Visually guided pointing movements are driven by the salience map

M. Zehetleitner; M. Hegenloh; H. J. Muller

doi:10.1167/11.1.24

Preferential activity of dentate neurons during limb movements guided by vision

Journal of Neurophysiology ◽

10.1152/jn.1993.70.6.2660 ◽

1993 ◽

Vol 70 (6) ◽

pp. 2660-2664 ◽

Cited By ~ 63

Author(s):

H. Mushiake ◽

P. L. Strick

Keyword(s):

Reaction Time ◽

Visual Cues ◽

Dentate Nucleus ◽

Tracking Task ◽

Visually Guided ◽

Peak Activity ◽

Light Emitting ◽

Pointing Movements ◽

Task Conditions ◽

Exclusive Or

1. We recorded the activity of dentate neurons while monkeys (n = 2) performed sequential pointing movements under two task conditions: visually guided and remembered. For both conditions, a monkey faced a panel with five touch pads. The animal began a trial by placing his right hand on a hold key in front of him. In the Remembered Sequence Task, light-emitting diodes (LEDs) over three touch pads were illuminated in a sequence as an instruction to the monkey. At the end of a variable instruction period, an auditory “Go” signal told the monkey to release the hold key and press the touch pads according to the instructed sequence. In the Tracking Task, the monkey was required to press three touch pads immediately after the LED over each of them was illuminated. 2. We recorded from 172 neurons in the dentate that showed task-related changes in activity during the reaction time (RT) period (i.e., the interval between the onset of the Go signal and the release of the hold key). Approximately 40% of these neurons were considered task-dependent because they displayed exclusive or enhanced (> +/- 50%) changes in peak activity during the RT period for one of the two task conditions. Almost 80% of the task-dependent neurons displayed exclusive or enhanced activity changes during the Tracking Task. Many of these neurons were located ventral and lateral to dentate neurons, which were not task-dependent. 3. These results suggest that a portion of the dentate nucleus is preferentially involved in the generation and/or guidance of movement based on visual cues.(ABSTRACT TRUNCATED AT 250 WORDS)

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Detection and costs of force perturbations during visually-guided pointing movements

Journal of Vision ◽

10.1167/5.8.625 ◽

2010 ◽

Vol 5 (8) ◽

pp. 625-625

Author(s):

K. Drewing ◽

J. Trommershaeuser

Keyword(s):

Visually Guided ◽

Pointing Movements

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Hemispheric Asymmetry in the Remapping and Maintenance of Visual Saliency Maps: A TMS Study

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2009.21356 ◽

2010 ◽

Vol 22 (8) ◽

pp. 1730-1738 ◽

Cited By ~ 43

Author(s):

Martijn Gerbrand van Koningsbruggen ◽

Shai Gabay ◽

Ayelet Sapir ◽

Avishai Henik ◽

Robert D. Rafal

Keyword(s):

Parietal Cortex ◽

Hemispheric Asymmetry ◽

Inhibition Of Return ◽

Visual Experience ◽

Visual Saliency ◽

Visually Guided ◽

Saliency Maps ◽

Neural Substrate ◽

Manual Reaction Time ◽

Salience Map

Parietal cortex has been implicated in the updating, after eye movements, of a salience map that is required for coherent visual experience and for the control of visually guided behavior. The current experiment investigated whether TMS over anterior intraparietal cortex (AIPCx), just after a saccade, would affect the ability to update and maintain a salience map. In order to generate a salience map, we employed a paradigm in which an uninformative cue was presented at one object in a display to generate inhibition of return (IOR)—an inhibitory tag that renders the cued object less salient than others in the display, and that slows subsequent responses to visual transients at its location. Following the cue, participants made a saccade to either left or right, and we then probed for updating of the location of IOR by measuring manual reaction time to targets appearing at cued location of the cued compared to an uncued object. Between the time of saccade initiation and target appearance, dual-pulse TMS was targeted over right (Experiment 1) or left AIPCx (Experiment 2), and a vertex control side. Updating of the location of IOR was eliminated by TMS over right, but not the left, AIPCx, suggesting that right parietal cortex is involved in the remapping of IOR. Remapping was eliminated by right AIPCx, regardless of whether the saccade was made to the left (contralateral), or right (ipsilateral) visual field, and regardless of which field the target appeared in. We conclude that right AIPCx is the neural substrate for maintaining a salience map across saccades, and not simply for propagating an efference copy of saccade commands.

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