Why is novel stimuli important

Bavaria invests up to million euros in the competitive development of the Martinsried Max Planck Campus into an outstanding international research hub. Many publications by Max Planck scientists in were of great social relevance or met with a great media response.

We have selected 13 articles to present you with an overview of some noteworthy research of the year. Researchers increase the speed of signal transmission along nerve fibres in mice by switching off a protein. Severed nerve tracts are very difficult to treat. If at all, the damage so far can only be repaired through complex operations. At the Max Planck Institute for Polymer Research, we have developed materials that stimulate damaged nerves into growth. Results from initial tests on mice show that nerve tracts can regenerate this way.

Homepage Newsroom From the Institutes Neurons differentiate between novel and familiar stimuli. Neurons differentiate between novel and familiar stimuli Scientists unravel circuit and synaptic mechanisms that allow animals to distinguish between unexpected and predictable stimuli.

Social Cognitive and Affective Neuroscience , 8 2 , — A unique role for the human amygdala in novelty detection. Neuroimage , 50 3 , — Cai L. Yohimbine anxiogenesis in the elevated plus maze is disrupted by bilaterally disconnecting the bed nucleus of the stria terminalis from the central nucleus of the amygdala. Neuroscience , , — 8. Cisler J. Mechanisms of attentional biases towards threat in anxiety disorders: an integrative review. Clinical Psychology Review , 30 2 , — Cox R.

AFNI: software for analysis and visualization of functional magnetic resonance neuroimages. Computers and Biomedical Research , 29 3 , — Daselaar S. Triple dissociation in the medial temporal lobes: recollection, familiarity, and novelty. Journal of Neurophysiology , 96 4 , — Davis M. The amygdala: vigilance and emotion. Molecular Psychiatry , 6 1 , 13 — De Rosario-Martinez H. Degnan K. Temperament and the environment in the etiology of childhood anxiety. Journal of Child Psychology and Psychiatry , 51 4 , — Dickie E.

Amygdala responses to unattended fearful faces: interaction between sex and trait anxiety. Psychiatry Research: Neuroimaging , 1 , 51 — 7. Etkin A.

Individual differences in trait anxiety predict the response of the basolateral amygdala to unconsciously processed fearful faces. Neuron , 44 6 , — Fakra E. Archives of General Psychiatry , 66 1 , 33 — Fischl B. Whole brain segmentation: automated labeling of neuroanatomical structures in the human brain. Neuron , 33 3 , — Fox J. Google Preview. Fox N. Behavioral inhibition: linking biology and behavior within a developmental framework.

Annual Review of Psychology , 56 , — Gonzalez L. Brain Research , , — Grunwald T. Verbal novelty detection within the human hippocampus proper. Grupe D. Uncertainty and anticipation in anxiety: an integrated neurobiological and psychological perspective.

Nature Reviews Neuroscience , 14 7 , — Hariri A. Divergent effects of genetic variation in endocannabinoid signaling on human threat- and reward-related brain function. Biological Psychiatry , 66 1 , 9 — The neurobiology of individual differences in complex behavioral traits. Annual Review of Neuroscience , 32 , — Hughes R. Neotic preferences in laboratory rodents: issues, assessment and substrates.

Neuroscience and Biobehavioral Reviews , 31 3 , — Hyde L. Perceived social support moderates the link between threat-related amygdala reactivity and trait anxiety. Neuropsychologia , 49 4 , — 6. Khoshbouei H. Modulatory effects of galanin in the lateral bed nucleus of the stria terminalis on behavioral and neuroendocrine responses to acute stress. Neuropsychopharmacology , 27 1 , 25 — Killgore W. Social anxiety predicts amygdala activation in adolescents viewing fearful faces.

Neuroreport , 16 15 , — 5. Kirwan C. Medial temporal lobe activity can distinguish between old and new stimuli independently of overt behavioral choice. Three distinct fiber pathways of the bed nucleus of the stria terminalis to the amygdala and prefrontal cortex.

Laeger I. Amygdala responsiveness to emotional words is modulated by subclinical anxiety and depression. Behavioural Brain Research , 2 , — Lang P. International affective picture system IAPS : affective ratings of pictures and instruction manual technical report A Lever C. Environmental novelty elicits a later theta phase of firing in CA1 but not subiculum.

Hippocampus , 20 2 , — Lungwitz E. Orexin-A induces anxiety-like behavior through interactions with glutamatergic receptors in the bed nucleus of the stria terminalis of rats. McGann J. Associative learning and sensory neuroplasticity: how does it happen and what is it good for? Menon V. Analysis of a distributed neural system involved in spatial information, novelty, and memory processing. Human Brain Mapping , 11 2 , — Mumford J.

Deconvolving BOLD activation in event-related designs for multivoxel pattern classification analyses. Neuroimage , 59 3 , — Navarro J. Anxiogenic-like activity of 3,4-methylenedioxy-methamphetamine 'ecstasy' in the social interaction test is accompanied by an increase of c-fos expression in mice amygdala. Ousdal O. Increased amygdala and visual cortex activity and functional connectivity towards stimulus novelty is associated with state anxiety.

Plos One , 9 4 , e Dissociation of the morphological correlates of stress-induced anxiety and fear. European Journal of Neuroscience , 27 6 , — They can provide affectively neutral control stimuli in research exploring cognitive and behavioural responses to emotional stimuli or stimuli within emotional contexts.

For example, experiments with people with spider phobia might use the Fribbles as a neutral baseline from which to assess individual differences in approach and avoidance or the neural or physiological substrates of such behavioural responses e.

This might be particularly useful where one is investigating the effects of approach or avoidance on attention towards stimulus features and one requires affectively neutral stimuli with numerous stimulus features e. Real-world stimuli might not be suitable for such purposes given individual differences in valence. Also, shapes and words might lack the anatomical complexity and generalisability to clinical disorders necessary to provide an adequate comparison stimulus, particularly in neuroscientific paradigms.

Another potentially fruitful use for the Fribbles that is being pursued at present is in prospective investigations into the factors that contribute towards the development of clinical disorder. For example, after a conditioning experience where a Fribble is paired with an aversive event, one might relate the way that participants generalize their fear for this one Fribble to other, similar, Fribbles to the ways in which individuals differ in the ways they generalize their fears for real-world stimuli.

Differences in this gradient of generalization might be attributable to such mechanisms as the forgetting of some of the Fribbles features and individual differences in memory specificity. This might mean that after conditioning to a Fribble with a square head, fear might generalize to all Fribbles with the square head irrespective of its other unique features Riccio et al. This would be analogous to the way that after an aversive event such as a dog bite might lead to the development of a phobia when one begins to fear all dogs Rowe and Craske, Researchers could also use the Fribbles to explore the role of attention in anxiety disorders by measuring the orientation and duration of gaze towards Fribbles from within a species.

Aside from the use of Fribbles, the methodological and statistical techniques employed herein could also be used to inform the selection of stimuli from other stimulus sets. For example, other research that tests generalization gradients amongst spiders of different kinds might use this procedure to quantify the degree of similarity between each spider.

They could also use that data to compute similarity and difference indices and test the effects of changes in different stimulus features on similarity judgements between spiders and correlate this with the generalization of fear. The online procedure in this study no doubt limits the conclusions that can be drawn. Given that participants completed the experiment on their own computer, we did not control for the computer or the screen that was used in the experiment.

Differences in hardware between participants may have influenced the visual quality of the Fribbles that in turn may have influenced judgements of similarity.

Nevertheless this study is valuable in simply presenting a potentially fruitful stimulus set and also in outlining the potential issues that must be considered when selecting them for research. One limitation of this investigation was that there was no assessment of color-blindness or whether participants had normal or corrected-to-normal vision.

Given the nature of the stimuli, accurate perception of features is essential in the ability to differentiate Fribbles from one another. Future research using the Fribbles should take this into consideration. One other limitation of the current investigation could be that each Fribble was only compared to the prototype and not to other Fribbles within their species or any other species.

This means that firm conclusions about the degree of difference between species cannot be made. However, this did not seem necessary given the apparent differences between species and the suggestion by the original creator, Williams , that they were designed to differ between species in the same way that rhinos might be said to differ from ducks. Additionally, given the size of the Fribble stimulus set, it was beyond the scope of the present investigation to make all possible comparisons between all species and so only two Fribble species were compared.

However, the recommendations made here in with regards to stimulus selection will no doubt transfer to all other Fribble species. Further research could confirm this by exploring similarity in the other Fribble species and potential differences in similarity between species.

The use of a previously untested rating scale for the judgements of similarity might also be a limitation of the present study.

A point scale was used to attempt to capture the full variability in judgements of similarity between stimuli that are somewhat similar. Further research could confirm the reliability of this scale in assessments of similarity. The number of trials in the experiment may also have been a limitation. In these cases, participants may not notice some of the more subtle differences between body parts where they no longer pay attention to the individual features and instead look more generally at the Fribbles and form their judgements according to the composite.

The Fribbles can be of great value to research, not only in terms of the experimental control they confer but also in terms of their applicability within the investigation of real-world clinical phenomena.

This article has presented some of the possible ways in which Fribbles might be used in research — although this list is by no means exhaustive — and some of the factors that should be considered when selecting Fribbles. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Tom J. Barry is a research assistant for the FWO. We gratefully acknowledge the support of the FWO to Dr. Griffith GP. Armstrong, T. Eye tracking of attention in the affective disorders: a meta-analytic review and synthesis. Baas, J. Individual differences in predicting aversive events and modulating contextual anxiety in a context and cue conditioning paradigm. Barense, M. The human medial temporal lobe processes online representations of complex objects.

Neuropsychologia 45, — Bar-Haim, Y. Threat-related attentional bias in anxious and nonanxious individuals: a meta-analytic study. Behrmann, M. Impairments in part-whole representations of objects in two cases of integrative visual agnosia. Boddez, Y.

Validity of US expectancy. Psychiatry 44, — Casasanto, D. Embodiment of abstract concepts: good and bad in right- and left-handers. Dye, M. Ernst, L. Controlled attention allocation mediates the relation between goal-oriented pursuit and approach — avoidance reactions to negative stimuli. Enactment of approach and avoidance behaviour influences the scope of perceptual and conceptual attention.

Social Psychol. CrossRef Full Text. Hein, G. Object familiarity and semantic congruency modulate responses in cortical audiovisual integration areas. Knutson, A. Visual discrimination performance, memory, and medial temporal lobe function. Lenaert, B. Williams differed Fribbles within a species in terms of the number of shared features with a prototype. However, there was no investigation of whether, given the range of features on offer, all of the possible feature variants differed from the prototype features to the same degree.

For example, if a prototype has a square head, a second Fribble that is the same in every way except it has a circular head will be judged as dissimilar to the prototype. However, it is unclear whether this second Fribble will be judged as equally dissimilar to the prototype as a third Fribble with a star-shaped head. We might also ask whether a fourth Fribble that has the same head as the prototype but has different legs will be judged as more or less dissimilar to the prototype as the second Fribble with the changed head.

The question then becomes whether the number of shared features is sufficient to explain differences in similarity between Fribbles or whether research that uses Fribbles to form similarity comparisons needs to also consider the influence of different features and their forms on similarity. Knutson et al. They used a modified Fribble set that differed from one another, within a species, in terms of the color of the bodies and the appendages in order to make these parts seem more or less salient.

However, as Knutson et al. There has been no investigation into the degree of similarity between each of the possible variants of Fribble within each species.

Until such an investigation takes place, the selection of individual stimuli from the wider Fribble set to form, or to avoid, any sort of similarity gradient is speculative and unsupported by data. In other behavioural research, the effect of such speculation is that individual features of a given stimulus set may have an unexpected confounding effect. For example, Lenaert et al. Face A was first paired with a lightning bolt image and in the subsequent phase they measured the extent to which participants expected the lightning bolt for each of the faces along the morphological gradient between Face A and B.

They expected a linear decrease in expectancy as participants were shown faces further away from Face A and closer towards Face B. This finding may be attributable to the saliency of the head hair in the images and the contribution of this to similarity judgements where the two faces at the middle of the gradient had noticeably different hair.

This was despite their being positioned equally from the other faces on the morphological gradient. Lenaert et al. Similarly, in their original presentation Williams suggests that they expect Fribbles to be linearly dissimilar from one another based on the number of shared features with a prototype, but they do not provide data on whether individual Fribble features can have different effects on similarity.

Thus the present research attempts to provide data supporting the use of Fribbles in behavioural research with a focus on analysing the similarity between Fribbles to better inform their selection in future experiments. We have two overarching hypotheses.

First, we anticipate that Fribbles with increasing dissimilarity from the prototype, be it in terms of the number of common elements or the form that these elements take, will be judged as increasingly dissimilar by participants. Second, that the characteristics addressed within the first hypothesis have the same impact on similarity judgements between species. Within the first hypothesis, we conducted separate analyses concerning each of the possible stimulus characteristics that might contribute towards similarity.

First, we explored the influence of the number of common elements shared between an exemplar and the prototype on similarity judgements. Second, we explored whether body parts contribute equally to similarity, or whether some body parts have a greater impact on similarity than others; for example, whether changing the head of a Fribble has a greater impact on similarity to the prototype than if one was to change the legs. Third, we assessed the contribution of the different types within each body part to similarity judgements and whether this contribution is the same across all body parts and species.

For example, are Fribbles with circular or star-shaped heads judged as being equally as similar to a prototype with a square head, and is this true for other body parts and their variants and does the same hold true for different species of Fribble. Participants were contacted through an e-mail database made up of participants from previous, unrelated, experiments and were asked if they would complete the survey. All participants reported having never seen or heard of the Fribbles.

There was no reward for completing the survey. Seventy-six persons started the survey 51 females and 25 males , 41 of which completed all of the survey ratings 30 females and 11 males ; that is, 41 participants had no missing data.

The available data from all 76 persons were used in the analysis. Four of the 12 Fribble species were used in the present investigation. Two of these species referred to as FA2 and FC2 — of which eight exemplars were used — appeared within the training phase in order to give participants some experience as to the degrees of difference that would feature in the main investigation.

These example comparisons included Fribbles for each number of possible common elements from the prototype one to four. All exemplars from the other two species FA1 and FC1 featured in the actual similarity survey.

The Fribbles are designed and named such that in species FA1, a Fribble named , for example, represents the same head, tail2 and legs as the prototype named , but the two in the name represents a different type of tail1. Whereas, a Fribble in this species named denotes a change at tail2. The same is true for the head and legs of species FC1 but with referring to a change of tail2 and referring to a change of tail1. The Fribbles were in. The survey was created in Dutch and English.

Both versions were included in the same survey such that the English translation was presented in parenthesis after the Dutch version of each text.

Participants were informed that the survey would take approximately 15 min to complete and that their data would be held anonymously. A brief summary of the task was then presented, followed by demographic questions. A single prototype Fribble was used within each species. During the survey, each trial compared the prototype Fribble for each species with an exemplar from the same species. Participants were asked to rate the similarity between the exemplar and the prototype on a scale from 1 very dissimilar to 20 very similar.

Each exemplar was presented one time along with the prototype Fribble from the same species. Stimuli remained on the screen until participants responded. The order of all presentations was randomized but the positioning of the prototype and exemplars remained constant throughout, with the prototype being presented on the left side of the screen and the exemplars on the right. The survey consisted of a training phase of 16 trials: eight trials with one species FA2 and eight trials with another FC2.

At the end of the experiment, participants were asked what strategy they used to make their similarity judgements. Huynh—Feldt corrected p values were used to account for violations of sphericity. Fribbles with more elements in common with the prototype were judged to be more similar than those with fewer elements in common although this similarity gradient showed slight curvature suggesting that there was less difference between similarity ratings for three and four elements in common than for other comparisons.

Further, those with four elements in common were judged much more similar than those with other numbers of common elements. When asked post hoc what strategy they used to make their judgements, participants most often reported using the number of common elements and the shape and form of the elements to make their judgements. Mean similarity ratings for exemplar Fribbles for each possible configuration of elements in common with the prototype Fribble for both species FA1 and FC1.

Higher means scores indicate greater similarity with the prototype. Error bars are one standard deviation. Our second set of analyses explored whether body parts contribute equally to similarity, or whether some body parts have a greater impact on similarity than others. We computed indices of similarity, for each Fribble species separately, for each of the body parts using the following formula:.

In this formula, we use a to refer to the mean similarity score for Fribbles with the same body part type as the exemplar, b is the mean similarity score for Fribbles with the second type, and c is the mean score for the third variant.

For example, where the prototype has a square head, a refers to Fribbles that also have the square head, b refers to Fribbles with a circular head and c refers to star-headed Fribbles.