227/2107) read newsprint-sized text (0.21 degrees) more slowly than 80 words/min, a level previously shown to be necessary for sustained reading. Poor visual acuity, presence of psychiatric symptoms, and less satisfaction with vision were associated with being in the group that read slowly and reported difficulty with reading. Better cognition, better visual acuity, more years of education, white race, and fewer psychiatric symptoms were associated with being in the group that read more quickly and reported minimal difficulty. When reading the text size at which subjects read their fastest, only 2.6% of those with minimal difficulty remained discrepant. These individuals were more likely to have less education, be male, be African American, and have poorer cognitive status than those who did not remain discrepant. CONCLUSIONS: A subset of the elderly population have a substantial discrepancy between self-reported reading difficulty and measured reading speed. In some, this discrepancy may be based on underlying expectations and experiences, and in others it may represent a transition from no visual impairment to visual impairment. (+info)
Plasticity of language-related brain function during recovery from stroke.
BACKGROUND AND PURPOSE: This study was undertaken to correlate functional recovery from aphasia after acute stroke with the temporal evolution of the anatomic, physiological, and functional changes as measured by MRI. METHODS: Blood oxygenation level-dependent contrast and echo-planar MRI were used to map language comprehension in 6 normal adults and in 2 adult patients during recovery from acute stroke presenting with aphasia. Perfusion, diffusion, sodium, and conventional anatomic MRI were used to follow physiological and structural changes. RESULTS: The normal activation pattern for language comprehension showed activation predominately in left-sided Wernicke's and Broca's areas, with laterality ratios of 0.8 and 0.3, respectively. Recovery of the patient confirmed as having a completed stroke affecting Broca's area occurred rapidly with a shift of activation to the homologous region in the right hemisphere within 3 days, with continued rightward lateralization over 6 months. In the second patient, in whom mapping was performed fortuitously before stroke, recovery of a Wernicke's aphasia showed a similar increasing rightward shift in activation recruitment over 9 months after the event. CONCLUSIONS: Recovery of aphasia in adults can occur rapidly and is concomitant with an activation pattern that changes from left to a homologous right hemispheric pattern. Such recovery occurs even when the stroke evolves to completion. Such plasticity must be considered when evaluating stroke interventions based on behavioral and neurological measurements. (+info)
Unidirectional dyslexia in a polyglot.
Alexia is usually seen after ischaemic insults to the dominant parietal lobe. A patient is described with a particular alexia to reading Hebrew (right to left), whereas no alexia was noted when reading in English. This deficit evolved after a hypertensive right occipitoparietal intracerebral haemorrhage, and resolved gradually over the ensuing year as the haematoma was resorbed. The deficit suggests the existence of a separate, language associated, neuronal network within the right hemisphere important to different language reading modes. (+info)
Cortical auditory signal processing in poor readers.
Magnetoencephalographic responses recorded from auditory cortex evoked by brief and rapidly successive stimuli differed between adults with poor vs. good reading abilities in four important ways. First, the response amplitude evoked by short-duration acoustic stimuli was stronger in the post-stimulus time range of 150-200 ms in poor readers than in normal readers. Second, response amplitude to rapidly successive and brief stimuli that were identical or that differed significantly in frequency were substantially weaker in poor readers compared with controls, for interstimulus intervals of 100 or 200 ms, but not for an interstimulus interval of 500 ms. Third, this neurological deficit closely paralleled subjects' ability to distinguish between and to reconstruct the order of presentation of those stimulus sequences. Fourth, the average distributed response coherence evoked by rapidly successive stimuli was significantly weaker in the beta- and gamma-band frequency ranges (20-60 Hz) in poor readers, compared with controls. These results provide direct electrophysiological evidence supporting the hypothesis that reading disabilities are correlated with the abnormal neural representation of brief and rapidly successive sensory inputs, manifested in this study at the entry level of the cortical auditory/aural speech representational system(s). (+info)
Reading with simulated scotomas: attending to the right is better than attending to the left.
Persons with central field loss must learn to read using eccentric retina. To do this, most adopt a preferred retinal locus (PRL), which substitutes for the fovea. Patients who have central field loss due to age-related macular degeneration (AMD), most often adopt PRL adjacent to and to the left of their scotoma in visual field space. It has been hypothesized that this arrangement of PRL and scotoma would benefit reading. We tested this hypothesis by asking normally-sighted subjects to read with the left or right half of their visual field plus 3.2 degrees in the contralateral field masked from view. Letter identification, word identification, and reading were all slower when only the information in the left visual field was available. This was primarily due to the number of saccades required to successfully read to stimuli. These data imply that patients would be better off with PRL to the right of their scotoma than to the left for the purposes of reading. (+info)
Reading with central field loss: number of letters masked is more important than the size of the mask in degrees.
When the center of a readers, visual field is blocked from view, reading rates decline and eye movement patterns change. This is true whether the central visual field is blocked artificially (i.e. a mask) or through disease (e.g. a retinal scotoma due to macular degeneration). In past studies, when mask size was defined in terms of the number of letters masked from view, reading rates declined sharply as number of letters masked increased. Patients with larger central scotomas (in degrees of visual angle) also read slower. We sought to determine whether number of letters masked or size of the mask in degrees is the predominant factor affecting reading rates and eye movement behavior. By matching number of letters masked across several mask sizes (and compensating for reduced acuity in the periphery), we found that number of letters masked is the more important factor until mask size is quite large (> or = -7.5 degrees) and number of letters masked from view is more than seven. (+info)