The maintenance and disambiguation of object representations depend upon feature contrast within and between objects

Caplovitz, Gideon P.; Shapiro, Arthur; Stroud, Sarah

doi:10.1167/11.14.1

Cited by 18 publications

(21 citation statements)

References 49 publications

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“…Indeed, recent evidence suggests that DBS stimulation of the STN may have some involvement in modifying attentional cerebral networks [47]. Noteworthy, attention is also important for human motor control and for oculomotor performance [52,53]. Hence, one cannot rule out that improvements in attention and cognition partly account for the improvements recorded in oculomotor performance with STN stimulation.…”

Section: Discussionmentioning

confidence: 99%

Subthalamic deep brain stimulation improves smooth pursuit and saccade performance in patients with Parkinson’s disease

Nilsson

Patel

Rehncrona

et al. 2013

J NeuroEngineering Rehabil

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BackgroundDeep brain stimulation (DBS) in the subthalamic nucleus (STN) significantly reduces symptoms of Parkinson’s disease (PD) such as bradykinesia, tremor and rigidity. It also reduces the need for anti-PD medication, and thereby potential side-effects of L-Dopa. Although DBS in the STN is a highly effective therapeutic intervention in PD, its mechanism and effects on oculomotor eye movement control and particularly smooth pursuit eye movements have to date rarely been investigated. Furthermore, previous reports provide conflicting information. The aim was to investigate how DBS in STN affected oculomotor performance in persons with PD using novel analysis techniques.MethodsTwenty-five patients were eligible (22 males, 3 females) according to the clinical inclusion criteria: idiopathic PD responsive to L-Dopa and having had bilateral STN stimulation for at least one year to ensure stable DBS treatment. Fifteen patients were excluded due to the strict inclusion criteria applied to avoid interacting and confounding factors when determining the effects of DBS applied alone without PD medication. One patient declined participation. Nine PD patients (median age 63, range 59–69 years) were assessed after having their PD medications withdrawn overnight. They were examined with DBS ON and OFF, with the ON/OFF order individually randomized.ResultsDBS ON increased smooth pursuit velocity accuracy (p < 0.001) and smooth pursuit gain (p = 0.005), especially for faster smooth pursuits (p = 0.034). DBS ON generally increased saccade amplitude accuracy (p = 0.007) and tended to increase peak saccade velocity also (p = 0.087), specifically both saccade velocity and amplitude accuracy for the 20 and 40 degree saccades (p < 0.05). Smooth pursuit latency tended to be longer (p = 0.090) approaching normal with DBS ON. Saccade latency was unaffected.ConclusionsSTN stimulation from DBS alone significantly improved both smooth pursuit and saccade performance in patients with PD. The STN stimulation enhancement found for oculomotor performance suggests clear positive implications for patients’ ability to perform tasks that rely on visual motor control and visual feedback. The new oculomotor analysis methods provide a sensitive vehicle to detect subtle pathological modifications from PD and the functional enhancements produced by STN stimulation from DBS alone.

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Section: Discussionmentioning

confidence: 99%

Subthalamic deep brain stimulation improves smooth pursuit and saccade performance in patients with Parkinson’s disease

Nilsson

Patel

Rehncrona

et al. 2013

J NeuroEngineering Rehabil

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“…For example, the perception of ambiguous motion in Ternus displays is biased by object shape and even by semantic properties (Kramer & Rudd, 1999;Shechter, Hochstein, & Hillman, 1988;Yu, 2000). Similarly, the perception of object continuity in the stream/bounce paradigm is also influenced by shape and other object properties (Caplovitz, Shapiro, & Stroud, 2011;Feldman & Tremoulet, 2006;Kawachi, Kawabe, & Gyoba, 2011). Presumably, these types of sensory memory help to ensure object persistence when visibility is interrupted due to occlusion (Flombaum & Scholl, 2006;Hollingworth & Franconeri, 2009) or during eye movements (Richard et al, 2008;Tas et al, 2012).…”

Section: Related Forms Of Sensory Memorymentioning

confidence: 99%

“…For example, in the case of ambiguous object translation (streaming/bouncing), object size, color, or luminance are just as disambiguating as object shape (Caplovitz et al, 2011;Feldman & Tremoulet, 2006;Kawachi et al, 2011).…”

Section: Related Forms Of Sensory Memorymentioning

confidence: 99%

Sensory memory of structure-from-motion is shape-specific

Pastukhov¹,

Füllekrug²,

Braun³

2013

Atten Percept Psychophys

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Perceptual priming can stabilize the phenomenal appearance of multistable visual displays (Leopold, Wilke, Maier, & Logothetis, Nature Neuroscience, 5, 605-609, 2002). Prior exposure to such displays induces a sensory memory of their appearance, which persists over long intervals and intervening stimulation, and which facilitates renewed perception of the same appearance. Here, we investigated perceptual priming for the apparent rotation in depth of ambiguous structure-from-motion (SFM) displays. Specifically, we generated SFM objects with different threedimensional shapes and presented them in random order and with intervening blank periods. To assess perceptual priming, we established the probability that a perceived direction of rotation would persist between successive objects. In general, persistence was greatest between identical objects, intermediate between similar objects, and negligible between dissimilar objects. These results demonstrate unequivocally that sensory memory for apparent rotation is specific to three-dimensional shape, contrary to previous reports (e.g., Maier, Wilke, Logothetis, & Leopold, Current Biology, 13, 1076-1085. Because persistence did not depend on presentation order for any pair of objects, it provides a commutative measure for the similarity of object shapes. However, it is not clear exactly which features or aspects of object shape determine similarity. At least, we did not find simple, low-level features (such as volume overlap, heterogeneity, or rotational symmetry) that could have accounted for all observations. Accordingly, it seems that sensory memory of SFM (which underlies priming of ambiguous rotation) engages higher-level representations of object surface and shape.

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“…Flombaum, Scholl, and Pylyshyn (2008) found that an object’s spatial extent was maintained during occlusion using a dot probe task during multiple object tracking. Similarity and dissimilarity between object features can also determine their degree of binding to objects, suggesting that features are actively being represented (Caplovitz, Shaprio, and Stroud 2011; Hein and Moore 2012). Feature-based grouping can also occur during multiple object tracking and is sometimes used automatically by the visual system to either facilitate or hurt tracking performance (Erlikhman, Keane, Mettler, Horowitz, and Kellman 2013; Keane, Mettler, Tsoi, and Kellman 2011).…”

Section: Introductionmentioning

confidence: 99%

Decoding information about dynamically occluded objects in visual cortex

Erlikhman

Caplovitz

2017

NeuroImage

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During dynamic occlusion, an object passes behind an occluding surface and then later reappears. Even when completely occluded from view, such objects are experienced as continuing to exist or persist behind the occluder, even though they are no longer visible. The contents and neural basis of this persistent representation remain poorly understood. Questions remain as to whether there is information maintained about the object itself (i.e. its shape or identity) or, non-object-specific information such as its position or velocity as it is tracked behind an occluder as well as which areas of visual cortex represent such information. Recent studies have found that early visual cortex is activated by “invisible” objects during visual imagery and by unstimulated regions along the path of apparent motion, suggesting that some properties of dynamically occluded objects may also be neurally represented in early visual cortex. We applied functional magnetic resonance imaging in human subjects to examine the representation of information within visual cortex during dynamic occlusion. For gradually occluded, but not for instantly disappearing objects, there was an increase in activity in early visual cortex (V1, V2, and V3). This activity was spatially-specific, corresponding to the occluded location in the visual field. However, the activity did not encode enough information about object identity to discriminate between different kinds of occluded objects (circles vs. stars) using MVPA. In contrast, object identity could be decoded in spatially-specific subregions of higher-order, topographically organized areas such as ventral, lateral, and temporal occipital areas (VO, LO, and TO) as well as the functionally defined LOC and hMT+. These results suggest that early visual cortex may represent the dynamically occluded object’s position or motion path, while later visual areas represent object-specific information.

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The maintenance and disambiguation of object representations depend upon feature contrast within and between objects

Cited by 18 publications

References 49 publications

Subthalamic deep brain stimulation improves smooth pursuit and saccade performance in patients with Parkinson’s disease

Subthalamic deep brain stimulation improves smooth pursuit and saccade performance in patients with Parkinson’s disease

Sensory memory of structure-from-motion is shape-specific

Decoding information about dynamically occluded objects in visual cortex

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