Discounting the effect of memory on repeated measures of beauty judgment

The intrinsic variance of beauty judgment is key to modeling beauty ratings. However, in repeated measures of beauty, observers surely make use of what they remember. To test how memory contributes to repeated beauty ratings, we asked participants to rate 75 arbitrarily named images (e.g., Fred). Initially, participants rated (1 to 7) how much beauty they felt from looking at a named image. Then participants completed two conditions. In the memory condition, participants saw only the name of an image and were asked to remember the image corresponding to that name and rate how much beauty they felt. In the repeat condition, they once again rated how much beauty they felt from looking at a named image. Lastly, in a memory check, participants tried to select which image was associated with a name. Only considering the correctly remembered trials (60%), we calculated the distribution of the differences between the initial beauty rating and that from either the memory condition or the repeat condition. The variance for the memory condition was more than double that of the repeat condition. Likewise, the initial beauty ratings predicted 84% of the variance in the repeat ratings but only 30% of the variance in the memory ratings. Cue combination studies report that observers typically combine cues by the optimal Bayesian rule: The combined reliability is the sum of the separate reliabilities for each cue, where reliability is one over variance. Assuming optimal combination of memory and immediate-perception judgment, we can discount the contribution of memory to estimate the variance of the immediate-perception judgment. Thus, in our paradigm the 0.83 variance of the repeated beauty rating corresponds to a 0.97 immediate-perception judgment variance (without memory). Overall, since there also was no significant difference in means, our results indicate that memory contributes little to repeated beauty ratings

Serotonergic signalling suppresses ataxin 3 aggregation and neurotoxicity in animal models of Machado-Joseph disease

Polyglutamine diseases are a class of dominantly inherited neurodegenerative disorders for which there is no effective treatment. Here we provide evidence that activation of serotonergic signalling is beneficial in animal models of Machado-Joseph disease. We identified citalopram, a selective serotonin reuptake inhibitor, in a small molecule screen of FDA-approved drugs that rescued neuronal dysfunction and reduced aggregation using a Caenorhabditis elegans model of mutant ataxin 3-induced neurotoxicity. MOD-5, the C. elegans orthologue of the serotonin transporter and cellular target of citalopram, and the serotonin receptors SER-1 and SER-4 were strong genetic modifiers of ataxin 3 neurotoxicity and necessary for therapeutic efficacy. Moreover, chronic treatment of CMVMJD135 mice with citalopram significantly reduced ataxin 3 neuronal inclusions and astrogliosis, rescued diminished body weight and strikingly ameliorated motor symptoms. These results suggest that small molecule modulation of serotonergic signalling represents a promising therapeutic target for Machado-Joseph disease.This work was supported by Fundação para a Ciência e Tecnologia (FCT) and COMPETE through the projects ‘[PTDC/SAU-GMG/112617/2009] (to P.M.) and [EXPL/ BIM-MEC/0239/2012] (to A.T.C.)’, by National Ataxia foundation (to P.M.), by Ataxia UK (to P.M.), by National Institutes of Health (NIH) ‘[GM038109, GM081192, AG026647, and NS047331] (to R.I.M.)’, by The Chicago Biomedical Consortium (to R.I.M.) and by the Ellison Medical Foundation (to R.I.M.). A.T.C., A.J., S.E., L.S.S., C.B., S.D.S., A.S.F. and A.N.C. were supported by the FCT individual fellowships SFRH/BPD/79469/2011, SFRH/BD/76613/2011, SFRH/BD/78554/2011, SFRH/BD/ 84650/2012, SFRH/BPD/74452/2010, SFRH/BD/78388/ 2011, SFRH/BPD/91562/2012 and SFRH/BD/51059/2010, respectively. FCT fellowships are co-financed by POPH, QREN, Governo da República Portuguesa and EU/FSE.info:eu-repo/semantics/publishedVersio

Without social cues it's male: Children perceive amorphous drawing of adults as male, but less so in social contexts

Peoples strong tendency to assign male gender to neutrally described persons has been termed the people = male bias. We aimed to assess whether this effect can be elicited using amorphous visual stimuli instead of verbal descriptions and whether it is already evident in childhood. We presented 53 children (4 to 12 yrs., 27 boys) with black-and-white amorphous drawings of humans and asked them whether the adult depicted was a man or a woman. The option to choose "I dont know" was also provided. In order to assess whether social contexts influenced childrens gender attributions (as has been previously reported for adults) we placed the same amorphous humans in three different contexts: 1) the adult was depicted alone, 2) the adult was passively involved in a social situation with a child and 3) the adult was actively helping a child. Children showed a clear tendency to assign male gender to the amorphous adults across all context variations; this was equally true for boys and for girls. However, when the adult was shown in a social context the proportion of male gender attributions was lower compared to the condition without social context. The older the children were, the more likely they were to attribute female gender to a higher proportion of amorphous figures across all contexts. Median response times were higher for "female" ratings, indicating that this decision was associated with greater cognitive effort. Our results show that a strong bias towards attributing male gender to visually presented amorphous figures is evident already in childhood and that it somewhat decreases with age. For children, just as it has been demonstrated for adults, social contexts lead to a larger proportion of female gender attributions. These results encourage future research to include developmental aspects for explaining the mechanisms underlying gender perception and stereotypes

Feeling the need of others: Children's emotional ratings of need-of-help depictions

Helping behavior as a prosocial action emerges early in childhood and is of interest for psychologists in a broad range of sub disciplines as well as for society. One necessary precondition for active helping is the ability to recognize that somebody needs help. The NeoHelp stimulus set used in this study was developed to enable the assessment and quantification of need-of-help recognition abilities. Previous research with the NeoHelp stimuli has shown that children of different ages are able to recognize their content. Specific effects of age and gender on need-of-help recognition have also been observed. How children subjectively experience these stimuli and thus how they rate depictions of need-of-help and no-need-of-help situations emotionally has not been assessed before. Here we report analyses of valence and arousal ratings for the complete NeoHelp stimulus set obtained from a diverse sample of 46 children. We employed the SAM-scales because they are an established rating instrument validated for diverse populations of adults. However, their use with children still needs further investigation. Thus, there were two main goals of the presented study: 1) Validating that the SAM arousal and valence scales may be used with young children below school age, and 2) investigating children's subjective emotional experience of need-of-help depictions. Our study demonstrates that the SAM scales, if properly explained, may be used reliably with children at and above five years of age. Ratings of younger and older children covered the whole range of the 5-point scales used. There was a linear relationship between arousal and valence ratings across all pictures: the higher the arousal ratings, the lower the valence ratings. Pictures showing a child in need-of-help were rated as lower in valence and higher in arousal than the corresponding no-need-of-help-stimuli regardless of children’s age or gender. With increasing age, arousal ratings for no-need-of-help depictions decreased, but arousal ratings for need-of-help depictions remained on the same higher level across ages. We thus provide first evidence that need-of-help depictions elicit differential subjective emotional responses in children on both, valence and arousal dimensions. This emotional component of need-of-help recognition has to be considered when assessing children's need-of-help recognition abilities

Bribing the eye: expected reward modulates smooth pursuit eye movements

Introduction: Reward expectancies can have profound effects on behavioral choices: primates select the target that is associated with the highest expected reward or value. Previous studies on smooth pursuit eye movements, the eyes’ main response to visual motion, showed that eye velocity dynamically reflects selection in favor of targets with higher expected reward. The current study examined whether reward also modulates basic kinematics of human smooth pursuit: does expecting a higher reward make us track moving objects better? Methods: We recorded eye position in 22 untrained human observers who were instructed to accurately track a small spot of light, moving at constant speed across a computer monitor; luminance contrast of the spot was either high (exp1) or low (exp2). Expected reward was manipulated by using pictures of Canadian 5 or 25 cent coins as cues (presented for 1000 ms preceding stimulus motion) indicating a low or high-reward trial, respectively. The ratio of low- to high-reward trials was 4:1; reward cues were equal in size and luminance. Observers were told that for each high-reward trial 25 cents would be added to their remuneration as a reward for accurate tracking. A control condition without reward cues served as a baseline. Results: We found consistent effects of reward expectation on smooth pursuit in both experiments. In high-reward trials, pursuit was initiated faster (higher acceleration and velocity) and maintained with better accuracy (gain) and lower velocity error. High reward also resulted in smoother pursuit responses with fewer and smaller catch-up saccades. Conclusion: We found adaptive improvements of smooth pursuit as a result of high reward expectation across the entire pursuit response. Reward may increase neuronal sensitivity, thereby boosting the system’s capability of processing visual motion information for pursuit