Different Types Of Stimuli Research Articles

Assessment of a standardized EEG reactivity protocol after cardiac arrest

ObjectiveReactivity assessment during EEG might provide important prognostic information in post-anoxic coma. It is still unclear how best to perform reactivity testing and how it might be affected by hypothermia. Our primary aim was to determine and compare the effectiveness, inter-rater reliability and prognostic value of different types of stimulus for EEG reactivity testing, using a standardized stimulation protocol and standardized definitions. Our secondary aims were to assess the effect of hypothermia on these measures, and to determine the prognostic value of a simplified sequence with the three most efficient stimuli. MethodsProspective single-center cohort of post-anoxic comatose patients admitted to the intensive care unit of an academic medical center between January 1, 2016 and December 31, 2018 and receiving continuous EEG monitoring (CEEG). Reactivity was assessed using standardized definitions and standardized sequence of stimuli: auditory (mild noise and loud noise), tactile (shaking), nociceptive (nostril tickling, trapezius muscle squeezing, endotracheal tube suctioning), and visual (passive eye opening). Gwet’s AC1 and percent agreement (PA) were used to measure inter-rater agreement (IRA). Ability to predict favorable neurological outcome (defined as a Cerebral Performance Category of 1 to 2: no disability to moderate disability) was measured with sensitivity (Se), specificity (Sp), accuracy, and odds ratio [OR]. These were calculated for each stimulus type and at the level of the entire sequence comprising all the stimuli. ResultsOne-hundred and fifteen patients were included and 242 EEG epochs were analyzed. Loud noise, shaking and trapezius muscle squeezing most frequently elicited EEG reactivity (42%, 38% and 38%, respectively) but were all inferior to the entire sequence, which elicited reactivity in 58% cases. The IRA for reactivity to individual stimuli varied from moderate to good (AC1:58–69%; PA:56–68%) and was the highest for loud noise (AC1:69%; PA:68%), trapezius muscle squeezing (AC1:67%; PA:65%) and passive eye opening (AC1:68%; PA:64%). Mild (odds ratio [OR]:11.0; Se:70% and Sp:86%) and loud noises (OR:27.0; Se:73% and Sp:75%), and trapezius muscle squeezing (OR:15.3; Se:76% and Sp:83%) during hypothermia had the best predictive value for favorable neurological outcome, although each was inferior to the whole sequence (OR:60.2; Se:91% and Sp:73%). A simplified sequence of loud noise, shaking and trapezius muscle squeezing had the same performance for predicting neurological outcome as the entire sequence. Hypothermia did not significantly affect the effectiveness of stimulation, but IRA was slightly better during hypothermia, for all stimuli. Similarly, the predictive value was higher during hypothermia than during normothermia. ConclusionsDespite a standardized stimulation protocol and standardized definitions, the IRA of EEG reactivity testing in post-anoxic comatose patients was only good at best (AC1 < 70%), and its predictive value for neurological outcome remained imperfect, in particular with Sp values < 90%. While no single stimulus appeared superior to others, a full sequence using all stimuli or a simplified sequence comprising loud noise, shaking and trapezius muscle squeezing had the best combination of IRA and predictive value. SignificanceThis study stresses the necessity to use multiple stimulus types to improve the predictive value of reactivity testing in post-anoxic coma and confirms that it is not affected by hypothermia.

Functional brain response to painful mechanical stimulation and painful stimulation in areas of secondary mechanical hyperalgesia: A meta-analysis

This study evaluated brain activity in response to painful and nonpainful mechanical stimuli within an area of secondary mechanical hyperalgesia (SMH) compared to non-sensitized areas. We performed a meta-analysis summarizing responses to three different types of stimuli. Furthermore, we summarize reported results of contrast maps comparing brain responses to mechanical stimuli in SMH that in non-sensitized regions. We investigated 3 categories of brain responses to 1) nonpainful mechanical stimuli in 226 participants across 16 studies, 2) painful mechanical stimuli in 164 participants across 11 studies, 3) mechanical stimuli in SMH in 84 participants across 7 studies, and 4) contrast maps of brain responses to mechanical stimuli in SMH versus painful mechanical stimuli in 107 participants across 7 studies. We used GingerALE 3.0.2 to create meta-analytic statistical parametric maps. We generated summary Z-maps by subtracting negative maps from positive maps. Maps were Z-value thresholded at 3.29 and a cluster size of 272 mm3. Nonpainful mechanical stimuli activated bilateral parietal operculum (PO), right inferior frontal gyrus (IFG) and inferior parietal lobule. Painful mechanical stimuli activated bilateral PO, bilateral IFG pars opercularis, and deactivation in bilateral superior occipital gyri. Mechanical stimuli in SMH activated bilateral PO, bilateral dorsal anterior insula, left postcentral gyrus and supragenual anterior cingulate cortex. The contrast of mechanical stimuli in SMH versus painful mechanical stimuli included greater activation in right thalamus, left lateral periaqueductal gray, right dorsolateral prefrontal (DLPFC), right Rolandic opercular, bilateral primary somatosensory, anterior midcingulate, and right middle insular cortices. Contrast results revealed greater activation during SMH compared to painful mechanical stimulation in right thalamus, right DLPFC, and left lateral periaqueductal gray. These areas are involved in pain modulation (hyperalgesic and analgesic), while responses in mid insula and mid cingulate cortices are prominent in processing salient and painful stimuli. Neurosurgery Pain Research Institute, Postdoctoral Scholarship (TJM). This study evaluated brain activity in response to painful and nonpainful mechanical stimuli within an area of secondary mechanical hyperalgesia (SMH) compared to non-sensitized areas. We performed a meta-analysis summarizing responses to three different types of stimuli. Furthermore, we summarize reported results of contrast maps comparing brain responses to mechanical stimuli in SMH that in non-sensitized regions. We investigated 3 categories of brain responses to 1) nonpainful mechanical stimuli in 226 participants across 16 studies, 2) painful mechanical stimuli in 164 participants across 11 studies, 3) mechanical stimuli in SMH in 84 participants across 7 studies, and 4) contrast maps of brain responses to mechanical stimuli in SMH versus painful mechanical stimuli in 107 participants across 7 studies. We used GingerALE 3.0.2 to create meta-analytic statistical parametric maps. We generated summary Z-maps by subtracting negative maps from positive maps. Maps were Z-value thresholded at 3.29 and a cluster size of 272 mm3. Nonpainful mechanical stimuli activated bilateral parietal operculum (PO), right inferior frontal gyrus (IFG) and inferior parietal lobule. Painful mechanical stimuli activated bilateral PO, bilateral IFG pars opercularis, and deactivation in bilateral superior occipital gyri. Mechanical stimuli in SMH activated bilateral PO, bilateral dorsal anterior insula, left postcentral gyrus and supragenual anterior cingulate cortex. The contrast of mechanical stimuli in SMH versus painful mechanical stimuli included greater activation in right thalamus, left lateral periaqueductal gray, right dorsolateral prefrontal (DLPFC), right Rolandic opercular, bilateral primary somatosensory, anterior midcingulate, and right middle insular cortices. Contrast results revealed greater activation during SMH compared to painful mechanical stimulation in right thalamus, right DLPFC, and left lateral periaqueductal gray. These areas are involved in pain modulation (hyperalgesic and analgesic), while responses in mid insula and mid cingulate cortices are prominent in processing salient and painful stimuli. Neurosurgery Pain Research Institute, Postdoctoral Scholarship (TJM).

Perceptual Asymmetries and Auditory Processing of Estonian Quantities.

Similar to visual perception, auditory perception also has a clearly described “pop-out” effect, where an element with some extra feature is easier to detect among elements without an extra feature. This phenomenon is better known as auditory perceptual asymmetry. We investigated such asymmetry between shorter or longer duration, and level or falling of pitch of linguistic stimuli that carry a meaning in one language (Estonian), but not in another (Russian). For the mismatch negativity (MMN) experiment, we created four different types of stimuli by modifying the duration of the first vowel [ɑ] (170, 290 ms) and pitch contour (level vs. falling pitch) of the stimuli words (‘SATA,’ ‘SAKI’). The stimuli were synthesized from Estonian words (‘SATA,’ ‘SAKI’) and follow the Estonian language three-way quantity system, which incorporates tonal features (falling pitch contour) together with temporal patterns. This made the meaning of the word dependent on the combination of both features and allows us to compare the relative contribution of duration and pitch contour in discrimination of language stimuli in the brain via MMN generation. The participants of the experiment were 12 Russian native speakers with little or no experience in Estonian and living in Estonia short-term, and 12 Estonian native speakers (age 18–27 years). We found that participants’ perception of the linguistic stimuli differed not only according to the physical features but also according to their native language, confirming that the meaning of the word interferes with the early automatic processing of phonological features. The GAMM and ANOVA analysis of the reversed design results showed that the deviant with longer duration among shorter standards elicited a MMN response with greater amplitude than the short deviant among long standards, while changes in pitch contour (falling vs. level pitch) produced neither strong MMN nor asymmetry. Thus, we demonstrate the effect of language background on asymmetric perception of linguistic stimuli that aligns with those of previous studies (Jaramillo et al., 2000), and contributes to the growing body of knowledge supporting auditory perceptual asymmetry.

Auditory and visual short-term memory: influence of material type, contour, and musical expertise

Short-term memory has mostly been investigated with verbal or visuospatial stimuli and less so with other categories of stimuli. Moreover, the influence of sensory modality has been explored almost solely in the verbal domain. The present study compared visual and auditory short-term memory for different types of materials, aiming to understand whether sensory modality and material type can influence short-term memory performance. Furthermore, we aimed to assess if music expertise can modulate memory performance, as previous research has reported better auditory memory (and to some extent, visual memory), and better auditory contour recognition for musicians than non-musicians. To do so, we adapted the same recognition paradigm (delayed-matching to sample) across different types of stimuli. In each trial, participants (musicians and non-musicians) were presented with two sequences of events, separated by a silent delay, and had to indicate whether the two sequences were identical or different. The performance was compared for auditory and visual materials belonging to three different categories: (1) verbal (i.e., syllables); (2) nonverbal (i.e., that could not be easily denominated) with contour (based on loudness or luminance variations); and (3) nonverbal without contour (pink noise sequences or kanji letters sequences). Contour and no-contour conditions referred to whether the sequence can entail (or not) a contour (i.e., a pattern of up and down changes) based on non-pitch features. Results revealed a selective advantage of musicians for auditory no-contour stimuli and for contour stimuli (both visual and auditory), suggesting that musical expertise is associated with specific short-term memory advantages in domains close to the trained domain, also extending cross-modally when stimuli have contour information. Moreover, our results suggest a role of encoding strategies (i.e., how the material is represented mentally during the task) for short-term-memory performance.

Attentional bias during emotional processing: Behavioral and electrophysiological evidence from an Emotional Flanker Task.

Threatening stimuli seem to capture attention more swiftly than neutral stimuli. This attention bias has been observed under different experimental conditions and with different types of stimuli. It remains unclear whether this adaptive behaviour reflects the function of automatic or controlled attention mechanisms. Additionally, the spatiotemporal dynamics of its neural correlates are largely unknown. The present study investigates these issues using an Emotional Flanker Task synchronized with EEG recordings. A group of 32 healthy participants saw response-relevant images (emotional scenes from IAPS or line drawings of objects) flanked by response-irrelevant distracters (i.e., emotional scenes flanked by line drawings or vice versa). We assessed behavioural and ERP responses drawn from four task conditions (Threat-Central, Neutral-Central, Threat-Peripheral, and Neutral-Peripheral) and subjected these responses to repeated-measures ANOVA models. When presented as response-relevant targets, threatening images attracted faster and more accurate responses. They did not affect response accuracy to targets when presented as response-irrelevant flankers. However, response times were significantly slower when threatening images flanked objects than when neutral images were shown as flankers. This result replicated the well-known Emotional Flanker Effect. Behavioural responses to response-relevant threatening targets were accompanied by significant modulations of ERP activity across all time-windows and regions of interest and displayed some meaningful correlations. The Emotional Flanker Effect was accompanied by a modulation over parietal and central-parietal regions within a time-window between 550-690ms. Such a modulation suggests that the attentional disruption to targets caused by response-irrelevant threatening flankers appears to reflect less neural resources available, which are seemingly drawn away by distracting threatening flankers. The observed spatiotemporal dynamics seem to concur with understanding of the important adaptive role attributed to threat-related attention bias.

Sympathy for the underdog: people are inclined to adopt the emotional perspective of powerless (versus powerful) others

ABSTRACT Upon learning of the story of Cinderella, most people spontaneously adopt the emotional perspective of this helpless young woman rather than of her older sisters who oppress her. The present research examines whether this pattern reveals a general human tendency to empathise more with the emotions of individuals with low (versus high) power. Six experiments (N = 878) examined how power influences the focus of people’s emotional attributions. Participants were presented with situations in which one character exercised power over another one and had to resolve a referential ambiguity by considering the perspective of one or the other character. Results show that participants largely privileged the emotional states of the low-power character over those of the high-power character. This effect was observed with different types of stimuli (comics and video clips), with high- and low-power roles attributed to pairs of different genders (Experiments 1–4) or same gender (Experiments 5–6). Finally, the tendency persisted – though it was reduced – when participants adopted a less passive role with respect to the characters (Experiment 3) and when power occurred in a less despotic way (Experiment 6). Results are discussed with respect to social attention and sensitivity to fairness.

Age impairs mnemonic discrimination of objects more than scenes: A web-based, large-scale approach across the lifespan

Recent findings suggest that the effect of aging on recognition memory is modality-dependent, affecting memory for objects and scenes differently. However, the lifespan trajectory of memory decline in these domains remains unclear. A major challenge for assessing domain-specific trajectories is the need to utilize different types of stimuli for each domain (objects and scenes). We tested the large sample required to cover much of the adult lifespan using a large stimulus range via web-based assessments. 1554 participants (18–77 years) performed an online mnemonic discrimination task, tested on a pool of 2708 stimuli (Berron et al., 2018). Using corrected hit-rate (Pr) as a measure of performance, we show age-related decline in mnemonic discrimination in both domains, notably with a stronger decline in object memory, driven by a linear increase in the false recognition rate with advancing age. These data are the first to identify a linear age-related decline in mnemonic discrimination and a stronger, linear trajectory of decline in the object domain. Our data can inform basic and clinical memory research on the effects of aging on memory and help advancing the implementation of digital cognitive research tools.

Effect of Video Observation and Motor Imagery on Simple Reaction Time in Cadet Pilots.

Neuromotor training can improve motor performance in athletes and patients. However, few data are available about their effect on reaction time (RT). We investigated the influence of video observation/motor imagery (VO/MI) on simple RT to visual and auditory stimuli. The experimental group comprised 21 cadets who performed VO/MI training over 4 weeks. Nineteen cadets completed a sham intervention as control. The main outcome measure was RT to auditory and visual stimuli for the upper and lower limbs. The RT to auditory stimuli improved significantly post-intervention in both groups (control vs. experimental mean change for upper limbs: −40 ms vs. −40 ms, p = 0.0008; for lower limbs: −50 ms vs. −30 ms, p = 0.0174). A trend towards reduced RT to visual stimuli was observed (for upper limbs: −30 ms vs. −20 ms, p = 0.0876; for lower limbs: −30 ms vs. −20 ms, p = 0.0675). The interaction term was not significant. Only the specific VO/MI training produced a linear correlation between the improvement in the RT to auditory and visual stimuli for the upper (r = 0.703) and lower limbs (r = 0.473). In conclusion, VO/MI training does not improve RT when compared to control, but it may be useful in individuals who need to simultaneously develop a fast response to different types of stimuli.

Bioinspired Programmable Engineering of a Color-Change Biointerface based on Dual-Stimulation Regulation.

Some animals can change their skin colors in response to multiple stimuli by controlling the skin pigment cell or guanine crystals. An artificial color-change interface inspired by these natural properties has been developed; the interface responded to different types of stimuli, however, is still rare. Herein, we design a color-change biointerface that responds to the cooperative stimulation of light and DNA by changing the conformation of DNA structures to achieve programmable activation of the interface. We construct the biointerface by the combination of a fluorescent dye-labeled hairpin DNA with a photoresponsive molecule, which is cleaved by the first stimulation of UV light (stimulus 1, S1) to expose the toehold domain. Then, the biointerface gets color changed through the toehold-mediated DNA strand displacement reaction with the second stimulation of the invading DNA probe (stimulus 2, S2). Moreover, the transformation efficiency of the biointerface increased from 6.8 to 64% with an increase of S1 from 0 to 600 s in the presence of S2. Also, after the stimulation of S1, the effective transformation efficiency was also tuned from 5.3 to 72% by different amounts of S2 in the complex matrix, indicating the potential for a high response in real-world settings.

Chicago Face Database: Multiracial expansion

Multiracial individuals represent a growing segment of the population and have been increasingly the focus of empirical study. Much of this research centers on the perception and racial categorization of multiracial individuals. The current paper reviews some of this research and describes the different types of stimuli that have been used in these paradigms. We describe the strengths and weaknesses associated with different operationalizations of multiracialism and highlight the dearth of research using faces of real multiracial individuals, which we posit may be due to the lack of available stimuli. Our research seeks to satisfy this need by providing a free set of high-resolution, standardized images featuring 88 real multiracial individuals along with extensive norming data and objective physical measures of these faces. These data are offered as an extension of the widely used Chicago Face Database and are available for download at www.chicagofaces.org for use in research.

Effects of sensory mode in prey discrimination and predatory behaviour of rock lizards

Abstract An essential part of foraging ecology is to understand the processes of detection, recognition and discrimination of prey, as well as the sensorial modalities involved. Often, predators do not rely on a single sensory system but on multiple interacting senses. Specifically, lizards mainly use vision and vomerolfaction for prey pursuit. Here, we used an experimental approach to study how the Carpetan rock lizard, Iberolacerta cyreni, responds to different types of stimuli (chemical, visual, or both combined) from two prey species. The number of individuals approaching the prey and the number of attacks differed between treatments, however, we did not find differences in latency time, number of individuals attacking the prey or number of tongue flicks. Our results suggested that visual cues combined with chemical stimuli enhanced detection of both prey species and that prey discrimination occurred posteriorly and independently of using any or both types of stimuli.

Detachable Flexible ISFET‐Based pH Sensor Array with a Flexible Connector

AbstractFlexible sensors that can detect different types of stimuli simultaneously from any surface are attractive in many fields, including the Internet of Things. An important function of a flexible sensor sheet is multiple sensing without sacrificing mechanical flexibility, conformability, and device cost on the macroscale. This study proposes a macroscale detachable pH sensor array consisting of a disposable pH sensitive membrane sheet and a reusable flexible transistor array via a flexible electrical connector. Mechanical flexibility and stable electrical connection are realized by a soft Ag electrode and sticky polydimethylsiloxane/polyethylenimine layer for the connector. After laminating the two sheets, a fundamental study reveals a sensitivity of about 66.5 mV per pH. Although a small potential change in the pH membrane is observed as the temperature changes, the pH value can be monitored using the detachable flexible transistor‐based pH sensor sheet with a sufficient resolution. As a proof‐of‐concept for solution diffusion monitoring using the pH change, a 5 × 5 array sensor sheet is successfully demonstrated. The sensor array can measure the pH distribution with a different pH diffuses into a solution bath within a few seconds.

Four Self-Related IRAPs: Analyzing and Interpreting Effects in Light of the DAARRE Model

Two studies are presented that involved exploring four different versions of the implicit relational assessment procedure (IRAP) to target self-relevant stimulus relations. Experiment 1 employed stimuli from previous research that used the IRAP to target stimulus relations pertaining to self, and self-esteem in particular. Experiment 2 aimed to explore the use of different types of stimuli (i.e., pictures as well as words), that again focused on self-related stimulus relations, and their potential correlations with measures of self-esteem and psychological distress. Experiment 1 yielded broadly similar findings to those reported previously. Experiment 2 showed that only one trial type from the IRAP using pictures depicting success versus failure correlated with the measures of self-esteem and psychological distress; none of the remaining 11 trial types across the three IRAPs yielded any significant correlations. The current findings may be seen as relatively progressive when presented in the context of a theoretical model that may be used, albeit in a post-hoc manner, to interpret the specific IRAP response patterns obtained in the current and previously published research. In particular, an in-depth RFT conceptual analysis of the findings using a recently proposed model of IRAP effects is presented.

Visual crowding effect in the parvocellular and magnocellular visual pathways.

The crowding effect, defined as the detrimental effects of nearby items on visual object recognition, has been extensively investigated. Previous studies have primarily focused on finding the stage(s) in the visual hierarchy where crowding starts to limit target processing, while little attention has been focused on potential differences between the parvocellular (P) and magnocellular (M) pathways in crowding mechanisms. Here, we investigated the crowding effect in these parallel visual pathways. In Experiment 1, stimuli were designed to separately engage the P or M pathway, by tuning stimulus and background features (e.g., temporal frequency and color) to activate the targeted pathway and saturate the other pathway, respectively. Results showed that at the same eccentricity and with the same tasks, targets processed in the M pathway appeared to be more vulnerable to crowding effect. In Experiment 2, crowding effects were studied using three different types of stimuli and visual tasks (form, color, and motion), presumably with different degrees of dependence on the P and M pathways. Results revealed that color, motion, and form discrimination were increasingly more affected by crowding. We conclude that processing in the M and P pathways are differentially impacted by crowding; and importantly, crowding seems to affect processing of spatial forms more than other stimulus properties.

Some consideration on expressive audiovisual speech corpus acquisition using a multimodal platform

In this paper, we present a multimodal acquisition setup that combines different motion-capture systems. This system is mainly aimed for recording expressive audiovisual corpus in the context of audiovisual speech synthesis. When dealing with speech recording, the standard optical motion-capture systems fail in tracking the articulators finely, especially the inner mouth region, due to the disappearing of certain markers during the articulation. Also, some systems have limited frame rates and are not suitable for smooth speech tracking. In this work, we demonstrate how those limitations can be overcome by creating a heterogeneous system taking advantage of different tracking systems. In the scope of this work, we recorded a prototypical corpus using our combined system for a single subject. This corpus was used to validate our multimodal data acquisition protocol and to assess the quality of the expressiveness before recording a large corpus. We conducted two evaluations of the recorded data, the first one concerns the production aspect of speech and the second one focuses on the speech perception aspect (both evaluations concern visual and acoustic modalities). Production analysis allowed us to identify characteristics specific to each expressive context. This analysis showed that the expressive content of the recorded data is globally in line with what is commonly expected in the literature. The perceptual evaluation, conducted as a human emotion recognition task using different types of stimulus, confirmed that the different recorded emotions were well perceived.

Binocular rivalry from luminance and contrast

Binocular rivalry is the phenomenon that when two incompatible images are simultaneously presented, one to each eye, the two images compete with each other to be the dominant percept. Studying the underlying neural mechanisms of binocular rivalry is useful for understanding the mechanisms of interocular inhibition. Levelt’s Propositions, a set of four propositions that were originally published over fifty years ago, are not only useful for characterizing the perceptual dynamics of binocular rivalry, but can also provide a metric for assessing the common or differential neural mechanisms of binocular rivalry when diverse stimulus types are used. In the present study, we conducted a series of psychophysics experiments, where we compared the rivalry dynamics of two quite different types of stimuli. Orthogonal gratings, a classic type of rivalry stimulus, were contrasted with luminance patches, a type of rivalry stimulus that is relatively less studied. Our results showed that, similar to the orthogonal gratings, the alternate percepts in luminance-only rivalry were described by the modified Levelt’s Propositions, despite the clearly slower alternation rates for luminance patches. However, unlike the mixed percepts observed during transitions between oriented gratings, fusion percepts during luminance rivalry were common, could be lustrous, and obeyed the same Propositions, suggesting a regime of tri-stability. Overall, both types of rivalry are consistent with recent models that posit separate binocular and monocular channels embedded within neural circuits that also accomplish contrast normalization. Finally, luminance rivalry is discussed in the contexts of binocular summation and suppression, as well as Fechner’s paradox.

Negative content enhances stimulus-specific cerebral activity during free viewing of pictures, faces, and words.

Negative visual stimuli have been found to elicit stronger brain activation than do neutral stimuli. Such emotion effects have been shown for pictures, faces, and words alike, but the literature suggests stimulus‐specific differences regarding locus and lateralization of the activity. In the current functional magnetic resonance imaging study, we directly compared brain responses to passively viewed negative and neutral pictures of complex scenes, faces, and words (nouns) in 43 healthy participants (21 males) varying in age and demographic background. Both negative pictures and faces activated the extrastriate visual cortices of both hemispheres more strongly than neutral ones, but effects were larger and extended more dorsally for pictures, whereas negative faces additionally activated the superior temporal sulci. Negative words differentially activated typical higher‐level language processing areas such as the left inferior frontal and angular gyrus. There were small emotion effects in the amygdala for faces and words, which were both lateralized to the left hemisphere. Although pictures elicited overall the strongest amygdala activity, amygdala response to negative pictures was not significantly stronger than to neutral ones. Across stimulus types, emotion effects converged in the left anterior insula. No gender effects were apparent, but age had a small, stimulus‐specific impact on emotion processing. Our study specifies similarities and differences in effects of negative emotional content on the processing of different types of stimuli, indicating that brain response to negative stimuli is specifically enhanced in areas involved in processing of the respective stimulus type in general and converges across stimuli in the left anterior insula.

Behavioural and ERP correlates of bilingual language control and general-purpose inhibitory control predicted by L1 and L2 proficiency

Abstract Cognitive control is the ability to adapt flexibly to current demands by promoting task-relevant information in the face of interference, and this has been asserted as an advantage with bilinguals. Bilingual language control and general-purpose cognitive control are discussed in the literature using different types of stimuli, cognitive tasks, component processes (selection, interference, inhibition, switching) and groups (bilingual vs. monolingual; high proficient vs. low proficient bilingual). The present study was designed to investigate the neurocognitive correlates of inhibitory control with linguistic (i.e., words) and nonlinguistic (i.e., line drawings of objects) stimuli in Hindi-English bilingual adults. We conducted the behavioural experiment first to establish the linguistic version of identity negative priming paradigm followed by the Event-related potential (ERP) experiment using the linguistic and nonlinguistic negative priming task. Results show the presence of inhibition effect using mean reaction times as well as ERP data while comparing the control and ignored repetition conditions, and this pattern varied with different stimuli – linguistic vs. nonlinguistic. Thus, the current study suggests that bilingual language control is not entirely subsidiary to general-purpose cognitive control and shows differences based on the stimulus type. Also, proficiency in L1 and L2 differentially predicts performance on the nonlinguistic and linguistic negative priming paradigm, respectively. These results are indicative of a dynamic cognitive control system associated with bilingualism, which varies as a function of stimulus type as well as language proficiency.

Modeling the interaction of numerosity and perceptual variables with the diffusion model

Ratcliff and McKoon (2018) proposed integrated diffusion models for numerosity judgments in which a numerosity representation provides evidence used to drive the decision process. We extend this modeling framework to examine the interaction of non-numeric perceptual variables with numerosity by assuming that drift rate and non-decision time are functions of those variables. Four experiments were conducted with two different types of stimuli: a single array of intermingled blue and yellow dots in which both numerosity and dot area vary over trials and two side-by-side arrays of dots in which numerosity, dot area, and convex hull vary over trials. The tasks were to decide whether there were more blue or yellow dots (two experiments), more dots on which side, or which dots have a larger total area. Development of models started from the principled models in Ratcliff and McKoon (2018) and became somewhat ad hoc as we attempted to capture unexpected patterns induced by the conflict between numerosity and perceptual variables. In the three tasks involving numerosity judgments, the effects of the non-numeric variables were moderated by the number of dots. Under a high conflict, judgments were dominated by perceptual variables and produced an unexpected shift in the leading edge of the reaction time (RT) distributions. Although the resulting models were able to predict most of the accuracy and RT patterns, the models were not able to completely capture this shift in the RT distributions. However, when subjects judged area, numerosity affected perceptual judgments but there was no leading edge effect. Based on the results, it appears that the integrated diffusion models provide an effective framework to study the role of numerical and perceptual variables in numerosity tasks and their context-dependency.

Spectral hallmark of auditory-tactile interactions in the mouse somatosensory cortex

To synthesize a coherent representation of the external world, the brain must integrate inputs across different types of stimuli. Yet the mechanistic basis of this computation at the level of neuronal populations remains obscure. Here, we investigate tactile-auditory integration using two-photon Ca2+ imaging in the mouse primary (S1) and secondary (S2) somatosensory cortices. Pairing sound with whisker stimulation modulates tactile responses in both S1 and S2, with the most prominent modulation being robust inhibition in S2. The degree of inhibition depends on tactile stimulation frequency, with lower frequency responses the most severely attenuated. Alongside these neurons, we identify sound-selective neurons in S2 whose responses are inhibited by high tactile frequencies. These results are consistent with a hypothesized local mutually-inhibitory S2 circuit that spectrally selects tactile versus auditory inputs. Our findings enrich mechanistic understanding of multisensory integration and suggest a key role for S2 in combining auditory and tactile information.