Questo lavoro è stato sostenuto da una borsa di studio dalla National Science Foundation svizzero (CE: PBEZP3-131154)

1. Reclutamento dei soggetti <ol><li> I soggetti sono reclutati tramite un on-line 5 database contenente un elenco di circa 3000 studenti volontari. Da questa lista abbiamo solo contatti donne che non hanno partecipato in precedenza a simili studi e chiedere loro se sono interessati a partecipare a questo studio. Invitiamo le donne esclusivamente come l&#39;andamento nel tempo degli effetti neurofisiologici dopo la somministrazione di testosterone acuta è ben consolidata tra le donne 6,7. Per gli uomini, questo corso tempo non è ancora ben compreso. </li><li> I soggetti interessati sono poi proiettati in una intervista telefonica per escludere l&#39;assunzione di farmaci, malattie somatiche, la contraccezione ormonale o disturbi neurologici o psichiatrici. </li><li> Perché i livelli endogeni di ormoni sessuali tendono ad essere bassi e stabili nella prima parte del ciclo mestruale femminile conduciamo un secondo colloquio telefonico per ottenere informazioni sulla stabilità e la durata del ciclo. I soggetti sono poi invitati a venire a sperimentare entro 10 giorni dall&#39;inizio del loro ciclo mestruale. Sono ulteriormente consigliato di astenersi dal consumo di alcool o caffeina e fumo per 24 ore prima dell&#39;esperimento. </li><li> I soggetti sono invitati a gruppi di una dimensione media di 12 al laboratorio sperimentale dell&#39;Istituto per la ricerca empirica in economia, a Zurigo, Svizzera. </li></ol> 2. Procedura sperimentale <ol><li> Tutte le sessioni inizio alle 01:00 per controllare la variazione circadiana dei livelli degli ormoni steroidei. </li><li> Conduciamo un test di gravidanza prima dell&#39;inizio dell&#39;esperimento per impedire la gravidanza. </li><li> In preparazione di questo esperimento, il testosterone e pillole placebo visivamente indistinguibile sono distribuiti in modo casuale a dodici postazioni di lavoro contrassegnati 11:59 all&#39;interno della stanza di laboratorio da una persona che non è coinvolta nell&#39;esperimento altrimenti. </li><li> All&#39;ingresso del laboratorio, ciascuno dei soggetti dodici pesca una carta con un numero nascosto su di esso. I numeri variano da uno a dodici. </li><li> I soggetti sono poi portati nella sala laboratorio, che è dotato di un totale di 36 posti di lavoro del computer. I soggetti sono istruiti a cercare e sedersi dal posto di lavoro contrassegnati con lo stesso numero indicato sulla carta hanno tratto all&#39;ingresso. </li><li> Tutti i soggetti leggere e firmare il modulo di consenso informato. </li><li> Misuriamo testosterone salivare basale e le concentrazioni di cortisolo utilizzando la IBL SaliCaps Kit (IBL-Hamburg, Amburgo, Germania) per la raccolta dei campioni di saliva. I soggetti sono invitati a trasferire 1 ml di saliva nelle provette, che vengono poi immediatamente congelati a -80 ° C. </li><li> I soggetti sono invitati a prendere la pillola sublinguale in bocca, di masticare e mantenere la sostanza si disintegrò in bocca per un minuto. Per raggiungere il contatto massimo di HP-β-CD complesso inclusione testosterone con la mucosa orale, i soggetti sono istruiti a fare movimenti girando con la loro lingua. Dopo un minuto, il resto della sostanza è ingerito con 100 ml di acqua. </li><li> Immediatamente dopo la somministrazione sostanza, i soggetti sono tenuti a compilare questionari differenti. Misuriamo l&#39;umore e l&#39;eccitazione per mezzo del Questionario Mood (Multidimensional MDBF) 8 e l&#39;ansia e la rabbia tratti e gli stati, per mezzo della State-Trait Anxiety Inventory 9 e la State-Trait Anger Expression Inventory 10. Questi questionari hanno lo scopo di controllare per i possibili effetti degli stati incidentali soggetti &#39;stato d&#39;animo, rabbia e ansia, nonché per le caratteristiche di personalità. Inoltre, i soggetti completare le versioni convalidato tedesca del 90-voce Lista di controllo dei sintomi (versione riveduta) 11 per misurare la loro salute psicologica. Coloro che hanno punteggi molto alti (due deviazioni standard al di sopra della media, indicando cattiva salute psicologica) sono esclusi dall&#39;analisi dei dati. A causa del lasso di tempo stabilito di quattro ore per la comparsa di effetti comportamentali dopo l&#39;applicazione sublinguale di 0,5 mg di testosterone a giovani, donne sane 6,7, per un lungo periodo di attesa è parte integrante del nostro studio. Durante questo periodo, i nostri soggetti sono tenuti a rimanere nella stanza di laboratorio e tenersi tranquillamente occupati. Questo per garantire che nessuna interazione sociale al di fuori del laboratorio si svolge che potrebbe dar luogo a provvedimenti confusi. </li></ol> 3. Ultimatum Gioco <ol><li> Soggetti quindi ricevere le istruzioni per il loro ruolo nel gioco e le regole di profitto su carta e si richiede di leggerli. Controlliamo la loro comprensione della struttura dei payoff facendoli completa domande di controllo diversi, alla fine delle istruzioni. </li><li> Abbiamo poi riassumere la procedura sperimentale per via orale. La ragione di questo è di garantire che le persone sanno che tutti gli altri hanno le stesse informazioni circa la struttura del gioco e come il payoff are determinato, che è anche indicato come &quot;conoscenza comune&quot;. La sintesi è la seguente: </li><li> &quot;Il gioco dell&#39;ultimatum è giocato con due tipi di giocatori, un proponente e un risponditore, che devono accordarsi sulla ripartizione delle 10 unità monetaria (MUS). Il proponente può decidere sulla distribuzione delle unità motorie 10. In questo esperimento, il proponenti possono proporre le offerte di 5, 3, 2, o 0 MU al risponditore automatico. Il risponditore deve quindi accettare o rifiutare questa proposta. Se il soccorritore accetta l&#39;offerta del proponente, la ripartizione proposta sarà attuata e pagato. Tuttavia, il risponditore può anche respingere la proposta, in questo caso nessuna delle parti si guadagna niente &quot;. </li><li> Garantiamo una netta separazione tra l&#39;offerta che viene considerata come equa (5 MU) e le offerte che sono percepite come ingiuste (3, 2 o 0 MU) limitando le offerte a 5, 3, 2 o 0 Mus. I soggetti sono assegnati in modo casuale e anonima al ruolo sia del proponente o il risponditore e poi rimanere in questo ruolo per l&#39;intero esperimento. Ogni proponente fa tre proposte sulla distribuzione delle unità motorie, mentre in coppia con tre partner diversi interazione selezionati in modo casuale. Nessuna coppia di soggetti interagisce più di una volta. Non hanno mai conoscere l&#39;identità delle persone con cui sono abbinati nell&#39;esperimento. Il proponente non riceve un feedback sulle scelte responder &#39;fino alla fine dell&#39;esperimento. Tutte le decisioni nel gioco dell&#39;ultimatum sono implementati nel software zTree e presentato sullo schermo del computer 12. </li><li> Il testosterone è uno degli ormoni più dibattuti nella stampa popolare, è possibile che alcuni soggetti hanno una credenza preformato (vero o falso) circa i suoi effetti 13. Inoltre, poiché le preoccupazioni etiche richiedono ricercatori per informare i soggetti che saranno entrambi ricevono un placebo o di testosterone la conoscenza preventiva di testosterone può inquinare un possibile impatto di testosterone sul comportamento. Pertanto valutiamo la cessione del gruppo percepita dai soggetti chiedendo se pensano di aver ricevuto testosterone o la pillola placebo. </li><li> L&#39;assegnazione gruppo percepito è registrato nel questionario finale insieme ad alcune caratteristiche socio-economiche. Durante il questionario scorso ci prepariamo pagamento soggetti &#39;. </li></ol> 4. Oggetto di pagamento <ol><li> Soggetti ricevono una tariffa di base di 100 franchi svizzeri per la partecipazione alla sperimentazione. L&#39;uso di reali incentivi monetari riduce notevolmente una tendenza potenziale desiderabilità sociale e di parte di auto-percezione. Pertanto, ogni soggetto riceve un franco svizzero (circa 1 US $) per ogni MU guadagnati nel gioco dell&#39;ultimatum. Ogni soggetto riceve guadagni il suo consistente della quota base più UM guadagnato in privato, alla fine dell&#39;esperimento. </li></ol>

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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+Androgen+Stimulation+and+Aggressive+Behavior+in+Male+and+Female+Mice.">Early Androgen Stimulation and Aggressive Behavior in Male and Female Mice.</a> Physiology &#38; Behav. 4, 333-338 (1969).</li><li>Archer, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Testosterone+and+human+aggression:+an+evaluation+of+the+challenge+hypothesis.">Testosterone and human aggression: an evaluation of the challenge hypothesis.</a> Neurosci Biobehav R. 30, 319-345 (2006).</li><li>Mazur, A., Booth, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Testosterone+and+dominance+in+men.">Testosterone and dominance in men.</a> Behav Brain Sci. 21, 353-363 (1998).</li><li>Josephs, R. A., Newman, M. L., Brown, R. P., Beer, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Status,+testosterone,+and+human+intellectual+performance:+stereotype+threat+as+status+concern.">Status, testosterone, and human intellectual performance: stereotype threat as status concern.</a> Psychol Sci. 14, 158-163 (2003).</li><li>Greiner, B., Kremer, K., Macho, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Forschung und wissenschaftliches Rechnen: GWDG Bericht 63. , 79-93 (2004).</li><li>van Honk, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+single+administration+of+testosterone+induces+cardiac+accelerative+responses+to+angry+faces+in+healthy+young+women.">A single administration of testosterone induces cardiac accelerative responses to angry faces in healthy young women.</a> Behav Neurosci. 115, 238-242 (2001).</li><li>van Honk, J., Peper, J. S., Schutter, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Testosterone+reduces+unconscious+fear+but+not+consciously+experienced+anxiety:+implications+for+the+disorders+of+fear+and+anxiety.">Testosterone reduces unconscious fear but not consciously experienced anxiety: implications for the disorders of fear and anxiety.</a> Biol Psychiatry. 58, 218-225 (2005).</li><li>Steyer, R., Schwenkmezger, P., Notz, P., Eid, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Der Mehrdimensionale Befindlichkeitsfragebogen (MDBF) [Multidimensional Mood Questionnaire. , (1997).</li><li>Laux, L., Glanzmann, P., Schaffner, P., Spielberger, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Das State-Trait-Angstinventar (Manual for the State-Trait Anxiety Inventory. , (1981).</li><li>Schwenkmezger, P., Hodapp, V., Spielberger, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Das State-Trait-Aergerausdruck-Inventar STAXI [The State-Trait Anger Expression Inventory (STAXI)]. , (1992).</li><li>Derogatis, L. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> SCL-90-R, administration, scoring &amp;amp; procedures manual-I for the R(evised) version. , (1977).</li><li>Fischbacher, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=z-Tree:+Zurich+toolbox+for+ready-made+economic+experiments.">z-Tree: Zurich toolbox for ready-made economic experiments.</a> Experimental Economics. 10, 171-178 (2007).</li><li>Bjorkqvist, K., Nygren, T., Bjorklund, A. C., Bjorkqvist, S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Testosterone+Intake+and+Aggressiveness+-+Real+Effect+or+Anticipation.">Testosterone Intake and Aggressiveness - Real Effect or Anticipation.</a> Aggressive Behav. 20, 17-26 (1994).</li><li>Camerer, C. 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P., Loomes, G., Moffatt, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Experimental economics : rethinking the rules. , (2009).</li><li>Eisenegger, C., Naef, M., Snozzi, R., Heinrichs, M., Fehr, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prejudice+and+truth+about+the+effect+of+testosterone+on+human+bargaining+behaviour.">Prejudice and truth about the effect of testosterone on human bargaining behaviour.</a> Nature. 463, 356-359 (2010).</li></ol>

Nessun conflitto di interessi dichiarati.

L&#39;indicazione che i risultati siano validi è se le offerte media osservata è simile a quello che altri studi trovati. Tipicamente, offre medi sono tra i 30 - 40% del totale e circa la metà dei soggetti offre il 14 parti uguali. D&#39;altra parte, un indicatore di probabilità che i soggetti non capire le regole del gioco è se offre di più del 50% sono stati osservati. Vale la pena notare, tuttavia, che ci sia una notevole eterogeneità nella distribuzione e nella media offre osservati negli studi di ...

combining behavioral endocrinology and experimental economics: testosterone and social decision making

Comportamentali di ricerca endocrinologica in esseri umani così come negli animali suggeriscono che il testosterone gioca un ruolo chiave nelle interazioni sociali. Gli studi sui roditori hanno dimostrato un legame diretto tra testosterone e comportamento aggressivo 1 e saggezza popolare si adatta questi risultati agli esseri umani, suggerendo che il testosterone induce comportamenti antisociali, egoista o addirittura aggressivo 2. Tuttavia, molti ricercatori dubbio un diretto collegamento testosterone-aggressione negli esseri umani, sostenendo invece che il testosterone è principalmente coinvolto in stato di comportamento relativo 3,4. Come un elevato status può essere ottenuta anche con mezzi aggressivi e antisociali può essere difficile distinguere tra anti-sociale e lo stato il comportamento di ricerca. Abbiamo quindi creato un ambiente di sperimentazione, in cui lo stato può essere raggiunto solo con mezzi prosociali. In un esperimento in doppio cieco e controllato con placebo, abbiamo somministrato una singola dose sublinguale di 0,5 mg di testosterone (con un idrossipropil-β-ciclodestrina carrier) a 121 donne e studiato il loro comportamento sociale in un paradigma di interazione contrattazione economica. Reali incentivi monetari sono in gioco in questo paradigma, ogni giocatore A riceve una certa quantità di denaro e deve fare un&#39;offerta ad un altro giocatore B su come condividere i soldi. Se B accetta, si fa ciò che è stato offerto e il giocatore A mantiene il resto. Se B rifiuta l&#39;offerta, nessuno prende nulla. Lo stato cerca il giocatore A è previsto per evitare di essere rifiutato da comportarsi in maniera prosociale, cioè facendo offerte più elevate. I risultati mostrano che se le aspettative circa l&#39;ormone sono controllati per la somministrazione di testosterone porta ad un aumento significativo nella contrattazione fiera offre rispetto al placebo. Il ruolo delle aspettative si riflette nel fatto che i soggetti che riferiscono che credono di aver ricevuto testosterone fare offerte inferiori rispetto a quelli che dicono di credere che essi sono stati trattati con un placebo. Questi risultati suggeriscono che l&#39;approccio sperimentale l&#39;economia è sensibile per la rilevazione di effetti neurobiologici sottile come quelli ottenuti con la somministrazione di ormoni. Inoltre, i risultati puntare verso l&#39;importanza di entrambi i fattori psicosociali e neuroendocrina nel determinare l&#39;influenza del testosterone sul comportamento sociale umano.

Watch this Scientific Journal Video about Combining Behavioral Endocrinology and Experimental Economics: Testosterone and Social Decision Making at JoVE.com

Combining Behavioral Endocrinology and Experimental Economics: Testosterone and Social Decision Making

La procedura descritta in questo protocollo dimostra che la somministrazione di testosterone e credenze popolari circa il testosterone può essere associato con comportamenti sociali direttamente opposti.

Combinando comportamentali Endocrinologia ed Economia Sperimentale: Decisione testosterone e sociale Fare

Behavioral endocrinological research in humans as well as in animals suggests that testosterone plays a key role in social interactions. Studies in ...

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15.0K Views.  University of Zurich. La procedura descritta in questo protocollo dimostra che la somministrazione di testosterone e credenze popolari circa il testosterone può essere associato con comportamenti sociali direttamente opposti.

Video: Combining Behavioral Endocrinology and Experimental Economics: Testosterone and Social Decision Making

Combining Computer Game-Based Behavioural Experiments With High-Density EEG and Infrared Gaze Tracking

Experimental paradigms are valuable insofar as the timing and other parameters of their stimuli are well specified and controlled, and insofar as they yield data relevant to the cognitive processing that occurs under ecologically valid conditions. These two goals often are at odds, since well controlled stimuli often are too repetitive to sustain subjects' motivation. Studies employing electroencephalography (EEG) are often especially sensitive to this dilemma between ecological validity and experimental control: attaining sufficient signal-to-noise in physiological averages demands large numbers of repeated trials within lengthy recording sessions, limiting the subject pool to individuals with the ability and patience to perform a set task over and over again. This constraint severely limits researchers' ability to investigate younger populations as well as clinical populations associated with heightened anxiety or attentional abnormalities. Even adult, non-clinical subjects may not be able to achieve their typical levels of performance or cognitive engagement: an unmotivated subject for whom an experimental task is little more than a chore is not the same, behaviourally, cognitively, or neurally, as a subject who is intrinsically motivated and engaged with the task. A growing body of literature demonstrates that embedding experiments within video games may provide a way between the horns of this dilemma between experimental control and ecological validity. The narrative of a game provides a more realistic context in which tasks occur, enhancing their ecological validity (Chaytor &amp; Schmitter-Edgecombe, 2003). Moreover, this context provides motivation to complete tasks. In our game, subjects perform various missions to collect resources, fend off pirates, intercept communications or facilitate diplomatic relations. In so doing, they also perform an array of cognitive tasks, including a Posner attention-shifting paradigm (Posner, 1980), a go/no-go test of motor inhibition, a psychophysical motion coherence threshold task, the Embedded Figures Test (Witkin, 1950, 1954) and a theory-of-mind (Wimmer &amp; Perner, 1983) task. The game software automatically registers game stimuli and subjects' actions and responses in a log file, and sends event codes to synchronise with physiological data recorders. Thus the game can be combined with physiological measures such as EEG or fMRI, and with moment-to-moment tracking of gaze. Gaze tracking can verify subjects' compliance with behavioural tasks (e.g. fixation) and overt attention to experimental stimuli, and also physiological arousal as reflected in pupil dilation (Bradley et al., 2008). At great enough sampling frequencies, gaze tracking may also help assess covert attention as reflected in microsaccades - eye movements that are too small to foveate a new object, but are as rapid in onset and have the same relationship between angular distance and peak velocity as do saccades that traverse greater distances. The distribution of directions of microsaccades correlates with the (otherwise) covert direction of attention (Hafed &amp; Clark, 2002).

Procedures for recording high-density EEG and gaze data during computer game-based cognitive tasks are described. Using a video game to present cognitive tasks enhances ecological validity without sacrificing experimental control.

Computer Game-Based combinando esperimenti comportamentali ad alta densità tracking Gaze EEG e infrarossi

Experimental paradigms are valuable insofar as the timing and other parameters of their stimuli are well specified and controlled, and insofar as they ...

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Brain Imaging Investigation of the Neural Correlates of Observing Virtual Social Interactions

The ability to gauge social interactions is crucial in the assessment of others&#x2019; intentions. Factors such as facial expressions and body language affect our decisions in personal and professional life alike 1. These "friend or foe" judgements are often based on first impressions, which in turn may affect our decisions to "approach or avoid". Previous studies investigating the neural correlates of social cognition tended to use static facial stimuli 2. Here, we illustrate an experimental design in which whole-body animated characters were used in conjunction with functional magnetic resonance imaging (fMRI) recordings. Fifteen participants were presented with short movie-clips of guest-host interactions in a business setting, while fMRI data were recorded; at the end of each movie, participants also provided ratings of the host behaviour. This design mimics more closely real-life situations, and hence may contribute to better understanding of the neural mechanisms of social interactions in healthy behaviour, and to gaining insight into possible causes of deficits in social behaviour in such clinical conditions as social anxiety and autism 3.

This article demonstrates an experimental design in which whole-body animated characters are used in conjunction with functional magnetic resonance imaging (fMRI) to investigate the neural correlates of observing virtual social interactions.

Indagine del cervello Imaging i correlati neurali di osservazione virtuale interazioni sociali

The ability to gauge social interactions is crucial in the assessment of others&#x2019; intentions. Factors such as facial expressions and body language ...

Measuring the Subjective Value of Risky and Ambiguous Options using Experimental Economics and Functional MRI Methods

Most of the choices we make have uncertain consequences. In some cases the probabilities for different possible outcomes are precisely known, a condition termed "risky". In other cases when probabilities cannot be estimated, this is a condition described as "ambiguous". While most people are averse to both risk and ambiguity1,2, the degree of those aversions vary substantially across individuals, such that the subjective value of the same risky or ambiguous option can be very different for different individuals. We combine functional MRI (fMRI) with an experimental economics-based method3 to assess the neural representation of the subjective values of risky and ambiguous options4. This technique can be now used to study these neural representations in different populations, such as different age groups and different patient populations.
In our experiment, subjects make consequential choices between two alternatives while their neural activation is tracked using fMRI. On each trial subjects choose between lotteries that vary in their monetary amount and in either the probability of winning that amount or the ambiguity level associated with winning. Our parametric design allows us to use each individual's choice behavior to estimate their attitudes towards risk and ambiguity, and thus to estimate the subjective values that each option held for them. Another important feature of the design is that the outcome of the chosen lottery is not revealed during the experiment, so that no learning can take place, and thus the ambiguous options remain ambiguous and risk attitudes are stable. Instead, at the end of the scanning session one or few trials are randomly selected and played for real money. Since subjects do not know beforehand which trials will be selected, they must treat each and every trial as if it and it alone was the one trial on which they will be paid. This design ensures that we can estimate the true subjective value of each option to each subject. We then look for areas in the brain whose activation is correlated with the subjective value of risky options and for areas whose activation is correlated with the subjective value of ambiguous options.

Using functional MRI and behavioral methods to determine the neural representation of the subjective value of risky and ambiguous options in the human brain.

Misurare il valore soggettivo di opzioni rischiose e ambigui utilizzando Economia Sperimentale e funzionali metodi MRI

Most of the choices we make have uncertain consequences. In some cases the probabilities for different possible outcomes are precisely known, a condition ...

C. elegans Tracking and Behavioral Measurement

We have developed instrumentation, image processing, and data analysis techniques to quantify the locomotory behavior of C. elegans as it crawls on the surface of an agar plate. For the study of the genetic, biochemical, and neuronal basis of behavior, C. elegans is an ideal organism because it is genetically tractable, amenable to microscopy, and shows a number of complex behaviors, including taxis, learning, and social interaction1,2. Behavioral analysis based on tracking the movements of worms as they crawl on agar plates have been particularly useful in the study of sensory behavior3, locomotion4, and general mutational phenotyping5. Our system works by moving the camera and illumination system as the worms crawls on a stationary agar plate, which ensures no mechanical stimulus is transmitted to the worm. Our tracking system is easy to use and includes a semi-automatic calibration feature. A challenge of all video tracking systems is that it generates an enormous amount of data that is intrinsically high dimensional. Our image processing and data analysis programs deal with this challenge by reducing the worms shape into a set of independent components, which comprehensively reconstruct the worms behavior as a function of only 3-4 dimensions6,7. As an example of the process we show that the worm enters and exits its reversal state in a phase specific manner.

C. elegans Tracking and Behavioral Measurement

We have developed a video-rate tracking microscope system that can record and quantify C. elegans behavior at high resolution and high speeds. We have also developed computational methods to reduce the dimensionality of the worm images to a fundamental set of measurements that completely describe the shape of the worm.

C. elegans Monitoraggio e valutazione del comportamento

We have developed instrumentation, image processing, and data analysis techniques to quantify the locomotory behavior of C. elegans as it crawls on the ...

A Low Cost Setup for Behavioral Audiometry in Rodents

In auditory animal research it is crucial to have precise information about basic hearing parameters of the animal subjects that are involved in the experiments. Such parameters may be physiological response characteristics of the auditory pathway, e.g. via brainstem audiometry (BERA). But these methods allow only indirect and uncertain extrapolations about the auditory percept that corresponds to these physiological parameters. To assess the perceptual level of hearing, behavioral methods have to be used. A potential problem with the use of behavioral methods for the description of perception in animal models is the fact that most of these methods involve some kind of learning paradigm before the subjects can be behaviorally tested, e.g. animals may have to learn to press a lever in response to a sound. As these learning paradigms change perception itself 1,2 they consequently will influence any result about perception obtained with these methods and therefore have to be interpreted with caution. Exceptions are paradigms that make use of reflex responses, because here no learning paradigms have to be carried out prior to perceptual testing. One such reflex response is the acoustic startle response (ASR) that can highly reproducibly be elicited with unexpected loud sounds in na&iuml;ve animals. This ASR in turn can be influenced by preceding sounds depending on the perceptibility of this preceding stimulus: Sounds well above hearing threshold will completely inhibit the amplitude of the ASR; sounds close to threshold will only slightly inhibit the ASR. This phenomenon is called pre-pulse inhibition (PPI) 3,4, and the amount of PPI on the ASR gradually depends on the perceptibility of the pre-pulse. PPI of the ASR is therefore well suited to determine behavioral audiograms in na&iuml;ve, non-trained animals, to determine hearing impairments or even to detect possible subjective tinnitus percepts in these animals. In this paper we demonstrate the use of this method in a rodent model (cf. also ref. 5), the Mongolian gerbil (Meriones unguiculatus), which is a well know model species for startle response research within the normal human hearing range (e.g. 6).

A fast and inexpensive method for the behavioral determination of hearing parameters like hearing thresholds, hearing impairments or phantom perceptions (subjective tinnitus) is described. It uses pre-pulse inhibition of the acoustic startle response and can be easily implemented in a personal computer using a programmable AD/DA-converter and a piezo sensor.

Un programma di installazione a basso costo per audiometria comportamentale nei roditori

In auditory animal research it is crucial to have precise information about basic hearing parameters of the animal subjects that are involved in the ...

Simultaneous Detection of c-Fos Activation from Mesolimbic and Mesocortical Dopamine Reward Sites Following Naive Sugar and Fat Ingestion in Rats

This study uses cellular c-fos activation to assess effects of novel ingestion of fat and sugar on brain dopamine (DA) pathways in rats. Intakes of sugars and fats are mediated by their innate attractions as well as learned preferences. Brain dopamine, especially meso-limbic and meso-cortical projections from the ventral tegmental area (VTA), has been implicated in both of these unlearned and learned responses. The concept of distributed brain networks, wherein several sites and transmitter/peptide systems interact, has been proposed to mediate palatable food intake, but there is limited evidence empirically demonstrating such actions. Thus, sugar intake elicits DA release and increases c-fos-like immunoreactivity (FLI) from individual VTA DA projection zones including the nucleus accumbens (NAC), amygdala (AMY) and medial prefrontal cortex (mPFC) as well as the dorsal striatum. Further, central administration of selective DA receptor antagonists into these sites differentially reduce acquisition and expression of conditioned flavor preferences elicited by sugars or fats. One approach by which to determine whether these sites interacted as a distributed brain network in response to sugar or fat intake would be to simultaneous evaluate whether the VTA and its major mesotelencephalic DA projection zones (prelimbic and infralimbic mPFC, core and shell of the NAc, basolateral and central-cortico-medial AMY) as well as the dorsal striatum would display coordinated and simultaneous FLI activation after oral, unconditioned intake of corn oil (3.5%), glucose (8%), fructose (8%) and saccharin (0.2%) solutions. This approach is a successful first step in identifying the feasibility of using cellular c-fos activation simultaneously across relevant brain sites to study reward-related learning in ingestion of palatable food in rodents.

The goal of this study is to identify reward-related distributed brain networks by delineating a reliable immunohistological technique using cellular c-fos activation to measure simultaneous changes in dopamine pathways and terminal sites after novel ingestion of fat and sugar in rats.

Rilevazione simultanea di c-Fos attivazione da mesolimbico e mesocorticali Siti Reward dopamina seguito Ingenuo zuccheri e grassi ingestione in Rats

This study uses cellular c-fos activation to assess effects of novel ingestion of fat and sugar on brain dopamine (DA) pathways in rats. Intakes of sugars ...

Effects of Transcranial Alternating Current Stimulation on the Primary Motor Cortex by Online Combined Approach with Transcranial Magnetic Stimulation

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific frequency and in turn modulate ongoing cortical oscillatory activity. This neurotool allows the establishment of a causal link between endogenous oscillatory activity and behavior. Most of the tACS studies have shown online effects of tACS. However, little is known about the underlying action mechanisms of this technique because of the AC-induced artifacts on Electroencephalography (EEG) signals. Here we show a unique approach to investigate online physiological frequency-specific effects of tACS of the primary motor cortex (M1) by using single pulse Transcranial Magnetic Stimulation (TMS) to probe cortical excitability changes. In our setup, the TMS coil is placed over the tACS electrode while Motor Evoked Potentials (MEPs) are collected to test the effects of the ongoing M1-tACS. So far, this approach has mainly been used to study the visual and motor systems. However, the current tACS-TMS setup can pave the way for future investigations of cognitive functions. Therefore, we provide a step-by-step manual and video guidelines for the procedure.

Transcranial Alternating Current Stimulation (tACS) allows the modulation of cortical excitability in a frequency-specific fashion. Here we show a unique approach which combines online tACS with single pulse Transcranial Magnetic Stimulation (TMS) in order to "probe" cortical excitability by means of Motor Evoked Potentials.

Effetti della stimolazione transcranica con corrente alternata la corteccia motoria primaria di approccio combinato Online con stimolazione magnetica transcranica

Transcranial Alternating Current Stimulation (tACS) is a neuromodulatory technique able to act through sinusoidal electrical waveforms in a specific ...

Operant Protocols for Assessing the Cost-benefit Analysis During Reinforced Decision Making by Rodents

Reinforcement-guided decision making is the ability to choose between competing courses of action based on the relative value of the benefits and their consequences. This process is integral to the normal human behavior and has been shown to be disrupted by neurological and psychiatric disorders such as addiction, schizophrenia, and depression. Rodents have long been used to uncover the neurobiology of human cognition. To this end, several behavioral tasks have been developed; however, most are non-automated and are labor-intensive. The recent development of the open-source microcontroller has enabled researchers to automate operant-based tasks for assessing a variety of cognitive tasks, standardizing the stimulus presentation, improving the data recording and consequently, improving the research output. Here, we describe an automated delay-based reinforcement-guided decision-making task, using an operant T-maze controlled by custom-written software programs. Using these decision-making tasks, we show the changes in the local field potential activities in the anterior cingulate cortex of a rat whilst it performs a delay-based cost-and-benefit decision-making task.

A cost-benefit analysis is a weighing-scale approach that the brain performs during the course of decision making. Here, we propose a protocol to train rats on an operant-based decision-making paradigm where rats choose higher rewards at the expense of waiting for 15 s to receive them.

Protocolli dell'operatore per valutare l'analisi costi-benefici durante la risoluzione rinforzato dai roditori

Reinforcement-guided decision making is the ability to choose between competing courses of action based on the relative value of the benefits and their ...

Abbiategrasso Brain Bank Protocol for Collecting, Processing and Characterizing Aging Brains

In a constantly aging population, the prevalence of neurodegenerative disorders is expected to rise. Understanding disease mechanisms is the key to find preventive and curative measures. The most effective way to achieve this is through direct examination of diseased and healthy brain tissue. The authors present a protocol to obtain, process, characterize and store good quality brain tissue donated by individuals registered in an antemortem brain donation program. The donation program includes a face-to-face empathic approach to people, a collection of complementary clinical, biological, social and lifestyle information and serial multi-dimensional assessments over time to track individual trajectories of normal aging and cognitive decline. Since many neurological diseases are asymmetrical, our brain bank offers a unique protocol for slicing fresh specimens. Brain sections of both hemispheres are alternately frozen (at -80 &#176;C) or fixed in formalin; a fixed slice on one hemisphere corresponds to a frozen one on the other hemisphere. With this approach, a complete histological characterization of all frozen material can be obtained, and omics studies can be performed on histologically well-defined tissues from both hemispheres thus offering a more complete assessment of neurodegenerative disease mechanisms. Correct and definite diagnosis of these diseases can only be achieved by combining the clinical syndrome with the neuropathological evaluation, which often adds important etiological clues necessary to interpret the pathogenesis. This method can be time consuming, expensive and limited as it only covers a limited geographical area. Regardless of its limitations, the high degree of characterization it provides can be rewarding. Our ultimate goal is to establish the first Italian Brain Bank, all the while emphasizing the importance of neuropathologically verified epidemiological studies.

This protocol describes a method to track individual brain-aging trajectories through a brain donation program and proper characterization of brains. Brain donors are involved in a long-term longitudinal study including serial multi-dimensional assessments. The protocol contains a detailed description of brain processing and an accurate diagnostic methodology.

Abbiategrasso Brain Bank Protocol per la raccolta, l'elaborazione e la caratterizzazione dei cervelli di invecchiamento

In a constantly aging population, the prevalence of neurodegenerative disorders is expected to rise. Understanding disease mechanisms is the key to find ...

Post-Movie Subliminal Measurement (PMSM), for Investigating Implicit Social Bias

New knowledge is continuously gained from a social environment that can influence how people respond to each other. Such responses often occur implicitly, at a subliminal perceptual level, and related brain mechanisms can be experimentally isolated by presenting the stimuli quickly. Subliminal presentation of faces that belong to different ethnicity groups, races, or gender has been shown to be successful in investigating social implicit responses. However, many implicit responses are based on knowledge previously gained about the faces (e.g., sexual orientation, political views, and socioeconomic status) and not solely on physical appearance. Here, a novel method called post-movie subliminal measurement (PMSM) is presented. When watching a socially engaging movie, a spectator gains knowledge about the protagonist and becomes familiar with his/her identity and world views. When the face of the protagonist is presented subliminally after the movie, it evokes an implicit neural response depending on what is learned about the protagonist. With a vast number of movies available, each depicting a variety of people with different identities, the PMSM method enables investigation of the brain&#39;s complex implicit biases in a manner that resembles real-life social perceptions.

Post-Movie Subliminal Measurement PMSM, for Investigating Implicit Social Bias

This protocol describes the use of movies to investigate brain mechanisms underlying implicit social biases during functional magnetic resonance imaging. When the face of a protagonist is presented after a movie subliminally, it evokes an implicit response based on knowledge of the protagonist gained during the movie.

Misurazione subliminale post-film (PMSM), per indagare implicito Sociale Bias

New knowledge is continuously gained from a social environment that can influence how people respond to each other. Such responses often occur implicitly, ...