Read by QxMD icon Read

Stimulus equivalence

Jamie Cummins, Bryan Roche, Ian Tyndall, Aoife Cartwright
Implicit measures have been hypothesized to allow researchers to ascertain the existence and strength of relations between stimuli, often in the context of research on attitudes. However, little controlled behavioral research has focused on whether stimulus relations, and the degree of relatedness within such relations, are indexed by implicit measures. The current study eamined this issue using a behavior-analytic implicit-style stimulus relation indexing procedure known as the Function Acquisition Speed Test (FAST)...
May 17, 2018: Journal of the Experimental Analysis of Behavior
Daniel C Comstock, Ramesh Balasubramaniam
Tapping in synchrony to an isochronous rhythm involves several key functions of the sensorimotor system including timing, prediction and error correction. While auditory sensorimotor synchronization (SMS) has been well studied, much less is known about mechanisms involved in visual SMS. By comparing error correction in auditory and visual SMS, it can be determined if the neural mechanisms for detection and correction of synchronization errors are generalized or domain specific. To study this problem, we measured EEG while subjects tapped in synchrony to separate visual and auditory metronomes that both contained small temporal perturbations to induce errors...
May 13, 2018: Neuropsychologia
H N Phillips, T E Cope, L E Hughes, J Zhang, J B Rowe
Choosing between equivalent response options requires the resolution of ambiguity. One could facilitate such decisions by monitoring previous actions and implementing transient or arbitrary rules to differentiate response options. This would reduce the entropy of chosen actions. We examined voluntary action decisions during magnetoencephalography, identifying the spatiotemporal correlates of stimulus- and choice-entropy. Negative correlations between frontotemporal activity and entropy of past trials were observed after participants' responses, reflecting sequential monitoring of recent events...
May 8, 2018: Scientific Reports
Ghaith Tarawneh, Vivek Nityananda, Ronny Rosner, Steven Errington, William Herbert, Sandra Arranz-Paraíso, Natalie Busby, Jimmy Tampin, Jenny Read, Ignacio Serrano-Pedraza
Recently, we showed a novel property of the Hassenstein-Reichardt detector, namely that insect motion detection can be masked by 'undetectable' noise, i.e. visual noise presented at spatial frequencies at which coherently moving gratings do not elicit a response (Tarawneh et al., 2017). That study compared the responses of human and insect motion detectors using different ways of quantifying masking (contrast threshold in humans and masking tuning function in insects). In addition, some adjustments in experimental procedure, such as presenting the stimulus at a short viewing distance, were necessary to elicit a response in insects...
April 26, 2018: Biology Open
Pradeep Lal, Hideyuki Tanabe, Maximiliano L Suster, Deepak Ailani, Yuri Kotani, Akira Muto, Mari Itoh, Miki Iwasaki, Hironori Wada, Emre Yaksi, Koichi Kawakami
BACKGROUND: Fear conditioning is a form of learning essential for animal survival and used as a behavioral paradigm to study the mechanisms of learning and memory. In mammals, the amygdala plays a crucial role in fear conditioning. In teleost, the medial zone of the dorsal telencephalon (Dm) has been postulated to be a homolog of the mammalian amygdala by anatomical and ablation studies, showing a role in conditioned avoidance response. However, the neuronal populations required for a conditioned avoidance response via the Dm have not been functionally or genetically defined...
April 25, 2018: BMC Biology
F Ravanetti, F Gazza, D D'Arrigo, G Graiani, A Zamuner, M Zedda, E Manfredi, M Dettin, A Cacchioli
Osteoblast cell adhesion to the extracellular matrix is established through two main pathways: one is mediated by the binding between integrin and a minimal adhesion sequence (RGD) on the extracellular protein, the other is based on the interactions between transmembrane proteoglycans and heparin-binding sequences found in many matrix proteins. The aim of this study is the evaluation in an in vivo endosseous implant model of the early osteogenic response of the peri-implant bone to a biomimetic titanium surface functionalized with the retro-inverso 2DHVP peptide, an analogue of Vitronectin heparin binding site...
April 18, 2018: Annals of Anatomy, Anatomischer Anzeiger: Official Organ of the Anatomische Gesellschaft
Liang Xu, Hongyu Su, Xiaoyuan Xie, Pei Yan, Junjiao Li, Xifu Zheng
Fear generalization is an etiologically significant indicator of anxiety disorders, and understanding how to inhibit it is important in their treatment. Prior studies have found that reducing fear generalization using a generalization stimulus (GS) is ineffective in removing a conditioned fear that incorporates local features, and that topological properties appear to play a comparatively more significant role in the processes of perception and categorization. Our study utilized a conditioned-fear generalization design to examine whether the topological properties of stimuli influence the generalization and return of fear...
2018: Frontiers in Psychology
Iris Grothe, David Rotermund, Simon David Neitzel, Sunita Mandon, Udo Alexander Ernst, Andreas K Kreiter, Klaus Richard Pawelzik
Selective attention allows focusing on only part of the incoming sensory information. Neurons in the extrastriate visual cortex reflect such selective processing when different stimuli are simultaneously present in their large receptive fields. Their spiking response then resembles the response to the attended stimulus when presented in isolation. Unclear is where in the neuronal pathway attention intervenes to achieve such selective signal routing and processing. To investigate this question, we tagged two equivalent visual stimuli by independent broadband luminance noise and used the spectral coherence of these behaviorally irrelevant signals with the field potential of a local neuronal population in male macaque monkeys' area V4 as a measure for their respective causal influences...
April 4, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Madeline Dykes, Aylin Klarer, Blake Porter, Jonas Rose, Michael Colombo
We recorded from neurons in the nidopallium caudolaterale, the avian equivalent of the mammalian prefrontal cortex, in four birds. The birds were required to peck a stimulus that indicated the amount of reward they would receive (small or large) after a certain delay (short or long). We found that the activity of neurons in the nidopallium caudolaterale was modulated by the value of the reward that would be received based on the reward amount and the delay to reward. We found that value coding was most prominent during the presentation of the sample period, and less so during the delay period and during the presentation of the reward itself...
March 29, 2018: Scientific Reports
Joaquín Menéndez, Federico Sánchez, Ignacio Polti, Sebastián Idesis, Matías Avellaneda, Ángel Tabullo, Alberto Iorio
This study investigates the influences of: 1) the task order of two stimulus equivalence classes (SEC) probes, and 2) the possible differences within the equivalence trial types. These factors were analyzed together on both behavioral and event-related potentials (ERP) data. Two groups of normal subjects participated in two successive sessions. In the first session, all participants were trained in the baseline relations among visual stimuli (pseudo-words). In the second session, one group performed the matching-to-sample (MTS) equivalence tests before the equivalence-relatedness-priming (EBRP) task, while the other group performed both tasks in reverse order...
March 20, 2018: Behavioural Brain Research
Erica C Dresselhaus, Matthew C H Boersma, Mollie K Meffert
Long-term forms of brain plasticity share a requirement for changes in gene expression induced by neuronal activity. Mechanisms that determine how the distinct and overlapping functions of multiple activity-responsive transcription factors, including nuclear factor kappa B (NF-κB), give rise to stimulus-appropriate neuronal responses remain unclear. We report that the p65/RelA subunit of NF-κB confers subcellular enrichment at neuronal dendritic spines and engineer a p65 mutant that lacks spine-enrichment (ΔSEp65) but retains inherent transcriptional activity equivalent to wild-type p65...
March 19, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Dana Maslovat, Joelle Hajj, Anthony N Carlsen
During reaction time (RT) tasks, participants respond faster to multiple stimuli from different modalities as compared to a single stimulus, a phenomenon known as the redundant signal effect (RSE). Explanations for this effect typically include coactivation arising from the multiple stimuli, which results in enhanced processing of one or more response production stages. The current study compared empirical RT data with the predictions of a model in which initiation-related activation arising from each stimulus is additive...
March 16, 2018: Neuroscience Letters
Emily Lauren Graczyk, Benoit Delhaye, Matthew A Schiefer, Sliman J Bensmaia, Dustin J Tyler
Sensory systems adapt their sensitivity to ambient stimulation levels to improve their responsiveness to changes in stimulation. The sense of touch is also subject to adaptation, as evidenced by the desensitization produced by prolonged vibratory stimulation of the skin. Electrical stimulation of nerves elicits tactile sensations that can convey feedback for bionic limbs. In this study, we investigate whether artificial touch is also subject to adaptation, despite the fact that the peripheral mechanotransducers are bypassed...
March 19, 2018: Journal of Neural Engineering
William J McIlvane, Joanne B Kledaras, Christophe J Gerard, Lorin Wilde, David Smelson
A few noteworthy exceptions notwithstanding, quantitative analyses of relational learning are most often simple descriptive measures of study outcomes. For example, studies of stimulus equivalence have made much progress using measures such as percentage consistent with equivalence relations, discrimination ratio, and response latency. Although procedures may have ad hoc variations, they remain fairly similar across studies. Comparison studies of training variables that lead to different outcomes are few. Yet to be developed are tools designed specifically for dynamic and/or parametric analyses of relational learning processes...
March 12, 2018: Behavioural Processes
Mahan Azadpour, Colette M McKay, Mario A Svirsky
Stimulation pulse rate affects current amplitude discrimination by cochlear implant (CI) users, indicated by the evidence that the JND (just noticeable difference) in current amplitude delivered by a CI electrode becomes larger at higher pulse rates. However, it is not clearly understood whether pulse rate would affect discrimination of speech intensities presented acoustically to CI processors, or what the size of this effect might be. Intensity discrimination depends on two factors: the growth of loudness with increasing sound intensity and the loudness JND (or the just noticeable loudness increment)...
March 12, 2018: Journal of the Association for Research in Otolaryngology: JARO
Nino Andricevic, Mirko Junge, Jonas Krampe
OBJECTIVE: The objective of this article was the construction of injury risk functions (IRFs) for front row occupants in oblique frontal crashes and a comparison to IRF of nonoblique frontal crashes from the same data set. METHOD: Crashes of modern vehicles from GIDAS (German In-Depth Accident Study) were used as the basis for the construction of a logistic injury risk model. Static deformation, measured via displaced voxels on the postcrash vehicles, was used to calculate the energy dissipated in the crash...
March 9, 2018: Traffic Injury Prevention
Kyoung-Ho Ryu, Keulame Song, Tae-Young Lim, Won-Jun Choi, Yun-Hong Kim, Hyun-Soo Kim
BACKGROUND: Minimum alveolar concentration (MAC) has traditionally been used to compare the potency of volatile anesthetics. However, as it reflects the spinal mechanism of immobility rather than the cerebral mechanism of analgesia and hypnosis, it is doubtful that equi-MAC connotes equivalent analgesic or hypnotic potency. The level of analgesia and hypnosis can be assessed using surgical pleth index and bispectral index (BIS) values, respectively. This study was designed to compare the surgical pleth index and BIS values produced by equi-MAC of desflurane and sevoflurane in patients undergoing single-agent volatile anesthesia...
June 2018: Anesthesiology
Elberto A Plazas, Carlos-Wilcen Villamil
This study presents three experiments that aimed to show the formation of stimulus equivalence relations among stimuli that had been previously related only by exclusion. In Experiment 1, participants were trained on baseline conditional discriminations to establish two 3-member equivalence classes. Then, they were exposed to exclusion trials, without feedback, in which undefined stimuli had to be matched by rejecting the defined baseline stimuli. Finally, participants responded to test trials evaluating the emergence of symmetry and transitivity among the undefined stimuli from the exclusion trials...
March 2018: Journal of the Experimental Analysis of Behavior
Anthony A Wright, Debbie M Kelly, Jeffrey S Katz
This article describes an approach for training a variety of species to learn the abstract concept of same/different, which in turn forms the basis for testing proactive interference and list memory. The stimulus set for concept-learning training was progressively doubled from 8, 16, 32, 64, 128 . . . to 1,024 different pictures with novel-stimulus transfer following learning. All species fully learned the same/different abstract concept: capuchin and rhesus monkeys learned more readily than pigeons; nutcrackers and magpies were at least equivalent to monkeys and transferred somewhat better following initial training sets...
February 28, 2018: Learning & Behavior
Xin Chen, Jinsong Gao, Bonan Kang
We introduce a structurally reconfigurable metasurface which is made of shape memory alloys (SMA). It could change the morphology of the unit cells repeatedly as we expect in response to a thermal stimulus and realize a tuning range from 13.3GHz to 17.2GHz for both polarizations simultaneously. Equivalent circuit models describe the operational principle and design methodology, the physical mechanism is interpreted with the variation of surface current distribution on the structure. The experimental results coincide with the numerical simulations, making the all-metal metasurface an attractive choice for manipulating the electromagnetic wave in a wide range of spectrums with the merits of higher controllability for dynamic behavior and greater freedom for design and manufacturing...
February 19, 2018: Optics Express
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"