Stimulus Control Research Articles

Realistic About Reference Production: Testing the Effects of Domain Size and Saturation.

Experiments on visually grounded, definite reference production often manipulate simple visual scenes in the form of grids filled with objects, for example, to test how speakers are affected by the number of objects that are visible. Regarding the latter, it was found that speech onset times increase along with domain size, at least when speakers refer to nonsalient target objects that do not pop out of the visual domain. This finding suggests that even in the case of many distractors, speakers perform object-by-object scans of the visual scene. The current study investigates whether this systematic processing strategy can be explained by the simplified nature of the scenes that were used, and if different strategies can be identified for photo-realistic visual scenes. In doing so, we conducted a preregistered experiment that manipulated domain size and saturation; replicated the measures of speech onset times; and recorded eye movements to measure speakers' viewing strategies more directly. Using controlled photo-realistic scenes, we find (1) that speech onset times increase linearly as more distractors are present; (2) that larger domains elicit relatively fewer fixation switches back and forth between the target and its distractors, mainly before speech onset; and (3) that speakers fixate the target relatively less often in larger domains, mainly after speech onset. We conclude that careful object-by-object scans remain the dominant strategy in our photo-realistic scenes, to a limited extent combined with low-level saliency mechanisms. A relevant direction for future research would be to employ less controlled photo-realistic stimuli that do allow for interpretation based on context.

Worry Postponement From the Metacognitive Perspective: A Randomized Waitlist-Controlled Trial.

Pathological worry is associated with appraisals of worrying as uncontrollable. Worry postponement (WP) with a stimulus control rationale appears to be effective in non-clinical samples. However, preliminary research in participants with generalized anxiety disorder (GAD) does not support its efficacy in reducing negative metacognitions or worry. The aim of this study was to investigate the efficacy of WP with a metacognitive rationale. Participants with GAD (n = 47) or hypochondriasis (HYP; n = 35) were randomly assigned to either an intervention group (IG) or waitlist (WL). The IG received a two-session long WP intervention aiming at mainly reducing negative metacognitions concerning uncontrollability of worrying. Participants were instructed to postpone their worry process to a predetermined later time during the six days between the two sessions. Participants completed questionnaires of negative metacognitions and worry at pre-assessment, post-assessment, and follow-up. We observed a significant Time*Group interaction for negative metacognitions and worry. Post-hoc analyses on the total sample and separately for GAD and HYP revealed significantly lower worry scores in the treated GAD sample compared to the WL, representing the only significant effect. In the GAD group, pre-post-effect sizes were small for negative metacognitions and large for worry. Effects persisted to a four-week follow-up. WP with a metacognitive rationale seems to be effective in reducing worry in participants with GAD. The effectiveness for HYP seems limited, possibly due to the small sample size.

Inter-subject correlation of electroencephalographic and behavioural responses reflects time-varying engagement with natural music.

Musical engagement can be conceptualized through various activities, modes of listening and listener states. Recent research has reported that a state of focused engagement can be indexed by the inter-subject correlation (ISC) of audience responses to a shared naturalistic stimulus. While statistically significant ISC has been reported during music listening, we lack insight into the temporal dynamics of engagement over the course of musical works-such as those composed in the Western classical style-which involve the formulation of expectations that are realized or derailed at subsequent points of arrival. Here, we use the ISC of electroencephalographic (EEG) and continuous behavioural (CB) responses to investigate the time-varying dynamics of engagement with functional tonal music. From a sample of adult musicians who listened to a complete cello concerto movement, we found that ISC varied throughout the excerpt for both measures. In particular, significant EEG ISC was observed during periods of musical tension that built to climactic highpoints, while significant CB ISC corresponded more to declarative entrances and points of arrival. Moreover, we found that a control stimulus retaining envelope characteristics of the intact music, but little other temporal structure, also elicited significantly correlated EEG and CB responses, though to lesser extents than the original version. In sum, these findings shed light on the temporal dynamics of engagement during music listening and clarify specific aspects of musical engagement that may be indexed by each measure.

Simple visual stimuli are sufficient to drive responses in action observation and execution neurons in macaque ventral premotor cortex.

Neurons responding during action execution and action observation were discovered in the ventral premotor cortex 3 decades ago. However, the visual features that drive the responses of action observation/execution neurons (AOENs) have not been revealed at present. We investigated the neural responses of AOENs in ventral premotor area F5c of 4 macaques during the observation of action videos and crucial control stimuli. The large majority of AOENs showed highly phasic responses during the action videos, with a preference for the moment that the hand made contact with the object. They also responded to an abstract shape moving towards but not interacting with an object, even when the shape moved on a scrambled background, implying that most AOENs in F5c do not require the perception of causality or a meaningful action. Additionally, the majority of AOENs responded to static frames of the videos. Our findings show that very elementary stimuli, even without a grasping context, are sufficient to drive responses in F5c AOENs.

Impact of a mindfulness-based intervention on neurobehavioral functioning and its association with large-scale brain networks in preterm young adolescents.

Adolescents born very preterm (VPT; <32 weeks of gestation) face an elevated risk of executive, behavioral, and socioemotional difficulties. Evidence suggests beneficial effects of mindfulness-based intervention (MBI) on these abilities. This study seeks to investigate the association between the effects of MBI on executive, behavioral, and socioemotional functioning and reliable changes in large-scale brain networks dynamics during rest in VPT young adolescents who completed an 8-week MBI program. Neurobehavioral assessments and resting-state functional magnetic resonance imaging were performed before and after MBI in 32 VPT young adolescents. Neurobehavioral abilities in VPT participants were compared with full-term controls. In the VPT group, dynamic functional connectivity was extracted by using the innovation-driven coactivation patterns framework. The reliable change index was used to quantify change after MBI. A multivariate data-driven approach was used to explore associations between MBI-related changes on neurobehavioral measures and temporal brain dynamics. Compared with term-born controls, VPT adolescents showed reduced executive and socioemotional functioning before MBI. After MBI, a significant improvement was observed for all measures that were previously reduced in the VPT group. The increase in executive functioning, only, was associated with reliable changes in the duration of activation of large-scale brain networks, including frontolimbic, amygdala-hippocampus, dorsolateral prefrontal, and visual networks. The improvement in executive functioning after an MBI was associated with reliable changes in large-scale brain network dynamics during rest. These changes encompassed frontolimbic, amygdala-hippocampus, dorsolateral prefrontal, and visual networks that are related to different executive processes including self-regulation, attentional control, and attentional awareness of relevant sensory stimuli.

Delay of reinforcement switches attention between elements of a compound stimulus in humans, Reynolds (1961) revisited

One experiment in instrumental conditioning studied the effect of delayed reinforcement on attention, considered as the stimulus control produced by each element of a compound sample stimulus (CSS). A two-element (shape and color) CSS indicated the response to be reinforced between three comparison stimuli in an online matching-to-sample task with human participants. Forty-eight university students were assigned to three groups with different reinforcement delays: 0 s, 8 s, and 16 s (D0, D8, and D16). After learning the task, a separate test took place, with the elements of the CSS presented separately. Group D0 responded more to the shape. The D8 group responded to both elements, while the D16 group responded more to the color. Results showed that attention to each element of the CSS changes as reinforcement delay increases. These findings are similar to those of Urcelay and Miller (2009) on Pavlovian conditioning, pointing out similarities between Reynolds’ findings and Pavlovian overshadowing.

The Analysis of Peer Attention as a Prerequisite for Observational Stimulus Control to Address Learning Conditions for Children with Disabilities

The Analysis of Peer Attention as a Prerequisite for Observational Stimulus Control to Address Learning Conditions for Children with Disabilities

Merging meaningful classes and abstract equivalence classes by exclusion.

The current experiment assessed whether relating abstract stimuli with familiar pictures by exclusion would produce the formation of a meaningful equivalence class. Ten participants learned conditional discrimination relations with abstract stimuli and established equivalence classes (ABC classes). They then learned DA (D1A1, D2A2, and D3A3) conditional discriminations with written words as D stimuli; two words (D1 and D2) were meaningful stimuli in the participants verbal community ("Dentist" and "Baker"), whereas the third (D3) was a pseudoword ("Tabilu"). In testing trials, participants evidenced derived relations between pictures related preexperimentally to D1 and D2 with the experimental equivalence classes related to D1 and D2. For some participants, the decontextualized stimuli were a set of boat pictures (Condition 1), whereas for others they were a set of miscellaneous pictures (Condition 2). Participants in both conditions successfully matched decontextualized pictures (unrelated to dentist and baker contexts) to all abstract stimuli in the class related to D3 (exclusion responding). In Condition 1 the meaning reported to the word Tabilu was similar across participants, but in Condition 2 participants showed more variations to answer to the meaning of Tabilu. These results suggest that exclusion learning can occur under different stimulus control topographies.

Exploring the impact of supercrip portrayal in TV drama: assessing attitude shifts toward people with autism spectrum disorder and intellectual disability

Media’s influence on societal views of disability remains an area of developing understanding. This study scrutinizes how ‘supercrip’ narratives in TV dramas—depictions of individuals with disabilities exhibiting superpowers or conquering challenges—affect public attitudes. Using two different ‘supercrip’ examples and a control, the study explores multidimensional attitude shifts toward individuals with Autism Spectrum Disorder (ASD) and Intellectual Disability (ID) following exposure to ‘supercrip’ portrayals in fiction alongside a control stimulus. While realistic disability narratives did not significantly alter attitudes, responses varied with the disability type. Unrealistic portrayals, though eliciting mixed reactions, notably increased engagement and awareness of disability issues. The study indicates that increased viewer engagement and awareness could lead to nuanced, long-term attitude shifts. Notably, more authentic portrayals of ID did not markedly change attitudes toward ID but influenced cognitive attitudes toward ASD, underlining the complexity of audience responses. Positive disability representations in media can catalyze cognitive attitude shifts, but their broader impact on societal attitudes remains partially understood. This highlights the potential of media portrayals to foster attitude changes through sustained exposure, emphasizing the importance of diverse and thoughtful representations in media.

Effects of script‐fading on social initiations during discrete‐trial teaching with children with autism

AbstractThe present study evaluated the use of auditory scripts and script‐fading procedures to teach three children with autism to request additional instruction, select teaching materials, and solicit confirmation during discrete‐trial teaching. Scripts were placed on instructional materials to evoke initiations, and script fading strategies were used to transfer stimulus control to the materials used for each discrete‐trial activity. A multiple‐probe across‐activities design was used. Generalization of initiations was promoted by teaching to multiple exemplars, including common stimuli, and using naturally maintaining contingencies. The results showed that scripts and script‐fading procedures were effective in increasing the number of initiations made during discrete‐trial teaching, and generalization across activities, settings, and instructors. These procedures provide a way to increase the number of opportunities for initiations during discrete‐trial teaching in place of passively waiting between instructor‐initiated trials.

From Conventional to Programmable Matter Systems: A Review of Design, Materials, and Technologies

Programmable matter represents a system of elements whose interactions can be programmed for a certain behavior to emerge (e.g., color, shape) upon suitable commands (e.g., instruction, stimuli) by altering its physical characteristics. Even though its appellation may refer to a morphable physical material, programmable matter has been represented through several approaches from different perspectives (e.g., robots, smart materials) that seek the same objective: controllable behavior such as smart shape alteration. Researchers, engineers, and artists have expressed interest in the development of smart modeling clay as a novel alternative to conventional matter and classical means of prototyping. Henceforth, users will be able to do/undo/redo forms based on computed data (CAD) or interactions (sensors), which will help them unlock more features and increase the usefulness of their products. However, with such a promising technology, many challenges need to be addressed, as programmable matter relies on energy consumption, data transmission, stimuli control, and shape formation mechanisms. Furthermore, numerous devices and technologies are created under the name of programmable matter, which may pose ambiguity to the control strategies. In this study, we determine the basic operations required to form a shape, then review different realizations using the shape shifting ability of programmable matter and their fitting classifications, and finally discuss potential challenges.

Impact of equivalence class training on same/different learning by pigeons.

Separating and isolating the contributions of perception to concept formation in animals has been a long-standing and persistent challenge. Here we describe a novel approach to assessing this question by using equivalence training consisting of unrelated images as the basis for subsequent same/different (S/D) learning. Following equivalence class training, two groups of pigeons attempted to learn a go/no-go discrimination task constructed from these classes. In the go/no-go task, a consistent group was given an S/D assignment that aligned with this prior training (same vs. different classes). An inconsistent group was given go/no-go assignments that were misaligned with their established classes. The consistent group exhibited better learning and stimulus control in their S/D task than did the inconsistent group. These results suggest that pigeons can use trained properties derived from class-based information to learn an S/D task without the aid of perceptual similarity. This novel approach holds promise for helping to evaluate the contribution of perceptual similarity to different types of concept learning. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

0445 Comparing Adherence for a Prescription Digital Therapeutic for Insomnia Across Controlled and Real-world Settings

Abstract Introduction Digital Cognitive Behavioral Therapy for insomnia (dCBT-I) offers scalable first-line treatment versus face-to-face care, but a potential trade-off is lower treatment adherence. In clinical trials, adherence rates to dCBT-I have been variable, and there is no defined standard for acceptable adherence to dCBT-I. Further, the generalizability of adherence data from clinical trials to real-world settings is unknown. This study compared adherence data from two dCBT-I clinical trials to adherence within a real-world study. Methods The dCBT-I intervention was a prescription digital therapeutic (Somryst) that includes 6 treatment Cores (e.g., sleep restriction, stimulus control) delivered over 9 weeks. Participants must complete a Core and wait 7 days before starting the next Core. Clinical trial adherence data was derived from two RCTs previously submitted to FDA as part of its authorization (RCT-1 [USA; N=151, age 21-65 years] and RCT-2 [Australia; N=574, age 18-64 years]). Real-world adherence data was derived from a prospective, single-arm, pragmatic clinical study (DREAM [USA; N=991, age ≥18 years]). Adherence was defined as the percentage of participants with dCBT-I access who completed each treatment Core. Automated notifications prompt engagement with the therapeutic. Results Real-world adherence rates from the DREAM study were 94.1%, 71.1%, 60.7%, 55.7%, 49.1%, and 42.8% for Cores 1-6. For RCT-1, adherence rates of Cores 1-6 were 93.4%, 88.1%, 76.8%, 67.5%, 66.9%, and 60.3%, respectively, whereas adherence rates of Cores 1-6 in RCT-2 were 80.8%, 67.9%, 60.5%, 54.0%, 47.6%, and 40.8%. Conclusion Real-world adherence to dCBT-I appears comparable to RCTs, with the largest decrease occurring between Cores 1 and 2. These findings support the generalizability of adherence data from RCTs and potential opportunities to increase adherence early in treatment. Further work is needed to determine acceptable standards for adherence to dCBT-I in the real world. Support (if any) DREAM study: Pear Therapeutics, Inc. RCT-1: NIMH grant #R01 MH86758; NCT01438697. RCT-2: NHMRC project grant #1005867; ACTRN12611000121965. Additional support provided by Nox Health, Inc.

Beyond visual integration: sensitivity of the temporal-parietal junction for objects, places, and faces

One important role of the TPJ is the contribution to perception of the global gist in hierarchically organized stimuli where individual elements create a global visual percept. However, the link between clinical findings in simultanagnosia and neuroimaging in healthy subjects is missing for real-world global stimuli, like visual scenes. It is well-known that hierarchical, global stimuli activate TPJ regions and that simultanagnosia patients show deficits during the recognition of hierarchical stimuli and real-world visual scenes. However, the role of the TPJ in real-world scene processing is entirely unexplored. In the present study, we first localized TPJ regions significantly responding to the global gist of hierarchical stimuli and then investigated the responses to visual scenes, as well as single objects and faces as control stimuli. All three stimulus classes evoked significantly positive univariate responses in the previously localized TPJ regions. In a multivariate analysis, we were able to demonstrate that voxel patterns of the TPJ were classified significantly above chance level for all three stimulus classes. These results demonstrate a significant involvement of the TPJ in processing of complex visual stimuli that is not restricted to visual scenes and that the TPJ is sensitive to different classes of visual stimuli with a specific signature of neuronal activations.

The generalization-across-dimensions model applied to conditional temporal discrimination.

Can simple choice conditional-discrimination choice be accounted for by recent quantitative models of combined stimulus and reinforcer control? In Experiment 1, two sets of five blackout durations, one using shorter intervals and one using longer intervals, conditionally signaled which subsequent choice response might provide food. In seven conditions, the distribution of blackout durations across the sets was varied. An updated version of the generalization-across-dimensions model nicely described the way that choice changed across durations. In Experiment 2, just two blackout durations acted as the conditional stimuli and the durations were varied over 10 conditions. The parameters of the model obtained in Experiment 1 failed adequately to predict choice in Experiment 2, but the model again fitted the data nicely. The failure to predict the Experiment 2 data from the Experiment 1 parameters occurred because in Experiment 1 differential control by reinforcer locations progressively decreased with blackout durations, whereas in Experiment 2 this control remained constant. These experiments extend the ability of the model to describe data from procedures based on concurrent schedules in which reinforcer ratios reverse at fixed times to those from conditional-discrimination procedures. Further research is needed to understand why control by reinforcer location differed between the two experiments.

Strangers like me: birds respond equally to a familiar and an unfamiliar sentinel species' alarm calls, but respond less to non‐core and non‐sentinel's alarm calls

Alarm signals have evolved to communicate imminent threats to conspecifics but animals may also perceive other species' alarm displays to obtain adaptive information. In birds, mixed‐species foraging flocks are often structured around a focal sentinel species, which produces reliable alarm calls that inform eavesdropping non‐sentinel heterospecifics about predation risk. Ongoing work has revealed that several species can recognize the alarm calls of certain sentinel species even without prior encounters, including when these are from distant biogeographic regions. Similar work has yet to examine whether naive subjects' responses to unfamiliar sentinel alarm calls differ from responses to non‐sentinel alarm calls. Here we played the alarm calls of three subtropical Asian bird species that participate in mixed species flocks, to temperate North American birds. Birds responded most to the alarm call of an allopatric core sentinel and a local sympatric sentinel control species, less so to an allopatric non‐core sentinel, and least so to an allopatric non‐sentinel and a negative control stimulus. These patterns provide evidence that broad phylogenetic and geographic recognition is a pertinent aspect of sentinel alarm calls in general.

MGlu2 and mGlu3 receptor negative allosteric modulators attenuate the interoceptive effects of alcohol in male and female rats

RationaleThe subjective effects of alcohol are associated with alcohol use disorder (AUD) vulnerability and treatment outcomes. The interoceptive effects of alcohol are part of these subjective effects and can be measured in animal models using drug discrimination procedures. The newly developed mGlu2 and mGlu3 negative allosteric modulators (NAMs) are potential therapeutics for AUD and may alter interoceptive sensitivity to alcohol. ObjectivesTo determine the effects of mGlu2 and mGlu3 NAMs on the interoceptive effects of alcohol in rats. MethodsLong-Evans rats were trained to discriminate the interoceptive stimulus effects of alcohol (2.0 g/kg, i.g.) from water using both operant (males only) and Pavlovian (male and female) drug discrimination techniques. Following acquisition training, an alcohol dose-response (0, 0.5, 1.0, 2.0 g/kg) experiment was conducted to confirm stimulus control over behavior. Next, to test the involvement of mGlu2 and mGlu3, rats were pretreated with the mGlu2-NAM (VU6001966; 0, 3, 6, 12 mg/kg, i.p.) or the mGlu3-NAM (VU6010572; 0, 3, 6, 12 mg/kg, i.p.) before alcohol administration (2.0 g/kg, i.g.). ResultsIn Pavlovian discrimination, male rats showed greater interoceptive sensitivity to 1.0 and 2.0 g/kg alcohol compared to female rats. Both mGlu2-NAM and mGlu3-NAM attenuated the interoceptive effects of alcohol in male and female rats using Pavlovian and operant discrimination. There may be a potential sex difference in response to the mGlu2-NAM at the highest dose tested. ConclusionsMale rats may be more sensitive to the interoceptive effects of the 2.0 g/kg alcohol training dose compared to female rats. Both mGlu2-and mGlu3-NAM attenuate the interoceptive effects of alcohol in male and female rats. These drugs may have potential for treatment of AUD in part by blunting the subjective effects of alcohol.

Naturalistic use of psychedelics does not modulate processing of self-related stimuli (but it might modulate attentional mechanisms): An event-related potentials study.

Classic psychedelics are able to profoundly alter the state of consciousness and lead to acute experiences of ego dissolution - the blurring of the distinction between representations of self and the external world. However, whether repeated use of psychedelics is associated with more prolonged and permanent modifications to the concept of self remains to be investigated. Therefore, we conducted a preregistered, cross-sectional study in which experienced psychedelics users (15 or more lifetime experiences with psychedelics; N = 56) were compared to nonusers (N = 57) in terms of neural reactivity to a Self-name (i.e., each participant's own name) stimulus, which is known to robustly activate a representation of self. Two control stimuli were additionally used: an Other-name stimulus, as a passive control condition in which no reaction was required, and a Target-name stimulus, to which participants provided a manual response and which thus constituted an active control condition. Analysis of the amplitude of the P300 ERP component evoked by the Self- or Target-names revealed no difference between the psychedelics users and nonusers. However, psychedelic users exhibited increased P300 amplitude during perception of Other-names. In addition, in comparison to nonusers, psychedelics users exhibited a smaller increase in P300 amplitude when processing the task-relevant Target-names (in relation to both Self- and Other-names). Therefore, our data suggests that regular naturalistic use of psychedelics may not be related to long-term changes in the representation of self, but it might potentially affect the allocation of attentional resources to task-relevant stimuli.

Elevator music as a tool for the quantitative characterization of reward.

While certain musical genres and songs are widely popular, there is still large variability in the music that individuals find rewarding or emotional, even among those with a similar musical enculturation. Interestingly, there is one Western genre that is intended to attract minimal attention and evoke a mild emotional response: elevator music. In a series of behavioral experiments, we show that elevator music consistently elicits low pleasure and surprise. Participants reported elevator music as being less pleasurable than music from popular genres, even when participants did not regularly listen to the comparison genre. Participants reported elevator music to be familiar even when they had not explicitly heard the presented song before. Computational and behavioral measures of surprisal showed that elevator music was less surprising, and thus more predictable, than other well-known genres. Elevator music covers of popular songs were rated as less pleasurable, surprising, and arousing than their original counterparts. Finally, we used elevator music as a control for self-selected rewarding songs in a proof-of-concept physiological (electrodermal activity and piloerection) experiment. Our results suggest that elevator music elicits low emotional responses consistently across Western music listeners, making it a unique control stimulus for studying musical novelty, pleasure, and surprise.

The Motion-Silencing Illusion Depends on Object-Centered Representation.

Motion silencing is a striking and unexplained visual illusion wherein changes that are otherwise salient become difficult to perceive when the changing elements also move. We develop a new method for quantifying illusion strength (Experiments 1a and 1b), and we demonstrate a privileged role for rotational motion on illusion strength compared with highly controlled stimuli that lack rotation (Experiments 2a to 3b). These contrasts make it difficult to explain the illusion in terms of lower-level detection limits. Instead, we explain the illusion as a failure to attribute changes to locations. Rotation exacerbates the illusion because its perception relies upon structured object representations. This aggravates the difficulty of attributing changes by demanding that locations are referenced relative to both an object-internal frame and an external frame. Two final experiments (4a and 4b) add support to this account by employing a synchronously rotating external frame of reference that diminishes otherwise strong motion silencing. All participants were Johns Hopkins University undergraduates.