Altered Functions of Visual Brain Areas: Review of Recent Evidence from Blind Human Subjects

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 219-219
Author(s):  
T Kujala ◽  
K Alho
Keyword(s):  
Visual Cortex ◽  
Auditory Processing ◽  
Visual Information ◽  
Late Onset ◽  
Human Subjects ◽  
Brain Activity ◽  
Event Related Potential ◽  
Auditory Modality ◽  
Somatosensory Processing ◽  
Brain Areas

We investigated the functional role of human visual brain areas deprived of visual information. To this end, we recorded brain activity elicited by auditory and somatosensory stimuli in blind human subjects. Activity was recorded in the ‘Attend’ condition, in which subjects detected occasional deviant stimuli presented among repetitive standard stimuli and in the ‘Ignore’ condition, in which subjects did not attend to the stimuli. The results indicate that in the early-blinded subjects, event-related potential (ERP) topography elicited by deviant auditory and somatosensory target stimuli is posterior to that in the sighted (Kujala et al, 1995 Experimental Brain Research104 519 – 526). This suggests involvement of posterior brain areas in auditory and somatosensory processing in the blind humans. For the auditory modality, activated areas were located with magnetoencephalography (MEG), which indicates involvement of extrastriate occipital areas in detection of auditory targets (Kujala et al, 1995 Experimental Brain Research103 143 – 146). Visual-cortex plasticity was further studied in subjects who had lost their vision after childhood in order to clarify whether these cross-modal changes are specific to visual deprivation of early onset. In that study, auditory ERP topographies of late-blinded, early-blinded, and sighted subjects were compared. Comparison of posterior topography of ERPs elicited by deviant target stimuli in both early-blinded and late-blinded subjects with that in the sighted subjects suggests visual-cortex involvement in auditory processing even in late-onset blindness (Kujala et al, 1977 Psychophysiology34 213 – 216). Preliminary MEG recordings in one late-blinded subject provided further support for posterior generators (parietal-occipital) in auditory processing.

scholarly journals Rapid orienting of spatial attention toward and away from aggressive voices

2017 ◽  
Author(s):  
Nicolas Burra ◽  
Dirk Kerzel ◽  
David Munoz ◽  
Didier Grandjean ◽  
Leonardo Ceravolo
Keyword(s):  
Spatial Attention ◽  
Auditory Processing ◽  
Temporal Dynamics ◽  
Detection System ◽  
Stimulus Onset ◽  
Event Related Potential ◽  
Auditory Modality ◽  
Attentional Processing ◽  
Auditory Spatial Attention ◽  
Vocal Signals

Salient vocalizations, especially aggressive voices, are believed to attract attention due to an automatic threat detection system. However, studies assessing the temporal dynamics of auditory spatial attention to aggressive voices are missing. Using event-related potential markers of auditory spatial attention (N2ac and LPCpc), we show that attentional processing of threatening vocal signals is enhanced at two different stages of auditory processing. As early as 200 ms post stimulus onset, attentional orienting/engagement is enhanced for threatening as compared to happy vocal signals. Subsequently, as early as 400 ms post stimulus onset, the reorienting of auditory attention to the center of the screen (or disengagement from the target) is enhanced. This latter effect is consistent with the need to optimize perception by balancing the intake of stimulation from left and right auditory space. Our results extend the scope of theories from the visual to the auditory modality by showing that threatening stimuli also bias early spatial attention in the auditory modality. Although not the focus of the present work, we observed that the attentional enhancement was more pronounced in female than male participants.

scholarly journals Psychophysiology and Imaging of Visual Cortical Functions in the Blind: A Review

2008 ◽  
Vol 20 (3-4) ◽  
pp. 71-81 ◽  
Author(s):  
Stephanie L. Simon-Dack ◽  
P. Dennis Rodriguez ◽  
Wolfgang A. Teder-Sälejärvi
Keyword(s):  
Visual Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Visual Information ◽  
Magnetic Stimulation ◽  
Late Onset ◽  
Event Related Potentials ◽  
Cortical Activation ◽  
Future Research ◽  
Related Potentials ◽  
Visual Cortical

Imaging, transcranial magnetic stimulation, and psychophysiological recordings of the congenitally blind have confirmed functional activation of the visual cortex but have not extensively explained the functional significance of these activation patterns in detail. This review systematically examines research on the role of the visual cortex in processing spatial and non-visual information, highlighting research on individuals with early and late onset blindness. Here, we concentrate on the methods utilized in studying visual cortical activation in early blind participants, including positron emissions tomography (PET), functional magnetic resonance imaging (fMRI), transcranial magnetic stimulation (TMS), and electrophysiological data, specifically event-related potentials (ERPs). This paper summarizes and discusses findings of these studies. We hypothesize how mechanisms of cortical plasticity are expressed in congenitally in comparison to adventitiously blind and short-term visually deprived sighted participants and discuss potential approaches for further investigation of these mechanisms in future research.

scholarly journals Somatosensory Plasticity in Pediatric Cerebral Palsy following Constraint-Induced Movement Therapy

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Pawel J. Matusz ◽  
Alexandra P. Key ◽  
Shirley Gogliotti ◽  
Jennifer Pearson ◽  
Megan L. Auld ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Brain Activity ◽  
Event Related Potential ◽  
Motor Dysfunction ◽  
Somatosensory Processing ◽  
Light Touch ◽  
Electrical Neuroimaging ◽  
Sensory Motor ◽  
A Prospective Study ◽  
Sensory Activation

Cerebral palsy (CP) is predominantly a disorder of movement, with evidence of sensory-motor dysfunction. CIMT1 is a widely used treatment for hemiplegic CP. However, effects of CIMT on somatosensory processing remain unclear. To examine potential CIMT-induced changes in cortical tactile processing, we designed a prospective study, during which 10 children with hemiplegic CP (5 to 8 years old) underwent an intensive one-week-long nonremovable hard-constraint CIMT. Before and directly after the treatment, we recorded their cortical event-related potential (ERP) responses to calibrated light touch (versus a control stimulus) at the more and less affected hand. To provide insights into the core neurophysiological deficits in light touch processing in CP as well as into the plasticity of this function following CIMT, we analyzed the ERPs within an electrical neuroimaging framework. After CIMT, brain areas governing the more affected hand responded to touch in configurations similar to those activated by the hemisphere controlling the less affected hand before CIMT. This was in contrast to the affected hand where configurations resembled those of the more affected hand before CIMT. Furthermore, dysfunctional patterns of brain activity, identified using hierarchical ERP cluster analyses, appeared reduced after CIMT in proportion with changes in sensory-motor measures (grip or pinch movements). These novel results suggest recovery of functional sensory activation as one possible mechanism underlying the effectiveness of intensive constraint-based therapy on motor functions in the more affected upper extremity in CP. However, maladaptive effects on the less affected constrained extremity may also have occurred. Our findings also highlight the use of electrical neuroimaging as feasible methodology to measure changes in tactile function after treatment even in young children, as it does not require active participation.

Age-equivalent Top–Down Modulation during Cross-modal Selective Attention

2014 ◽  
Vol 26 (12) ◽  
pp. 2827-2839 ◽  
Author(s):  
Maria J. S. Guerreiro ◽  
Joaquin A. Anguera ◽  
Jyoti Mishra ◽  
Pascal W. M. Van Gerven ◽  
Adam Gazzaley
Keyword(s):  
Selective Attention ◽  
Auditory Processing ◽  
Visual Information ◽  
Relevant Information ◽  
Irrelevant Information ◽  
Visual Modality ◽  
Auditory Modality ◽  
Auditory Information ◽  
Auditory Distraction ◽  
Top Down

Selective attention involves top–down modulation of sensory cortical areas, such that responses to relevant information are enhanced whereas responses to irrelevant information are suppressed. Suppression of irrelevant information, unlike enhancement of relevant information, has been shown to be deficient in aging. Although these attentional mechanisms have been well characterized within the visual modality, little is known about these mechanisms when attention is selectively allocated across sensory modalities. The present EEG study addressed this issue by testing younger and older participants in three different tasks: Participants attended to the visual modality and ignored the auditory modality, attended to the auditory modality and ignored the visual modality, or passively perceived information presented through either modality. We found overall modulation of visual and auditory processing during cross-modal selective attention in both age groups. Top–down modulation of visual processing was observed as a trend toward enhancement of visual information in the setting of auditory distraction, but no significant suppression of visual distraction when auditory information was relevant. Top–down modulation of auditory processing, on the other hand, was observed as suppression of auditory distraction when visual stimuli were relevant, but no significant enhancement of auditory information in the setting of visual distraction. In addition, greater visual enhancement was associated with better recognition of relevant visual information, and greater auditory distractor suppression was associated with a better ability to ignore auditory distraction. There were no age differences in these effects, suggesting that when relevant and irrelevant information are presented through different sensory modalities, selective attention remains intact in older age.

scholarly journals Happy you, happy me: expressive changes on a stranger’s voice recruit faster implicit processes than self-produced expressions

2019 ◽  
Author(s):  
Laura Rachman ◽  
Stéphanie Dubal ◽  
Jean-Julien Aucouturier
Keyword(s):  
Social Interactions ◽  
Auditory Processing ◽  
Mismatch Negativity ◽  
Visual Information ◽  
Oddball Paradigm ◽  
Auditory Modality ◽  
Implicit Processes ◽  
Self And Other ◽  
Socially Relevant ◽  
Onset Responses

AbstractIn social interactions, people have to pay attention both to the what and who. In particular, expressive changes heard on speech signals have to be integrated with speaker identity, differentiating e.g. self- and other-produced signals. While previous research has shown that self-related visual information processing is facilitated compared to non-self stimuli, evidence in the auditory modality remains mixed. Here, we compared electroencephalography (EEG) responses to expressive changes in sequence of self- or other-produced speech sounds, using a mismatch negativity (MMN) passive oddball paradigm. Critically, to control for speaker differences, we used programmable acoustic transformations to create voice deviants which differed from standards in exactly the same manner, making EEG responses to such deviations comparable between sequences. Our results indicate that expressive changes on a stranger’s voice are highly prioritized in auditory processing compared to identical changes on the self-voice. Other-voice deviants generate earlier MMN onset responses and involve stronger cortical activations in a left motor and somatosensory network suggestive of an increased recruitment of resources for less internally predictable, and therefore perhaps more socially relevant, signals.

Functional Organisation of Human Visual Cortex Revealed by fMRI

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 9-9 ◽  
Author(s):  
R B H Tootell ◽  
A M Dale ◽  
N Hadjikhani ◽  
A K Liu ◽  
S Marrett ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Visual Information ◽  
Visual Stimulation ◽  
Frequency Tuning ◽  
Human Subjects ◽  
Planar Imaging ◽  
Posterior Cortex ◽  
Human Visual Cortex ◽  
Wide Range ◽  
Functional Organisation

Until recently, comparatively little was known about the functional organisation of human visual cortex. Functional magnetic resonance imaging (fMRI), in conjunction with cortical flattening techniques and psychophysically relevant visual stimulation, has greatly clarified human visual-information processing. To date, we have completed cortical surface reconstructions (flattening), coupled with a wide range of visual stimulus testing, on 28 normal human subjects. Visual activation was acquired on a 1.5 T GE MR scanner with ANMR echo-planar imaging, with the use of a custom, bilateral, quadrature surface coil covering posterior cortex. Approximately ten visual cortical areas can now be functionally localised each with unique functional and topographical properties. The most well-defined areas are: V1, V2, V3, VP, V3A, V4v, MT, SPO, and perhaps MSTd. Most of the properties in these human areas are similar to those reported in presumably homologous areas of macaque, but distinctive species differences also appear to exist, notably in V3/VP, V4v, and V3A. Human areas showing prominant motion-selectivity include V3A, MT/MSTd, SPO, and a small area near the superior sylvian fissure. Retinotopic areas include V1, V2, V3, VP, V4v, and V3A. The human cortical magnification factor appears higher towards the fovea than in macaque, but, like macaque, preferred spatial frequency tuning varies inversely with eccentricity in all retinotopic areas in which sinusoidal gratings are effective stimuli.

scholarly journals Exploring alterations in sensory pathways in migraine

2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Noemi Meylakh ◽  
Luke A. Henderson
Keyword(s):  
Visual Cortex ◽  
Sensory Processing ◽  
Brain Activity ◽  
Activity Patterns ◽  
Oscillatory Activity ◽  
Somatosensory Processing ◽  
Somatosensory Cortices ◽  
And Gender ◽  
The Right ◽  
Sensory Processes

Abstract Background Migraine is a neurological disorder characterized by intense, debilitating headaches, often coupled with nausea, vomiting and sensitivity to light and sound. Whilst changes in sensory processes during a migraine attack have been well-described, there is growing evidence that even between migraine attacks, sensory abilities are disrupted in migraine. Brain imaging studies have investigated altered coupling between areas of the descending pain modulatory pathway but coupling between somatosensory processing regions between migraine attacks has not been properly studied. The aim of this study was to determine if ongoing functional connectivity between visual, auditory, olfactory, gustatory and somatosensory cortices are altered during the interictal phase of migraine. Methods To explore the neural mechanisms underpinning interictal changes in sensory processing, we used functional magnetic resonance imaging to compare resting brain activity patterns and connectivity in migraineurs between migraine attacks (n = 32) and in healthy controls (n = 71). Significant differences between groups were determined using two-sample random effects procedures (p < 0.05, corrected for multiple comparisons, minimum cluster size 10 contiguous voxels, age and gender included as nuisance variables). Results In the migraine group, increases in infra-slow oscillatory activity were detected in the right primary visual cortex (V1), secondary visual cortex (V2) and third visual complex (V3), and left V3. In addition, resting connectivity analysis revealed that migraineurs displayed significantly enhanced connectivity between V1 and V2 with other sensory cortices including the auditory, gustatory, motor and somatosensory cortices. Conclusions These data provide evidence for a dysfunctional sensory network in pain-free migraine patients which may be underlying altered sensory processing between migraine attacks.

scholarly journals Mindfulness meditators show altered distributions of early and late neural activity markers of attention in a response inhibition task

2018 ◽  
Author(s):  
NW Bailey ◽  
G Freedman ◽  
K Raj ◽  
CM Sullivan ◽  
NC Rogasch ◽  
...  
Keyword(s):  
Sustained Attention ◽  
Response Inhibition ◽  
Neural Activity ◽  
Visual Information ◽  
Mindfulness Meditation ◽  
Occipital Cortex ◽  
Event Related Potential ◽  
Brain Areas ◽  
Eeg Recordings ◽  
The Right

AbstractAttention is a vital executive function, since other executive functions are largely dependent on it. Mindfulness meditation has been shown to enhance attention. However, the components of attention altered by meditation and the related neural activities are underexplored. In particular, the contributions of inhibitory processes and sustained attention are not well understood. Additionally, it is not clear whether improvements in attention are related to increases in the strength of typically activated brain areas, or the recruitment of additional or alternative brain areas. To address these points, 34 meditators were compared to 28 age and gender matched controls during electroencephalography (EEG) recordings of neural activity during a Go/Nogo response inhibition task. This task generates a P3 event related potential, which is related to response inhibition processes in Nogo trials, and attention processes across both trial types. Compared with controls, meditators were more accurate at responding to Go and Nogo trials. Meditators showed a more frontally distributed P3 to both Go and Nogo trials, suggesting more frontal involvement in sustained attention rather than activity specific to response inhibition. Unexpectedly, meditators also showed increased positivity over the right parietal cortex prior to visual information reaching the occipital cortex. Both results were positively related to increased accuracy across both groups. The results suggest that meditators have an increased capacity to modulate a range of neural processes in order to meet task requirements, including higher order processes, and sensory anticipation processes. This increased capacity may underlie the improved attentional function observed in mindfulness meditators.

scholarly journals Exploring Alterations in Sensory Pathways in Migraine

2021 ◽  
Author(s):  
Noemi Meylakh ◽  
Luke A. Henderson
Keyword(s):  
Visual Cortex ◽  
Sensory Processing ◽  
Brain Activity ◽  
Activity Patterns ◽  
Oscillatory Activity ◽  
Somatosensory Processing ◽  
Somatosensory Cortices ◽  
And Gender ◽  
The Right ◽  
Sensory Processes

Abstract BackgroundMigraine is a neurological disorder characterized by intense, debilitating headaches, often coupled with nausea, vomiting and sensitivity to light and sound. Whilst changes in sensory processes during a migraine attack have been well-described, there is growing evidence that even between migraine attacks, sensory abilities are disrupted in migraine. Brain imaging studies have investigated altered coupling between areas of the descending pain modulatory pathway but coupling between somatosensory processing regions between migraine attacks has not been properly studied. The aim of this study was to determine if ongoing functional connectivity between visual, auditory, olfactory, gustatory and somatosensory cortices are altered during the interictal phase of migraine. MethodsTo explore the neural mechanisms underpinning interictal changes in sensory processing, we used functional magnetic resonance imaging to compare resting brain activity patterns and connectivity in migraineurs between migraine attacks (n= 32) and in healthy controls (n=71). Significant differences between groups were determined using two-sample random effects procedures (p<0.05, corrected for multiple comparisons, minimum cluster size 10 contiguous voxels, age and gender included as nuisance variables). ResultsIn the migraine group, increases in infra-slow oscillatory activity were detected in the right primary visual cortex (V1), secondary visual cortex (V2) and third visual complex (V3), and left V3. In addition, resting connectivity analysis revealed that migraineurs displayed significantly enhanced connectivity between V1 and V2 with other sensory cortices including the auditory, gustatory, motor and somatosensory cortices. ConclusionsThese data provide evidence for a dysfunctional sensory network in pain-free migraine patients which may be underlying altered sensory processing between migraine attacks.

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