Grabbing subitizing with both hands: bimanual number processing

Visual judgment of small numerosities (<4) is generally assumed to be done through subitizing, which is a faster process than counting. Subitizing has also been shown to occur in haptic judgment of the number of spheres in the hand. Furthermore, interactions have been shown to exist between visually perceived numbers and hand motor action. In this study, we compare enumeration of a set of spheres presented to one hand (unimanual) and enumeration of the same total number of spheres presented divided over the two hands (bimanual). Our results show that, like in vision, a combination of subitizing and counting is used to process numbers in active touch. This shows that numbers are processed in a modality-independent way. This suggests that there are not only interactions between perception of numbers and hand motor action, but rather that number representation is modality-independent

Differential gene expression in the mesocorticolimbic system of innately high- and low-impulsive rats

Impulsivity is an important component of many psychiatric illnesses and has been associated with a number of psychiatric disorders such as bipolar disorder and attention deficit / hyperactivity disorder (ADHD). Exploring the different aspects of impulsive behaviour and assigning these to specific neurobiological pathways would advance our interpretation of disorders for which impulsivity is key. Pharmacological studies have implicated a number of neurotransmitters in impulsivity, which in turn have been shown to be affected by several genes in both rodent and human studies of impulsivity. Here, we examine impulsivity-related differences in gene expression in finer detail, using the 2-choice serial reaction time task (2-CSRTT) to assess the molecular signature of impulsivity in brain regions previously linked to impulsive behaviour. Wistar rats were rated as high, (n = 6), intermediate, (n = 12) or low impulsive (n = 6), based on premature responses in the 2-CSRTT, after which RNA was extracted from the nucleus accumbens core (NAcc) and ventral prefrontal cortex (vPFC). RNA from the NAcc and vPFC of high and low impulsivity rats (n = 6 per group) was analysed for differential gene expression patterns and exon usage using RNA poly-A tail sequencing. Pnisr, Mal, and Tspan2 were significantly increased in the NAcc of highly impulsive rats, whereas Ube3a was significantly decreased. No differences were seen in the vPFC. In addition to changes in gene expression, Tspan2 displayed differential exon usage in impulsive rats, while functionally, gene expression changes were related to membrane depolarisation and changes in exon usage were linked to sphingolipid breakdown. The changes in gene expression and exon usage observed in this study represent an important step towards defining the molecular architecture of impulsivity. This study therefore represents an important starting point for analysis of the biological role of impulsivity in addiction and other neurological conditions associated with impulsive phenotypes

Seksueel overdraagbare aandoeningen, waaronder hiv, in Nederland in 2016

In 2016, the number of people who were tested at a Dutch STI clinic for a sexually transmitted infection (STI) increased, after a decrease in 2015. The percentage of people diagnosed with an STI has also increased, to 18.4 percent in 2016. It is estimated that the number of STI consultations at the general practitioner has decreased slightly. Chlamydia remains the most common STI in heterosexuals. Gonorrhoea is more common than chlamydia in men who have sex with men (MSM). STI clinics offer high-risk groups the opportunity for free STI testing. In 2016, a total of 143,139 consultations were registered at the STI clinics, an increase of 5 percent compared to 2015. The percentage of detected STIs varied per municipal health centre (GGD), ranging from 12.8 to 20.9 percent. Most STIs were detected in people infected with HIV, followed by people who had been notified for an STI. Chlamydia In 2016, 14.5 percent of STI clinic attendees were infected with chlamydia (20,698 diagnoses; an increase of 11 percent compared to the previous year). This increase can be explained in part because, since 2015, STI clinics more strictly prioritise people with a high risk of STI. The biggest increase was seen in heterosexual men (from 16.1 in 2015 to 18.0 percent in 2016). In women, the percentage of chlamydia diagnoses increased from 14.2 to 15.4. In MSM, the percentage has been stable around 10 percent for years. Gonorrhoea The number of gonorrhoea diagnoses at the STI clinics has risen in the past year with 13 percent, to 6,092 infections. The percentage of positive tests in heterosexual men (1.7 percent) and women (1.4 percent) remained stable, compared to previous years. In MSM, the percentage has increased from 10.7 percent in 2015 to 11.3 percent in 2016. The STI clinics have not yet found cases of gonorrhoea resistant to the first option antibiotic, Ceftriaxone. The number of gonorrhoea infections diagnosed by general practitioners in 2015 saw a slight decline among women, but an increase among men of 20 percent compared to 2014. Syphilis In 2016, the number of syphilis diagnoses increased by 30 percent compared to 2015, totalling 1,223 infections. This increase is mainly caused by an increase in the number of diagnoses in MSM, both those with and without HIV. Out of all syphilis infections, 95 percent was diagnosed in MSM. The percentage of positive diagnoses in heterosexual men and women remains very low; 0.19 and 0.07 percent of all consultations that tested for syphilis, respectively. HIV In 2016, 285 new HIV diagnoses were detected at the STI clinics, approximately the same number as in 2015 (288); 93 percent was detected in MSM. The percentage of HIV diagnoses in MSM decreased, from 2.8 percent in 2007 to 0.8 percent in 2016. The number of HIV patients that had their 'first care' encounter at a Dutch HIV treatment centre decreased again, from 1,033 cases in 2015 to 976 in 2016. Out of these people, 666 received their diagnosis in 2016Het aantal mensen dat zich bij een Centrum Seksuele Gezondheid (CSG) heeft laten testen op een seksueel overdraagbare aandoening (soa) is, na een daling in 2015, in 2016 weer toegenomen. Het percentage bij wie een soa werd vastgesteld is ook gestegen, tot 18,4 procent in 2016. Naar schatting is het aantal soa-consulten bij huisartsen licht gedaald. Chlamydia blijft de meest voorkomende soa onder heteroseksuelen. Onder mannen die seks hebben met mannen (MSM) werd vaker gonorroe dan chlamydia gevonden. De CSG's bieden hoog-risicogroepen de mogelijkheid om zich gratis te laten testen op soa's. In totaal zijn er in 2016 143.139 consulten geregistreerd bij de CSG's, een stijging van 5 procent ten opzichte van 2015. Het percentage gevonden soa's varieerde tussen de GGD-en; van 12,8 tot 20,9. De meeste soa's zijn gevonden bij mensen met hiv, gevolgd door mensen die waren gewaarschuwd voor een soa. Chlamydia In 2016 had 14,5 procent van de CSG-bezoekers een chlamydia-infectie (20.698 diagnoses; een toename van 11 procent ten opzichte van het jaar ervoor). Deze stijging is mogelijk deels te verklaren doordat GGD-en sinds 2015 eerder voorrang verlenen aan personen met hoog risico op soa. De grootste toename was te zien bij heteroseksuele mannen (van 16,1 in 2015 naar 18,0 procent in 2016). Bij vrouwen nam het percentage vastgestelde chlamydia toe van 14,2 naar 15,4. Onder MSM ligt dit percentage al jaren rond 10 procent. Gonorroe Het aantal gonorroe-diagnoses bij de CSG is het afgelopen jaar met 13 procent toegenomen tot 6.092 infecties. Het percentage positieven onder heteroseksuele mannen (1,7 procent) en vrouwen (1,4 procent) bleef stabiel ten opzichte van voorgaande jaren. Onder MSM is het percentage toegenomen van 10,7 procent in 2015 naar 11,3 procent in 2016. Bij CSG-bezoekers is nog steeds geen gonorroe resistent gevonden tegen het 'eerstekeus' antibioticum ceftriaxon. Het aantal gonorroe-infecties gediagnosticeerd door huisartsen in 2015 nam licht af onder vrouwen, maar steeg onder mannen met 20 procent ten opzichte van 2014. Syfilis In 2016 is het aantal diagnoses van syfilis met 30 procent gestegen ten opzichte van 2015, tot 1.223 infecties. Deze stijging komt voornamelijk door een toename in het aantal diagnoses onder MSM, zowel met als zonder hiv. Van alle syfilis-infecties werd 95 procent bij MSM vastgesteld. Het percentage positieve diagnoses onder heteroseksuele mannen en vrouwen blijft zeer laag; respectievelijk 0,19 en 0,07 procent van alle consulten waarin getest werd op syfilis. Hiv In 2016 zijn 285 nieuwe diagnoses van hiv gesteld bij de CSG, vrijwel evenveel als in 2015 (288). Drieënnegentig procent daarvan werd bij MSM vastgesteld. Het percentage hiv-diagnoses bij MSM is gedaald van 2,8 procent in 2007 tot 0,8 procent in 2016. Het aantal hiv-patiënten dat voor het eerst 'in zorg' was bij de Nederlandse hiv-behandelcentra daalde opnieuw, van 1.033 gevallen in 2015 tot 976 in 2016. Van hen hadden 666 personen de diagnose in 2016 gekregenMinisterie van VW

The Role of Visual Information in Numerosity Estimation

Mainstream theory suggests that the approximate number system supports our non-symbolic number abilities (e.g. estimating or comparing different sets of items). It is argued that this system can extract number independently of the visual cues present in the stimulus (diameter, aggregate surface, etc.). However, in a recent report we argue that this might not be the case. We showed that participants combined information from different visual cues to derive their answers. While numerosity comparison requires a rough comparison of two sets of items (smaller versus larger), numerosity estimation requires a more precise mechanism. It could therefore be that numerosity estimation, in contrast to numerosity comparison, might rely on the approximate number system. To test this hypothesis, we conducted a numerosity estimation experiment. We controlled for the visual cues according to current standards: each single visual property was not informative about numerosity. Nevertheless, the results reveal that participants were influenced by the visual properties of the dot arrays. They gave a larger estimate when the dot arrays consisted of dots with, on average, a smaller diameter, aggregate surface or density but a larger convex hull. The reliance on visual cues to estimate numerosity suggests that the existence of an approximate number system that can extract numerosity independently of the visual cues is unlikely. Instead, we propose that humans estimate numerosity by weighing the different visual cues present in the stimuli

The effect of feature saliency on haptic subitizing

‘Subitizing’ refers to fast and error-free numerosity judgment for small (<4) sets of items. For larger sets, the slower process of ‘counting’ is used. Counting has a serial character, whereas subitizing is believed to have a parallel character. While subitizing was initially found in vision, it has been shown to exist in touch as well. In vision, it has been demonstrated that adding distractor items to a set of target items influences numerosity judgment of the target items. Subitizing was in this case only possible if the distractor item is highly salient among the targets. In the present study, we investigated the effect of adding a distractor item on haptic judgement of a set of target items. To this end, we asked subjects to judge the number of spheres grasped in their hand. Either a cube or an ellipsoid could be added to the set. A cube among spheres has been shown to be highly salient, while an ellipsoid among spheres is not. Our results show that adding a distractor item led to an increase in the response time slopes regardless of the distractor shape. Subitizing was, however, only possible in the case of a salient distractor. This is in agreement with results from vision

Range dependent processing of visual numerosity: similarities across vision and haptics

‘Subitizing’ refers to fast and accurate judgement of small numerosities, whereas for larger numerosities either counting or estimation are used. Counting is slow and precise, whereas estimation is fast but imprecise. In this study consisting of five experiments we investigated if and how the numerosity judgement process is affected by the relative spacing between the presented numerosities. To this end we let subjects judge the number of dots presented on a screen and recorded their response times. Our results show that subjects switch from counting to estimation if the relative differences between subsequent numerosities are large (a factor of 2), but that numerosity judgement in the subitizing range was still faster. We also show this fast performance for small numerosities only occurred when numerosity information is present. This indicates this is typical for number processing and not magnitude estimation in general. Furthermore, comparison with a previous haptic study suggests similar processing in numerosity judgement through haptics and vision

Inferring Binding Energies from Selected Binding Sites

We employ a biophysical model that accounts for the non-linear relationship between binding energy and the statistics of selected binding sites. The model includes the chemical potential of the transcription factor, non-specific binding affinity of the protein for DNA, as well as sequence-specific parameters that may include non-independent contributions of bases to the interaction. We obtain maximum likelihood estimates for all of the parameters and compare the results to standard probabilistic methods of parameter estimation. On simulated data, where the true energy model is known and samples are generated with a variety of parameter values, we show that our method returns much more accurate estimates of the true parameters and much better predictions of the selected binding site distributions. We also introduce a new high-throughput SELEX (HT-SELEX) procedure to determine the binding specificity of a transcription factor in which the initial randomized library and the selected sites are sequenced with next generation methods that return hundreds of thousands of sites. We show that after a single round of selection our method can estimate binding parameters that give very good fits to the selected site distributions, much better than standard motif identification algorithms