Nathalie Peira

Mind the body!: designing a mobile stress management application encouraging personal reflection

We have designed a stress management biofeedback mobile service for everyday use, aiding users to reflect on both positive and negative patterns in their behavior. To do so, we embarked on a complex multidisciplinary design journey, learning that: detrimental stress results from complex processes related to e.g. the subjective experience of being able to cope (or not) and can therefore not be measured and diagnosed solely as a bodily state. We learnt that it is difficult, sometimes impossible, to make a robust analysis of stress symptoms based on biosensors worn outside the laboratory environment they were designed for. We learnt that rather than trying to diagnose stress, it is better to mirror short-term stress reactions back to them, inviting their own interpretations and reflections. Finally, we identified several experiential qualities that such an interface should entail: ambiguity and openness to interpretation, interactive history of prior states, fluency and aliveness.

Recognizing Masked Threat: Fear Betrays, But Disgust You Can Trust

If emotions guide consciousness, people may recognize degraded objects in center view more accurately if they either fear the objects or are disgusted by them. Therefore, we studied whether recognition of spiders and snakes correlates with individual differences in spider fear, snake fear, and disgust sensitivity. Female students performed a recognition task with pictures of spiders, snakes, flowers, and mushrooms as well as blanks. Pictures were backward masked to reduce picture visibility. Signal detection analyses showed that recognition of spiders and snakes was correlated with disgust sensitivity but not with fear of spiders or snakes. Further, spider fear correlated with the tendency to misinterpret blanks as threatening (response bias). These findings suggest that effects on recognition and response biases to emotional pictures vary for different emotions and emotional traits. Whereas fear may induce response biases, disgust may facilitate recognition.

Never mind the spider: Late positive potentials to phobic threat at fixation are unaffected by perceptual load

Research suggests that processing of emotional stimuli may be eliminated if a concurrent task places sufficient demands on attentional resources. To test whether this holds for stimuli with strong emotional significance, pictures of spiders as well as mushrooms were presented at fixation to spider-fearful and non-fearful participants. Concurrently, perceptual load was manipulated in two levels with a peripheral letter discrimination task. Results of event-related potentials showed that, compared with non-fearful participants, spider-fearful participants showed greater late positive potentials (LPP) to spiders than mushrooms, which provides a manipulation check that spiders were emotionally meaningful to spider-fearful participants. Critically, this effect was not affected by level of perceptual load. These findings suggest that strong emotional stimuli at fixation may resist manipulations of perceptual load.

Who are you looking at? The influence of face gender on visual attention and memory for own- and other-race faces

Previous research suggests that the own-race bias (ORB) in memory for faces is a result of other-race faces receiving less visual attention at encoding. As women typically display an own-gender bias in memory for faces and men do not, we investigated whether face gender and sex of viewer influenced visual attention and memory for own- and other-race faces, and if preferential viewing of own-race faces contributed to the ORB in memory. Participants viewed pairs of female or male own- and other-race faces while their viewing time was recorded. Afterwards, they completed a surprise memory test. We found that (1) other-race males received the initial focus of attention, (2) own-race faces were viewed longer than other-race faces over time, although the difference was larger for female faces, and (3) even though longer viewing time increased the probability of remembering a face, it did not explain the magnified ORB in memory for female faces. Importantly, these findings highlight that face gender moderates attentional responses to and memory for own- and other-race faces.

Brain systems underlying attentional control and emotional distraction during working memory encoding

Goal-directed behavior requires that cognitive operations can be protected from emotional distraction induced by task-irrelevant emotional stimuli. The brain processes involved in attending to relevant information while filtering out irrelevant information are still largely unknown. To investigate the neural and behavioral underpinnings of attending to task-relevant emotional stimuli while ignoring irrelevant stimuli, we used fMRI to assess brain responses during attentional instructed encoding within an emotional working memory (WM) paradigm. We showed that instructed attention to emotion during WM encoding resulted in enhanced performance, by means of increased memory performance and reduced reaction time, compared to passive viewing. A similar performance benefit was also demonstrated for recognition memory performance, although for positive pictures only. Functional MRI data revealed a network of regions involved in directed attention to emotional information for both positive and negative pictures that included medial and lateral prefrontal cortices, fusiform gyrus, insula, the parahippocampal gyrus, and the amygdala. Moreover, we demonstrate that regions in the striatum, and regions associated with the default-mode network were differentially activated for emotional distraction compared to neutral distraction. Activation in a sub-set of these regions was related to individual differences in WM and recognition memory performance, thus likely contributing to performing the task at an optimal level. The present results provide initial insights into the behavioral and neural consequences of instructed attention and emotional distraction during WM encoding.

What You Fear Will Appear: Detection of Schematic Spiders in Spider Fear

Various experimental tasks suggest that fear guides attention. However, because these tasks often lack ecological validity, it is unclear to what extent results from these tasks can be generalized to real-life situations. In change detection tasks, a brief interruption of the visual input (i.e., a blank interval or a scene cut) often results in undetected changes in the scene. This setup resembles real-life viewing behavior and is used here to increase ecological validity of the attentional task without compromising control over the stimuli presented. Spider-fearful and nonfearful women detected schematic spiders and flowers that were added to one of two identical background pictures that alternated with a brief blank in between them (i.e., flicker paradigm). Results showed that spider-fearful women detected spiders (but not flowers) faster than did nonfearful women. Because spiders and flowers had similar low-level features, these findings suggest that fear guides attention on the basis of object features rather than simple low-level features.

Emotional responses in spider fear are closely related to picture awareness

Theories of emotion propose that responses to emotional pictures can occur independently of whether or not people are aware of the picture content. Because evidence from dissociation paradigms is inconclusive, we manipulated picture awareness gradually and studied whether emotional responses varied with degree of awareness. Spider fearful and non-fearful participants viewed pictures of spiders and flowers at four levels of backward masking while electrodermal activity and heart rate were measured continuously. Recognition ratings confirmed that participants’ picture awareness decreased with masking. Critically, effects of spider fear on emotion ratings and heart rate also decreased with masking. These findings suggest that effects of spider fear on emotion ratings and heart rate are closely related to picture awareness.

Age differences in brain systems supporting transient and sustained processes involved in prospective memory and working memory

In prospective memory (PM), an intention to act in response to an external event is formed, retained, and at a later stage, when the event occurs, the relevant action is performed. PM typically shows a decline in late adulthood, which might affect functions of daily living. The neural correlates of this decline are not well understood. Here, 15 young (6 female; age range=23-30years) and 16 older adults (5 female; age range=64-74years) were scanned with fMRI to examine age-related differences in brain activation associated with event-based PM using a task that facilitated the separation of transient and sustained components of PM. We show that older adults had reduced performance in conditions with high demands on prospective and working memory, while no age-difference was observed in low-demanding tasks. Across age groups, PM task performance activated separate sets of brain regions for transient and sustained responses. Age-differences in transient activation were found in fronto-striatal and MTL regions, with young adults showing more activation than older adults. Increased activation in young, compared to older adults, was also found for sustained PM activation in the IFG. These results provide new evidence that PM relies on dissociable transient and sustained cognitive processes, and that age-related deficits in PM can be explained by an inability to recruit PM-related brain networks in old age.