The right way to kiss: directionality bias in head-turning during kissing

Humans have a bias for turning to the right in a number of settings. Here we document a bias in head-turning to the right in adult humans, as tested in the act of kissing. We investigated head-turning bias in both kiss initiators and kiss recipients for lip kissing, and took into consideration differences due to sex and handedness, in 48 Bangladeshi heterosexual married couples. We report a significant male bias in the initiation of kissing and a significant bias in head-turning to the right in both kiss initiators and kiss recipients, with a tendency among kiss recipients to match their partners’ head-turning direction. These interesting outcomes are explained by the influences of societal learning or cultural norms and the potential neurophysiological underpinnings which together offer novel insights about the mechanisms underlying behavioral laterality in humans

Is Reduced Visual Processing the Price of Language?

We suggest a later timeline for full language capabilities in Homo sapiens, placing the emergence of language over 200,000 years after the emergence of our species. The late Paleolithic period saw several significant changes. Homo sapiens became more gracile and gradually lost significant brain volumes. Detailed realistic cave paintings disappeared completely, and iconic/symbolic ones appeared at other sites. This may indicate a shift in perceptual abilities, away from an accurate perception of the present. Language in modern humans interact with vision. One example is the McGurk effect. Studies show that artistic abilities may improve when language-related brain areas are damaged or temporarily knocked out. Language relies on many pre-existing non-linguistic functions. We suggest that an overwhelming flow of perceptual information, vision, in particular, was an obstacle to language, as is sometimes implied in autism with relative language impairment. We systematically review the recent research literature investigating the relationship between language and perception. We see homologues of language-relevant brain functions predating language. Recent findings show brain lateralization for communicative gestures in other primates without language, supporting the idea that a language-ready brain may be overwhelmed by raw perception, thus blocking overt language from evolving. We find support in converging evidence for a change in neural organization away from raw perception, thus pushing the emergence of language closer in time. A recent origin of language makes it possible to investigate the genetic origins of language.publishedVersio

The impact of reward value on early sensory processing and its interaction with selective attention

Reward value affects the earliest stages of sensory perception. Whereas a host of previous studies have investigated the underlying mechanisms of reward-driven modulation of visual perception, reward effects in other sensory modalities have remained underexplored. Specifically, it has remained unknown how reward signals should be coordinated and communicated across sensory modalities. The current PhD thesis aimed to gain insight into the underlying mechanisms of reward-driven modulation of perception and its interaction with attention across sensory modalities. To this end, three experiments were conducted to identify the behavioral and electrophysiological correlates of reward effects. In Study 1, we found that high reward, task-irrelevant visual cues (intra-modal) elicited an early suppression of visual event-related potentials (ERPs). High reward auditory cues (cross-modal), on the other hand, led to a later modulation of visual ERPs and facilitated behavioral performance. Study 2 tested the dependence of reward effects on the spatial and temporal arrangement of intra-modal and cross-modal cues relative to the target, and showed that each reward cue maximally exerts its effect under a specific size of attentional focus. Study 3 explicitly manipulated the spatial attention and tested how reward associations of an audiovisual stimulus influence the allocation of attention. We found that auditory rewards enhanced the attentional modulation of both visual and auditory ERPs. Interestingly, although visual rewards did not lead to a distinguishable ERP modulation, they led to strong modulations when they were combined with auditory rewards, suggesting that integration across modalities boosts the reward effects. Taken together, the current PhD thesis identified the behavioral and neural signatures of reward-driven modulation of perception under different modes of reward signaling and different degrees of attentional engagement. Our findings inspire a two-stage model of reward processing, with local, intra-modal reward effects occurring at an early stage and long-range, multimodal reward effects arising at a later stage. Cross-modal reward signals have important ramifications for clinical applications where the impaired function of one sense can be rehabilitated by motivational signals conveyed through another sensory modality.2021-11-2

Estudio de polimorfismos genéticos asociados con la inhibición global y selectiva de respuestas

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Psicología, leída el 27/01/2021. Tesis formato europeo (compendio de artículos)This doctoral dissertation titled “Study of genetic polymorphisms associated with global and selective response inhibition” delves into the study of the genetic correlates of these two types of inhibition. Global or simple response inhibition refers to the ability to suppress a single planned or already initiated motor response after the appearance of a single stop stimulus, and previous studies show that it is at least partially heritable. Its genetic basis has been studied mainly through association studies of candidate polymorphisms in genes linked to dopamine, serotonin and noradrenaline neurotransmission. These studies yield contradictory results, in that associations found have not always been replicated, or even occur in opposite directions. On the other hand, selective response inhibition refers to the ability to suppress a response to some specific stimuli and continue to emit it to other stimuli. It has recently been observed that participants can adopt various strategies to complete selective response inhibition tasks, some of which are characterized by selective inhibition to some stimuli and not others as theoretically expected, but others by indiscriminate inhibition to all stimuli. To our knowledge, the genetic correlates of selective inhibition have not been explored until now. Therefore, the first objective of this doctoral dissertation was to systematically review and meta-analyse previous literature to identify which candidate polymorphisms of the monoaminergic pathways are associated with behavioural correlates of global response inhibition, in adult and non-clinical populations. These correlates are the percentage of commission errors derived from Go/No-Go tasks and the Stop-Signal Reaction Time (or SSRT) derived from Stop-Signal tasks. The second objective has been to examine for the first time the genetic correlates of selective response inhibition in an experimental study with adult and non-clinical populations. This study focused on dopaminergic polymorphisms due to a stronger theoretical rationale involving dopamine as an essential neurotransmitter for the function of brain areas possibly required for selective inhibition (such as the dorsolateral prefrontal cortex and the striatum)...La presente tesis doctoral titulada “Estudio de polimorfismos genéticos asociados con la inhibición global y selectiva de respuestas” profundiza en el estudio de los correlatos genéticos de estos dos tipos de inhibición. La inhibición global o simple de la respuesta se refiere a la capacidad de suprimir una única respuesta motora planeada o ya iniciada tras la aparición de un único estímulo de parada, y estudios previos demuestran que es al menos parcialmente heredable. Su base genética se ha estudiado sobre todo a través de estudios de asociación de polimorfismos candidatos en genes vinculados con la neurotransmisión de la dopamina, serotonina y noradrenalina. Estos estudios obtienen datos contradictorios, en tanto que las asociaciones encontradas no siempre se han replicado, o incluso ocurren en dirección opuesta. Por otra parte, la inhibición selectiva de respuestas se refiere a la capacidad para suprimir una respuesta ante determinados estímulos, pero continuar emitiéndola ante otros. Se ha observado recientemente que los participantes pueden adoptar diversas estrategias para completar las tareas de inhibición selectiva de respuesta, algunas de las cuales se caracterizan por inhibir selectivamente ante unos estímulos y no otros como se esperaría teóricamente, pero otras por inhibir indiscriminadamente ante todos los estímulos. Los correlatos genéticos de la inhibición selectiva no han sido explorados hasta ahora, según nuestro conocimiento. Por lo tanto, el primer objetivo de esta tesis doctoral fue realizar una revisión sistemática y meta-analítica de la literatura previa para conocer qué polimorfismos candidatos de las vías monoaminérgicas se asocian con correlatos conductuales de la inhibición global de la respuesta en población adulta. Estos correlatos son el porcentaje de errores de comisión derivado de las tareas tipo Go/No-Go y el tiempo estimado de inhibición (SSRT por sus siglas en inglés) derivado de las tareas tipo Stop-Signal. El segundo objetivo fue examinar, por primera vez, los correlatos genéticos de la inhibición selectiva de respuestas en un estudio experimental con población adulta. Este estudio se centró en polimorfismos dopaminérgicos debido a una mayor fundamentación teórica que implica a la dopamina como neurotransmisor esencial en el funcionamiento de áreas cerebrales posiblemente requeridas para la inhibición selectiva (como la corteza prefrontal dorsolateral y el estriado)...Fac. de PsicologíaTRUEunpu

The effects of dopamine and dopamine precursor medication on impairments to high-level vision in Parkinson\u27s disease

The goal of this study was to examine how dopamine (DA) and dopaminergic medications affect the performance of high-level visual tasks in individuals with Parkinson’s disease (PD). Various studies have reported that PD is associated with impairments on visual tasks known to depend on processing in the ventral visual pathway of the brain. Because most behavioral symptoms in PD arise from chronic dopamine deficiency, the author sought to investigate the role that DA played in cognitive vision. Accordingly, five complex visual tasks were chosen that were known to recruit processing from different constellations of brain areas, either in the ventral pathway or to which the ventral pathway was known to send projections. The tasks included discrimination of abstract objects and three-dimensional face stimuli, visual working memory for these same stimuli, and mental rotation of three-dimensional wire-frame objects. An additional task, in which participants were required to discriminate between pairs of lines with varying orientations, was included as a control. Individuals with PD, as well as healthy age- and sex-matched control participants, completed all five of these tasks twice, and individuals with PD, in particular, were asked to complete them once on and once off of their prescribed dopaminergic medications. The PD group performed significantly worse than the group of healthy control participants across all five tasks. Strikingly, the performance of individuals in the PD group did not differ significantly depending on their medication state. This finding indicates either that dopamine deficiency is not responsible for cognitive visual impairments in PD, or that the dopaminergic circuitry responsible for these impairments is incapable of responding to the administration of dopaminergic medication. Further, since all tasks, including the line orientation discrimination task, showed an effect of group, the results of this study are insufficient to rule out the possibility that impairments that have been reported elsewhere as cognitive visual deficits in PD are simply the result of deficits in more basic visual processing. Finally, the results of this study provide preliminary evidence that impairments of mental rotation in PD are the result of impaired processing in brain regions traditionally associated with motor functioning

Anticlockwise or clockwise?:a dynamic perception-action-laterality model for directionality bias in visuospatial functioning

AbstractOrientation bias and directionality bias are two fundamental functional characteristics of the visual system. Reviewing the relevant literature in visual psychophysics and visual neuroscience we propose here a three-stage model of directionality bias in visuospatial functioning. We call this model the ‘Perception-Action-Laterality’ (PAL) hypothesis. We analyzed the research findings for a wide range of visuospatial tasks, showing that there are two major directionality trends in perceptual preference: clockwise versus anticlockwise. It appears these preferences are combinatorial, such that a majority of people fall in the first category demonstrating a preference for stimuli/objects arranged from left-to-right rather than from right-to-left, while people in the second category show an opposite trend. These perceptual biases can guide sensorimotor integration and action, creating two corresponding turner groups in the population. In support of PAL, we propose another model explaining the origins of the biases – how the neurogenetic factors and the cultural factors interact in a biased competition framework to determine the direction and extent of biases. This dynamic model can explain not only the two major categories of biases in terms of direction and strength, but also the unbiased, unreliably biased or mildly biased cases in visuosptial functioning

On the Role of Dopamine in Cognitive Vision

Abstract. Although dopamine is one of the most studied neurotransmitter in the brain, its exact function is still unclear. This short review focuses on its role in different levels of cognitive vision: visual processing, visual attention and working memory. Dopamine can influence cognitive vision either through direct modulation of visual cells or through gating of basal ganglia functioning. Even if its classically assigned role is to signal reward prediction error, we review evidence that dopamine is also involved in novelty detection and attention shifting and discuss the possible implications for computational modeling.