The feasibility of an automated eye-tracking-modified Fagan test of memory for human faces in younger Ugandan HIV-exposed children

Objective: The Fagan Test of Infant Intelligence (FTII) uses longer gaze length for unfamiliar versus familiar human faces to gauge visual-spatial encoding, attention, and working memory in infants. Our objective was to establish the feasibility of automated eye tracking with the FTII in HIV-exposed Ugandan infants.

Method: The FTII was administered to 31 perinatally HIV-exposed noninfected (HEU) Ugandan children 6–12 months of age (11 boys; M = 0.69 years, SD = 0.14; 19 girls; M = 0.79, SD = 0.15). A series of 10 different faces were presented (familiar face exposure for 25 s followed by a gaze preference trial of 15 s with both the familiar and unfamiliar faces). Tobii X2-30 infrared camera for pupil detection provided automated eye-tracking measures of gaze location and length during presentation of Ugandan faces selected to correspond to the gender, age (adult, child), face expression, and orientation of the original FTII. Eye-tracking gaze length for unfamiliar faces was correlated with performance on the Mullen Scales of Early Learning (MSEL).

Results: Infants gazed longer at the novel picture compared to familiar across 10 novelty preference trials. Better MSEL cognitive development was correlated with proportionately longer time spent looking at the novel faces (r(30) = 0.52, p = .004); especially for the Fine Motor Cognitive Sub-scale (r(30) = 0.54, p = .002).

Conclusion: Automated eye tracking in a human face recognition test proved feasible and corresponded to the MSEL composite cognitive development in HEU infants in a resource-constrained clinical setting. Eye tracking may be a viable means of enhancing the validity and accuracy of other neurodevelopmental measures in at-risk children in sub-Saharan Africa.     

Tracking the identity of moving words: Stimulus complexity and familiarity affects tracking accuracy

In two experiments, participants tracked the identity and location of moving words. The task bears resemblance to one performed by air traffic controllers who track multiple moving aircraft, where they are identified with relatively complex alphanumeric call signs. In Experiment 1, stimulus familiarity was manipulated by comparing the tracking of familiar words and pseudowords. In Experiment 2, also stimulus complexity was varied by having the participants track short and long words. Stimulus complexity affected tracking: Short words were easier to track than long words. Moreover, familiarity of identity affected tracking of short words (short familiar words were easier to track than short pseudo-words) but not of long words. The results are interpreted within the framework of the model of multiple identity tracking model. Mathematical simulations suggest that observers may not have enough time for full identification of complex identities in a dynamic situation. Practical implications of the results for air traffic control are discussed.     

Attentional engagement during syllable discrimination: The role of salient prosodic cues in 6- to 8-month-old infants

Prosodic cues drive speech segmentation and guide syllable discrimination. However, less is known about the attentional mechanisms underlying an infant's ability to benefit from prosodic cues. This study investigated how 6- to 8-month-old Italian infants allocate their attention to strong vs. weak syllables after familiarization with four repeats of a single CV sequence with alternating strong and weak syllables (different syllables on each trial). In the discrimination test-phase, either the strong or the weak syllable was replaced by a pure tone matching the suprasegmental characteristics of the segmental syllable, i.e., duration, loudness and pitch, whereas the familiarized stimulus was presented as a control. By using an eye-tracker, attention deployment (fixation times) and cognitive resource allocation (pupil dilation) were measured under conditions of high and low saliency that corresponded to the strong and weak syllabic changes, respectively. Italian learning infants were found to look longer and also to show, through pupil dilation, more attention to changes in strong syllable replacement rather than weak syllable replacement, compared to the control condition. These data offer insights into the strategies used by infants to deploy their attention towards segmental units guided by salient prosodic cues, like the stress pattern of syllables, during speech segmentation.     

Age effects and gaze patterns in recognising emotional expressions: An in-depth look at gaze measures and covariates

The present study investigated predictors of age effects in emotion recognition accuracy. Older and younger adults were tested on a battery of cognitive, vision, and affective questionnaires; participants' eyes were also tracked while they completed an emotion recognition task. Older adults were worse at recognising sad, angry, and fearful expressions than younger adults. When controlling for covariates related to emotion recognition accuracy, younger adults still outperformed older adults in recognising anger and sadness. Younger adults tended to pay more attention to the eyes than older adults. Results suggest that age-related gaze patterns in emotion recognition may depend on the specific emotion being recognised and may not generalise across stimuli sets.     

Being of two minds: Switching mindsets exhausts self-regulatory resources

The human psyche is equipped with the capacity to solve problems using different mental states or mindsets. Different mindsets can lead to different judgment and decision making styles, each associated with its own perspective and biases. To change perspective, people can, and often do, switch mindsets. We argue, however, that mindset switching can be costly for subsequent decisions. We propose that mindset switching is an executive function that relies on the same psychological resource that governs other acts of executive functioning, including self-regulation. This implies that there are psychic costs to switching mindsets that are borne out in depleted executive resources. One implication of this framework is that switching mindsets should render people more likely to fail at subsequent self-regulation than they would if maintaining a consistent mindset. The findings from experiments that manipulated mindset switching in five domains support this model.     

Similarity and difference in the processing of same- and other-race faces as revealed by eye tracking in 4- to 9-month-olds

Fixation duration for same-race (i.e., Asian) and other-race (i.e., Caucasian) female faces by Asian infant participants between 4 and 9 months of age was investigated with an eye-tracking procedure. The age range tested corresponded with prior reports of processing differences between same- and other-race faces observed in behavioral looking time studies, with preference for same-race faces apparent at 3 months of age and recognition memory differences in favor of same-race faces emerging between 3 and 9 months of age. The eye-tracking results revealed both similarity and difference in infants’ processing of own- and other-race faces. There was no overall fixation time difference between same race and other race for the whole face stimuli. In addition, although fixation time was greater for the upper half of the face than for the lower half of the face and trended higher on the right side of the face than on the left side of the face, face race did not impact these effects. However, over the age range tested, there was a gradual decrement in fixation time on the internal features of other-race faces and a maintenance of fixation time on the internal features of same-race faces. Moreover, the decrement in fixation time for the internal features of other-race faces was most prominent on the nose. The findings suggest that (a) same-race preferences may be more readily evidenced in paired comparison testing formats, (b) the behavioral decline in recognition memory for other-race faces corresponds in timing with a decline in fixation on the internal features of other-race faces, and (c) the center of the face (i.e., the nose) is a differential region for processing same- versus other-race faces by Asian infants.     

Contagious resource depletion and anxiety? Spreading effects of evaluative concern and impression formation in dyadic social interaction

Two studies examined how adopting an impression formation or evaluative concern mindset affects individuals' own and their interaction partner's experience of potentially stressful social exchanges, such as first meeting situations and interethnic interaction. Our main hypothesis was that adopting an impression formation mindset would, by diverting individuals' focus away from themselves and toward others, reduce both their own and their partner's cognitive resource depletion and negative affect. Consistent with predictions, positive effects of impression formation were evident and were “contagious” in that they were evident across individuals who received the mindset instructions and their partners, who were unaware of the manipulation. The positive effects of impression formation instructions were generally evident both in comparison to evaluative concern instructions, which provided similar structure, and in comparison to no instructions at all. Thus, adopting an impression formation mindset seems an effective strategy for minimizing negative outcomes experienced in stressful social interactions.     

Force and electromyography responses during isometric force release of different rates and step-down magnitudes

This study investigated motor responses of force release during isometric elbow flexion by comparing effects of different ramp durations and step-down magnitudes. Twelve right-handed participants (age: 23.1 ± 1.1) performed trajectory tracking tasks. Participants were instructed to release their force from the reference magnitude (REF; 40% of maximal voluntary contraction force) to a step-down magnitude of 67% REF or 33% REF and maintain the released magnitude. Force release was guided by ramp durations of either 1 s or 5 s. Electromyography of the biceps brachii and triceps brachii was performed during the experimental task, and the co-contraction ratio was evaluated. Force output was recorded to evaluate the parameters of motor performance, such as force variability and overshoot ratio. Although a longer ramp duration of 5 s decreased the force variability and overshoot ratio than did shorter ramp duration of 1 s, higher perceived exertion and co-contraction ratio were followed. Force variability was greater when force was released to the step-down magnitude of 33% REF than that when the magnitude was 67% REF, however, the overshoot ratio showed opposite results. This study provided evidence proving that motor control strategies adopted for force release were affected by both duration and step-down magnitude. In particular, it implies that different control strategies are required according to the level of step-down magnitude with a relatively short ramp duration.