The role of the human pulvinar in visual attention and action: evidence from temporal-order judgment, saccade decision, and antisaccade tasks (original) (raw)
Related papers
Contributions of the human pulvinar to linking vision and action
Cognitive Affective & Behavioral Neuroscience, 2004
In 3 patients with unilateral pulvinar lesions, we tested the pulvinar’s role in selective attention processing. Each patient completed four variants of a flanker interference task in which they reported the color of a square of a specified size while ignoring an irrelevant flanker that appeared either contralesionally or ipsilesionally to the target. The main finding was that when target location was not known and target and flanker were associated with competing responses, reaction times to contralesional targets were longer than those to ipsilesional targets. Our findings suggest that pulvinar damage produces a contralesional deficit in response competition.
Dissociating Vision and Visual Attention In the Human Pulvinar
Journal of …, 2009
The pulvinar region of the thalamus has repeatedly been linked with the control of attention. However, the functions of the pulvinar remain poorly characterized, both in human and in nonhuman primates. In a functional MRI study, we examined the relative contributions to activity in the human posterior pulvinar made by visual drive (the presence of an unattended visual stimulus) and attention (covert spatial attention to the stimulus). In an event-related design, large optic flow stimuli were presented to the left and/or right of a central fixation point. When unattended, the stimuli robustly activated two regions of the pulvinar, one medial and one dorsal with respect to the lateral geniculate. The activity in both regions shows a strong contralateral bias, suggesting retinotopic organization. Primate physiology suggests that the two regions could be two portions of the same double map of the visual field. In our paradigm, attending to the stimulus enhanced the response by about 20%. Thus attention is not necessary to activate the human pulvinar and the degree of attentional enhancement matches, but does not exceed, that seen in the cortical regions with which the posterior pulvinar connects.
The role of the pulvinar in distractor processing and visual search
Human Brain Mapping, 2013
The pulvinar nuclei of the thalamus are hypothesized to coordinate attentional selection in the visual cortex. Different models have, however, been proposed for the precise role of the pulvinar in attention. One proposal is that the pulvinar mediates shifts of spatial attention; a different proposal is that it serves the filtering of distractor information. At present, the relation between these possible operations and their relative importance in the pulvinar remains unresolved. We address this issue by contrasting these proposals in two fMRI experiments. We used a visual search paradigm that permitted us to dissociate neural activity reflecting shifts of attention from activity underlying distractor filtering. We find that distractor filtering, but not the operation of shifting attention, is associated with strong activity enhancements in dorsal and ventral regions of the pulvinar as well as in early visual cortex areas including the primary visual cortex. Our observations indicate that distractor filtering is the preponderant attentional operation subserved by the pulvinar, presumably mediated by a modulation of processing in visual areas where spatial resolution is sufficiently high to separate target from distractor input. Hum Brain Mapp 00:000-000,
Pulvinar-Cortex Interactions in Vision and Attention
Neuron, 2016
The ventro-lateral pulvinar is reciprocally connected with the visual areas of the ventral stream important for object recognition. To understand the mechanisms of attentive stimulus processing in this pulvinar-cortex loop, we investigated the interactions between the pulvinar, area V4, and IT cortex in a spatial attention task. Sensory processing and the influence of attention in the pulvinar appeared to reflect its cortical inputs. However, pulvinar deactivation led to a reduction of attentional effects on firing rates and gamma synchrony in V4, a reduction of sensory-evoked responses and overall gamma coherence within V4, and severe behavioral deficits in the affected portion of the visual field. Conversely, pulvinar deactivation caused an increase in low frequency cortical oscillations, often associated with inattention or sleep. Thus, cortical interactions with the ventro-lateral pulvinar are necessary for normal attention and sensory processing, and for maintaining the cortex in an active state.
Proceedings of the National Academy of Sciences, 2009
We examined the contributions of the human pulvinar to goal directed selection of visual targets in 3 patients with chronic, unilateral lesions involving topographic maps in the ventral pulvinar. Observers completed 2 psychophysical tasks in which they discriminated the orientation of a lateralized target grating in the presence of vertically-aligned distracters. In experiment 1, where distracter contrast was varied while target contrast remained constant, the patients' contralesional contrast thresholds for discriminating the orientation of grating stimuli were elevated only when the task required selection of a visual target in the face of competition from a salient distracter. Attentional selectivity was restored in the patients in experiment 2 where target contrast was varied while distracter contrast remained constant. These observations provide the first evidence that the human pulvinar plays a necessary role in modulating physical saliency in attentional selection, and supports a homology in global pulvinar structure between humans and monkey.
Behavioural Neurology, 2002
The effects of damage to the pulvinar nucleus of the thalamus in humans on reflexive orienting and selective attention were investigated. In a spatial orienting task three patients with unilateral pulvinar damage determined the location of a visual target that followed a cue that was not informative as to the targets location. Contralesional targets were responded to more slowly than ipsilesional targets. Also, at long cue target intervals patients responses to contralesional targets that appeared at previously cued locations were slower than to non-cued locations indicating that pulvinar damage does not affect inhibition of return. In the selective attention task two of the patients identified a target that appeared at one level of a global-local hierarchical stimulus while ignoring a distractor present at the other level. The distractor indicated either the same response as the target or a different response. Response times to targets in both visual fields were similar as were int...
Memory and attention interact. Information held in working memory (WM) can bias visual selection toward matching stimuli in a subsequent search display, while a search target that is different from the memory stimulus can interfere with its subsequent recognition. In recent fMRI studies, the pulvinar has been consistently shown to have an enhanced response when an item in WM matches a search target and a reduced response when the WM item matches a distracter in search. Here we used Granger causality analysis to help understand the role of the pulvinar in resolving competition between memory and selection processes. Across three experiments the results showed increased coupling between the pulvinar and the ipsilateral superior frontal gyrus, contralateral temporal–parietal junction (TPJ) and calcarine sulcus when a visual search distracter matched the item held in memory. This connection pattern suggests that the pulvinar suppresses visual responses to the target when a contralateral distracter contains information held in working memory. We propose that this suppression acts to protect the memory item from interference arising from information associated with the search target. Consistent with this proposal we showed that the strength of the thalamus-to-visual connection predicted performance on a subsequent memory test. The data therefore suggest that the thalamus modulates bottom up processing in sensory cortex to minimize interference to WM content.
The Pulvinar Regulates Information Transmission Between Cortical Areas Based on Attention Demands
Science, 2012
The Conductor in the Thalamus The pulvinar is the largest thalamic nucleus in the brain but its functions remain unclear. The pulvinar is ideally positioned to synchronize activity across the visual cortex. Saalmann et al. (p. 753 ) combined diffusion tensor imaging with multi-electrode recordings from three different brain areas in monkeys to probe thalamo-cortical interactions during visual attention. The pulvinar was found to play a vital role in attention by routing behaviorally relevant information across the visual cortex.