Freely Moving Visuomotor Learning Assay with Reversal Learning v1

2022 ◽  
Author(s):  
Constantinos Eleftheriou
Keyword(s):  
Reversal Learning ◽  
Visual Stimulus ◽  
Visual Stimuli ◽  
Visuomotor Learning ◽  
Water Reward ◽  
Motor Strategy ◽  
Freely Moving

The goal of this protocol is to assess visuomotor learning and motor flexibility in freely-moving mice, using the Visiomode touchscreen platform. Water-restricted mice first learn to associate touching a visual stimulus on the screen with a water reward. They then learn to discriminate between different visual stimuli on the touchscreen by nose-poking, before asked to switch their motor strategy to forelimb reaching.

Freely Moving Visual Discrimination Assay with Visiomode v2

2021 ◽  
Author(s):  
Constantinos Eleftheriou
Keyword(s):  
Citric Acid ◽  
Visual Stimulus ◽  
Visual Discrimination ◽  
Water Deprivation ◽  
Visual Stimuli ◽  
Water Restriction ◽  
Visuomotor Learning ◽  
Water Reward ◽  
Motor Strategy ◽  
Freely Moving

The goal of this protocol is to assess visuomotor learning and motor flexibility in freely-moving mice, using the Visiomode touchscreen platform. Water-restricted mice first learn to associate touching a visual stimulus on the screen with a water reward. They then learn to discriminate between different visual stimuli on the touchscreen by nose-poking, before asked to switch their motor strategy to forelimb reaching. Version 1 of the protocol uses traditional water deprivation and water rewards in the task as a means of motivating mice to perform the task. Version 2 of the protocol uses Citric Acid for water restriction and sucrose as rewards in the task instead of the traditional water deprivation protocol.

Freely Moving Visual Discrimination Assay with Visiomode v2

2021 ◽  
Author(s):  
Constantinos Eleftheriou
Keyword(s):  
Visual Stimulus ◽  
Visual Discrimination ◽  
Visual Stimuli ◽  
Visuomotor Learning ◽  
Water Reward ◽  
Motor Strategy ◽  
Freely Moving

The goal of this protocol is to assess visuomotor learning and motor flexibility in freely-moving mice, using the Visiomode touchscreen platform. Water-restricted mice first learn to associate touching a visual stimulus on the screen with a water reward. They then learn to discriminate between different visual stimuli on the touchscreen by nose-poking, before asked to switch their motor strategy to forelimb reaching.

Freely Moving Visuomotor Learning Assay with Reversal Learning v2

2022 ◽  
Author(s):  
Constantinos Eleftheriou
Keyword(s):  
Reversal Learning ◽  
Visuomotor Learning ◽  
Learning Paradigm ◽  
Last Stage ◽  
Freely Moving

The goal of this protocol is to assess visuomotor learning and motor flexibility in freely-moving mice, using the Visiomode touchscreen platform. It modifies the original protocol's (dx.doi.org/10.17504/protocols.io.bumgnu3w) last stage by replacing forelimb reaching with a reversal learning paradigm

Activity of single neurons in the monkey amygdala during performance of a visual discrimination task

1992 ◽  
Vol 67 (6) ◽  
pp. 1447-1463 ◽  
Author(s):  
K. Nakamura ◽  
A. Mikami ◽  
K. Kubota
Keyword(s):  
Visual Stimulus ◽  
Visual Discrimination ◽  
Discrimination Task ◽  
Discharge Rate ◽  
Visual Stimuli ◽  
Delay Period ◽  
Visual Discrimination Task ◽  
Single Neurons ◽  
Visual Neurons ◽  
Human Faces

1. The activity of single neurons was recorded extracellularly from the monkey amygdala while monkeys performed a visual discrimination task. The monkeys were trained to remember a visual stimulus during a delay period (0.5-3.0 s), to discriminate a new visual stimulus from the stimulus, and to release a lever when the new stimulus was presented. Colored photographs (human faces, monkeys, foods, and nonfood objects) or computer-generated two-dimensional shapes (a yellow triangle, a red circle, etc.) were used as visual stimuli. 2. The activity of 160 task-related neurons was studied. Of these, 144 (90%) responded to visual stimuli, 13 (8%) showed firing during the delay period, and 9 (6%) responded to the reward. 3. Task-related neurons were categorized according to the way in which various stimuli activated the neurons. First, to evaluate the proportion of all tested stimuli that elicited changes in activity of a neuron, selectivity index 1 (SI1) was employed. Second, to evaluate the ability of a neuron to discriminate a stimulus from another stimulus, SI2 was employed. On the basis of the calculated values of SI1 and SI2, neurons were classified as selective and nonselective. Most visual neurons were categorized as selective (131/144), and a few were characterized as nonselective (13/144). Neurons active during the delay period were also categorized as selective visual and delay neurons (6/13) and as nonselective delay neurons (7/13). 4. Responses of selective visual neurons had various temporal and stimulus-selective properties. Latencies ranged widely from 60 to 300 ms. Response durations also ranged widely from 20 to 870 ms. When the natures of the various effective stimuli were studied for each neuron, one-fourth of the responses of these neurons were considered to reflect some categorical aspect of the stimuli, such as human, monkey, food, or nonfood object. Furthermore, the responses of some neurons apparently reflected a certain behavioral significance of the stimuli that was separate from the task, such as the face of a particular person, smiling human faces, etc. 5. Nonselective visual neurons responded to a visual stimulus, regardless of its nature. They also responded in the absence of a visual stimulus when the monkey anticipated the appearance of the next stimulus. 6. Selective visual and delay neurons fired in response to particular stimuli and throughout the subsequent delay periods. Nonselective delay neurons increased their discharge rates gradually during the delay period, and the discharge rate decreased after the next stimulus was presented. 7. Task-related neurons were identified in six histologically distinct nuclei of the amygdala.(ABSTRACT TRUNCATED AT 400 WORDS)

Receiver operating characteristic (ROC) analysis of neurons in the cat's lateral geniculate nucleus during tonic and burst response mode

1995 ◽  
Vol 12 (4) ◽  
pp. 723-741 ◽  
Author(s):  
W. Guido ◽  
S.-M. Lu ◽  
J.W. Vaughan ◽  
Dwayne W. Godwin ◽  
S. Murray Sherman
Keyword(s):  
Visual Stimulus ◽  
Action Potentials ◽  
Operating Characteristic ◽  
Visual Stimuli ◽  
Roc Curves ◽  
Response Mode ◽  
Burst Mode ◽  
Low Threshold Spike ◽  
Low Threshold ◽  
Roc Area

AbstractRelay cells of the lateral geniculate nucleus respond to visual stimuli in one of two modes: burst and tonic. The burst mode depends on the activation of a voltage-dependent, Ca2+ conductance underlying the low threshold spike. This conductance is inactivated at depolarized membrane potentials, but when activated from hyperpolarized levels, it leads to a large, triangular, nearly all-or-none depolarization. Typically, riding its crest is a high-frequency barrage of action potentials. Low threshold spikes thus provide a nonlinear amplification allowing hyperpolarized relay neurons to respond to depolarizing inputs, including retinal EPSPs. In contrast, the tonic mode is characterized by a steady stream of unitary action potentials that more linearly reflects the visual stimulus. In this study, we tested possible differences in detection between response modes of 103 geniculate neurons by constructing receiver operating characteristic (ROC) curves for responses to visual stimuli (drifting sine-wave gratings and flashing spots). Detectability was determined from the ROC curves by computing the area under each curve, known as the ROC area. Most cells switched between modes during recording, evidently due to small shifts in membrane potential that affected the activation state of the low threshold spike. We found that the more often a cell responded in burst mode, the larger its ROC area. This was true for responses to optimal and nonoptimal visual stimuli, the latter including nonoptimal spatial frequencies and low stimulus contrasts. The larger ROC areas associated with burst mode were due to a reduced spontaneous activity and roughly equivalent level of visually evoked response when compared to tonic mode. We performed a within-cell analysis on a subset of 22 cells that switched modes during recording. Every cell, whether tested with a low contrast or high contrast visual stimulus exhibited a larger ROC area during its burst response mode than during its tonic mode. We conclude that burst responses better support signal detection than do tonic responses. Thus, burst responses, while less linear and perhaps less useful in providing a detailed analysis of visual stimuli, improve target detection. The tonic mode, with its more linear response, seems better suited for signal analysis rather than signal detection.

Motor intention activity in the macaque's lateral intraparietal area. I. Dissociation of motor plan from sensory memory

1996 ◽  
Vol 76 (3) ◽  
pp. 1439-1456 ◽  
Author(s):  
P. Mazzoni ◽  
R. M. Bracewell ◽  
S. Barash ◽  
R. A. Andersen
Keyword(s):  
Eye Movements ◽  
Visual Stimulus ◽  
Visual Stimuli ◽  
Saccadic Eye Movements ◽  
Stimulus Location ◽  
Sensory Memory ◽  
Lateral Intraparietal Area ◽  
Preferred Direction ◽  
Motor Plan ◽  
Stimulation Of

1. The lateral intraparietal area (area LIP) of the monkey's posterior parietal cortex (PPC) contains neurons that are active during saccadic eye movements. These neurons' activity includes visual and saccade-related components. These responses are spatially tuned and the location of a neuron's visual receptive field (RF) relative to the fovea generally overlaps its preferred saccade amplitude and direction (i.e., its motor field, MF). When a delay is imposed between the presentation of a visual stimulus and a saccade made to its location (memory saccade task), many LIP neurons maintain elevated activity during the delay (memory activity, M), which appears to encode the metrics of the next intended saccadic eye movements. Recent studies have alternatively suggested that LIP neurons encode the locations of visual stimuli regardless of where the animal intends to look. We examined whether the M activity of LIP neurons specifically encodes movement intention or the locations of recent visual stimuli, or a combination of both. In the accompanying study, we investigated whether the intended-movement activity reflects changes in motor plan. 2. We trained monkeys (Macaca mulatta) to memorize the locations of two visual stimuli and plan a sequence of two saccades, one to each remembered target, as we recorded the activity of single LIP neurons. Two targets were flashed briefly while the monkey maintained fixation; after a delay the fixation point was extinguished, and the monkey made two saccades in sequence to each target's remembered location, in the order in which the targets were presented. This "delayed double saccade" (DDS) paradigm allowed us to dissociate the location of visual stimulation from the direction of the planned saccade and thus distinguish neuronal activity related to the target's location from activity related to the saccade plan. By imposing a delay, we eliminated the confounding effect of any phasic responses coincident with the appearance of the stimulus and with the saccade. 3. We arranged the two visual stimuli so that in one set of conditions at least the first one was in the neuron's visual RF, and thus the first saccade was in the neuron's motor field (MF). M activity should be high in these conditions according to both the sensory memory and motor plan hypotheses. In another set of conditions, the second stimulus appeared in the RF but the first one was presented outside the RF, instructing the monkey to plan the first saccade away from the neuron's MF. If the M activity encodes the motor plan, it should be low in these conditions, reflecting the plan for the first saccade (away from the MF). If it is a sensory trace of the stimulus' location, it should be high, reflecting stimulation of the RF by the second target. 4. We tested 49 LIP neurons (in 3 hemispheres of 2 monkeys) with M activity on the DDS task. Of these, 38 (77%) had M activity related to the next intended saccade. They were active in the delay period, as expected, if the first saccade was in their preferred direction. They were less active or silent if the next saccade was not in their preferred direction, even when the second stimulus appeared in their RF. 5. The M activity of 8 (16%) of the remaining neurons specifically encoded the location of the most recent visual stimulus. Their firing rate during the delay reflected stimulation of the RF independently of the saccade being planned. The remaining 3 neurons had M activity that did not consistently encode either the next saccade or the stimulus' location. 6. We also recorded the activity of a subset of neurons (n = 38) in a condition in which no stimulus appeared in a neuron's RF, but the second saccade was in the neuron's MF. In this case the majority of neurons tested (23/38, 60%) became active in the period between the first and second saccade, even if neither stimulus had appeared in their RF. Moreover, this activity appeared only after the first saccade had started in all but two of

scholarly journals Comparative analysis of reactions to visual and auditory stimuli in research on EEG evoked potentials

2018 ◽  
Vol 7 ◽  
pp. 172-177
Author(s):  
Łukasz Tyburcy ◽  
Małgorzata Plechawska-Wójcik
Keyword(s):  
Comparative Analysis ◽  
Evoked Potentials ◽  
Auditory Stimulus ◽  
Visual Stimulus ◽  
Visual Stimuli ◽  
Reaction Times ◽  
Auditory Stimuli

The paper describes results of comparison of reactions times to visual and auditory stimuli using EEG evoked potentials. Two experiments were used to applied. The first one explored reaction times to visual stimulus and the second one to auditory stimulus. After conducting an analysis of data, received results enable determining that visual stimuli evoke faster reactions than auditory stimuli.

scholarly journals Visuo-proprioceptive integration and recalibration with multiple visual stimuli

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nienke B. Debats ◽  
Herbert Heuer ◽  
Christoph Kayser
Keyword(s):  
Visual Stimulus ◽  
Hand Movement ◽  
Sensory Modality ◽  
Visual Stimuli ◽  
Multisensory Perception ◽  
Proprioceptive Information ◽  
Additional Information ◽  
Cursor Control ◽  
Sensory Recalibration ◽  
Winner Takes All

AbstractTo organize the plethora of sensory signals from our environment into a coherent percept, our brain relies on the processes of multisensory integration and sensory recalibration. We here asked how visuo-proprioceptive integration and recalibration are shaped by the presence of more than one visual stimulus, hence paving the way to study multisensory perception under more naturalistic settings with multiple signals per sensory modality. We used a cursor-control task in which proprioceptive information on the endpoint of a reaching movement was complemented by two visual stimuli providing additional information on the movement endpoint. The visual stimuli were briefly shown, one synchronously with the hand reaching the movement endpoint, the other delayed. In Experiment 1, the judgments of hand movement endpoint revealed integration and recalibration biases oriented towards the position of the synchronous stimulus and away from the delayed one. In Experiment 2 we contrasted two alternative accounts: that only the temporally more proximal visual stimulus enters integration similar to a winner-takes-all process, or that the influences of both stimuli superpose. The proprioceptive biases revealed that integration—and likely also recalibration—are shaped by the superposed contributions of multiple stimuli rather than by only the most powerful individual one.

scholarly journals Pure tones modulate the representation of orientation and direction in the primary visual cortex

2019 ◽  
Vol 121 (6) ◽  
pp. 2202-2214 ◽  
Author(s):  
John P. McClure ◽  
Pierre-Olivier Polack
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Stimulus ◽  
Visual Stimuli ◽  
Direction Selectivity ◽  
Multimodal Integration ◽  
Visual Responses ◽  
V1 Neurons ◽  
Pure Tones ◽  
The Impact

Multimodal sensory integration facilitates the generation of a unified and coherent perception of the environment. It is now well established that unimodal sensory perceptions, such as vision, are improved in multisensory contexts. Whereas multimodal integration is primarily performed by dedicated multisensory brain regions such as the association cortices or the superior colliculus, recent studies have shown that multisensory interactions also occur in primary sensory cortices. In particular, sounds were shown to modulate the responses of neurons located in layers 2/3 (L2/3) of the mouse primary visual cortex (V1). Yet, the net effect of sound modulation at the V1 population level remained unclear. In the present study, we performed two-photon calcium imaging in awake mice to compare the representation of the orientation and the direction of drifting gratings by V1 L2/3 neurons in unimodal (visual only) or multimodal (audiovisual) conditions. We found that sound modulation depended on the tuning properties (orientation and direction selectivity) and response amplitudes of V1 L2/3 neurons. Sounds potentiated the responses of neurons that were highly tuned to the cue’s orientation and direction but weakly active in the unimodal context, following the principle of inverse effectiveness of multimodal integration. Moreover, sound suppressed the responses of neurons untuned for the orientation and/or the direction of the visual cue. Altogether, sound modulation improved the representation of the orientation and direction of the visual stimulus in V1 L2/3. Namely, visual stimuli presented with auditory stimuli recruited a neuronal population better tuned to the visual stimulus orientation and direction than when presented alone. NEW & NOTEWORTHY The primary visual cortex (V1) receives direct inputs from the primary auditory cortex. Yet, the impact of sounds on visual processing in V1 remains controverted. We show that the modulation by pure tones of V1 visual responses depends on the orientation selectivity, direction selectivity, and response amplitudes of V1 neurons. Hence, audiovisual stimuli recruit a population of V1 neurons better tuned to the orientation and direction of the visual stimulus than unimodal visual stimuli.

Neurons in the cat pretectum that project to the dorsal lateral geniculate nucleus are activated during saccades

1996 ◽  
Vol 76 (5) ◽  
pp. 2907-2918 ◽  
Author(s):  
M. Schmidt
Keyword(s):  
Eye Movements ◽  
Lateral Geniculate Nucleus ◽  
Visual Stimulus ◽  
Visual Stimuli ◽  
Saccadic Eye Movements ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Response Latencies ◽  
Retinal Slip ◽  
Response Properties ◽  
Dorsal Lateral Geniculate

1. Neurons in the pretectal nuclear complex that project to the ipsilateral dorsal lateral geniculate nucleus (LGNd) were identified by antidromic activation after electrical LGNd stimulation in awake cats, and their response properties were characterized to retinal image shifts elicited either by external visual stimulus movements or during spontaneous saccadic eye movements on a stationary visual stimulus, and to saccades in darkness. Eye position was monitored with the use of a scleral search coil and care was taken to assure stability of the eyes during presentation of moving visual stimuli. 2. Of a total sample of 134 cells recorded, 27 neurons were antidromically activated by electrical LGNd stimulation. In addition, responses from neurons that were not activated from the LGNd were also analyzed, including 19 “retinal slip” cells, which selectively respond to slow horizontal stimulus movements, and 21 “jerk” cells, which are specifically activated by rapid stimulus shifts. All recorded neurons were located in the nucleus of the optic tract and in the posterior pretectal nucleus. 3. In the light, neurons identified as projecting to the LGNd responded maximally to saccadic eye movements and to externally generated sudden shifts of large visual stimuli. Slow stimulus drifts did not activate these neurons. Response latencies were shorter and peak activities were increased during saccades compared with pure visual stimulation. No systematic correlation between response latency, response duration, or the number of spikes in the response and saccade direction, saccade amplitude, or saccade duration was found. Saccades and rapid stimulus shifts in the light also activated jerk cells but not retinal slip cells. 4. All 27 antidromically activated neurons also responded to spontaneous saccadic eye movements in complete darkness. Responses to saccades in the dark, however, had longer response latencies and lower peak activities than responses to saccades in light. As in the light, response parameters in darkness seemed not to code specific saccade parameters. Cells that were not activated from LGNd were found to be unresponsive to saccades in the dark. 5. According to their specific activation by saccades in darkness, LGNd-projecting pretectal neurons are termed “saccade neurons” to distinguish them from other pretectal cell populations, in particular from jerk neurons, which show similar response properties in light. 6. The saccade-related activation of pretectal saccade neurons may be used to modulate visual responses of LGNd relay cells following saccadic eye movements. Because the pretectogeniculate projection in cat most likely is GABAergic and terminates on inhibitory LGNd interneurons, its activation may lead to a saccade-locked disinhibition of relay cells. This input could counter the strong inhibition induced in the LGNd after shifts of gaze direction and lead to a resetting of LGNd cell activity.

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