Location Of Reward Research Articles

Great apes use landmark cues over spatial relations to find hidden food

We investigated whether chimpanzees, bonobos, and orangutans encoded the location of a reward hidden underneath one of three identical cups in relation to (1) the other cups in the array-i.e., the relative position of the baited cup within the array; or (2) the landmarks surrounding the cups-e.g., the edge of the table. Apes witnessed the hiding of a food reward under one of three cups forming a straight line on a platform. After 30s, they were allowed to search for the reward. In three different experiments, we varied the distance of the cups to the edge of the platform and the distance between the cups. Results showed that both manipulated variables affected apes' retrieval accuracy. Subjects' retrieval accuracy was higher for the outer cups compared with the Middle cup, especially if the outer cups were located next to the platform's edge. Additionally, the larger the distance between the cups, the better performance became.

Effect of reward in a new localization test method for children under 5.

Absolute localization ability in children under 5 has rarely been measured. One of the reasons for this is the difficulty of keeping the child engaged long enough in the task to obtain sufficient data. This was addressed by developing an uninstructed game-like localization task in which children must find the location of sounds. Correct localization responses, defined as a head or eye movement toward the sound’s location, are reinforced with visual rewards. These are presented on video walls surrounding the child. This study investigated how varying the location of the visual reward affected the number of correct responses obtained. The study used three visual reward strategies: (I) the reward always presented at 0 deg (front), (II) the reward presented at the sound’s location, and (III) the reward varied randomly ± 20 deg about the sound’s location. Preliminary analysis of data from 24 children (15–56 months) shows a significant effect of reward strategy and age. More correct responses were generally obtained using reward strategies (II) and (III). Reward strategy (III) is preferred for use in a refined localization test because the reward is not presented at a fixed set of locations, helping to avoid visual learning of the test directions.

Advance cueing produces enhanced action-boundary patterns of spike activity in the sensorimotor striatum

One of the most characteristic features of habitual behaviors is that they can be evoked by a single cue. In the experiments reported here, we tested for the effects of such advance cueing on the firing patterns of striatal neurons in the sensorimotor striatum. Rats ran in a T-maze with instruction cues about the location of reward given at the start of the runs. This advance cueing about reward produced a highly augmented task-bracketing pattern of activity at the beginning and end of procedural task performance relative to the patterns found previously with midtask cueing. Remarkably, the largest increase in activity early during the T-maze runs was not associated with the instruction cues themselves, the earliest predictors of reward; instead, the highest peak of early activity was associated with the beginning of the motor period of the task. We suggest that the advance cueing, reducing midrun demands for decision making but adding a working-memory load, facilitated chunking of the maze runs as executable scripts anchored to sensorimotor aspects of the task and unencumbered by midtask decision-making demands. Our findings suggest that the acquisition of stronger task-bracketing patterns of striatal activity in the sensorimotor striatum could reflect this enhancement of behavioral chunking. Deficits in such representations of learned sequential behaviors could contribute to motor and cognitive problems in a range of neurological disorders affecting the basal ganglia, including Parkinson's disease.

Hippocampal Representation of Touch-Guided Behavior in Rats: Persistent and Independent Traces of Stimulus and Reward Location

Understanding the mechanisms by which sensory experiences are stored remains a compelling challenge for neuroscience. Previous work has described how the activity of neurons in the sensory cortex allows rats to discriminate the physical features of an object contacted with their whiskers. But to date there is no evidence about how neurons represent the behavioural significance of tactile stimuli, or how they are encoded in memory. To investigate these issues, we recorded single-unit firing and local field potentials from the CA1 region of hippocampus while rats performed a task in which tactile stimuli specified reward location. On each trial the rat touched a textured plate with its whiskers, and then turned towards the Left or Right water spout. Two textures were associated with each reward location. To determine the influence of the rat's position on sensory coding, we placed it on a second platform in the same room where it performed the identical texture discrimination task. Over 25 percent of the sampled neurons encoded texture identity – their firing differed for two stimuli associated with the same reward location – and over 50 percent of neurons encoded the reward location with which the stimuli were associated. The neuronal population carried texture and reward location signals continuously, from the moment of stimulus contact until the end of reward collection. The set of neurons discriminating between one texture pair was found to be independent of, and partially overlapping, the set of neurons encoding the discrimination between a different texture pair. In a given neuron, the presence of a tactile signal was uncorrelated with the presence, magnitude, or timing of reward location signals. These experiments indicate that neurons in CA1 form a texture representation independently of the action the stimulus is associated with and retain the stimulus representation through reward collection.

Ventral tegmental area disruption selectively affects CA1/CA2 but not CA3 place fields during a differential reward working memory task.

Hippocampus (HPC) receives dopaminergic (DA) projections from the ventral tegmental area (VTA) and substantia nigra. These inputs appear to provide a modulatory signal that influences HPC dependent behaviors and place fields. We examined how efferent projections from VTA to HPC influence spatial working memory and place fields when the reward context changes. CA1 and CA3 process environmental context changes differently and VTA preferentially innervates CA1. Given these anatomical data and electrophysiological evidence that implicate DA in reward processing, we predicted that CA1 place fields would respond more strongly to both VTA disruption and changes in the reward context than CA3 place fields. Rats (N = 9) were implanted with infusion cannula targeting VTA and recording tetrodes aimed at HPC. Then they were tested on a differential reward, win-shift working memory task. One recording session consisted of 5 baseline and 5 manipulation trials during which place cells in CA1/CA2 (N = 167) and CA3 (N = 94) were recorded. Prior to manipulation trials rats were infused with either baclofen or saline and then subjected to control or reward conditions during which the learned locations of large and small reward quantities were reversed. VTA disruption resulted in an increase in errors, and in CA1/CA2 place field reorganization. There were no changes in any measures of CA3 place field stability during VTA disruption. Reward manipulations did not affect performance or place field stability in CA1/CA2 or CA3; however, changes in the reward locations "rescued" performance and place field stability in CA1/CA2 when VTA activity was compromised, perhaps by trigging compensatory mechanisms. These data support the hypothesis that VTA contributes to spatial working memory performance perhaps by maintaining place field stability selectively in CA1/CA2.

Inferential reasoning by exclusion in great apes, lesser apes, and spider monkeys.

Using the cups task, in which subjects are presented with limited visual or auditory information that can be used to deduce the location of a hidden reward, Call (2004) found prima facie evidence of inferential reasoning by exclusion in several great ape species. One bonobo (Pan paniscus) and two gorillas (Gorilla gorilla) appeared to make such inferences in both the visual and auditory domains. However, common chimpanzees (Pan troglodytes) were successful only in the visual domain, and Bornean orangutans (Pongo pygmaeus) in neither. The present research built on this paradigm, and Experiment 1 yielded prima facie evidence of inference by exclusion in both domains for two common chimpanzees, and in the visual domain for two Sumatran orangutans (Pongo abelii). Experiments 2 and 3 demonstrated that two specific associative learning explanations could not readily account for these results. Because an important focus of the program of research was to assess the cognitive capacities of lesser apes (family Hylobatidae), we modified Call's original procedures to better suit their attentional and dispositional characteristics. In Experiment 1, testing was also attempted with three gibbon genera (Symphalangus, Nomascus, Hylobates), but none of the subjects completed the standard task. Further testing of three siamangs (Symphalangus syndactylus) and a spider monkey (Ateles geoffroyi) using a faster method yielded prima facie evidence of inferential reasoning by exclusion in the visual domain among the siamangs (Experiment 4).

Dopamine-Mediated Learning and Switching in Cortico-Striatal Circuit Explain Behavioral Changes in Reinforcement Learning

The basal ganglia are thought to play a crucial role in reinforcement learning. Central to the learning mechanism are dopamine (DA) D1 and D2 receptors located in the cortico-striatal synapses. However, it is still unclear how this DA-mediated synaptic plasticity is deployed and coordinated during reward-contingent behavioral changes. Here we propose a computational model of reinforcement learning that uses different thresholds of D1- and D2-mediated synaptic plasticity which are antagonized by DA-independent synaptic plasticity. A phasic increase in DA release caused by a larger-than-expected reward induces long-term potentiation (LTP) in the direct pathway, whereas a phasic decrease in DA release caused by a smaller-than-expected reward induces a cessation of long-term depression, leading to LTP in the indirect pathway. This learning mechanism can explain the robust behavioral adaptation observed in a location-reward-value-association task where the animal makes shorter latency saccades to reward locations. The changes in saccade latency become quicker as the monkey becomes more experienced. This behavior can be explained by a switching mechanism which activates the cortico-striatal circuit selectively. Our model also shows how D1- or D2-receptor blocking experiments affect selectively either reward or no-reward trials. The proposed mechanisms also explain the behavioral changes in Parkinson's disease.

Coping with Sleep Deprivation: Shifts in Regional Brain Activity and Learning Strategy

dissociable cognitive strategies are used for place navigation. Spatial strategies rely on the hippocampus, an area important for flexible integration of novel information. Response strategies are more rigid and involve the dorsal striatum. These memory systems can compensate for each other in case of temporal or permanent damage. Sleep deprivation has adverse effects on hippocampal function. However, whether the striatal memory system can compensate for sleep-deprivation-induced hippocampal impairments is unknown. with a symmetrical maze paradigm for mice, we examined the effect of sleep deprivation on learning the location of a food reward (training) and on learning that a previously nonrewarded arm was now rewarded (reversal training). five hours of sleep deprivation after each daily training session did not affect performance during training. However, in contrast with controls, sleep-deprived mice avoided a hippocampus-dependent spatial strategy and preferentially used a striatum-dependent response strategy. In line with this, the training-induced increase in phosphorylation of the transcription factor cAMP response-element binding protein (CREB) shifted from hippocampus to dorsal striatum. Importantly, although sleep-deprived mice performed well during training, performance during reversal training was attenuated, most likely due to rigidity of the striatal system they used. together, these findings suggest that the brain compensates for negative effects of sleep deprivation on the hippocampal memory system by promoting the use of a striatal memory system. However, effects of sleep deprivation can still appear later on because the alternative learning mechanisms and brain regions involved may result in reduced flexibility under conditions requiring adaptation of previously formed memories.

Memory for reward location is enhanced even though acetylcholine efflux within the amygdala is impaired in rats with damage to the diencephalon produced by thiamine deficiency

A rodent model of diencephalic amnesia produced by thiamine deficiency (pyrithiamine-induced thiamine deficiency [PTD]) was implemented to assess both changes in behavior and acetylcholine (ACh) efflux in the amygdala across four training sessions of a delayed alternation task. Two versions of the delayed alternation task were used. In one version, when a correct alternation was made a unique reward was paired with each spatial location ([left arm—chocolate milk] or [right arm—rat chow]). This paradigm is called the differential outcomes procedure (DOP). In the second version of the task, correct delayed alternation resulted in the same rewards but randomized across location (Nondifferential Outcomes Procedure [NOP]). The PTD rats were impaired on the first session of delayed alternation testing. However, both control and PTD rats using the DOP performed significantly better on delayed alternation than rats trained with the NOP. This effect was driven primarily by the PTD rats in the DOP condition outperforming all other groups on sessions 2–4. Although ACh efflux in the amygdala increased during delayed alternation testing in all groups, the NOP-trained rats had a greater rise in training-related ACh release in the post-training period. This suggests that increased amygdalar cholinergic activation is more critical for processing spatial information than episodic reward information. These data correspond with the idea that cholinergic activation of the amygdala promotes processing in other neural systems.

Dogs choose a human informant: Metacognition in canines

The presence of metacognition in animals has been suggested by the observation that non-human primates will seek out information about the location of a hidden reward before responding. In experiment 1, dogs failed to make an information-seeking response that involved re-positioning themselves in space so that they could view a cue that indicated the location of food. In experiments 2 and 3, dogs were allowed to choose between two people, an informant that pointed to the location of food and a non-informant that provided no information. Dogs showed a clear preference for the informant, even when choice of the informant led to no greater chance of reward than choice of the non-informant. In a procedure that involves human communication, dogs show information-seeking behavior.

10-Month-Olds Visually Anticipate an Outcome Contingent on Their Own Action.

It is known that young infants can learn to perform an action that elicits a reinforcer, and that they can visually anticipate a predictable stimulus by looking at its location before it begins. Here, in an investigation of the display of these abilities in tandem, I report that 10-month-olds anticipate a reward stimulus that they generate through their own action: .5 sec before pushing a button to start a video reward, they increase their rate of gaze shifts to the reward location; and during periods of extinction, reward location gaze shifts correlate with bouts of button pushing. The results are consistent with the hypothesis that the infants have an expectation of the outcome of their actions: several alternative hypotheses are ruled out by yoked controls. Such an expectation may, however, be procedural, have minimal content, and is not necessarily sufficient to motivate action.

Plant volatiles

Plant volatiles are the metabolites that plants release into the air. The quantities released are not trivial. Almost one-fifth of the atmospheric CO2 fixed by land plants is released back into the air each day as volatiles. Plants are champion synthetic chemists; they take advantage of their anabolic prowess to produce volatiles, which they use to protect themselves against biotic and abiotic stresses and to provide information - and potentially disinformation - to mutualists and competitors alike. As transferors of information, volatiles have provided plants with solutions to the challenges associated with being rooted in the ground and immobile.

Reward-Associated Gamma Oscillations in Ventral Striatum Are Regionally Differentiated and Modulate Local Firing Activity

Oscillations of local field potentials (LFPs) in the gamma range are found in many brain regions and are supposed to support the temporal organization of cognitive, perceptual, and motor functions. Even though gamma oscillations have also been observed in ventral striatum, one of the brain's most important structures for motivated behavior and reward processing, their specific function during ongoing behavior is unknown. Using a movable tetrode array, we recorded LFPs and activity of neural ensembles in the ventral striatum of rats performing a reward-collection task. Rats were running along a triangle track and in each round collected one of three different types of rewards. The gamma power of LFPs on subsets of tetrodes was modulated by reward-site visits, discriminated between reward types, between baitedness of reward locations and was different before versus after arrival at a reward site. Many single units in ventral striatum phase-locked their discharge pattern to the gamma oscillations of the LFPs. Phase-locking occurred more often in reward-related than in reward-unrelated neurons and LFPs. A substantial number of simultaneously recorded LFPs correlated poorly with each other in terms of gamma rhythmicity, indicating that the expression of gamma activity was heterogeneous and regionally differentiated. The orchestration of LFPs and single-unit activity by way of gamma rhythmicity sheds light on the functional architecture of the ventral striatum and the temporal coordination of ventral striatal activity for modulating downstream areas and regulating synaptic plasticity.

Domesticated Dogs’ (Canis familiaris) Response to Dishonest Human Points

Pointing is a conventional communicative gesture used by humans to direct others’ attention to an environmental feature. Several researchers have argued that pointing becomes so ingrained for humans from a young age that children often have difficulty interpreting the gesture in a novel way. Recent research suggests domestic dogs are also sensitive to human gestures (including points) and proficient in recognizing and acting on humans’ visual attention. We explored the role of pointing indogs’ choice behavior and whether dogs, like human children, have difficulty interpreting the gesture novelly. In Experiment 1, we explored whether dogs would differentially follow a static human point when it was administered by a familiar or unfamiliar individual and that individual indicated or failed to indicate the correct location of a food reward. The results indicated dogs chose the container specified by the demonstrators’ point in the honest and dishonest condition. Demonstrator familiarity did not alter performance. In Experiment 2, we compared dogs’ propensity to follow a static point versus other cues (momentary point, standing location) when the cue never indicated the correct location of a food reward, which was either visible or hidden during choice. The results suggested dogs did not inhibit their approach to a location indicated by a deceptive static point even when thelocation of a reward was visibly available during choice. However, dogs used a deceptive momentary point or standing location to locate food in both visible and hidden trials. In Experiment 3, we explored if dogs could overcome their tendency to follow a deceptive static point. These results indicated dogs learned to inhibit their approach to a deceptive static point when the reward was visible during choice. However, when information about the reward’s location was later hidden, dogs reverted to following the demonstrator’s static point.

Neural correlates of spatial short-term memory in the rodent frontal orienting field

Event Abstract Back to Event Neural correlates of spatial short-term memory in the rodent frontal orienting field Jeffrey C. Erlich1*, Max Bialek1 and Carlos D. Brody1 1 HHMI and Princeton University, United States We have trained rats on a memory-guided delayed orienting task, inspired by delayed saccade tasks performed by human and non-human primates. The delayed orienting task requires rats to ’fixate’ by holding their nose in a central nose port while a light is on in the port. During the fixation, a brief sound (the "target stimulus") indicates to the rat whether it should orient to the right or to the left after the end of fixation in order to obtain a reward. The end of fixation is indicated by the offset of the center light. We randomly interleave two types of trials: memory and non-memory. In memory trials, the target stimulus is presented shortly after the beginning of fixation and 700 ms before its end. In these trials, the rat must inhibit the impulse to respond immediately and must also remember the reward location (either as a retrospective memory of the stimulus or a prospective motor plan/prediction of reward location). These two elements, inhibition and planning, make the delayed-orienting task suitable for understanding the neural basis of cognitive control. In non-memory trials, the target stimulus is presented at the end of the fixation period, and no memory is required for correct performance. The two types of trials allow us to distinguish activity associated with spatial memory from activity associated with fixation only. The electrophysiological properties of neurons in the rodent orientation system remain largely unexplored. One cortical area of potential interest is the Frontal Orienting Field (FOF, +2 AP, ±1.3 ML [mm from Bregma]). Previous anatomical data has suggested that the FOF is homologous to primate frontal eye fields: in particular, the FOF connects strongly to both prefrontal cortex and the superior colliculus. Nevertheless, almost no electrophysiological recordings from the FOF exist. To our knowledge, no previous studies have recorded from FOF using repeated, identically prepared trials requiring an orientation movement, whether memory or non-memory-based. We have now recorded from over 500 single-units from the FOF while rats performed the delayed orienting task. We found that a significant portion of neurons in this region (approx 30%) show spatial working memory: after the offset of the stimulus, and before the onset of the movement, firing rates are selective for the rat’s upcoming choice. We have preliminary lesion and pharmacological evidence indicating that unilateral disruption of activity in the FOF creates a contralateral impairment. For example, rats with left FOF lesions are impaired at making rightward responses. Thus, we have both correlational physiological evidence and causal evidence that the FOF is an important element of the rat’s neural circuit for spatial orientation and spatial short-term memory. Conference: Computational and Systems Neuroscience 2010, Salt Lake City, UT, United States, 25 Feb - 2 Mar, 2010. Presentation Type: Poster Presentation Topic: Poster session I Citation: Erlich JC, Bialek M and Brody CD (2010). Neural correlates of spatial short-term memory in the rodent frontal orienting field. Front. Neurosci. Conference Abstract: Computational and Systems Neuroscience 2010. doi: 10.3389/conf.fnins.2010.03.00019 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 17 Feb 2010; Published Online: 17 Feb 2010. * Correspondence: Jeffrey C Erlich, HHMI and Princeton University, Princeton, United States, jerlich@princeton.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Jeffrey C Erlich Max Bialek Carlos D Brody Google Jeffrey C Erlich Max Bialek Carlos D Brody Google Scholar Jeffrey C Erlich Max Bialek Carlos D Brody PubMed Jeffrey C Erlich Max Bialek Carlos D Brody Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Reorienting strategies in a rectangular array of landmarks by domestic chicks (gallus gallus).

Spatial reorientation in a rectangular array of four landmarks located in the center of a circular enclosure was investigated in domestic chicks (Gallus gallus). One of the landmark possessed unique visual features, indicating the location of a food reward. After training, chicks were tested (a) with the same array as during the training; (b) with four identical landmarks of the type previously nonrewarded, of the type previously rewarded, or of a new type; (c) after having transformed one of the landmarks located at the geometric incorrect location into the type of landmark previously rewarded; or (d) with a fifth landmark of the rewarded type at a new location. Chicks encoded information provided by local featural cues but not the geometric information provided by the shape of the array. Moreover, when trained in a rectangular array of identical landmarks chicks failed to reorient. In a second series of experiments, the array was located in correspondence to the corners of a rectangular enclosure. This time chicks successfully learned to locate the reward using geometric information. However, when the rectangular array was located in the center of a larger rectangular enclosure, chicks failed to reorient, indicating that the geometric information given by the macroscopic layout of arena surfaces was not used to specify different locations. These results suggest that chicks reorient on the basis of a local representation of single landmarks and that encoding of the global aspects of geometry only occurs with respect to the large, extended surfaces of an enclosure.

Rewarded Outcomes Enhance Reactivation of Experience in the Hippocampus

Remembering experiences that lead to reward is essential for survival. The hippocampus is required for forming and storing memories of events and places, but the mechanisms that associate specific experiences with rewarding outcomes are not understood. Event memory storage is thought to depend on the reactivation of previous experiences during hippocampal sharp wave ripples (SWRs). We used a sequence switching task that allowed us to examine the interaction between SWRs and reward. We compared SWR activity after animals traversed spatial trajectories and either received or did not receive a reward. Here, we show that rat hippocampal CA3 principal cells are significantly more active during SWRs following receipt of reward. This SWR activity was further enhanced during learning and reactivated coherent elements of the paths associated with the reward location. This enhanced reactivation in response to reward could be a mechanism to bind rewarding outcomes to the experiences that precede them.

Spatial relational learning and memory abilities do not differ between men and women in a real-world, open-field environment

This study assesses gender differences in spatial and non-spatial relational learning and memory in adult humans behaving freely in a real-world, open-field environment. In Experiment 1, we tested the use of proximal landmarks as conditional cues allowing subjects to predict the location of rewards hidden in one of two sets of three distinct locations. Subjects were tested in two different conditions: (1) when local visual cues marked the potentially-rewarded locations, and (2) when no local visual cues marked the potentially-rewarded locations. We found that only 17 of 20 adults (8 males, 9 females) used the proximal landmarks to predict the locations of the rewards. Although females exhibited higher exploratory behavior at the beginning of testing, males and females discriminated the potentially-rewarded locations similarly when local visual cues were present. Interestingly, when the spatial and local information conflicted in predicting the reward locations, males considered both spatial and local information, whereas females ignored the spatial information. However, in the absence of local visual cues females discriminated the potentially-rewarded locations as well as males. In Experiment 2, subjects (9 males, 9 females) were tested with three asymmetrically-arranged rewarded locations, which were marked by local cues on alternate trials. Again, females discriminated the rewarded locations as well as males in the presence or absence of local cues. In sum, although particular aspects of task performance might differ between genders, we found no evidence that women have poorer allocentric spatial relational learning and memory abilities than men in a real-world, open-field environment.

Associative learning in zebrafish ( Danio rerio) in the plus maze

Zebrafish has been gaining increasing amount of interest in behavioral neuroscience as this species may represent a good compromise between system complexity and practical simplicity. Particularly successful have been those studies that utilized zebrafish as a screening tool. Given the complexity of the mechanisms of learning, for example, forward genetic screens with zebrafish could potentially reveal previously unknown genes and molecular pathways that subserve this function. These screens, however, require appropriate phenotypical (e.g. behavioral) paradigms. A step in this direction is the characterization of learning abilities of zebrafish. Here we employ two classical learning tasks in a plus maze. In the first, zebrafish are required to associate a visible cue with food reward irrespective of the location of this pairing. In the second, zebrafish are required to associate the spatial location of food reward irrespective of intra-maze cues. Our results demonstrate that zebrafish perform well in both tasks and show significant acquisition of the association between cue and reward as well as between location and reward. We conclude that zebrafish, similar to classical laboratory rodents, may have utility in the biological analysis of simple as well as complex forms of associative learning.

Low and high gamma oscillations in rat ventral striatum have distinct relationships to behavior, reward, and spiking activity on a learned spatial decision task

Local field potential (LFP) oscillations in the brain reflect organization thought to be important for perception, attention, movement, and memory. In the basal ganglia, including dorsal striatum, dysfunctional LFP states are associated with Parkinson's disease, while in healthy subjects, dorsal striatal LFPs have been linked to decision-making processes. However, LFPs in ventral striatum have been less studied. We report that in rats running a spatial decision task, prominent gamma-50 (45–55 Hz) and gamma-80 (70–85 Hz) oscillations in ventral striatum had distinct relationships to behavior, task events, and spiking activity. Gamma-50 power increased sharply following reward delivery and before movement initiation, while in contrast, gamma-80 power ramped up gradually to reward locations. Gamma-50 power was low and contained little structure during early learning, but rapidly developed a stable pattern, while gamma-80 power was initially high before returning to a stable level within a similar timeframe. Putative fast-spiking interneurons (FSIs) showed phase, firing rate, and coherence relationships with gamma-50 and gamma-80, indicating that the observed LFP patterns are locally relevant. Furthermore, in a number of FSIs such relationships were specific to gamma-50 or gamma-80, suggesting that partially distinct FSI populations mediate the effects of gamma-50 and gamma-80.