scholarly journals Interactions between target location and reward size modulate the rate of microsaccades in monkeys

2015 ◽  
Vol 114 (5) ◽  
pp. 2616-2624 ◽  
Author(s):  
Mati Joshua ◽  
Stefanie Tokiyama ◽  
Stephen G. Lisberger
Keyword(s):  
Indirect Effects ◽  
Large Reward ◽  
Opposite Effect ◽  
Target Location ◽  
Small Reward ◽  
Target Motion ◽  
Pursuit Initiation ◽  
Future Reward ◽  
Exogenous Cue ◽  
A Site

We have studied how rewards modulate the occurrence of microsaccades by manipulating the size of an expected reward and the location of the cue that sets the expectations for future reward. We found an interaction between the size of the reward and the location of the cue. When monkeys fixated on a cue that signaled the size of future reward, the frequency of microsaccades was higher if the monkey expected a large vs. a small reward. When the cue was presented at a site in the visual field that was remote from the position of fixation, reward size had the opposite effect: the frequency of microsaccades was lower when the monkey was expecting a large reward. The strength of pursuit initiation also was affected by reward size and by the presence of microsaccades just before the onset of target motion. The gain of pursuit initiation increased with reward size and decreased when microsaccades occurred just before or after the onset of target motion. The effect of the reward size on pursuit initiation was much larger than any indirect effects reward might cause through modulation of the rate of microsaccades. We found only a weak relationship between microsaccade direction and the location of the exogenous cue relative to fixation position, even in experiments where the location of the cue indicated the direction of target motion. Our results indicate that the expectation of reward is a powerful modulator of the occurrence of microsaccades, perhaps through attentional mechanisms.

Role of Anticipation in Schizophrenia-Related Pursuit Initiation Deficits

2006 ◽  
Vol 95 (2) ◽  
pp. 593-601 ◽  
Author(s):  
Matthew T. Avila ◽  
L. Elliot Hong ◽  
Amanda Moates ◽  
Kathleen A. Turano ◽  
Gunvant K. Thaker
Keyword(s):  
Target Motion ◽  
Motion Information ◽  
Control Groups ◽  
Pursuit Initiation ◽  
Information Studies ◽  
Pursuit System ◽  
Velocity Information ◽  
And Control ◽  
Eye Velocity

Schizophrenia patients exhibit several smooth pursuit abnormalities including poor pursuit initiation. Velocity discrimination is also impaired and is correlated with pursuit initiation performance—suggesting that pursuit deficits are related to impairments in processing velocity information. Studies suggest that pursuit initiation is influenced by prior target motion information and/or expectations and that this is likely caused by expectation-based changes in the perceptual inputs to the pursuit system. We examined whether poor pursuit initiation in schizophrenia results from inaccurate encoding of immediate velocity signals, or whether these deficits reflect a failure to use prior target motion information to “optimize” the response. Twenty-eight patients and 24 controls performed an adapted version of a “remembered pursuit task.” Trials consisted of a series of target motions, the first of which occurred unexpectedly, followed by four to seven identical targets each preceded by an auditory cue and a “catch target” in which a cue was given followed by target extinction. Initiation eye velocity in response to unexpected, first targets was similar in the patient and control groups. In contrast, patients showed lower eye velocity in response to repeated, cued targets compared with controls. Patients also showed reduced eye velocity in response to catch targets. Reduction in pursuit latency across repeated targets was less robust in patients. Results suggest that processing of immediate velocity information is unaffected in schizophrenia and that pursuit initiation deficits reflect an inability to accurately generate, store, and/or access “remembered” velocity signals.

scholarly journals Effects of early life and current housing on sensitivity to reward loss in a successive negative contrast test in pigs

2019 ◽  
Vol 23 (1) ◽  
pp. 121-130 ◽  
Author(s):  
L. Luo ◽  
I. Reimert ◽  
E. A. M. Graat ◽  
S. Smeets ◽  
B. Kemp ◽  
...  
Keyword(s):  
Early Life ◽  
Large Reward ◽  
Small Reward ◽  
Affective State ◽  
Negative Contrast ◽  
Lower Probability ◽  
Housing Conditions ◽  
Long Term Effects ◽  
Sensitivity To Reward ◽  
Successive Negative Contrast

Abstract Animals in a negative affective state seem to be more sensitive to reward loss, i.e. an unexpected decrease in reward size. The aim of this study was to investigate whether early-life and current enriched vs. barren housing conditions affect the sensitivity to reward loss in pigs using a successive negative contrast test. Pigs (n = 64 from 32 pens) were housed in barren or enriched conditions from birth onwards, and at 7 weeks of age experienced either a switch in housing conditions (from barren to enriched or vice versa) or not. Allotting pigs to the different treatments was balanced for coping style (proactive vs. reactive). One pig per pen was trained to run for a large reward and one for a small reward. Reward loss was introduced for pigs receiving the large reward after 11 days (reward downshift), i.e. from then onwards, they received the small reward. Pigs housed in barren conditions throughout life generally had a lower probability and higher latency to get the reward than other pigs. Proactive pigs ran overall slower than reactive pigs. After the reward downshift, all pigs ran slower. Nevertheless, reward downshift increased the latency and reduced the probability to get to the reward, but only in pigs exposed to barren conditions in early life, which thus were more sensitive to reward loss than pigs from enriched early life housing. In conclusion, barren housed pigs seemed overall less motivated for the reward, and early life housing conditions had long-term effects on the sensitivity to reward loss.

Effect of Varied Magnitude of Reward on Runway Performance

1964 ◽  
Vol 14 (1) ◽  
pp. 199-202
Author(s):  
Douglas L. Grimsley ◽  
Robert D. McDonald
Keyword(s):  
Large Reward ◽  
Small Reward ◽  
Runway Performance ◽  
Continuous Reinforcement ◽  
Reward Group ◽  
Varied Reinforcement

Runway speed was investigated in 3 groups of water-deprived rats ( n = 14 per group) given one trial per day for 100 days. No statistically significant differences were found between Ss continuously receiving 0.8 cc (large reward group) or 0.1 cc (small reward group) of water and those given 0.8 cc and 0.1 cc (varied reward group) semirandomly. These data are not consistent with a position derived from a micromolar theory holding that continuous reinforcement training results in better performance than varied reinforcement training.

scholarly journals Smooth pursuit preparation modulates neuronal responses in visual areas MT and MST

2015 ◽  
Vol 114 (1) ◽  
pp. 638-649 ◽  
Author(s):  
Vincent P. Ferrera
Keyword(s):  
Smooth Pursuit ◽  
Motor Response ◽  
Visual Motion ◽  
Neuronal Response ◽  
Direction Selectivity ◽  
Relative Strength ◽  
Target Motion ◽  
Motion Onset ◽  
Pursuit Initiation ◽  
Visual Cortical

Primates are able to track small moving visual targets using smooth pursuit eye movements. Target motion for smooth pursuit is signaled by neurons in visual cortical areas MT and MST. In this study, we trained monkeys to either initiate or withhold smooth pursuit in the presence of a moving target to test whether this decision was reflected in the relative strength of “go” and “no-go” processes. We found that the gain of the motor response depended strongly on whether monkeys were instructed to initiate or withhold pursuit, thus demonstrating voluntary control of pursuit initiation. We found that the amplitude of the neuronal response to moving targets in areas MT and MST was also significantly lower on no-go trials (by 2.1 spikes/s on average). The magnitude of the neural response reduction was small compared with the behavioral gain reduction. There were no significant differences in neuronal direction selectivity, spatial selectivity, or response reliability related to pursuit initiation or the absence thereof. Variability in eye speed was negatively correlated with firing rate variability after target motion onset during go trials but not during no-go trials, suggesting that MT and MST activity represents an error signal for a negative feedback controller. We speculate that modulation of the visual motion signals in areas MT and MST may be one of the first visual cortical events in the initiation of smooth pursuit and that the small early response modulation may be amplified to produce an all-or-none motor response by downstream areas.

scholarly journals In monkeys making value-based decisions, amygdala neurons are sensitive to cue value as distinct from cue salience

2017 ◽  
Vol 117 (4) ◽  
pp. 1499-1511 ◽  
Author(s):  
Marvin L. Leathers ◽  
Carl R. Olson
Keyword(s):  
Large Reward ◽  
Small Reward ◽  
Macaque Monkey ◽  
Neuronal Responses ◽  
Variable Size ◽  
Motivational Salience ◽  
Cue Salience ◽  
Activity Dependent ◽  
The Brain ◽  
Identical Task

Neurons in the lateral intraparietal (LIP) area of macaque monkey parietal cortex respond to cues predicting rewards and penalties of variable size in a manner that depends on the motivational salience of the predicted outcome (strong for both large reward and large penalty) rather than on its value (positive for large reward and negative for large penalty). This finding suggests that LIP mediates the capture of attention by salient events and does not encode value in the service of value-based decision making. It leaves open the question whether neurons elsewhere in the brain encode value in the identical task. To resolve this issue, we recorded neuronal activity in the amygdala in the context of the task employed in the LIP study. We found that responses to reward-predicting cues were similar between areas, with the majority of reward-sensitive neurons responding more strongly to cues that predicted large reward than to those that predicted small reward. Responses to penalty-predicting cues were, however, markedly different. In the amygdala, unlike LIP, few neurons were sensitive to penalty size, few penalty-sensitive neurons favored large over small penalty, and the dependence of firing rate on penalty size was negatively correlated with its dependence on reward size. These results indicate that amygdala neurons encoded cue value under circumstances in which LIP neurons exhibited sensitivity to motivational salience. However, the representation of negative value, as reflected in sensitivity to penalty size, was weaker than the representation of positive value, as reflected in sensitivity to reward size. NEW & NOTEWORTHY This is the first study to characterize amygdala neuronal responses to cues predicting rewards and penalties of variable size in monkeys making value-based choices. Manipulating reward and penalty size allowed distinguishing activity dependent on motivational salience from activity dependent on value. This approach revealed in a previous study that neurons of the lateral intraparietal (LIP) area encode motivational salience. Here, it reveals that amygdala neurons encode value. The results establish a sharp functional distinction between the two areas.

scholarly journals Overt attentional capture by reward-related stimuli overcomes inhibitory suppression

2019 ◽  
Author(s):  
Daniel Pearson ◽  
Poppy Watson ◽  
Phillip Cheng ◽  
Mike Le Pelley
Keyword(s):  
Large Reward ◽  
Search Task ◽  
Visual Search Task ◽  
Small Reward ◽  
Eye Gaze ◽  
Negative Consequences ◽  
Target Template ◽  
Irrelevant Distractors ◽  
Separate Line ◽  
Special Priority

Salient-but-irrelevant distractors can automatically capture attention and eye-gaze in visualsearch. However, recent findings have suggested that attention to salient-but-irrelevant stimulican be suppressed when observers use a specific target template to guide their search (i.e.,feature search). A separate line of research has indicated that attentional selection isinfluenced by factors other than the physical salience of a stimulus and the observer’s goals.For instance, pairing a stimulus with reward has been shown to increase the extent to which itcaptures attention and gaze (as though it has become more physically salient), even when suchcapture has negative consequences for the observer. Here we used eye-tracking with arewarded visual search task to investigate whether capture by reward can be suppressed in thesame way as capture by physical salience. When participants were encouraged to use featuresearch, attention to a distractor paired with relatively small reward was suppressed. However,under the same conditions attention was captured by a distractor paired with large reward,even when such capture resulted in reward omission. These findings suggest thatreward-related stimuli are given special priority within the visual attention system over andabove physically-salient stimuli, and have implications for our understanding of real-worldbiases to reward-related stimuli, such as those seen in addiction.

Effects of Preshift Small Magnitude of Reward Received during Goalbox Placements on the Negative Contrast Effect

2004 ◽  
Vol 94 (2) ◽  
pp. 683-686 ◽  
Author(s):  
Richard S. Calef ◽  
Michael C. Choban ◽  
Katherine R. Glenney ◽  
Ruth A. Calef ◽  
Errika M. Mace ◽  
...  
Keyword(s):  
Contrast Effect ◽  
Large Reward ◽  
Food Reward ◽  
Small Reward ◽  
Negative Contrast Effect ◽  
Negative Contrast ◽  
Straight Alley ◽  
Control Group ◽  
Small Magnitude ◽  
Experimental Group

During preshift, one experimental group of rats was given a large magnitude of food reward following a traversal of a straight alley and during a goalbox placement, while the other experimental group was given a small reward during goalbox placement and a large reward following a run. During postshift, all experimental groups were given a small reward of food following a traversal down the runway and during a goalbox placement. A control group was maintained on small reward during placements and following a traversal throughout the study. Only the group who received preshift large reward during placement and following a runway response ran slower to small reward during postshift than the control group maintained on small reward (negative contrast effect).

Secondary Reinforcement Effects as a Function of Reward Magnitude Training Methods

1964 ◽  
Vol 15 (1) ◽  
pp. 7-10 ◽  
Author(s):  
William F. Reynolds ◽  
William B. Pavlik ◽  
Ellen Goldstein
Keyword(s):  
Reward Magnitude ◽  
Large Reward ◽  
Small Reward ◽  
Secondary Reinforcement ◽  
Albino Rats ◽  
Training Methods ◽  
Magnitude Effect ◽  
Discrete Trial ◽  
Test Conditions ◽  
Trial Test

5 groups of 10 albino rats were trained by direct goalbox placement to either a black or striped goalbox. Two groups were trained under absolute conditions with either large (A-L) or small reward (A-S), and 2 groups were discrimination trained to the goalboxes with either large (D-L) or small (D-S) reward. A fifth group received differential training with large reward to one goalbox and small reward to the other (Df). The test period, consisting of free and forced-choice T-maze trials extended over 10 days. It was found that only the A-S mean failed to exceed chance, the Df mean significantly exceeded the A-L mean but not the D-L or D-S means, and even under highly controlled discrete-trial test conditions, differential training produces a stronger reward magnitude effect than absolute training.

Multiple Shifts in Magnitude of Reward

1981 ◽  
Vol 49 (1) ◽  
pp. 335-338 ◽  
Author(s):  
David T. Goomas
Keyword(s):  
Contrast Effect ◽  
Large Reward ◽  
Small Reward ◽  
Negative Contrast Effect ◽  
Negative Contrast ◽  
Positive Contrast ◽  
Positive Contrast Effect ◽  
Shift Group

Three groups of 5 rats were administered either large reward (10 pellets), small reward (2 pellets), or multiple shifts (Iarge-small-large-etc.) in an alleyway. The multiple-shift group received a total of 7 large and 6 small phases of reinforcement. Early in training the shifted group exhibited positive contrast effect to a shift to large reward and negative contrast effect to a shift to small reward. Later in training, the same group showed neither effect perhaps because experience with the shift provided a smaller discrepancy between the upshifts and downshifts in magnitude of reward.

scholarly journals Study of Intertemporal Discounting According to Age Groups

2021 ◽  
Vol 10 (2) ◽  
pp. 126-139
Author(s):  
Jiri Rotschedl ◽  
Jiri Rotschedl
Keyword(s):  
Discount Rate ◽  
Large Reward ◽  
Small Reward ◽  
Age Groups ◽  
Aging Population ◽  
Time Discounting ◽  
Impulsive Behaviour ◽  
Delayed Reward ◽  
Intertemporal Discounting ◽  
Basic Hypothesis

The paper focuses on the topic of intertemporal discounting of individuals according to age groups. Using the sample of examined individuals, it aims to verify the hypothesis that the patience of individuals decreases with their increasing age. The study included a total of 599 individuals with an average age of 38.3 years (min. 16 and max. 82 years) who answered classical questions focused on time discounting and impulsive behaviour. In total, four possible scenarios were analysed: a small reward (CZK 100) with a delay of 1 day, a small reward with a delay of 1 month, a large reward (CZK 100,000) with a delay of 1 day and a large reward with a delay of 1 month. The delayed reward was always increased by 10% (i.e., CZK 110 or CZK 110,000). The basic hypothesis was that with increasing age, the subjective discount rate increases i.e., patience decreases. The above-mentioned 4 scenarios were evaluated for the hypotheses, while only three of the four scenarios were confirmed for all hypotheses. The results in the examined individuals suggest that with increasing age, there is a decrease in patience and at the same time a decrease in impulsive behaviour. These findings may have an overlap in consumption or savings in relation to the aging population.

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