Contralateral Neglect Research Articles

Awake craniotomy for low-grade gliomas

Aim: The aim of this study was to evaluate the efficacy of awake brain surgery for benign glial brain tumours in the Department of Neurosurgery of the Military Institute of Medicine in Warsaw. Materials and methods: Between 2020 and 2021, 9 out of 17 patients with a radiological diagnosis of a low-grade glioma located within or in the vicinity of eloquent brain areas were operated on under awake conditions. The average preoperative tumour volume was 29.6 cm3. Preoperative management included a repeat magnetic resonance imaging supplemented with functional magnetic resonance imaging and tractography, as well as neuropsychological assessment. The cortex and subcortical structures were stimulated intraoperatively at 1.5–4 mA. The intraoperative assessment covered: motor functions, speech, and, additionally in two patients, visual field width and contralateral neglect. Results: Based on magnetic resonance imaging on the first postoperative day, complete removal of the tumour was confirmed in 7 patients. In 2 patients, resection was subtotal due to the fact that part of the tumour that infiltrated eloquent structures was left. In 6 patients, transient neurological deterioration was observed in the early perioperative period, which resolved within 2 months after surgery. In 3 patients, histopathological examination revealed a tumour with a higher grade of malignancy than expected. Conclusions: Our experience confirms that surgical treatment of benign glial tumours using direct electrical stimulation in awake patients is an effective and safe method allowing effective tumour resection with a minimised risk of adverse neurological sequelae.

A Case of Anton-Babinski Syndrome in an older adult: A case report

<h3>Introduction</h3> Anton-Babinski syndrome is a rare neuropsychiatric syndrome described by Gabriel Anton and Joseph Babinski early in the 19th century. This syndrome represents a rare differential that can mimic the advanced stages of dementia with similar apraxia, poor insight, while presenting different management needs and treatment response. Anton-Babinski syndrome results from damage to the non-dominant parietal lobe of the cerebral cortex and associated connections. It is the right-hemisphere equivalent of Gerstmann Syndrome and is to be distinguished from Anton's syndrome, caused by bilateral occipital cortical damage. Anton-Babinski syndrome presents with contralateral sensory neglect, anosognosia with anosodiaphoria (affective indifference), construction, and dressing apraxia. It can lead to significant functional impairment and a substantial risk of falls in affected subjects, as we present in our case. There is a relative paucity of data regarding this syndrome due to its remarkable rarity. <h3>Methods</h3> N/A <h3>Results</h3> N/A <h3>Conclusions</h3> Despite presenting initially for management of possible vascular major neurocognitive disorder with neuropsychiatric symptoms, detailed assessment and work-up revealed her presentation to be most consistent with the rare Anton-Babinski syndrome. Awareness of such disease entities can inform treatment planning. In her case, she will most likely benefit from deprescribing cognitive enhancers, which worsen her bradycardia and increase her fall risk, while optimizing occupational and physical therapy to improve her quality of life and home safety. <h3>This research was funded by</h3> None

A Novel Three-Choice Touchscreen Task to Examine Spatial Attention and Orienting Responses in Rodents.

Mammalian orienting behavior consists of coordinated movements of the eyes, head, pinnae, vibrissae, or body to attend to an external stimulus. The present study aimed to develop a novel operant task using a touch-screen system to measure spatial attention. In this task, rats were trained to nose-poke a light stimulus presented in one of three locations. The stimulus was presented more frequently in the center location to develop spatial attention bias toward the center stimulus. Changes in orienting responses were detected by measuring the animals’ response accuracy and latency to stimuli at the lateral locations, following reversible unilateral chemogenetic inactivation of the superior colliculus (SC). Additionally, spontaneous turning and rotation behavior was measured using an open-field test (OFT). Our results show that right SC inactivation significantly increased the whole body turn angle in the OFT, in line with previous literature that indicated an ipsiversive orientating bias and the presence of contralateral neglect following unilateral SC lesions. In the touch screen orienting task, unilateral SC inactivation significantly increased bias toward the ipsilateral side, as measured by response frequency in various experimental conditions, and a very large left-shift of a respective psychometric function. Our results demonstrate that this novel touchscreen task is able to detect changes in spatial attention and orienting responses because of e.g. experimental manipulations or injury with very high sensitivity, while taking advantage of the touch screen technology that allows for high transferability of the task between labs and for open-source data sharing through https://www.mousebytes.ca.

Clinical and functional differences between right and left stroke with and without contralateral spatial neglect.

To examine the clinical and functional characteristics associated with contralateral spatial neglect in right compared with left subacute stroke, and to investigate the correlations between neglect severity and stroke severity, functional ability and outcome. Cross-sectional study comparing neurological impairment and disability. The same data-set was used in part 2 of this study. Contralateral neglect was present in 79.7% of right stroke and 68.3% of left stroke rehabilitants, and was, on average, equally mild. Left stroke rehabilitants with neglect had higher stroke severity, cognitive and total disability and dependence level and more impaired sphincter control than right stroke rehabilitants with neglect, while the occurrence of depression, motor and sensory impairment was similar. Rehabilitants with neglect, irrespective of stroke side, had higher stroke severity, cognitive, motor and total disability and dependence level than rehabilitants without neglect. In left and right stroke rehabilitants with equally mild neglect, those with left stroke had higher stroke severity, cognitive and total disability and dependence level. Neglect severity correlated with right or left stroke severity and functional ability, moderate to severe neglect correlated significantly more with functioning. Neglect severity was independently associated with functional outcome in right stroke.

Comparison of functional recovery and outcome at discharge from subacute inpatient rehabilitation in patients with right or left stroke with and without contralateral spatial neglect.

To compare to what extent the presence of contralateral spatial neglect affects functional recovery and outcome among patients with right or left stroke after subacute inpatient rehabilitation. Observational cohort study comparing functional improvement and outcome. The same admission data-set was used as in part 1 of this study. Right and left stroke rehabilitants with equally mild neglect and those without neglect (a total of 4 subgroups) all improved proportionally as much, but those with neglect, irrespective of stroke side needed a longer stay in inpatient rehabilitation. At discharge, total disability did not differ significantly between the 2 neglect subgroups, but those with left stroke had significantly lower Functional Independence Measure cognitive sub-score and score in communication. Rehabilitants with neglect, irrespective of stroke side had higher motor, cognitive and total disability and were more often institutionalized than those without neglect. Mild neglect did not impair recovery after right or left stroke, but rehabilitants with neglect were more disabled and needed a longer rehabilitation inpatient stay than those without neglect.

Auditory neglect in children following perinatal stroke

Auditory neglect has been found in adults with right hemisphere focal brain lesions following strokes. Visual and tactile neglect has been found in children following both left and right hemisphere lesions resulting from perinatal strokes. The present cross-sectional study assessed auditory neglect in children with early unilateral brain damage from perinatal stroke. Twenty-six children with perinatal stroke and matched controls participated. All were asked to identify the location of a pure tone presented in left or right auditory fields. We found that children who had experienced left hemisphere perinatal strokes were significantly better at localizing sounds on the left side of space than the right side of space, and that response times improved with age on a normal trajectory relative to controls in left hemispace, while they did not improve normally in right hemispace. Children with right hemisphere perinatal strokes were significantly worse at localizing sounds on the right side of space relative to typically developing controls, and did not follow control trajectories for improvement in response times on the left or the right sides of space. Our preliminary results suggest that left hemisphere perinatal strokes may result in contralateral auditory neglect, while right hemisphere perinatal strokes may result in bilateral auditory neglect. Neglect was more severe in children with parietal lobe involvement, suggesting that the parietal lobe may play a dominant role in auditory attention in the developing brain.

The right hemisphere is independent from the left hemisphere in allocating visuospatial attention.

The capacity to allocate visuospatial attention is traditionally considered right-lateralized according to the effects of unilateral cerebral lesions. Contralateral hemi-spatial neglect occurs much more frequently after lesions of the right hemisphere, which has therefore been dubbed as 'dominant'. This pattern of symptoms is supported by functional models that postulate either independence or reciprocal influences between the two hemispheres. Here we specifically explored the dependency of the right hemisphere (RH) from the left hemisphere (LH) in spatial attention. We capitalized on the well-known effect of online transcranial magnetic stimulation (TMS) on the RH in healthy individuals, consisting in transient neglect-like manifestations in the left hemi-space. We assessed whether prior stimulation of the left posterior parietal cortex with a long-lasting neuromodulatory procedure (transcranial direct current stimulation - tDCS) affected the acute effects of TMS on the right posterior parietal cortex. We performed a within-subjects factorial study with two factors: LH tDCS (sham or real) and RH TMS (sham or real), resulting in a 2×2 design. The effects on spatial attention were examined separately for the two hemi-spaces by means of a modified line-bisection task. The results indicated that TMS over the RH produced a spatial attention deficit in the left hemi-space alone and the behavioural effects of TMS were not modulated by prior stimulation of the LH. Interestingly, additional analyses showed that tDCS over the LH alone produced a deficit in spatial attention to the right hemi-space. We interpret the current results as evidence for a largely independent contribution of each hemisphere to the allocation of visuospatial attention limited to the contralateral hemi-space.

Evolution of ischemic damage and behavioural deficit over 6 months after MCAo in the rat: Selecting the optimal outcomes and statistical power for multi-centre preclinical trials.

Key disparities between the timing and methods of assessment in animal stroke studies and clinical trial may be part of the reason for the failure to translate promising findings. This study investigates the development of ischemic damage after thread occlusion MCAo in the rat, using histological and behavioural outcomes. Using the adhesive removal test we investigate the longevity of behavioural deficit after ischemic stroke in rats, and examine the practicality of using such measures as the primary outcome for future studies. Ischemic stroke was induced in 132 Spontaneously Hypertensive Rats which were assessed for behavioural and histological deficits at 1, 3, 7, 14, 21, 28 days, 12 and 24 weeks (n>11 per timepoint). The basic behavioural score confirmed induction of stroke, with deficits specific to stroke animals. Within 7 days, these deficits resolved in 50% of animals. The adhesive removal test revealed contralateral neglect for up to 6 months following stroke. Sample size calculations to facilitate the use of this test as the primary experimental outcome resulted in cohort sizes much larger than are the norm for experimental studies. Histological damage progressed from a necrotic infarct to a hypercellular area that cleared to leave a fluid filled cavity. Whilst absolute volume of damage changed over time, when corrected for changes in hemispheric volume, an equivalent area of damage was lost at all timepoints. Using behavioural measures at chronic timepoints presents significant challenges to the basic science community in terms of the large number of animals required and the practicalities associated with this. Multicentre preclinical randomised controlled trials as advocated by the MultiPART consortium may be the only practical way to deal with this issue.

Corpus Callosum and Neglect Syndrome: Clinical Findings After Meningioma Removal and Anatomical Review.

Two types of neglect are described: hemispatial and motivational neglect syndromes. Neglect syndrome is a neurophysiologic condition characterized by a malfunction in one hemisphere of the brain, resulting in contralateral hemispatial neglect in the absence of sensory loss and the right parietal lobe lesion being the most common anatomical site leading to it. In motivational neglect, the less emotional input is considered from the neglected side where anterior cingulate cortex harbors the most frequent lesions. Nevertheless, there are reports of injuries in the corpus callosum (CC) causing hemispatial neglect syndrome, particularly located in the splenium. It is essential for a neurosurgeon to recognize this clinical syndrome as it can be either a primary manifestation of neurosurgical pathology (tumor, vascular lesion) or as a postoperative iatrogenic clinical finding. The authors report a postoperative hemispatial neglect syndrome after a falcotentorial meningioma removal that recovered 10 months after surgery and performs a clinical, anatomical, and histological review centered in CC as key agent in neglect syndrome.

The Evolutionary Concept of "Preadaptation" Applied to Cognitive Neurosciences.

The Evolutionary Concept of "Preadaptation" Applied to Cognitive Neurosciences.

Clock Drawing in Children With Perinatal Stroke

BackgroundChildren with perinatal stroke may show evidence of contralateral spatial neglect. The goal of this study was to determine whether the Clock Drawing Test commonly used in adults to identify neglect would be effective in detecting neglect in children with perinatal stroke. MethodsThirty-eight individuals (age range 6-21 years) with left hemisphere or right hemisphere perinatal onset unilateral lesions and 179 age-matched controls were given a free-drawn Clock Drawing Test in a cross-sectional design. An adapted scoring system that evaluated right- and left-sided errors separately was developed as part of the investigation. ResultsChildren with right hemisphere lesions made a greater number of errors on both the right and left sides of the clock drawings in all age subgroups (6-8 years, 9-14 years, and 15-21 years) compared with controls. Children with right hemisphere lesions showed greater left and right errors in the younger groups compared with controls, with significantly poorer performance on the left at 6-8 years, suggestive of contralateral neglect. However, by ages 15-21 years, the right hemisphere lesion subjects no longer differed from controls. ConclusionsClock drawing can identify spatial neglect in children with early hemispheric damage. However, brain development is a dynamic process, and as children age, spatial neglect may no longer be evident. These findings demonstrate the limitations of predicting long-term outcome after perinatal stroke from early neurocognitive data. Children with perinatal stroke may require different neural pathways to accomplish specific skills or to overcome deficits, but ultimately they may have “typical” outcomes.

Neural correlates of visuospatial consciousness in 3D default space: insights from contralateral neglect syndrome.

One of the most compelling questions still unanswered in neuroscience is how consciousness arises. In this article, we examine visual processing, the parietal lobe, and contralateral neglect syndrome as a window into consciousness and how the brain functions as the mind and we introduce a mechanism for the processing of visual information and its role in consciousness. We propose that consciousness arises from integration of information from throughout the body and brain by the thalamus and that the thalamus reimages visual and other sensory information from throughout the cortex in a default three-dimensional space in the mind. We further suggest that the thalamus generates a dynamic default three-dimensional space by integrating processed information from corticothalamic feedback loops, creating an infrastructure that may form the basis of our consciousness. Further experimental evidence is needed to examine and support this hypothesis, the role of the thalamus, and to further elucidate the mechanism of consciousness.

Characterisation of spatial neglect induced by unilateral 6-OHDA lesions on a choice reaction time task in rats

Unilateral dopamine depletion and excitotoxic lesions of the striatum have been shown to induce a contralateral neglect when rats have to respond in a choice reaction time setting. Whereas, in a lateralised setting when response options are to either side of the animal's head all contralateral responding is impaired, testing animals only on one side of the head per day but with a near and far response option, rats are able to correctly respond to contralateral stimuli, but rather bias their responses towards the near hole. Here, we further investigated the nature of the contralateral neglect in egocentric space coding in more detail. Firstly, we tested the effects of near-complete unilateral dopamine depletion on this type of task. Secondly, previous observations suggested that lesioned rats shifted their response strategy which resulted in a response bias towards the most proximal location in contralateral space. In order to “encourage” dopamine depleted rats to respond to the neglected response location we implemented an error correction procedure to the task. Near-complete unilateral dopamine depletion, via 6-hydroxydopamine infusions into the medial forebrain bundle of female Lister Hood rats, resulted in a reduction of usable trials, a near hole bias when animals were tested on the side contralateral to the lesion, as well as increased reaction and movement time latencies. The introduction of an error-correction procedure had no effect on the animals’ response bias towards the near contralateral location. Probe trials showed that the bias is most likely the result of responses being misdirected when in a choice situation. The findings further highlight the role of dopamine and an intact striatum to code responses into egocentrically defined space.

Spatial analysis after perinatal stroke: Patterns of neglect and exploration in extra-personal space

This study was conducted to determine whether school-aged children who had experienced a perinatal stroke demonstrate evidence of persistent spatial neglect, and if such neglect was specific to the visual domain or was more generalized. Two studies were carried out. In the first, 38 children with either left hemisphere (LH) or right hemisphere (RH) damage and 50 age-matched controls were given visual cancellation tasks varying in two factors: target stimuli and stimulus array. In the second study, tactile neglect was evaluated in 41 children with LH or RH damage and 72 age-matched controls using a blindfolded manual exploration task. On the visual cancellation task, LH subjects omitted more target stimuli on the right, but also on the left, compared with controls. Children with RH lesions also produced a larger number of omissions on both the left and right sides than controls, but with poorer performance on the left. On the manual exploration task, LH children required significantly longer times to locate the target on both sides of the board than did controls. RH children had significantly prolonged search times on the left side, but not on the right, compared with controls. In both tasks, LH subjects employed unsystematic search strategies more often than both control and RH children. The search strategy of RH children also tended to be erratic when compared to controls, but only in the random arrays of the visual cancellation tasks; structure of the target stimuli improved their organization. These results demonstrate that children with early LH brain damage display bilateral difficulties in visual and tactile modalities; a pattern that is in contrast to that seen in adults with LH damage. This may result from disorganized search strategies or other subtle spatial or attentional deficits. Results of performance of RH children suggests the presence of contralateral neglect in both the visual and tactile modalities; a finding that is similar to the neglect in adult stroke patients with RH lesions. The fact that deficits in spatial attention and organizational strategies are present after very early focal damage to either the LH or the RH broadens our understanding of the differences in functional lateralization between the immature and mature brain. These results also add to evidence for limitations to plasticity in the developing brain. Our findings may have therapeutic and rehabilitative implications for the management of children with early focal brain lesions.

Ipsilateral Neglect from a Subcortical Lesion

This report describes a patient with right putaminal hemorrhage who showed ipsilateral (right-sided) neglect. Although lesions to subcortical regions may result in contralateral hemispatial neglect, ipsilateral neglect from putaminal damage has not been reported. It has been posited that ipsilateral neglect from unilateral frontal lesions may be induced by a contralateral attentional grasp. This patient's putaminal hemorrhage may have induced frontal dysfunction with an attentional grasp. Because distracting stimuli, as well as close (vs. far) spatial position, may alter an attentional grasp and because fatigue may compromise the ability to disengage, we tested the patient with repeated trials of line bisection in peripersonal (close) and extrapersonal (far) space with left-sided, right-sided, and both-sided distractors. The patient's leftward bias increased with repeated trials, particularly with those in the close condition and with left-sided distractors. Right putaminal hemorrhage may produce ipsilateral neglect. Our patient's putaminal-white matter injury may have induced frontal dysfunction, and, with repeated trials, his right basal ganglia-frontal network may have fatigued. This fatigue, together with left-sided distractors in the close condition, seemed to increase his contralateral attentional grasp.

Evoked and Intrinsic Asymmetries during Auditory Attention: Implications for the Contralateral and Neglect Models of Functioning

Unlike the visual system, a direct mapping of extrapersonal space does not exist within human auditory cortex (AC). Thus, models (contralateral bias vs. neglect) of how auditory spatial attention is allocated remain debated, as does the role of hemispheric asymmetries. To further examine these questions, 27 participants completed an exogenous auditory orienting task while undergoing functional magnetic resonance imaging. Resting-state data were also collected to characterize intrinsic activity within the AC. Current results provide the first evidence of hemispheric specialization in the "where" (right secondary AC) auditory processing stream during both evoked (orienting task) and intrinsic (resting-state data) activity, suggesting that spontaneous and evoked activity may be synchronized by similar cortical hierarchies. Strong evidence for a contralateral bias model was observed during rapid deployment stages (facilitation) of auditory attention in bilateral AC. However, contralateral bias increased for left and decreased for right AC (neglect model) after longer stimulus onset asynchronies (inhibition of return), suggesting a role for higher-order cortical structures in modulating AC functioning. Prime candidates for attentional modulation include the frontoparietal network, which demonstrated right hemisphere lateralization across multiple attentional states.

Phenobarbital Augments Hypothermic Neuroprotection

Seizures are associated with adverse outcome in infants with hypoxic-ischemic encephalopathy. We hypothesized that early administration of the anticonvulsant phenobarbital after cerebral hypoxia ischemia could enhance the neuroprotective efficacy of delayed-onset hypothermia. We tested this hypothesis in a neonatal rodent model. Seven-d-old rats (n = 104) underwent right carotid ligation, followed by 90 min 8% O2 exposure; 15 min later, they received injections of phenobarbital (40 mg/kg) or saline. One or 3 h later, all were treated with hypothermia (30 degrees C, 3 h). Function and neuropathology were evaluated after 7 d (early outcomes) or 1 mo (late outcomes). Early outcome assessment demonstrated better sensorimotor performance and less cortical damage in phenobarbital-treated groups; there were no differences between groups in which the hypothermia delay was shortened from 3 to 1 h. Late outcome assessment confirmed sustained benefits of phenobarbital + hypothermia treatment; sensorimotor performance was better (persistent attenuation of contralateral forepaw placing deficits and absence of contralateral forepaw neglect); neuropathology scores were lower (median, phenobarbital 2 and saline 8.5, p < 0.05); and less ipsilateral cerebral hemisphere %Damage (mean +/- SD, 11 +/- 17 versus 28 +/- 22, p < 0.05). These results suggest that early posthypoxia-ischemia administration of phenobarbital may augment the neuroprotective efficacy of therapeutic hypothermia.

Preliminary clinical study in patients with hemispatial neglect after stroke by neglect test battery and 99mTc-ECD single-photon emission computed tomography

To explore the presence, clinical characteristics, anatomical foci in image and mechanism of hemispatial neglect (HSN), neglect test battery and single-photon emission computed tomography (SPECT) regional cerebral blood flow (rCBF) imaging were performed on patients with stroke. Thirty dextromanual patients who were diagnosed as having unilateral stroke clinically were recruited. A neglect test battery including line bisection test, star cancellation test and drawing test was performed on the subjects. The severity of neglect was measured on neglect tests. The lowest rCBF, the range with decreased rCBF, number of the foci with decreased rCBF, the flow deficit size and the total number of pixels in the foci were measured on SPECT rCBF imaging. Twenty-five patients were diagnosed as having HSN by the neglect test battery. Contralateral neglect (CN) and ipsilateral neglect (IN) were observed in both right and left hemisphere strokes. On SPECT imaging, the patients with neglect had decreased rCBF in the frontal cortex most often; followed by the parietal, occipital and temporal cortices; and basal ganglia and thalamus in some cases. The patients who had two or more regions damaged showed neglect more often and severity. The correlation coefficients between rCBF in the foci, the decreased percentage of rCBF of the foci and the severity of neglect were -0.119 (P>.05) and 0.221 (P>.05). The correlation coefficients between the range, number of foci, the flow deficit size, the total number of pixels of the foci and the severity of neglect were 0.537 (P<.05), 0.493 (P<.05), 0.561 (P<.05), 0.466 (P<.05), respectively. No difference between CN and IN on SPECT images reached statistical significance. The severity of neglect did not correlate with rCBF and the decreased percentage of rCBF in the foci, while it was significantly correlated with the range, number of foci, the flow deficit size and the total numbers of pixels of the foci significantly. And the patients with CN and IN did not show any difference in the presence of HSN, the manifestation on the neglect test battery and SPECT images. HSN showed damage on multiple sites, with combined damages resulting in more severe neglect.

Posterior parietal cortex as part of a neural network for directed attention in rats

A rodent model of directed attention has been developed based upon behavioral analysis of contralateral neglect, pharmacological manipulations, and anatomical analysis of neural circuitry. In each of these three domains the rodent model exhibits striking similarities to humans. We hypothesize that there is a specific thalamo-cortical-basal ganglia network that subserves spatial attentional functions. Key components of this network are medial agranular and posterior parietal cortex, dorsocentral striatum, and the lateral posterior thalamic nucleus. Several issues need to be addressed before we can hope to realistically understand or model the functions of this network. Among these are the roles of medial versus lateral posterior parietal cortex; cholinergic mechanisms in attention; interhemispheric interactions; the role of synchronous firing at the cortical, striatal, and thalamic levels; interactions between cortical and thalamic projections to the striatum; interactions between cortical and nigral inputs to the thalamus; the role of collicular inputs to the lateral posterior thalamic nucleus; the role of cerebral cortex versus superior colliculus in driving the motor output expressed as orienting behavior during directed attention; the extent to which the circuitry we describe for directed attention also plays a role in other forms of attention.

Topography in the projections of lateral posterior thalamus with cingulate and medial agranular cortex in relation to circuitry for directed attention and neglect

In the rat, the lateral posterior thalamic nucleus (LP) has reciprocal connections with areas of the cortex and the striatum involved in directed attention and its dysfunctional counterpart, contralateral neglect. It has also been shown that the medial portion of the mediorostral part of LP (mLPMR) is of special interest because it has connections with the dorsocentral striatum, a key node in this circuitry. In the present study we used neuroanatomical tracers to map the specific connections and topography of LP with the anterior cingulate cortex (ACC) and medial agranular cortex (AGm). We primarily used Alexa Fluor conjugates of the retrograde tracer cholera toxin subunit B, and injected two different colored conjugates into ACC and AGm in the same animal in order to directly compare the differential topography of the thalamocortical connections of mLPMR. The bidirectional tracer, dextran amine, was also used to examine anterograde corticothalamic projections of AGm and ACC. We found that mLPMR consists of two distinct groups of neurons, with the more dorsal group projecting to ACC and the more ventral group projecting to AGm. This is mirrored by a similar corticothalamic topography. These findings suggest that the ventral mLPMR is specifically associated with AGm and dorsocentral striatum, while dorsal mLPMR is associated with ACC. They also suggest that ACC may play a role in the circuitry for directed attention and contralateral neglect, as it is known to do in humans.