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1.
Neuropsychol Rehabil ; 34(2): 268-299, 2024 Mar.
Article in English | MEDLINE | ID: mdl-36908114

ABSTRACT

Effectiveness of innovative, gamified interventions (i.e., Augmented Reality, Computer-Based Cognitive Retraining [CBCR], and Virtual Reality [VR] in conjunction with a Serious Game) for cognitive training in paediatric ABI was evaluated. Studies were identified on PsycINFO, PubMed and Scopus; last searched 4 January 2022. Eligibility criteria were participants diagnosed with ABI and aged ≤ 18 years, experimental intervention to train cognition, cognition assessed pre- and post-intervention at: (1) The level of function, or (2) The level of activity, and written in English. ROB 2 and ROBINS-I were utilised to assess risk of bias. Extracted study characteristics were methods, participants, interventions, outcomes, and results. Seven studies were included, comprising six CBCR studies and one VR study, with 182 participants. Following CBCR: (1) Improvements were observed in several cognitive functions, but there was inconsistent evidence; (2) Improvements were reported in attention and executive functions (EF) at home and at school. Following VR: (1) Improvements were observed in attention and EF; (2) Not evaluated. Due to the small number of included studies with (relatively) small and heterogeneous samples, only a cautious interpretation of the evidence was provided. There is a need for carefully designed studies with more attention to inter-individual differences and generalisation to daily life.


Subject(s)
Brain Injuries , Virtual Reality , Humans , Child , Cognitive Training , Cognition , Executive Function
2.
Obes Surg ; 31(10): 4316-4326, 2021 10.
Article in English | MEDLINE | ID: mdl-34304380

ABSTRACT

PURPOSE: Lifelong multivitamin supplementation is recommended to prevent nutritional deficiencies. Despite this advice, deficiencies are common which may be due to poor adherence to MVS intake. The aim of this study was to identify which factors affect patient adherence to Multivitamin Supplement (MVS) intake after bariatric surgery. MATERIALS AND METHODS: A 42-item questionnaire was sent to 15,424 patients from four Dutch bariatric center. In total, 4975 patients wanted to participate of which 361 patients were excluded. A total of 4614 patients were included, and MVS users (n=4274, 92.6%) were compared to non-users (n=340, 7.4%). Most patients underwent Roux-en-Y gastric bypass (64.3%) or sleeve gastrectomy (32.3%). RESULTS: Seven hundred and ten patients (15.4%) reported inconsistent MVS use and 340 patients (7.4%) did not use any MVS at all. For inconsistent MVS users, most reported reasons included forgetting daily intake (68.3%), gastro-intestinal side effects (25.6%) and unpleasant taste or smell (22.7%), whereas for non-users gastro-intestinal side effects (58.5%), high costs (13.5%) and the absence of vitamin deficiencies (20.9%) were most frequently reported. Overall, 28.5% were dissatisfied about instructions on MVS use, attention paid to MVS use during medical consultation and the extent to which personal preferences were taken into account. CONCLUSION: The attitude of bariatric patients towards MVS use is predominantly negative. It is important to provide accurate information on different options for MVS intake and collect information about patient's personal preferences when prescribing supplements. Improving adherence to MVS intake is challenging and requires implementation of a shared decision-making process, further optimization of MVS formulas and exploring options for reimbursement.


Subject(s)
Bariatric Surgery , Gastric Bypass , Obesity, Morbid , Gastrectomy , Humans , Obesity, Morbid/surgery , Patient Compliance , Surveys and Questionnaires , Vitamins
3.
Exp Brain Res ; 238(3): 667-673, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32036413

ABSTRACT

Attention allows us to select important sensory information and enhances sensory information processing. Attention and our motor system are tightly coupled: attention is shifted to the target location before a goal-directed eye- or hand movement is executed. Congruent eye-hand movements to the same target can boost the effect of this pre-movement shift of attention. Moreover, visual information processing can be enhanced by, for example, auditory input presented in spatial and temporal proximity of visual input via multisensory integration (MSI). In this study, we investigated whether the combination of MSI and motor congruency can synergistically enhance visual information processing beyond what can be observed using motor congruency alone. Participants performed congruent eye- and hand movements during a 2-AFC visual discrimination task. The discrimination target was presented in the planning phase of the movements at the movement target location or a movement irrelevant location. Three conditions were compared: (1) a visual target without sound, (2) a visual target with sound spatially and temporally aligned (MSI) and (3) a visual target with sound temporally misaligned (no MSI). Performance was enhanced at the movement-relevant location when congruent motor actions and MSI coincide compared to the other conditions. Congruence in the motor system and MSI together therefore lead to enhanced sensory information processing beyond the effects of motor congruency alone, before a movement is executed. Such a synergy implies that the boost of attention previously observed for the independent factors is not at ceiling level, but can be increased even further when the right conditions are met.


Subject(s)
Eye Movements/physiology , Movement/physiology , Space Perception/physiology , Visual Perception/physiology , Adult , Attention/physiology , Cognition/physiology , Female , Humans , Male , Psychomotor Performance/physiology , Young Adult
4.
Neurosci Res ; 153: 8-21, 2020 Apr.
Article in English | MEDLINE | ID: mdl-30910735

ABSTRACT

When individuals are exposed to a constant change of the interplay with their environment, they are able to develop compensatory alterations of visuo-motor coordination in order to counteract the perturbation. Prism adaptation (PA) is a very simple tool that has been used for several decades to investigate adaptive processes. However, the specific terminology used in PA literature has continuously evolved and is still subjected to broad inconsistency. Growing confusion about the choice of terms used to describe specific processes and methods has yielded the critical need for clarifying the adaptation vocabulary. The aim of this terminology review is to consider and to describe the most common terms used in PA literature in order to ensure more consistent communication in future research. On the basis of a descriptive examination of previous studies on PA, we provide specification for each term, indicating whether it refers to a classical term in PA literature, and whether it is recommended or should be used with particular attention. This glossary represents a useful instrument to both new readers and experts in the field of PA in order to facilitate unambiguous communication and consensual comparisons between individual investigations. Recommendations for the use of consistent paradigms and reliable vocabulary are provided for future investigations, in both basic and clinical research.


Subject(s)
Adaptation, Physiological , Space Perception , Vocabulary , Attention , Eyeglasses , Functional Laterality , Humans , Optical Phenomena , Visual Perception
5.
Neuropsychologia ; 125: 23-29, 2019 03 04.
Article in English | MEDLINE | ID: mdl-30695711

ABSTRACT

Even though we frequently execute saccades, we perceive the external world as coherent and stable. An important mechanism of trans-saccadic perception is spatial remapping: the process of updating information across eye movements. Previous studies have indicated a right hemispheric dominance for spatial remapping, which has been proposed to translate into enhanced trans-saccadic memory for locations that are remapped into the right compared to the left hemisphere in healthy participants. Previous study designs suffered from several limitations, however (i.e. multiple eye movements had to be made instead of one, fixations were not controlled for, and ceiling effects were likely present). We therefore compared accuracy of trans-saccadic memory for central items after left- versus rightward eye movements, and secondary, for items that were remapped within the left versus right visual field. Participants memorized the location of a briefly presented item, made one saccade, and subsequently decided in what direction the item had shifted. We used a staircase to adjust task difficulty. Bayesian repeated measures ANOVAs were used to compare between left versus right eye movements and items in the left versus right visual field. We found most evidence against directional differences in trans-saccadic memory (BF10 = 0.23). We found some evidence suggestive of enhanced trans-saccadic memory for items that were remapped within the left compared to the right visual field (BF10 = 4.00). The latter result could be explained by a leftward spatial attention bias. As such, the hypothesized right hemispheric dominance for spatial remapping does not result in asymmetric trans-saccadic memory capacities in healthy participants.


Subject(s)
Memory , Saccades , Spatial Processing , Visual Perception , Adult , Female , Functional Laterality , Humans , Male , Visual Fields , Young Adult
6.
Perception ; 46(1): 6-17, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27484341

ABSTRACT

Multisensory integration (MSI) and exogenous spatial attention can both speedup responses to perceptual events. Recently, it has been shown that audiovisual integration at exogenously attended locations is reduced relative to unattended locations. This effect was observed at short cue-target intervals (200-250 ms). At longer intervals, however, the initial benefits of exogenous shifts of spatial attention at the cued location are often replaced by response time (RT) costs (also known as Inhibition of Return, IOR). Given these opposing cueing effects at shorter versus longer intervals, we decided to investigate whether MSI would also be affected by IOR. Uninformative exogenous visual spatial cues were presented between 350 and 450 ms prior to the onset of auditory, visual, and audiovisual targets. As expected, IOR was observed for visual targets (invalid cue RT < valid cue RT). For auditory and audiovisual targets, neither IOR nor any spatial cueing effects were observed. The amount of relative multisensory response enhancement and race model inequality violation was larger for uncued as compared with cued locations indicating that IOR reduces MSI. The results are discussed in the context of changes in unisensory signal strength at cued as compared with uncued locations.

7.
Ned Tijdschr Geneeskd ; 160: D393, 2016.
Article in Dutch | MEDLINE | ID: mdl-27966401

ABSTRACT

- Neglect occurs in 30-50% of patients in the subacute phase post-stroke. Patients with neglect ignore one side of their body or one part of the space around them. - Treatment of neglect is important, as patients with neglect recover more slowly and are less independent compared to patients without neglect.- Visual scanning training is currently recommended in the guidelines as a treatment. The focus of this intensive treatment is on compensation, not on recovery. Scientific evidence for its effectiveness is scarce. - Other treatments, such as prism adaptation, limb activation training and brain stimulation are being investigated. However, the available evidence for their effectiveness is insufficient as yet. - In addition to neuropsychological tests, outcome measures at the level of functioning in daily life should be included in studies regarding the treatment of neglect.- New research is increasingly focusing on combining different treatments, which should ultimately be adapted for each patient individually.


Subject(s)
Adaptation, Physiological , Perceptual Disorders/etiology , Perceptual Disorders/rehabilitation , Stroke/complications , Cognition Disorders/etiology , Cognition Disorders/rehabilitation , Functional Laterality/physiology , Humans , Neuropsychological Tests , Psychomotor Performance
8.
Exp Brain Res ; 234(5): 1175-88, 2016 May.
Article in English | MEDLINE | ID: mdl-25788009

ABSTRACT

A factor that is often not considered in multisensory research is the distance from which information is presented. Interestingly, various studies have shown that the distance at which information is presented can modulate the strength of multisensory interactions. In addition, our everyday multisensory experience in near and far space is rather asymmetrical in terms of retinal image size and stimulus intensity. This asymmetry is the result of the relation between the stimulus-observer distance and its retinal image size and intensity: an object that is further away is generally smaller on the retina as compared to the same object when it is presented nearer. Similarly, auditory intensity decreases as the distance from the observer increases. We investigated how each of these factors alone, and their combination, affected audiovisual integration. Unimodal and bimodal stimuli were presented in near and far space, with and without controlling for distance-dependent changes in retinal image size and intensity. Audiovisual integration was enhanced for stimuli that were presented in far space as compared to near space, but only when the stimuli were not corrected for visual angle and intensity. The same decrease in intensity and retinal size in near space did not enhance audiovisual integration, indicating that these results cannot be explained by changes in stimulus efficacy or an increase in distance alone, but rather by an interaction between these factors. The results are discussed in the context of multisensory experience and spatial uncertainty, and underline the importance of studying multisensory integration in the depth space.


Subject(s)
Auditory Perception/physiology , Distance Perception/physiology , Visual Perception/physiology , Acoustic Stimulation , Adult , Analysis of Variance , Female , Humans , Male , Models, Theoretical , Photic Stimulation , Reaction Time/physiology , Time Factors , Young Adult
9.
Acta Psychol (Amst) ; 162: 20-8, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26436587

ABSTRACT

Two processes that can give rise to multisensory response enhancement (MRE) are multisensory integration (MSI) and crossmodal exogenous spatial attention. It is, however, currently unclear what the relative contribution of each of these is to MRE. We investigated this issue using two tasks that are generally assumed to measure MSI (a redundant target effect task) and crossmodal exogenous spatial attention (a spatial cueing task). One block of trials consisted of unimodal auditory and visual targets designed to provide a unimodal baseline. In two other blocks of trials, the participants were presented with spatially and temporally aligned and misaligned audiovisual (AV) targets (0, 50, 100, and 200ms SOA). In the integration block, the participants were instructed to respond to the onset of the first target stimulus that they detected (A or V). The instruction for the cueing block was to respond only to the onset of the visual targets. The targets could appear at one of three locations: left, center, and right. The participants were instructed to respond only to lateral targets. The results indicated that MRE was caused by MSI at 0ms SOA. At 50ms SOA, both crossmodal exogenous spatial attention and MSI contributed to the observed MRE, whereas the MRE observed at the 100 and 200ms SOAs was attributable to crossmodal exogenous spatial attention, alerting, and temporal preparation. These results therefore suggest that there may be a temporal window in which both MSI and exogenous crossmodal spatial attention can contribute to multisensory response enhancement.


Subject(s)
Attention/physiology , Space Perception/physiology , Acoustic Stimulation , Adult , Auditory Perception/physiology , Cues , Female , Humans , Male , Photic Stimulation , Psychomotor Performance/physiology , Reaction Time/physiology , Young Adult
11.
Atten Percept Psychophys ; 77(2): 464-82, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25341648

ABSTRACT

Multisensory integration (MSI) and spatial attention are both mechanisms through which the processing of sensory information can be facilitated. Studies on the interaction between spatial attention and MSI have mainly focused on the interaction between endogenous spatial attention and MSI. Most of these studies have shown that endogenously attending a multisensory target enhances MSI. It is currently unclear, however, whether and how exogenous spatial attention and MSI interact. In the current study, we investigated the interaction between these two important bottom-up processes in two experiments. In Experiment 1 the target location was task-relevant, and in Experiment 2 the target location was task-irrelevant. Valid or invalid exogenous auditory cues were presented before the onset of unimodal auditory, unimodal visual, and audiovisual targets. We observed reliable cueing effects and multisensory response enhancement in both experiments. To examine whether audiovisual integration was influenced by exogenous spatial attention, the amount of race model violation was compared between exogenously attended and unattended targets. In both Experiment 1 and Experiment 2, a decrease in MSI was observed when audiovisual targets were exogenously attended, compared to when they were not. The interaction between exogenous attention and MSI was less pronounced in Experiment 2. Therefore, our results indicate that exogenous attention diminishes MSI when spatial orienting is relevant. The results are discussed in terms of models of multisensory integration and attention.


Subject(s)
Attention , Auditory Perception , Space Perception , Acoustic Stimulation , Adult , Cues , Female , Humans , Male , Photic Stimulation , Reaction Time , Young Adult
12.
Neuropsychologia ; 70: 335-49, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25498407

ABSTRACT

In this review, we evaluate the neurophysiological, neuropsychological, and psychophysical evidence relevant to the claim that multisensory information is processed differently depending on the region of space in which it happens to be presented. We discuss how the majority of studies of multisensory interactions in the depth plane that have been conducted to date have focused on visuotactile and audiotactile interactions in frontal peripersonal space and underline the importance of such multisensory interactions in defining peripersonal space. Based on our review of studies of multisensory interactions in depth, we question the extent to which peri- and extra-personal space (both frontal and rear) are characterized by differences in multisensory interactions (as evidenced by multisensory stimuli producing a different behavioral outcome as compared to unisensory stimulation). In addition to providing an overview of studies of multisensory interactions in different regions of space, our goal in writing this review has been to demonstrate that the various kinds of multisensory interactions that have been documented may follow very similar organizing principles. Multisensory interactions in depth that involve tactile stimuli are constrained by the fact that such stimuli typically need to contact the skin surface. Therefore, depth-related preferences of multisensory interactions involving touch can largely be explained in terms of their spatial alignment in depth and their alignment with the body. As yet, no such depth-related asymmetry has been observed in the case of audiovisual interactions. We therefore suggest that the spatial boundary of peripersonal space and the enhanced audiotactile and visuotactile interactions that occur in peripersonal space can be explained in terms of the particular spatial alignment of stimuli from different modalities with the body and that they likely reflect the result of prior multisensory experience.


Subject(s)
Attention/physiology , Personal Space , Sensation/physiology , Space Perception/physiology , Humans , Neuropsychology , Physical Stimulation , Psychophysics , PubMed/statistics & numerical data
13.
Behav Neurol ; 2014: 526407, 2014.
Article in English | MEDLINE | ID: mdl-24825959

ABSTRACT

BACKGROUND: Region-specific types of neglect (peripersonal and extrapersonal) have been dissociated, yet, differential behavioural consequences are unknown. OBJECTIVE: The aim of the current study was to investigate behavioural consequences at the level of basic activities of daily living of region-specific neglect, using the Catherine Bergego Scale (CBS). METHODS: 118 stroke patients were screened within the first two weeks after admission to the rehabilitation center for inpatient rehabilitation. RESULTS: Patients with peripersonal neglect and patients with neglect for both regions had significantly higher total score on the CBS compared to nonneglect patients. Total scores for patients with extrapersonal neglect were comparable to non-neglect patients. ADL impairments were found across activities (e.g., looking towards one side, forgetting body parts, colliding) for both patients with peripersonal neglect and patients with neglect for both regions. Patients with extrapersonal neglect were only impaired on the item on way finding. CONCLUSIONS: When diagnosing neglect, it is relevant to distinguish the type of region-specific neglect and, where needed, to adjust the rehabilitation program accordingly. As the CBS is not developed to typically measure ADL in extrapersonal neglect, it would be of importance to add other (instrumental) activities that heavily rely on processing information in farther space.


Subject(s)
Activities of Daily Living , Perceptual Disorders/physiopathology , Stroke/physiopathology , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Neuropsychological Tests , Perceptual Disorders/diagnosis , Perceptual Disorders/etiology , Severity of Illness Index , Space Perception , Stroke/complications , Symptom Assessment
14.
Exp Brain Res ; 232(4): 1357-66, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24510352

ABSTRACT

Eye movements towards a new target can be guided or disrupted by input from multiple modalities. The degree of oculomotor competition evoked by a distractor depends on both distractor and target properties, such as distractor salience or certainty regarding the target location. The ability to localize the target is particularly important when studying saccades made towards auditory targets, since determination of elevation and azimuth of a sound are based on different processes, and these processes may be affected independently by a distractor. We investigated the effects of a visual distractor on saccadic eye movements made to an auditory target in a two-dimensional plane. Results showed that the competition evoked by a vertical visual distractor was stronger compared with a horizontal visual distractor. The eye movements that were not captured by the vertical visual distractor were still influenced by it: a deviation of endpoints was seen in the direction of the visual distractor. Furthermore, the interference evoked by a high-contrast visual distractor was stronger compared with low-contrast visual stimuli, which was reflected by a faster initiation of an eye movement towards the high-contrast visual distractor and a stronger shift of endpoints in the direction of the high-contrast visual distractor. Together, these findings show that the influence of a visual distractor on aurally guided eye movements depends strongly on its location relative to the target, and to a lesser extent, on stimulus contrast.


Subject(s)
Acoustic Stimulation/methods , Contrast Sensitivity/physiology , Photic Stimulation/methods , Psychomotor Performance/physiology , Saccades/physiology , Adult , Female , Humans , Male , Visual Perception/physiology , Young Adult
15.
Vision Res ; 84: 6-15, 2013 May 24.
Article in English | MEDLINE | ID: mdl-23523571

ABSTRACT

When a target and a distractor are presented in close proximity, an eye movement will generally land in between these two elements. This is known as the 'global effect' and has been claimed to be a reflection of the averaged saccade programs towards both locations. The aim of the present study was to systematically investigate whether there is only a limited area in the saccade map in which saccade averaging occurs. To this end, we examined various distances between target and distractor in two experiments and investigated whether the majority of eye movements landed in between the target and the distractor. Results indicated that the endpoint distribution was unimodal for distances up to 35° (in polar coordinates), with saccades generally landing in between the target and the distractor. When the distance was higher than 45°, the saccade endpoint distribution was predominantly bimodal, with saccades landing either on the target or on the distractor. The decrease in saccade averaging was linear until almost no averaging saccades were observed for the longest distances. As saccades landing in between target and distractor reflect a weak, or absent, top-down signal, the present study indicated that top-down information is unable to strongly influence the oculomotor system when target and distractor are presented in close proximity. In this situation, the resulting eye movement is determined by the weighted average of saccade vectors present in a restricted region in the motor map.


Subject(s)
Attention/physiology , Saccades/physiology , Visual Perception/physiology , Adult , Analysis of Variance , Female , Humans , Male , Photic Stimulation/methods , Reaction Time/physiology , Young Adult
16.
Exp Brain Res ; 221(4): 377-84, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22821077

ABSTRACT

The decision about which location should be the goal of the next eye movement is known to be determined by the interaction between auditory and visual input. This interaction can be explained by the vector theory that states that each element (either visual or auditory) in a scene evokes a vector in the oculomotor system. These vectors determine the direction in which the eye movement is initiated. Because auditory input is lateralized and localizable in most studies, it is currently unclear how non-lateralized auditory input interacts with the vectors evoked by visual input. In the current study, we investigated the influence of a non-lateralized auditory non-target on saccade accuracy (saccade angle deviation from the target) and latency in a single-target condition in Experiment 1 and a double-target condition in Experiment 2. The visual targets in Experiment 2 were positioned in such a way that saccades on average landed in between the two targets (i.e., a global effect). There was no effect of the auditory input on saccade accuracy in the single-target condition, but auditory input did influence saccade accuracy in the double-target condition. In both experiments, saccade latency increased when auditory input accompanied the visual target(s). Together, these findings show that non-lateralized auditory input enhances all vectors evoked by visual input. The results will be discussed in terms of their possible neural substrates.


Subject(s)
Auditory Perception/physiology , Fixation, Ocular/physiology , Functional Laterality , Oculomotor Muscles/physiology , Psychomotor Performance/physiology , Saccades/physiology , Adult , Female , Functional Laterality/physiology , Humans , Male , Oculomotor Muscles/innervation , Young Adult
17.
Vision Res ; 62: 108-15, 2012 Jun 01.
Article in English | MEDLINE | ID: mdl-22521658

ABSTRACT

When two elements are presented closely aligned, the average saccade endpoint will generally be located in between these two elements. This 'global effect' has been explained in terms of the center of gravity account which states that the saccade endpoint is based on the relative saliency of the different elements in the visual display. In the current study, we tested one of the implications of the center of gravity account: when two elements are presented closely aligned with the same size and the same distance from central fixation, the saccade should land on the intermediate location, irrespective of the stimulus size. To this end, two equally-sized elements were presented simultaneously and participants were required to execute an eye movement to the visual information presented on the display. Results showed that the strongest global effect was observed in the condition with smaller stimuli, whereas the saccade averaging was weaker when larger stimuli were presented. In a second experiment, in which only one element was presented, we observed that the width of the distribution of saccade endpoints is influenced by stimulus size in that the distribution is broader with smaller stimuli. We conclude that perfect saccade averaging is not always the default response by the oculomotor system. There appears to be a tendency to initiate an eye movement towards one of the visual elements, which becomes stronger with increasing stimulus size. This effect might be explained by an increased uncertainty in target localization for smaller stimuli, resulting in a higher probability of the merging of two stimulus representations into one representation.


Subject(s)
Saccades/physiology , Size Perception/physiology , Adult , Analysis of Variance , Female , Fixation, Ocular/physiology , Humans , Male , Middle Aged , Photic Stimulation , Reaction Time/physiology , Young Adult
18.
J Neurol Sci ; 316(1-2): 184-8, 2012 May 15.
Article in English | MEDLINE | ID: mdl-22285276

ABSTRACT

Palinopsia is an abnormal perseverative visual phenomenon, whose relation to normal afterimages is unknown. We measured palinoptic positive visual afterimages in a patient with a cerebral lesion. Positive afterimages were confined to the left inferior quadrant, which allowed a comparison between afterimages in the intact and the affected part of his visual field. Results showed that negative afterimages in the affected quadrant were no different from those in the unaffected quadrant. The positive afterimage in his affected field, however, differed both qualitatively and quantitatively from normal afterimages, being weaker but much more persistent, and displaced from the location of the inducing stimulus. These findings reveal distinctions between pathological afterimages of cerebral origin and physiological afterimages of retinal origin.


Subject(s)
Afterimage/physiology , Occipital Lobe/pathology , Photic Stimulation/methods , Vision Disorders/diagnosis , Humans , Male , Middle Aged , Vision Disorders/pathology , Vision Disorders/physiopathology , Visual Cortex/pathology , Visual Fields/physiology
19.
Neuropsychologia ; 50(1): 198-203, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22155181

ABSTRACT

The current study investigated the role of the frontal eye fields (FEF) in the suppression of an unwanted eye movement ('oculomotor inhibition'). Oculomotor inhibition has generally been investigated using the antisaccade task, in which an eye movement to a task-relevant onset must be inhibited. Various lines of research have suggested that successful inhibition in the antisaccade task relies heavily on the FEF. Here, we tested whether the FEF are also involved in the oculomotor inhibition of reflexive saccades. To this end, we used the oculomotor capture task in which the to-be-inhibited element is task-irrelevant. Performance of four patients with lesions to the FEF was measured on both the antisaccade and oculomotor capture task. In both tasks, the majority of the patients made more erroneous eye movements to contralesional elements than to ipsilesional elements. One patient showed no deficits in the antisaccade task, which could be explained by the developmental origin of his lesion. While we confirm the role of the FEF in the inhibition of task-relevant elements, the current study also reveals that the FEF play a crucial role in the oculomotor inhibition of task-irrelevant elements.


Subject(s)
Eye Movements/physiology , Functional Laterality/physiology , Inhibition, Psychological , Prefrontal Cortex/physiopathology , Saccades/physiology , Visual Perception/physiology , Aged , Aged, 80 and over , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neuropsychological Tests , Prefrontal Cortex/pathology
20.
Brain Cogn ; 74(1): 66-73, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20637537

ABSTRACT

Previous research has revealed that a stimulus presented in the blind visual field of participants with visual hemifield defects can evoke oculomotor competition, in the absence of awareness. Here we studied three cases to determine whether a distractor in a blind hemifield would be capable of inducing a global effect, a shift of saccade endpoint when target and distractor are close to each other, in participants with lesions of the optic radiations or striate cortex. We found that blind field distractors significantly shifted saccadic endpoints in two of three participants with lesions of either the striate cortex or distal optic radiations. The direction of the effect was paradoxical, however, in that saccadic endpoints shifted away from blind field distractors, whereas endpoints shifted towards distractors in the visible hemifields, which is the normal global effect. These results provide further evidence that elements presented in the blind visual field can generate modulatory interactions in the oculomotor system, which may differ from interactions in normal vision.


Subject(s)
Eye Movements/physiology , Perceptual Disorders/physiopathology , Visual Cortex/physiopathology , Visual Fields/physiology , Adult , Awareness/physiology , Female , Humans , Magnetic Resonance Imaging , Male , Photic Stimulation , Reaction Time/physiology
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