scholarly journals A spatial memory signal shows that the parietal cortex has access to a craniotopic representation of space

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Mulugeta Semework ◽  
Sara C Steenrod ◽  
Michael E Goldberg
Keyword(s):  
Spatial Memory ◽  
Parietal Cortex ◽  
Receptive Fields ◽  
Spatial Location ◽  
Visual Response ◽  
Lateral Intraparietal Area ◽  
Memory Response ◽  
Representation Of Space ◽  
Present Trial

Humans effortlessly establish a gist-like memory of their environment whenever they enter a new place, a memory that can guide action even in the absence of vision. Neurons in the lateral intraparietal area (LIP) of the monkey exhibit a form of this environmental memory. These neurons respond when a monkey makes a saccade that brings the spatial location of a stimulus that appeared on a number of prior trials, but not on the present trial, into their receptive fields (RFs). The stimulus need never have appeared in the neuron’s RF. This memory response is usually weaker, with a longer latency than the neuron’s visual response. We suggest that these results demonstrate that LIP has access to a supraretinal memory of space, which is activated when the spatial location of the vanished stimulus can be described by a retinotopic vector from the center of gaze to the remembered spatial location.

scholarly journals A spatial memory signal shows that the parietal cortex has access to a craniotopic representation of space

2017 ◽  
Author(s):  
Mulugeta Semework ◽  
Sara C. Steenrod ◽  
Michael E. Goldberg
Keyword(s):  
Receptive Field ◽  
Spatial Memory ◽  
Parietal Cortex ◽  
Receptive Fields ◽  
Spatial Location ◽  
Visual Response ◽  
Lateral Intraparietal Area ◽  
Representation Of Space ◽  
Present Trial

Humans effortlessly establish a gist-like memory of their environment whenever they enter a new place. They can then use this memory to guide action even in the absence of vision. Neurons in the lateral intraparietal area (LIP) of the monkey exhibit a form of this environmental memory, responding when a monkey makes a saccade that brings the spatial location of a stimulus that appeared on a number of prior trials, but not on the present trial into their receptive fields. The stimulus need never have appeared in the receptive field of the neuron. This response is usually weaker with a longer latency than the neuron's visual response. We suggest that these results demonstrate that LIP has access to a craniotopic memory of space, which is activated when the spatial location of the vanished stimulus can be described by a retinotopic vector from the center of gaze to the stimulus.

Nonspatial Saccade-Specific Activation in area LIP of Monkey Parietal Cortex

2003 ◽  
Vol 90 (4) ◽  
pp. 2460-2464 ◽  
Author(s):  
A. R. Dickinson ◽  
J. L. Calton ◽  
L. H. Snyder
Keyword(s):  
Signal Processing ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Motor Task ◽  
Dorsal Stream ◽  
Spatial Location ◽  
Visually Guided ◽  
Lateral Intraparietal Area ◽  
Present Evidence ◽  
Posterior Parietal

We present evidence that neurons in the lateral intraparietal area (LIP) of monkey posterior parietal cortex (PPC) are activated by the instruction to make an eye movement, even in the complete absence of a spatial target. This study employed a visually guided motor task that dissociated the type of movement to make (saccade or reach) from the location where the movement was to be made. Using this task, animals were instructed to prepare a specific type of movement prior to knowing the spatial location of the movement target. We found that 25% of the LIP neurons recorded in two animals were activated significantly more by the instruction to prepare a saccade than by the instruction to prepare a reach. This finding indicates that LIP is involved in more than merely spatial attention and provides further evidence for nonspatial effector-specific signal processing in the dorsal stream.

The Time Course of Perisaccadic Receptive Field Shifts in the Lateral Intraparietal Area of the Monkey

2003 ◽  
Vol 89 (3) ◽  
pp. 1519-1527 ◽  
Author(s):  
Makoto Kusunoki ◽  
Michael E. Goldberg
Keyword(s):  
Receptive Field ◽  
Time Course ◽  
Receptive Fields ◽  
Irrelevant Stimulus ◽  
Spatial Location ◽  
Field Size ◽  
Lateral Intraparietal Area ◽  
Significant Decrement ◽  
The Future ◽  
Field Shift

Neurons in the lateral intraparietal area of the monkey (LIP) have visual receptive fields in retinotopic coordinates when studied in a fixation task. However, in the period immediately surrounding a saccade these receptive fields often shift, so that a briefly flashed stimulus outside the receptive field will drive the neurons if the eye movement will bring the spatial location of that vanished stimulus into the receptive field. This is equivalent to a transient shift of the retinal receptive field. The process enables the monkey brain to process a stimulus in a spatially accurate manner after a saccade, even though the stimulus appeared only before the saccade. We studied the time course of this receptive field shift by flashing a task-irrelevant stimulus for 100 ms before, during, or after a saccade. The stimulus could appear in receptive field as defined by the fixation before the saccade (the current receptive field) or the receptive field as defined by the fixation after the saccade (the future receptive field). We recorded the activity of 48 visually responsive neurons in LIP of three hemispheres of two rhesus monkeys. We studied 45 neurons in the current receptive field task, in which the saccade removed the stimulus from the receptive field. Of these neurons 29/45 (64%) showed a significant decrement of response when the stimulus appeared 250 ms or less before the saccade, as compared with their activity during fixation. The average response decrement was 38% for those cells showing a significant ( P < 0.05 by t-test) decrement. We studied 39 neurons in the future receptive field task, in which the saccade brought the spatial location of a recently vanished stimulus into the receptive field. Of these 32/39 (82%) had a significant response to stimuli flashed for 100 ms in the future receptive field, even 400 ms before the saccade. Neurons never responded to stimuli moved by the saccade from a point outside the receptive field to another point outside the receptive field. Neurons did not necessarily show any saccadic suppression for stimuli moved from one part of the receptive field to another by the saccade. Stimuli flashed <250 ms before the saccade-evoked responses in both the presaccadic and the postsaccadic receptive fields, resulting in an increase in the effective receptive field size, an effect that we suggest is responsible for perisaccadic perceptual inaccuracies.

Neural Representation of Space Using Sinusoidal Arrays

1993 ◽  
Vol 5 (6) ◽  
pp. 869-884 ◽  
Author(s):  
David S. Touretzky ◽  
A. David Redish ◽  
Hank S. Wan
Keyword(s):  
Computer Simulations ◽  
Parietal Cortex ◽  
Spatial Information ◽  
Sine Wave ◽  
Spiking Neurons ◽  
Neural Representation ◽  
Temporal Dimension ◽  
Response Properties ◽  
Representation Of Space

O'Keefe (1991) has proposed that spatial information in rats might be represented as phasors: phase and amplitude of a sine wave encoding angle and distance to a landmark. We describe computer simulations showing that operations on phasors can be efficiently realized by arrays of spiking neurons that recode the temporal dimension of the sine wave spatially. Some cells in motor and parietal cortex exhibit response properties compatible with this proposal.

scholarly journals Change in Motor Plan, Without a Change in the Spatial Locus of Attention, Modulates Activity in Posterior Parietal Cortex

1998 ◽  
Vol 79 (5) ◽  
pp. 2814-2819 ◽  
Author(s):  
Lawrence H. Snyder ◽  
Aaron P. Batista ◽  
Richard A. Andersen
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Macaque Monkey ◽  
Case Control ◽  
Visually Guided ◽  
Lateral Intraparietal Area ◽  
Central Target ◽  
Motor Plan ◽  
Motor Intention ◽  
Posterior Parietal

Snyder, Lawrence H., Aaron P. Batista, and Richard A. Andersen. Change in motor plan, without a change in the spatial locus of attention, modulates activity in posterior parietal cortex. J. Neurophysiol. 79: 2814–2819, 1998. The lateral intraparietal area (LIP) of macaque monkey, and a parietal reach region (PRR) medial and posterior to LIP, code the intention to make visually guided eye and arm movements, respectively. We studied the effect of changing the motor plan, without changing the locus of attention, on single neurons in these two areas. A central target was fixated while one or two sequential flashes occurred in the periphery. The first appeared either within the response field of the neuron being recorded or else on the opposite side of the fixation point. Animals planned a saccade (red flash) or reach (green flash) to the flash location. In some trials, a second flash 750 ms later could change the motor plan but never shifted attention: second flashes always occurred at the same location as the preceding first flash. Responses in LIP were larger when a saccade was instructed ( n = 20 cells), whereas responses in PRR were larger when a reach was instructed ( n = 17). This motor preference was observed for both first flashes and second flashes. In addition, the response to a second flash depended on whether it affirmed or countermanded the first flash; second flash responses were diminished only in the former case. Control experiments indicated that this differential effect was not due to stimulus novelty. These findings support a role for posterior parietal cortex in coding specific motor intention and are consistent with a possible role in the nonspatial shifting of motor intention.

Context dependence of receptive field remapping in superior colliculus

2011 ◽  
Vol 106 (4) ◽  
pp. 1862-1874 ◽  
Author(s):  
Jan Churan ◽  
Daniel Guitton ◽  
Christopher C. Pack
Keyword(s):  
Receptive Field ◽  
Superior Colliculus ◽  
Visual Stimulation ◽  
Receptive Fields ◽  
Spatial Location ◽  
Macaque Monkey ◽  
Visual Signals ◽  
Perceptual Stability ◽  
Visual Background ◽  
The Brain

Our perception of the positions of objects in our surroundings is surprisingly unaffected by movements of the eyes, head, and body. This suggests that the brain has a mechanism for maintaining perceptual stability, based either on the spatial relationships among visible objects or internal copies of its own motor commands. Strong evidence for the latter mechanism comes from the remapping of visual receptive fields that occurs around the time of a saccade. Remapping occurs when a single neuron responds to visual stimuli placed presaccadically in the spatial location that will be occupied by its receptive field after the completion of a saccade. Although evidence for remapping has been found in many brain areas, relatively little is known about how it interacts with sensory context. This interaction is important for understanding perceptual stability more generally, as the brain may rely on extraretinal signals or visual signals to different degrees in different contexts. Here, we have studied the interaction between visual stimulation and remapping by recording from single neurons in the superior colliculus of the macaque monkey, using several different visual stimulus conditions. We find that remapping responses are highly sensitive to low-level visual signals, with the overall luminance of the visual background exerting a particularly powerful influence. Specifically, although remapping was fairly common in complete darkness, such responses were usually decreased or abolished in the presence of modest background illumination. Thus the brain might make use of a strategy that emphasizes visual landmarks over extraretinal signals whenever the former are available.

Covert orienting of attention in macaques. II. Contributions of parietal cortex

1995 ◽  
Vol 74 (2) ◽  
pp. 698-712 ◽  
Author(s):  
D. L. Robinson ◽  
E. M. Bowman ◽  
C. Kertzman
Keyword(s):  
Reaction Time ◽  
Receptive Field ◽  
Parietal Cortex ◽  
Visual Cues ◽  
Reaction Time Task ◽  
Visual Response ◽  
Attention Task ◽  
Time Task ◽  
Visual Spatial ◽  
Visual Targets

1. To understand some of the contributions of parietal cortex to the dynamics of visual spatial attention, we recorded from cortical cells of monkeys performing attentional tasks. We studied 484 neurons in the intraparietal sulcus and adjacent gyral tissue of two monkeys. We measured phasic responses to peripheral visual stimuli while the monkeys attended toward or away from the stimuli or when attention was not controlled. Neurons were tested while the monkeys gazed at a spot of light (simple fixation task), actively attended to a foveal target (foveal attention task), performed a reaction time task (cued reaction time task), made saccadic eye movements to visual targets (saccade task), or responded to a repetitious peripheral target (probability task). 2. In a previous paper we demonstrated that monkeys, like humans, responded more quickly to visual targets when the targets followed briefly flashed visual cues (validly cued targets) (Bowman et al. 1993). It has been hypothesized that the cue attracts attention to its locus and results in faster reaction times (Posner 1980). In the present physiological studies, visual cues consistently excited these neurons when they were flashed in the receptive field. Such activity might signal a shift of attention. Visual targets that fell within the receptive field and that immediately followed the cue evoked relatively weak responses. This response was due to a relative refractory period. 3. Next we tested attentional processes in these tasks that were independent of the visual response to the cue. We placed the cue outside of the receptive field and the target within the receptive field. We found that 23% of these cells had a significant decrease in their firing rate to validly cued targets in their receptive fields under these conditions. Strong responses were evoked by the same target when the cue was flashed in the opposite hemifield (invalidly cued targets). Thus this group of neurons responded best when attention was directed toward the opposite hemifield. 4. For another group of parietal cells (13%) there was an enhanced response to targets in the visual receptive field when the cue was in the same hemifield. For the remaining 64% of the cells there was no significant modulation in this task. 5. The cued reaction time task involved exogenous control of attention; the sensory cue gave spatial and temporal direction to attention. We used several other tasks to test for endogenous control of attention.(ABSTRACT TRUNCATED AT 400 WORDS)

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