User:Gmilbrat/sandbox/Speech Perception with Brain Damage

Speech Perception and Brain Disabilities following deep brain stimulation of the subthalamic nucleus Patients appear to perceive a difference after surgery, demonstrated by increase reports of difficulties. '''****The article stated that patients who got surgery to enhance the deep brain stimulation, perceived their speech difficulties much higher than patients who did not have surgery. *The Influence of Phonetic Dimensions on Aphasic Speech Perception
 * Self-perception of speech changes in patients with Parkinson’s disease
 * Most patients with Parkinson's disease (PD) experience speech disorders during the progression of their disease.
 * Levodopa is commonly used to treat the motor symptoms of Parkinson's disease. Patients on medication often experience cyclic fluctuations of their symptoms, described as being "on" (when motor symptoms are relieved) and "off" (when motor symptoms are present).
 * When drug therapies become less effective, surgical intervention may be required.
 * Deep brain stimulation of the subthalamic nucleus provides continuous electrical stimulation, improving the "off" period.
 * Increasing stimulation amplitude to relieve motor symptoms often increases speech difficulties and reduces intelligibility (krack, fraix.
 * Once deep brain stimulation has been surgically placed, the patients rate their voice and speech as more severly impaired than healthy controls (Fox & Ramig, 1997), indicating some awareness of their difficulties.
 * They also perceive their speech when reading and in conversation to be louder than its actual volume (Ho, Bradshaw, &Iansek, 2000).
 * The Lee Silverman Voice Treament (LSVT) has been shown to be an effective speech treatment for Parkinsonian voice difficulties (Ramig, Sapir, Countryman et al). It focuses on increasing vocal loudness and emphasizes thee need for self-monitoring, thus treating the voice difficulty by adapting the self-perception.
 * In both groups, 14 out of 20 participants scored their perceived current voice difficulties higher than previously.
 * http://content.ebscohost.com.gacproxy.mnpals.net/pdf23_24/pdf/2010/8NBH/01Oct10/53135260.pdf?T=P&P=AN&K=2010758873&S=R&D=rzh&EbscoContent=dGJyMNXb4kSep684v%2BbwOLCmr0qep7ZSr6u4TbKWxWXS&ContentCustomer=dGJyMPGutlC3rLZQuePfgeyx44Dt6fIA
 * This article talked about the deep brain stimulation from an advanced surgery to help motor functions. They had the patients describe their speech problems before surgery and after surgery.
 * Three (distinctive) phonetic dimensions 'place of articulation', 'manner of articulation', and voicing.
 * In their study, subjuects watched dubbed videos in which auditory and visual information did not match, and they were asked to report what they perceived. Instead of answering with auditory (/ba/) or the visual (/ga/) component of the video, they usually reported a fusion of auditory (/ba/) or the visual (/ga/) component of the video, they usually reported a fusion of both (/da/).  This even occured when the subjects were aware of the dubbing.  This is so called 'McGurk' effect actually shows the influence of speechreading.
 * The features 'mouth opening' and 'lip-shape' mainly convey information necessary to decode the 'place of articulation'.
 * Aphasic subjects with a disorder in analysing speech sounds will have problems in discrimination of items differing in fewer phonetic dimensions.
 * The aphasic patient improvedin discrimination of 'place of articulation" contrasts as well as 'manner of articulation; contrasts (also for untrained stimuli). These results cannot be explained by the model by Campbell (1988;1990) described above.  Influence on other dimensions than 'place of articulation' is not predicted by this model.  The results of Hessler and Stadie (2008) indicate that speechreading can be beneficial for perceiving the other dimensions as well.
 * There was also a significant advantage for the 'auditory only' over 'visual only' condition. This holds on an individual basis: The performance in the 'audiocisual' condition was better than in the 'auditory only' condition for five out of the six aphasic subjects.
 * http://content.ebscohost.com.gacproxy.mnpals.net/pdf25_26/pdf/2010/B6X/01Dec10/54621030.pdf?T=P&P=AN&K=2010840369&S=R&D=rzh&EbscoContent=dGJyMNXb4kSep684v%2BbwOLCmr0qep7ZSr624TLeWxWXS&ContentCustomer=dGJyMPGutlC3rLZQuePfgeyx44Dt6fIA

****Results demonstrated that individuals with LHD were unable to identify phonemic stress contrasts with better-than-chance accuracy; individuals with RHD performed worse than normal participants but significantly better than the patients with LHD--particularly with the original full-cue stimuli. '''**** The experiment found in summary, whereas early syntactic processes reflected in the early anterior negativity occurred for both PD patients (but extended to posterior electrode sites and midline sites) and age-matched controls, PD patients showed a reduced P600 effect for late controlled syntactic processes, as compared with their matched controls.  - Overview of Speech Perception''' - The Brain Processes *The Cortical organization of Speech Processing
 * The Role of Fundamental Frequency and Duration in the Perception of Linguistic Stress by Individuals with Brain Damage
 * http://web.ebscohost.com/ehost/detail?sid=c7e5c86e-5dfa-4e05-bca9-3ed459ff0741%40sessionmgr112&vid=11&hid=104&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=psyh&AN=1998-00088-002
 * This would be a good article to compare left and right hemisphere brain damaged patients.
 * Rhythm in Speech of a Person with Right Hemisphere Damage
 * http://web.ebscohost.com/ehost/detail?vid=6&hid=123&sid=9d921a0e-802c-46e9-a012-883857b7c6a9%40sessionmgr12&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=psyh&AN=2007-12490-006
 * This would be a good example of the rhythm of a Brain Disabled patient.
 * Inferencing Processes after Right Hemisphere Brain Damage: Inferencing
 * http://web.ebscohost.com/ehost/detail?vid=16&hid=123&sid=9d921a0e-802c-46e9-a012-883857b7c6a9%40sessionmgr12&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=psyh&AN=2009-06070-006
 * This article explains the inference level of patients who have damage done to their right hemisphere.
 * Inferencing Processes after Right Hemisphere Brain Damage: Contextual Bias
 * http://web.ebscohost.com/ehost/detail?vid=16&hid=123&sid=9d921a0e-802c-46e9-a012-883857b7c6a9%40sessionmgr12&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=psyh&AN=2009-06070-007
 * THis article is the same authors as the article before. They try to find the contextual biases of right hemisphere brain damaged patients in a predictability task.  Some of the questions had lower predictability, while the others had higher predictability.  This might help with their reasoning skills.
 * Syntactic Comprehension in Parkinson's Disease: Investigating Early Automatic and Late Integrational processes using event related brain potentials.
 * Patients with left temporoparietal lesions, often diagnosed as Wernicke's aphasia are more likely to reveal a major lexical-semantic deficit, whereas patients with left inferior frontal lesions, often called Broca's aphasics, are described as revealing a major syntactic deficit.
 * finding that posterior aphasic and patients with Alzheimer's disease demonstrate more errors in generating irregular verb forms (go-went), which are assumed to be stored in the lexicon as a full lexical entry, than in generating regular verb forms (cook-cooked), which are taken to be governed by a morphosyntactic rule (add-added). Anterior aphasics and Parkinson's disease (PD) patients, in contrast, show more errors with regular, rule governed than with irregular verb forms.
 * Aphasics with lesions in the left inferior frontal cortex (Brocas) are characterized by deficits in grammatical processing during language production and during comprehension when the interpretation relies on syntactic information.
 * Wernicke's aphasics, in contrast, clearly demonstrate a lexical-semantic deficit in production and most off-line comprehension tasks but show close to normal perforance in on-line semantic priming tasks (Blumstein).
 * The results demonstrate that early automatic syntactic processes are spared in PD patients' comprehension but that late syntactic integration processes are partially affected.
 * http://web.ebscohost.com/ehost/detail?vid=18&hid=123&sid=9d921a0e-802c-46e9-a012-883857b7c6a9%40sessionmgr12&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=psyh&AN=2003-01139-016
 * The present findings suggest that the basal ganglia primarily do not support early automatic syntactic processes during comprehension but rather support processes of syntactic integration.
 * Speech Perception
 * pdf file by the name of speech perception
 * This article would be good for the an overview of Speech Perception
 * The first hypothesis made claim that patients with auditory language comprehension disorders (Wernicke's) who typically had lesions of the left superior temporal gyrus (STG).
 * Deficits in the ability to perceive speech sounds contributed minimally to the auditory comprehension deficit in Wernicke's aphasia. Destruction of the left STG does not lead to deficits in the auditory comprehension of speech, but instead causes deficits in speech production.
 * Findings in mapping the neural circuits for speech perception was questionable, given that the ability to perform syllable discrimination and identification tasks double dissociated from the ability to comprehend aurally presented words: that is, there are patients who have impaired syllable discrimination but good word comprehension, and vice versa.
 * Wernicke's aphasia that are secondary to left temporal lobe lesions resulted from disruptions of semantic rather than phonological processes, whereas others postulated that the mapping between phonological and semantic representations was disrupted.
 * The term 'speech perception' describes the process of interest employ sublexical speech tasks, such as syllable discrimination, to the probe process.
 * Neural Processes supporting the ability to process speech sounds under ecologically valid conditions, that is, situations in which successful speech sound processing ultimately leads to contact with the mental lexicon and auditory comprehension.
 * model proposes that a ventral stream, which involves structures in the superior and middle portions of the temporal love, is incolved in processing speech signals for comprehension. A dorsal stream, which involves structures in the posterior frontal lobe and the posterior dorsal-most aspect of the temporal love and parietal operculum, is involved in translating acoustic speech signals into articulatory representations in the frontal lobe, which is essential for speech development and normal speech production.
 * The dorsal stream, is strongly left-dominant, which explains why production deficits are prominent sequelae of dorsal temporal and frontal lesions, and why left-hemisphere injury can substantially impair performance in speech perception tasks.
 * Speech perception levels: features, segments (phonemes), syllabic structure, phonological word forms, grammatical features, morphemic, and semantic information.
 * Damage to auditory-related regions in the left hemisphere results in speech production deficits.
 * Damage to the left dorsal STG or the temproparietal junction is associated with conduction aphasia, a syndrom that is characterized by good comprehension but frequent phonemic errors in speech production.
 * pdf file by the name of Cortical Organization

*Speech Perception: Cognitive Foundations and Cortical Implementations
 * speech perception refers to the set of operations that transform an auditory signal into mental representations of a type that can make contact with internally stored information or words.
 * mapping from sound to code forces a set of computations that translate the acoustic input into a discretized representation.
 * Dual Stream Model
 * First, research on acoustics of speech has shifted emphasis from more spectrally based investigations (ba or da) to more temporally based approaches, in which concepts such as the envelope of a speech signal (fluctuations in power over time) or the modulation spectrum (sound frequencies are modulated at which rates) are used to account for perceptual phenomena.
 * A second perspective shift concerns the potent role that task demands play.
 * The incoming signal's spectrotemporal properties are initially analyzed in the dorsal and posterior superior temporal gyrus and the superior temporal sulcus. Critically, these early computations are mediated bilaterally in the superior temporal cortex.
 * Two processing streams originate from this early spectrotemporal analysis.
 * A ventral pathway incorporates middle temporal gyrus, inferior temporal sulcus and perhaps the inferior temporal gyrus. The ventral stream maps from sensory.phonological representations to lexical or conceptual representations (meaning).
 * A dorsal pathway, including the sylvian parietotemporal are as well as the inferior frontal gyrus, anterior insula, and premotor cortex, forms the substrate for mapping from sensory /phonological representations to articulatory-motor representations.
 * http://web.ebscohost.com/ehost/pdfviewer/pdfviewer?sid=c7e5c86e-5dfa-4e05-bca9-3ed459ff0741%40sessionmgr112&vid=7&hid=104