The influence of memory on visual perception in infants, children, and adults

Perception is not an independent, in-the-moment event. Instead, perceiving involves integrating prior expectations with current observations. How does this ability develop from infancy through adulthood? We examined how prior visual experience shapes visual perception in infants, children, and adults. Using an identical task across age groups, we exposed participants to pairs of colorful stimuli and measured their ability to discriminate relative saturation levels. Results showed that adult participants were biased by previously-experienced exemplars, but exhibited weakened in-the-moment discrimination between different levels of saturation. In contrast, infants and children showed less influence of memory in their perception, and they actually outperformed adults in discriminating between current levels of saturation. Our findings suggest that as humans develop, their perception relies more on prior experience and less on current observation.

In Flow with Task Repetition During Collaborative Oral and Writing Tasks

The present study draws on Flow Theory to examine the relationship between task repetition and the quality of learners’ subjective experience during task execution. Flow is defined as a positive experiential state characterized by intense focus and involvement in meaningful and challenging, but doable tasks, which has been associated with enhanced self-confidence and task performance (Csikszentmihalyi, 2008). While research shows that certain task characteristics interact differentially with the quality of flow experiences, no research has specifically examined such interaction with task repetition. Participants (n=24) were randomly assigned to a Task Repetition or a Procedural Repetition group. All participants first completed a two-way decision-making gap task in both the oral and written modalities and either repeated the identical task or a comparable task one week later. Data were collected with a flow perception questionnaire, completed immediately following each task. Results show that repetition positively influenced learners’ flow experience, but that modality was an important mediating factor.

Collaboratively framed interactions increase the adoption of intentional stance towards robots

When humans interact with artificial agents, they adopt various stances towards them. On one side of the spectrum, people might adopt a mechanistic stance towards an agent and explain its behavior using its functional properties. On the other hand, people can adopt the intentional stance towards artificial agents and explain their behavior using mentalistic terms and explain the agents’ behavior using internal states (e.g., thoughts and feelings). While studies continue to investigate under which conditions people adopt the intentional stance towards artificial robots, here, we report a study in which we investigated the effect of social framing during a color-classification task with a humanoid robot, iCub. One group of participants were asked to complete the task with iCub, in collaboration, while the other group completed an identical task with iCub and were told that they were completing the task for themselves. Participants completed a task assessing their level of adoption of the Intentional Stance (the InStance test) prior to - and after completing the task. Results illustrate that participants who “collaborated” with iCub were more likely to adopt the intentional stance towards it after the interaction. These results suggest that social framing can be a powerful method to influence the stance that people adopt towards a robot.

Language as shaped by the environment: linguistic construal in a collaborative spatial task

What causes cultural groups to favour specific conventions over others? Recently, it has been suggested that cross-linguistic variation can be motivated by factors of the wider non-linguistic environment. Large-scale cross-sectional studies have found statistical differences among languages that pattern with environmental variables such as topography or population size. However, these studies are correlational in nature, revealing little about the possible mechanisms driving these cultural evolutionary processes. The present study sets out to experimentally investigate how environmental factors come to shape the emergence of linguistic conventions. To this end, we adapt the classical Maze Game task to test the hypothesis that participants routinize different linguistic strategies to communicate positions in the maze contingent on particular environmental affordances (i.e. structure of the mazes). Our results confirm that subtle environmental motivations drive the emergence of different communicative conventions in an otherwise identical task, suggesting that linguistic adaptations are highly sensitive to factors of the shared task environment. We speculate that these kinds of mechanisms found at a local interactional level, through processes of cultural evolution contribute to the systematic global variation observed among different languages.

In monkeys making value-based decisions, amygdala neurons are sensitive to cue value as distinct from cue salience

Neurons in the lateral intraparietal (LIP) area of macaque monkey parietal cortex respond to cues predicting rewards and penalties of variable size in a manner that depends on the motivational salience of the predicted outcome (strong for both large reward and large penalty) rather than on its value (positive for large reward and negative for large penalty). This finding suggests that LIP mediates the capture of attention by salient events and does not encode value in the service of value-based decision making. It leaves open the question whether neurons elsewhere in the brain encode value in the identical task. To resolve this issue, we recorded neuronal activity in the amygdala in the context of the task employed in the LIP study. We found that responses to reward-predicting cues were similar between areas, with the majority of reward-sensitive neurons responding more strongly to cues that predicted large reward than to those that predicted small reward. Responses to penalty-predicting cues were, however, markedly different. In the amygdala, unlike LIP, few neurons were sensitive to penalty size, few penalty-sensitive neurons favored large over small penalty, and the dependence of firing rate on penalty size was negatively correlated with its dependence on reward size. These results indicate that amygdala neurons encoded cue value under circumstances in which LIP neurons exhibited sensitivity to motivational salience. However, the representation of negative value, as reflected in sensitivity to penalty size, was weaker than the representation of positive value, as reflected in sensitivity to reward size. NEW & NOTEWORTHY This is the first study to characterize amygdala neuronal responses to cues predicting rewards and penalties of variable size in monkeys making value-based choices. Manipulating reward and penalty size allowed distinguishing activity dependent on motivational salience from activity dependent on value. This approach revealed in a previous study that neurons of the lateral intraparietal (LIP) area encode motivational salience. Here, it reveals that amygdala neurons encode value. The results establish a sharp functional distinction between the two areas.

Children, but not chimpanzees, have facial correlates of determination

Facial expressions have long been proposed to be important agents in forming and maintaining cooperative interactions in social groups. Human beings are inordinately cooperative when compared with their closest-living relatives, the great apes, and hence one might expect species differences in facial expressivity in contexts in which cooperation could be advantageous. Here, human children and chimpanzees were given an identical task designed to induce an element of frustration (it was impossible to solve). In children, but not chimpanzees, facial expressions associated with effort and determination positively correlated with persistence at the task. By contrast, bodily indicators of stress (self-directed behaviour) negatively correlated with task persistence in chimpanzees. Thus, children exhibited more behaviour as they persisted, and chimpanzees exhibited less. The facial expressions produced by children, could, therefore, function to solicit prosocial assistance from others.

Motor learning reveals the existence of multiple codes for movement planning

Coordinate systems for movement planning are comprised of an anchor point (e.g., retinocentric coordinates) and a representation (encoding) of the desired movement. One of two representations is often assumed: a final-position code describing desired limb endpoint position and a vector code describing movement direction and extent. The existence of movement-planning systems using both representations is controversial. In our experiments, participants completed reaches grouped by target location (providing practice for a final-position code) and the same reaches grouped by movement vector (providing vector-code practice). Target-grouped reaches resulted in the isotropic (circular) distribution of errors predicted for position-coded reaches. The identical reaches grouped by vector resulted in error ellipses aligned with the reach direction, as predicted for vector-coded reaches. Manipulating only recent movement history to provide better learning for one or the other movement code, we provide definitive evidence that both movement representations are used in the identical task.