Impaired Visual Processing Research Articles

Seeing the World as it is: Mimicking Veridical Motion Perception in Schizophrenia Using Non-invasive Brain Stimulation in Healthy Participants

Schizophrenia (Sz) is a mental health disorder characterized by severe cognitive, emotional, social, and perceptual deficits. Visual deficits are found in tasks relying on the magnocellular/dorsal stream. In our first experiment we established deficits in global motion processing in Sz patients compared to healthy controls. We used a novel task in which background optic flow produces a distortion of the apparent trajectory of a moving stimulus, leading control participants to provide biased estimates of the true motion trajectory under conditions of global stimulation. Sz patients were significantly less affected by the global background motion, and reported trajectories that were more veridically accurate than those of controls. In order to study the mechanism of this effect, we performed a second experiment where we applied transcranial electrical stimulation over area MT+ to selectively modify global motion processing of optic flow displays in healthy participants. Cathodal and high frequency random noise stimulation had opposite effects on trajectory perception in optic flow. The brain stimulation over a control site and in a control task revealed that the effect of stimulation was specific for global motion processing in area MT+. These findings both support prior studies of impaired early visual processing in Sz and provide novel approaches for measurement and manipulation of the underlying circuits.

Anti-Extinction in Patients With Schizophrenia

Background: Patients with schizophrenia demonstrate visual processing impairments; however, the nature of these impairments remains undetermined. Objectives: The present study aimed at investigating the visual processing of unilateral compared to bilateral visual stimuli in these patients. Methods: A group of 27 schizophrenia patients and a group of 27 matched controls (age, gender, education level and hand preference) (20 males in each group), were tested in 2 computerized tasks, namely circle and star and triangle. Unilateral and bilateral shapes were presented on the screen of a computer. In the circle task, stimuli were similar unilateral left, unilateral right and bilateral circles that appeared on a computer screen, whereas in the star and triangle task, there were different unilateral and bilateral stimuli. Participants were instructed to press the left key in unilateral and right key in bilateral trials. Results: In both tasks, the patients significantly detected bilateral displays more accurately than unilateral displays, and unilateral-left more accurately than unilateral-right trials. The similarity of stimuli on the star and triangle task, did not affect the patients’ performance. In contrast, individuals in the control group performed similarly across both unilateral and bilateral trials. Conclusions: These findings provide evidences of hemineglect and anti-extinction in patients with schizophrenia, suggesting bilateral advantage in visuospatial processing in the patients.

Effects of irrelevant background speech on eye movements during reading.

The irrelevant speech effect (ISE) refers to the impairment of visual information processing by background speech. Prior research on the ISE has focused on short-term memory for visually presented word lists. The present research extends this work by using measurements of eye movements to examine effects of irrelevant background speech during Chinese reading. This enabled an examination of the ISE for a language in which access to semantic representations is not strongly mediated by phonology. Participants read sentences while exposed to meaningful irrelevant speech, meaningless speech (scrambled meaningful speech) or silence. A target word of high or low lexical frequency was embedded in each sentence. The results show that meaningful, but not meaningless, background speech produced increased re-reading. In addition, the appearance of a normal word frequency effect, characterised by longer fixation times on low- compared to high-frequency words, was delayed when meaningful or meaningless speech was present in the background. These findings show that irrelevant background speech can disrupt normal processes of reading comprehension and, in addition, that background noise can interfere with the early processing of words. The findings add to evidence showing that normal reading processes can be disrupted by environmental noise such as irrelevant background speech.

Visual processing deficits in 22q11.2 Deletion Syndrome.

Carriers of the rare 22q11.2 microdeletion present with a high percentage of positive and negative symptoms and a high genetic risk for schizophrenia. Visual processing impairments have been characterized in schizophrenia, but less so in 22q11.2 Deletion Syndrome (DS). Here, we focus on visual processing using high-density EEG and source imaging in 22q11.2DS participants (N = 25) and healthy controls (N = 26) with an illusory contour discrimination task.Significant differences between groups emerged at early and late stages of visual processing. In 22q11.2DS, we first observed reduced amplitudes over occipital channels and reduced source activations within dorsal and ventral visual stream areas during the P1 (100–125 ms) and within ventral visual cortex during the N1 (150–170 ms) visual evoked components. During a later window implicated in visual completion (240–285 ms), we observed an increase in global amplitudes in 22q11.2DS. The increased surface amplitudes for illusory contours at this window were inversely correlated with positive subscales of prodromal symptoms in 22q11.2DS.The reduced activity of ventral and dorsal visual areas during early stages points to an impairment in visual processing seen both in schizophrenia and 22q11.2DS. During intervals related to perceptual closure, the inverse correlation of high amplitudes with positive symptoms suggests that participants with 22q11.2DS who show an increased brain response to illusory contours during the relevant window for contour processing have less psychotic symptoms and might thus be at a reduced prodromal risk for schizophrenia.

Colour discrimination thresholds in type 1 Bipolar Disorder: a pilot study

Although some studies have reported perceptual changes in psychosis, no definitive conclusions have been drawn about visual disturbances that are related to bipolar disorder (BPD). The purpose of the present study was to evaluate colour vision in BPD patients. Data were recorded from 24 participants: healthy control group (n = 12) and type 1 BPD group (n = 12). The participants were 20–45 years old and they were free from neurological disorders and identifiable ocular disease and had normal or corrected-to-normal visual acuity. Colour discrimination was evaluated using the Lanthony D-15d, Trivector and Ellipse tests, using a psychophysical forced-choice method. The relationship of visual measures to mood state and cognitive function was also investigated. The results showed that BPD patients had higher colour discrimination thresholds in the D15d (p < 0.001), Trivector (p < 0.001) and Ellipse (p < 0.01) tests compared with healthy controls. Linear regression analysis showed that mood state was related to colour discrimination. BPD individuals were not impaired in cognitive tasks. The present study provided new evidence of potential links between type 1 BPD and visual processing impairments. This research suggests a new direction for studies and the need for research in this field of study.

Morphometric and Connectivity White Matter Abnormalities in Obsessive Compulsive Disorder

Two psychological mechanisms seem to be associated with the obsessive-compulsive cycle: (1) an emotional mechanism characterized by intense emotional arousal associated with intrusive thoughts of impending danger; (2) a cognitive mechanism exemplified by difficulties with inhibitory control. More recently, several studies found more extensive cognitive deficits in Obsessive Compulsive Disorder (OCD) beyond problems of inhibitory control and emotional regulation, namely: visual-spatial processing and memory. Thus, there is now extensive research showing that alterations of these psychological mechanisms in OCD (i.e., inhibitory control, emotional regulation, working memory, and visual spatial processing) are associated with morphological gray matter alterations in widespread brain regions. More recently, researchers have started looking at white matter abnormalities in OCD. In this article we review the research looking at white matter morphometric and structural connectivity alterations in OCD. Altogether, while some contradictory findings are still present, there is now evidence for widespread white matter morphometric and connectivity abnormalities affecting major white matter tracts (superior longitudinal fasciculus, inferior fronto-occipital fasciculus, inferior longitudinal fasciculus, cingulum bundle, semioval center, internal capsule, different regions of the corpus callosum, thalamic radiation, uncinate fasciculus and optic radiation) as well as white matter in regions adjacent to gray matter structures (superior frontal gyrus, dorsolateral prefrontal medial frontal cortex; inferior frontal gyrus, caudate, insulate cortex, parietal cortex, supramarginal and lingual gyri, and thalamus). These white matter alterations may help explaining the diversity of OCD psychological impairments in inhibitory control, emotional regulation, memory and visual spatial processing.

Metabolic regional and network changes in Alzheimer's disease subtypes

Clinical variants of Alzheimer's disease (AD) include the common amnestic subtype as well as subtypes characterised by leading visual processing impairments or by multimodal neurocognitive deficits. We investigated regional metabolic patterns and networks between AD subtypes. The study comprised 9 age-matched controls and 25 patients with mild to moderate AD. Methods included clinical and neuropsychological assessment, high-resolution FDG PET and T1-weighted 3D MR imaging with PET-MR coregistration, grey matter segmentation, atlas-based regions-of-interest, linear mixed effects and regional correlation analysis. Regional metabolic patterns differed significantly between groups, but significant hypometabolism in the posterior cingulate cortex (PCC) was common to all subtypes. The most distinctive regional abnormality was occipital hypometabolism in the visual subtype. In controls, two large clusters of positive regional metabolic correlations were observed. The most pronounced breakdown of the normal correlation pattern was found in amnestic patients who, in contrast, showed the least regional focal metabolic deficits. The normal positive correlation between PCC and hippocampus was lost in all subtypes. In conclusion, PCC hypometabolism and metabolic correlation breakdown between PCC and hippocampus are the common functional core of all AD subtypes. Network alterations exceed focal regional impairment and are most prominent in the amnestic subtype.

Visual Sensory and Visual-Cognitive Function and Rate of Crash and Near-Crash Involvement Among Older Drivers Using Naturalistic Driving Data.

PurposeAn innovative methodology using naturalistic driving data was used to examine the association between visual sensory and visual-cognitive function and rates of future crash or near-crash involvement among older drivers.MethodsThe Strategic Highway Research Program (SHRP2) Naturalistic Driving Study was used for this prospective analysis. The sample consisted of N = 659 drivers aged ≥70 years and study participation lasted 1 or 2 years for most participants. Distance and near visual acuity, contrast sensitivity, peripheral vision, visual processing speed, and visuospatial skills were assessed at baseline. Crash and near-crash involvement were based on video recordings and vehicle sensors. Poisson regression models were used to generate crude and adjusted rate ratios (RRs) and 95% confidence intervals, while accounting for person-miles of travel.ResultsAfter adjustment, severe impairment of the useful field of view (RR = 1.33) was associated with an increased rate of near-crash involvement. Crash, severe crash, and at-fault crash involvement were associated with impaired contrast sensitivity in the worse eye (RRs = 1.38, 1.54, and 1.44, respectively) and far peripheral field loss in both eyes (RRs = 1.74, 2.32, and 1.73, respectively).ConclusionsNaturalistic driving data suggest that contrast sensitivity in the worse eye and far peripheral field loss in both eyes elevate the rates of crash involvement, and impaired visual processing speed elevates rates of near-crash involvement among older drivers. Naturalistic driving data may ultimately be critical for understanding the relationship between vision and driving safety.

Facial decoding in schizophrenia is underpinned by basic visual processing impairments

Schizophrenia is associated with a strong deficit in the decoding of emotional facial expression (EFE). Nevertheless, it is still unclear whether this deficit is specific for emotions or due to a more general impairment for any type of facial processing. This study was designed to clarify this issue. Thirty patients suffering from schizophrenia and 30 matched healthy controls performed several tasks evaluating the recognition of both changeable (i.e. eyes orientation and emotions) and stable (i.e. gender, age) facial characteristics. Accuracy and reaction times were recorded. Schizophrenic patients presented a performance deficit (accuracy and reaction times) in the perception of both changeable and stable aspects of faces, without any specific deficit for emotional decoding. Our results demonstrate a generalized face recognition deficit in schizophrenic patients, probably caused by a perceptual deficit in basic visual processing. It seems that the deficit in the decoding of emotional facial expression (EFE) is not a specific deficit of emotion processing, but is at least partly related to a generalized perceptual deficit in lower-level perceptual processing, occurring before the stage of emotion processing, and underlying more complex cognitive dysfunctions. These findings should encourage future investigations to explore the neurophysiologic background of these generalized perceptual deficits, and stimulate a clinical approach focusing on more basic visual processing.

Disentangling How the Brain is “Wired” in Cortical (Cerebral) Visual Impairment

Cortical (cerebral) visual impairment (CVI) results from perinatal injury to visual processing structures and pathways of the brain and is the most common cause of severe visual impairment or blindness in children in developed countries. Children with CVI display a wide range of visual deficits including decreased visual acuity, impaired visual field function, as well as impairments in higher-order visual processing and attention. Together, these visual impairments can dramatically influence a child's development and well-being. Given the complex neurologic underpinnings of this condition, CVI is often undiagnosed by eye care practitioners. Furthermore, the neurophysiological basis of CVI in relation to observed visual processing deficits remains poorly understood. Here, we present some of the challenges associated with the clinical assessment and management of individuals with CVI. We discuss how advances in brain imaging are likely to help uncover the underlying neurophysiology of this condition. In particular, we demonstrate how structural and functional neuroimaging approaches can help gain insight into abnormalities of white matter connectivity and cortical activation patterns, respectively. Establishing a connection between how changes within the brain relate to visual impairments in CVI will be important for developing effective rehabilitative and education strategies for individuals living with this condition.

Optic ataxia and the dorsal visual steam re-visited: Impairment in bimanual haptic matching performed without vision

The ‘two visual systems’ account proposed by Milner and Goodale (1992) argued that visual perception and the visual control of action depend upon functionally distinct and anatomically separable brain systems: a ventral stream of visual processing that mediates visual perception (object identification and recognition) and a dorsal stream of visual processing mediating visually guided action. Compelling evidence for this proposal was provided by the neuropsychological studies of brain injured patients, in particular the contrasting pattern of impaired and preserved visual processing abilities of the visual object agnostic patient [DF] and optic ataxic patients who it was argued presented with impaired dorsal stream function. Optic ataxia [OA] has thus become a cornerstone of this ‘two visual system’ account (Pisella et al., 2009). In the current study we re-examine this assumption by investigating how several individuals presenting with OA performed on a bimanual haptic matching task performed without vision, when the bar to be matched was presented haptically or visually. We demonstrate that, unlike neurologically healthy controls who perform the task with high levels of accuracy, all of the optic ataxic patients were unable to perform the task. We interpret this finding as further evidence that the key difficulty experienced by optic ataxic patients across a range of behavioural tasks may be an inability to simultaneously and directly compare two spatial representations so as to compute the difference between them.

Gender differences in nonlinear motor performance following concussion

PurposeTo quantify differences in nonlinear aspects of performance on a seated visual-motor tracking task between clinically asymptomatic males and females with and without a self-reported mild traumatic brain injury history. MethodsSeventy-three individuals with a self-reported concussion history (age: 21.40 ± 2.25 years, mean ± SD) and 75 without completed the visual-motor tracking task (age: 21.50 ± 2.00 years). Participants pressed an index finger against a force sensor, tracing a line across a computer screen (visual-motor tracking). The produced signal's root-mean-square error (RMSE), sample entropy (SampEn, a measure of regularity), and average power (AvP) between 0 and 12 Hz were calculated. ResultsMales with a history of 0 or 1 concussion had greater RMSE (worse performance) than females with 0 (p< 0.0001) and 1 concussion (p = 0.052). Additionally, females with 2+ concussions exhibited lower SampEn than females with no history (p = 0.001) or a history of 1 concussion (p = 0.026). Finally, females with 2+ concussions had lower 8–12 Hz AvP than males with 2+ concussions (p = 0.031). Few differences were observed in the male participants. ConclusionFemales with a self-reported history of multiple concussions exhibited lower SampEn in the visual-motor tracking-task force output structure as compared to those with no reported history of concussion and their male counterparts. Lower SampEn and lower power between 8 and 12 Hz indicated persistent impairment in visual processing and feed-forward or predictive motor control systems.

Visuospatial Functioning in Cerebral Amyloid Angiopathy: A Pilot Study.

Cerebral amyloid angiopathy (CAA) is a contributor to cognitive impairment in the elderly. We hypothesized that the posterior cortical predilection of CAA would cause visual-processing impairment. We systematically evaluated visuospatial abilities in 22 non-demented CAA patients. Neurocognitive evaluation demonstrated visuoperceptual impairment (23% on Benton Facial Recognition Test [BFRT] and 13.6% on Benton Judgment of Line Orientation Test [BJLO]). BFRT was inversely correlated with white matter hyperintensities volume and BJLO with parietal cerebral microbleeds. This pilot study highlights the presence of visual-processing deficits in CAA. The impairment could be related to global disease severity in addition to local brain injury.

Attention Orienting in Response to Non-conscious Hierarchical Arrows: Individuals with Higher Autistic Traits Differ in Their Global/Local Bias.

One aspect of the social communication impairments that characterize autism spectrum disorder (ASD) include reduced use of often subtle non-verbal social cues. People with ASD, and those with self-reported sub-threshold autistic traits, also show impairments in rapid visual processing of stimuli unrelated to social or emotional properties. Hence, this study sought to investigate whether perceptually non-conscious visual processing is related to autistic traits. A neurotypical sample of thirty young adults completed the Subthreshold Autism Trait Questionnaire and a Posner-like attention cueing task. Continuous Flash Suppression (CFS) was employed to render incongruous hierarchical arrow cues perceptually invisible prior to consciously presented targets. This was achieved via a 10 Hz masking stimulus presented to the dominant eye that suppressed information presented to the non-dominant eye. Non-conscious arrows consisted of local arrow elements pointing in one direction, and forming a global arrow shape pointing in the opposite direction. On each trial, the cue provided either a valid or invalid cue for the spatial location of the subsequent target, depending on which level (global or local) received privileged attention. A significant autism-trait group by global cue validity interaction indicated a difference in the extent of non-conscious local/global cueing between groups. Simple effect analyses revealed that whilst participants with lower autistic traits showed a global arrow cueing effect, those with higher autistic traits demonstrated a small local arrow cueing effect. These results suggest that non-conscious processing biases in local/global attention may be related to individual differences in autistic traits.

Risk Factors for Psychosis in Parkinson’s Disease

Psychosis is a characteristic neuropsychiatric symptom of Parkinson’s disease (PD) that is common and associated with worse outcomes. The purpose of this article is to review identified risk factors for visual hallucinations in PD, the most common manifestation of psychosis. With the possible exception of dopamine agonists, antiparkinsonian medications are only considered modifiers of psychosis in PD. Dementia in PD has consistently been shown to be associated with psychosis, and executive dysfunction and impairment in visual processing appear to play a role in its pathogenesis. The association of psychosis with disorders of sleep–wake dysregulation and autonomic dysfunction supports the involvement of brainstem dysfunction in PD psychosis. Despite many studies evaluating genetic risk factors for hallucinations, GBA mutations are the only variants consistently reported to be associated with an increased risk of hallucinations in PD. Lastly, psychosis in PD is associated with a more severe disease burden, both related and unrelated to PD pathology. Any explanatory model of psychosis in PD must incorporate pharmacological, neuroanatomic, pathological, and genetic factors before there can be a complete understanding of this common and disabling neuropsychiatric symptom.

Risk Factors for Psychosis in Parkinson’s Disease

Psychosis is a characteristic neuropsychiatric symptom of Parkinson’s disease (PD) that is common and associated with worse outcomes. The purpose of this article is to review identified risk factors for visual hallucinations in PD, the most common manifestation of psychosis. With the possible exception of dopamine agonists, antiparkinsonian medications are only considered modifiers of psychosis in PD. Dementia in PD has consistently been shown to be associated with psychosis, and executive dysfunction and impairment in visual processing appear to play a role in its pathogenesis. The association of psychosis with disorders of sleep–wake dysregulation and autonomic dysfunction supports the involvement of brainstem dysfunction in PD psychosis. Despite many studies evaluating genetic risk factors for hallucinations, GBA mutations are the only variants consistently reported to be associated with an increased risk of hallucinations in PD. Lastly, psychosis in PD is associated with a more severe disease burden, both related and unrelated to PD pathology. Any explanatory model of psychosis in PD must incorporate pharmacological, neuroanatomic, pathological, and genetic factors before there can be a complete understanding of this common and disabling neuropsychiatric symptom.

Impaired visual processing in patients with insomnia disorder revealed by a dissociation in visual search.

Insomnia disorder is associated with both subjective and objective daytime impairments. In particular, cognitive impairments are frequently reported. However, little is known about the effects of this pathology on perceptual processes. In this study we aim at evaluating the effect of insomnia disorder on visual processing by employing a visual search paradigm. Twenty-three patients with insomnia disorder and 20healthy age- and sex-matched control subjects participated in the study. After a polysomnographic recording night patients performed a visual search task in which they had to respond to the presence/absence of a target (letter T) embedded into a set of distractors (letters Os, Xs or Ls). Target's salience and distractors' numerosity were manipulated, while accuracy and reaction times were recorded as dependent variables. The results mainly confirmed the typical effects of a visual search task. An overall delay in performing the task was observed for patients with insomnia disorder. However, distinguishing the reaction times to stimuli containing the target from reaction times to stimuli in which the target was absent, the clinical group differed from controls solely in the condition of target absent. The performance (reaction times) of the subjects correlated with the age in the control group, whereas no correlation between reaction times and age, disease duration and quality of sleep was found in patients with insomnia disorder. These results experimentally demonstrate the presence of a daytime impairment in patients with insomnia disorder revealed by a dissociation in visual search, and are discussed in the light of the hyperarousal concept of insomnia.

Effects of Acute Ketamine Infusion on Visual Working Memory: Event-Related Potentials

BackgroundWorking memory (WM) deficits are a core feature of schizophrenia. Electrophysiological studies suggest that impaired early visual processing may contribute to impaired WM in the visual domain. Abnormal N-methyl-D-aspartate (NMDA) receptor function has been implicated both in WM and in early visual processing deficits in schizophrenia. We investigated whether ketamine, a noncompetitive NMDA antagonist, would replicate in healthy volunteers the WM performance and early visual processing abnormalities we and others have reported in patients with schizophrenia. MethodsForty-four healthy volunteers were randomly assigned to receive intravenous ketamine or placebo. During infusion, the effects of ketamine were recorded using standardized psychiatric scales. Visual evoked potentials (P100 and P300 components) were recorded during performance of a delayed matching to sample task. ResultsKetamine induced mild psychosis-like symptoms and impaired WM performance. It also significantly increased the P100 amplitude, while P300 amplitude decreased in a load-dependent manner. Amplitudes of P100 during retrieval correlated with cognitive performance only in the placebo group. ConclusionsWe confirmed previous studies showing that ketamine reproduces the impairment of WM performance and smaller P300 amplitudes observed in schizophrenia. However, ketamine increased visual P100 amplitude in contrast to our observation of reduced P100 amplitudes in established schizophrenia. The effects of ketamine on WM and P300 are likely to involve impaired NMDA function, as these receptors are implicated in changes of synaptic strength underlying associative learning and memory. Increased P100 amplitude may reflect the secondary disinhibition of cortical glutamate release that occurs after NMDA blockade.

Lexical decision with pseudohomophones and reading in the semantic variant of primary progressive aphasia: A double dissociation

The co-occurrence of semantic impairment and surface dyslexia in the semantic variant of primary progressive aphasia (svPPA) has often been taken as supporting evidence for the central role of semantics in visual word processing. According to connectionist models, semantic access is needed to accurately read irregular words. They also postulate that reliance on semantics is necessary to perform the lexical decision task under certain circumstances (for example, when the stimulus list comprises pseudohomophones). In the present study, we report two svPPA cases: M.F. who presented with surface dyslexia but performed accurately on the lexical decision task with pseudohomophones, and R.L. who showed no surface dyslexia but performed below the normal range on the lexical decision task with pseudohomophones. This double dissociation between reading and lexical decision with pseudohomophones is in line with the dual-route cascaded (DRC) model of reading. According to this model, impairments in visual word processing in svPPA are not necessarily associated with the semantic deficits characterizing this disease. Our findings also call into question the central role given to semantics in visual word processing within the connectionist account.

Characterizing Visual Field Deficits in Cerebral/Cortical Visual Impairment (CVI) Using Combined Diffusion Based Imaging and Functional Retinotopic Mapping: A Case Study.

Cortical/cerebral visual impairment (CVI) is the leading cause of pediatric visual impairment in children in developed countries and has become a significant public health concern (Kong et al., 2012). CVI is clinically defined as significant visual dysfunction resulting primarily from perinatal injury to visual pathways and structures rather than ocular pathology alone (Dutton, 2003). Perinatal hypoxia is the most common cause resulting in impaired maturation of key visual pathways such as the optic radiations; a general condition referred to as white matter damage of immaturity (WMDI). In preterm infants, this maldevelopment is often associated with periventricular leukomalacia (PVL), which is characterized by an enlargement of the lateral ventricles and focal gliosis of surrounding white matter pathways coursing on to the visual cortex (Good et al., 2001; Hoyt, 2007). Depending on the location and extent of the damage, children with CVI often present with a broad range and combination of visual dysfunctions such as decreased visual acuity, visual field deficits, and also impairments in oculomotor, visuomotor, and cognitive visual processing (Good et al., 2001; Dutton, 2003; Hoyt, 2007). The variability in the location and extent of brain injury across individuals makes the prediction of visual functional outcomes and recovery in CVI patients particularly challenging (McKillop and Dutton, 2008). Despite the increasing prevalence of this condition, the relationship between observed visual deficits in CVI and the underlying structural and functional changes resulting from damage to key visual pathways, remains poorly understood. Specifically, it remains unknown how the maldevelopment of key visual pathways relates to the organization of the visual cortex and further, how these structural and functional changes relate to visual impairments observed within the clinical setting. Standard clinical neuroimaging techniques such as computerized tomography (CT) and magnetic resonance imaging (MRI) can help characterize gross changes in cerebral structure. However, the underlying micro-architecture of key white matter pathways (such as the optic radiations) cannot be fully ascertained, nor can the function of visual cortical areas be assessed. Advances in diffusion based imaging (i.e., diffusion MRI) modalities such as high angular resolution diffusion based imaging (HARDI) combined with tractography analysis techniques can be used to reveal the organization of specific white matter projections (Jones, 2008) see also (Ffytche et al., 2010). At the same time, retinotopic mapping using functional magnetic resonance imaging (fMRI) can be employed to assess the organizational and functional integrity of early visual cortical areas (Wandell, 1999). In this study, we used a combined structural and functional multi-modal neuroimaging approach to characterize the underlying maldevelopment of the geniculo-striate pathway in an adolescent with CVI. The patient presented here had a documented inferior visual field deficit determined on clinical ophthalmic examination. Despite her diagnosis of CVI and associated visual impairments, she was able to participate in formal testing and provide reliable data (including maintaining fixation during perimetry and retinotopic stimulation) and also remain immobile in the scanner environment without the need of anesthesia. Thus, (and contrary to prior imaging studies with CVI individuals), we had the opportunity to obtain high quality structural and functional imaging data on the same subject in order to investigate the relationship between the structural integrity of the optic radiations and the functional organization of early visual cortical areas with respect to her clinical visual field impairment. We demonstrate the feasibility of combining this structural and functional imaging approach in a patient with CVI along with an age/gender matched normal developed control for comparison. By combining these imaging modalities, it is possible to provide further insight regarding the functional manifestations of early onset developmental damage to key visual pathways and their relation to specific impairments of visual function.