Examinando por Autor "Nelson, James Byron"

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Effects of stimulus intensity on response acquisition and generalization in a behavioral task with humans
(2019) Balea, Paula; Sanjuan, María del Carmen; Nelson, James Byron
We reviewed the literature on the relationship between conditioned stimulus (CS) intensity and conditioned response (CR) strength. Overall, studies indicate that both variables are positively related, however, such a relation has seldom been found in humans, especially when between-subjects designs are used. Moreover, in humans, the effect has only been investigated using auditory CSs in galvanic skin response and eyelid conditioning procedures. By using a videogame task, we assessed the relationship between CS intensity and the CR along two conditioning phases in human participants. In phase 1, participants were trained to respond to a light that signaled an imminent spaceship attack. The light could be bright or dim (between-groups). In phase 2, the alternate stimulus was used. The intensity had no effect on phase 1 but had a small effect in phase 2, after participants had the opportunity to compare both stimulus intensities. An assessment of the shift that occurred between phases showed a slight generalization decrement only in the bright-to-dim group, allowing some room for improvement during phase 2 in that group. The absence of a decrement with the stimulus shift in the dim-to-bright group could be ascribed to the bright stimulus having energizing properties that compensate for the decrement.
Extinction Contexts Fail to Transfer Control: Implications for Conditioned Inhibition and Occasion-Setting Accounts of Renewal
(American Psychological Association (APA), 2020) Balea, Paula; Nelson, James Byron; Ogallar, Pedro M.; Lamoureux, Jeffrey A.; Aranzubia-Olasolo, Manuel; Sanjuan, María del Carmen
The renewal effect is often explained as a side effect of the extinction context acting as a negative occasion setter. Four experiments tested whether extinction contexts show the selective-transfer property of occasion setters. Experiments 1–3 used a predictive judgment task where participants rated the probability of certain foods (cues) producing gastric malaise (outcomes) in different restaurants (contexts). Experiment 4 used a behavioral suppression task where sensor lights (cues) served as signals to suppress firing responses in certain galaxies (contexts). All 4 (Experiments 1–4) addressed whether a potentially negative occasion-setting context transferred its modulatory power to an extinguished (presumably occasion set) target in the test phase of an ABC renewal design. Experiments 2–4 further assessed the possibility that the extinction context acts as a conditioned inhibitor by testing a simple excitor on a context where extinction occurred. Neither selective (occasion-setting) nor nonselective transfer (conditioned inhibition) was demonstrated. Implications for theories of renewal and occasion setting are discussed.
Extinction may not result in occasion setting
(2018) Nelson, James Byron; Balea, Paula; Ogallar, Pedro M.; Fabiano, Andrew; Lamoureux, Jeffrey A.; Sanjuan, María del Carmen
Three experiments with humans (two predictive-learning tasks, one behavioral task) examined the occasion-setting properties of extinction contexts. Extinction performance was attenuated when an extinguished stimulus was tested in a different context, regardless of whether another stimulus had been extinguished there (all experiments). Extinction in the test context had no effect on a non-extinguished stimulus (experiment 3). An extinction context had neither the properties of a negative occasion setter nor a conditioned inhibitor.
Failure of transfer of occasion setting between extinction contexts
(2018) Balea, Paula; Sanjuan, María del Carmen; Ogallar, Pedro M.; Lamoureux, Jeffrey A.; Fabiano, Andrew; Nelson, James Byron
Three experiments with humans, two with a predictive-learning task and one with a behavioral-suppression task, tested whether extinction contexts act as negative occasion setters. Feature-negative occasion setters transfer control to other stimuli that have been occasion set, unlike conditioned inhibitors which affect any stimulus paired with the same outcome. All experiments used an ABC design where the target stimulus was conditioned and extinguished in contexts A and B, respectively, prior to being tested in C. In context C, some participants had also received extinction of another stimulus so that C could be a negative occasion setter and enable extinction performance or be a conditioned in inhibitor and suppress conditioning performance. Extinction in C had no effect on responding to the conditioned and extinguished target stimulus: Equal ABC renewal was observed (E1-E3). Neither did extinction in C affect responding to a non-extinguished CS (E3). There was no evidence of extinction producing occasion setting, nor conditioned inhibition in well-powered studies.
Intensity effects in human cue-outcome learning
(Elsevier, 2020) Balea, Paula; Nelson, James Byron
Literature on conditioned stimulus intensity effects is briefly reviewed and one experiment presented with human subjects and a video-game method. The intensity (Bright or Dim) or color (Red or Blue) of a cue that predicted the appearance of a spaceship was manipulated. Testing was conducted with either the alternate brightness or the alternate color. Responding to the cue was unaffected by its intensity in training. During testing, a downshift in brightness decreased responding while an upshift had no effect, suggesting an asymmetrical intensity gradient. Red tended to condition better than Blue in the first phase, but the same participants conditioned better in the second phase to Blue. The results are discussed with respect to prior demonstrations of intensity effects using within-subject designs and favor an explanation based on stimulus-sampling theory.
Learning to learn (LTL) in an associative learning task with humans
(2018) Balea, Paula; Sanjuan, Maria del Carmen; Nelson, James Byron
Three experiments examined LTL in a human conditioning paradigm. Compared to controls, without prior conditioning or extinction, phase-1 conditioning of A facilitated phase-2 conditioning with B. Though seldom observed in the literature, phase-3 extinction with A facilitated phase-4 extinction of B. The effects, appearing after one trial, depended on separate representations of the conditioning and extinction experiences, not on physical generalization, intermixing A and B trials, nor on the strength of the A-evoked US representation
Learning to learn and generalization in human conditioning
(2017) Balea, Paula; Nelson, James Byron; Sanjuan, María del Carmen
Each situation we encounter is at least in part unique. Thus, the flexible use of the information acquired in previous experiences becomes a fundamental skill to maximize our chances of success. While stimulus generalization is a form of transfer that relies on the sensory similarities of the stimuli, learning to learn (LTL) denotes a facilitation of learning in the form of an increased learning rate across tasks that share a common structure. The LTL effect has been clearly shown in cognitively oriented tasks, however, it is important to understand the effect at the level of basic processes such as associative learning, since they begin to indicate boundaries for the effect. For instance, it is not clear if extinction learning transfers across different stimuli. Several experiments assessed whether LTL can be obtained in classical conditioning procedures with humans while evaluating the extent to which generalization might contribute to transfer of learning. We used a science-fiction based videogame (Nelson, Navarro, & Sanjuan, 2014) where different conditioned stimuli (flashing lights or a tone) are associated with the appearance of an attacking spaceship (unconditioned stimulus). The procedure requires the participants to give an anticipatory response (charging a weapon) which allowed us to trace the course of learning trial by-trial along several repeated acquisition and extinction tasks. Our results indicate that the LTL effect is apparent even in situations where no stimulus generalization is present. Furthermore, the effect is present both in acquisition and extinction procedures.
Learning to learn in conditioning and extinction in humans
(Elsevier, 2018) Balea, Paula; Sanjuan, María del Carmen; Nelson, James Byron
Learning to Learn (LTL) is the transfer of learning, separate from stimulus generalization, that appears across tasks that share a similar structure. Three experiments examined this phenomenon in both conditioning and extinction learning in humans. The latter effect is of special interest given the failures in the literature to obtain transfer of extinction between stimuli. Conditioning and extinction with one stimulus increased the rate of conditioning and, surprisingly, extinction of a different stimulus (Experiment 1). The effects appeared in the absence of physical generalization. The transfer of extinction was not enhanced by conditions that increased the chances of a mediated extinction effect (Experiment 2). Finally, Experiment 3 ruled out three possible sources for the effect in extinction: a common unconditioned-stimulus representation, a common reinforcement history, and within-stimuli associations. Overall, the findings are consistent with the idea that LTL is an emergent (nonimmediate) form of mediated generalization that is dependent upon memory structures retrieved by trial outcomes. The over- or under-prediction of the outcome on the first trial with a new task might retrieve prior episodes associated with similar prediction errors promoting transfer.
The Effects of Stimulus Pre-Exposure and Conditioning on Overt Visual Attention
(American Psychological Association (APA), 2022) Nelson, James Byron; Navarro, Anton; Balea, Paula; Sanjuan, Maria del Carmen
Three experiments (a, b, c) combined to provide a well-powered examination of the effects of stimulus pre-exposure and conditioning on visual attention using an eye tracker and a space-shooter video game where a colored flashing light predicted an attacking spaceship. In each, group “control” received no pre-exposure to the light, group “same” received pre-exposure in the same context as conditioning, and group “different” received pre-exposure in a different context. Experiments differed in visual details regarding the game (1a vs. 1b and 1c) or minor details in the setup of the eye tracker (1a and 1b vs. 1c). Overall, pre-exposure retarded acquisition of keyboard responding. That effect was enhanced, rather than attenuated, by a context change. Separating participants by sign and goal trackers showed the context change enhanced the pre-exposure effect in goal trackers and reduced it in sign trackers. Visual attention to the light declined during pre-exposure and did not recover with either conditioning or a context switch. Visual attention to the light decreased during conditioning. Visual goal tracking toward where the spaceship would appear was also retarded with pre-exposure. Unlike the keyboard responding, a context change led to more normal goal-tracking acquisition. Results are discussed in terms of theories of attention and the potential effects of demand characteristics on the task.