Disentangling perceptual sensitivity from decision criterion in the detection of emotional expressions accessing awareness

Understanding faces and their emotional expressions is essential for social interaction. Past studies have prompted suggestions that some facial features may be processed unconsciously. Evidence for such unconscious processing has predominantly come from the Breaking Continuous Flash Suppression (b-CFS) paradigm, which measures the time it takes different stimuli to overcome interocular suppression. For instance, it has been claimed that suppressed fearful expressions are detected faster that neutral expressions. However, in the b-CFS procedure, observers can decide how much information they receive before committing to a report, so their detection responses may be influenced by differences in decision criteria and by stimulus identification. Here, we use a procedure that addresses these problems by using predefined exposure durations and measuring sensitivity and decision criteria for both detection and identification of facial expressions. We found that neither angry nor fearful expressions enjoy higher sensitivity in detection than happy or neutral expressions as they enter awareness. To test whether our procedure was sensitive to face-related effects, we combined our test of emotional expression with a test of face inversion. While upright faces enjoyed higher sensitivity in detection than inverted faces, again emotional expressions did not enjoy higher sensitivity than neutral or happy expressions. Finally, we measured detection thresholds using a staircase procedure but did not find differences between emotional expressions. Our findings cast doubts on past claims about emotional expressions enjoying prioritised access to awareness and call for the development of more stringent procedures.

Beyond the tracked line of sight - Evaluation of the peripheral usable field of view in a simulator setting

Combining advanced gaze tracking systems with the latest vehicle environment sensors opens up new fields of applications for driver assistance. Gaze tracking enables researchers to determine the location of a fixation, and under consideration of the visual saliency of the scene, to predict visual perception of objects. The perceptual limits, for stimulus identification, found in literature have mostly been determined in laboratory conditions using isolated stimuli, with a fixed gaze point, on a single screen with limited coverage of the field of view. The found limits are usually reported as hard limits. Such commonly used limits are therefore not applicable to settings with a wide field of view, natural viewing behavior and multi-stimuli. As handling of sudden, potentially critical driving maneuvers heavily relies on peripheral vision, the peripheral limits for feature perception need to be included in the determined perceptual limits. To analyze the human visual perception of different, simultaneously occurring, object changes (shape, color, movement) we conducted a study with 50 participants, in a driving simulator and we propose a novel way to determine perceptual limits, which is more applicable to driving scenarios.

Enhanced inter-regional coupling of neural responses and repetition suppression provide separate contributions to long-term behavioral priming

Stimulus identification commonly improves with repetition over long delays (“repetition priming”), whereas neural activity commonly decreases (“repetition suppression”). Multiple models have been proposed to explain this brain-behavior relationship, predicting alterations in functional and/or effective connectivity (Synchrony and Predictive Coding models), in the latency of neural responses (Facilitation model), and in the relative similarity of neural representations (Sharpening model). Here, we test these predictions with fMRI during overt and covert naming of repeated and novel objects. While we find partial support for predictions of the Facilitation and Sharpening models in the left fusiform gyrus and left frontal cortex, the data were most consistent with the Synchrony model, with increased coupling between right temporoparietal and anterior cingulate cortex for repeated objects that correlated with priming magnitude across participants. Increased coupling and repetition suppression varied independently, each explaining unique variance in priming and requiring modifications of all current models.

Variability of Practice, Information Processing, and Decision Making—How Much Do We Know?

Decision-making is a complex action requiring efficient information processing. Specifically, in movement in which performance efficiency depends on reaction time, e.g., open-loop controlled movements, these processes may play a crucial role. Information processing includes three distinct stages, stimulus identification, response selection, and response programming. Mainly, response selection may play a substantial contribution to the reaction time and appropriate decision making. The duration of this stage depends on the number of possible choices an individual has to “screen” to make a proper decision. Given that reaction time is crucial in many sports, the possibilities of reducing it through practice are very tempting. The information processing and its relationship to the manner an individual is practicing are discussed. Especially the variability of practice issues will be explored. In variable practice conditions, an individual has to react to one or more stimuli and has to produce one of the many variations of the same movement or different movements they learned. One has to identify a stimulus appropriately and has to select a response optimally, i.e., choosing from as few choices as possible to reduce the reaction time. On the other hand, in constant practice conditions, an individual can be exposed to one or many stimuli. Still, there is only one variation of the movement that can be executed in the presence of a learned stimulus. Based on the information processing theory and the results of the research focusing on variability of practice, I discuss how the practice conditions may affect reaction time and, as a result, the decision-making process. I conceptually frame the possible implications of practice conditions on decision making related to information processing. In this review, a possible mechanism and relationship between practice conditions and decision-making are presented. Future research directions are presented.

Dissociating perceptual sensitivity from decisional factors in unconscious processing of face orientation and gaze direction

Faces convey information essential for social interaction. Their importance has prompted suggestions that some facial features may be processed unconsciously. Although some studies have provided empirical support for this idea, it remains unclear whether these findings were due to perceptual processing or to post-perceptual decisional factors. Evidence for unconscious processing of facial features has predominantly come from the Breaking Continuous Flash Suppression (b-CFS) paradigm, which measures the time it takes different stimuli to overcome interocular suppression. However, this procedure suffers from important problems: Observers can decide how much information they receive before committing to a report, so their detection responses may be influenced by differences in decision criteria and by stimulus identification. Here, we developed a new procedure that uses predefined exposure durations, enabling independent measurement of perceptual sensitivity and decision criteria. We found higher detection sensitivity to both upright and direct-gaze (compared to inverted and averted-gaze) faces, with no effects on decisional factors. For identification, we found both greater sensitivity and more liberal criteria for upright faces. Our findings demonstrate that face orientation and gaze direction influence perceptual sensitivity, indicating that these facial features may be processed unconsciously.

A water destructible SnS2 QD/PVA film based transient multifunctional sensor and machine learning assisted stimulus identification for non-invasive personal care diagnostics

We demonstrate, for the first time, a transient, flexible multifunctional sensor (strain, pressure, and breath) using a water soluble SnS2-QD/PVA film.

ERP Correlates of Performance Monitoring: a Mouse-Tracking Study

Performance monitoring involves detection of action outcomes and initiation of appropriate behavioral adaptations. Psychophysiological mechanisms of performance monitoring remain largely understudied in the context of uncertainty that arises at the stage of stimulus identification and decision making, as well as in the context of inhibition/correction of the motor response. In the current study, we investigate relations between behavioral performance measures and several ERP components: N2, ERN/CRN and Pe. Participants performed a condensation task and made their responses by moving mouse cursor. Response registration using mouse tracking allowed us to obtain two independent behavioral measures: mouse movement initiation time and movement duration. Amplitude of N2 and CRN was dependent on movement initiation time: N2 was increased and CRN was decreased for ‘late’ correct responses compared with ‘early’ correct ones; this finding is compatible with the explanation that ‘late’ responses involve higher pre-response conflict and higher uncertainty compared with ‘early’ ones. Movement duration time was a novel independent behavioral parameter, that cannot be measured using traditional keystrokes. This behavioral measure was related to the early Pe: its amplitude was more positive for ‘long’ responses compared with ‘short’ ones. This finding may be explained by mechanisms of an ongoing response inhibition. We suggest that this effect is linked to response stopping, which may be related to outcome awareness.

Parsing the Flanker task to reveal behavioral and oscillatory correlates of unattended conflict interference

Stimulus-Response conflict is generated by an overlap between stimulus and response dimensions, but the intrinsic nature of this interaction is not yet deeply clarified. In this study, using a modified Eriksen flanker task, we have investigated how flankers have to be incongruent to target in order to produce an interference and whether and how this interference interacts with the one produced by Stimulus features overlap. To these aims, an Eriksen-like task employing oriented hands\arrows has been designed to distinguish between two types of Stimulus-Response (S-R) interferences: one derived by a short-term association and one based on automatic processes. Stimulus-Stimulus (S-S) conflict has been also included in the same factorial design. Behavioral, Event Related Potential (ERP) and oscillatory activity data have been measured. Results revealed distinct S-S and automatic S-R effects on behavioral performance. ERP and Theta band power modulation results suggested an early frontal S-S conflict processing followed by a posterior simultaneous S-S and automatic S-R conflict processing. These findings provide evidence that, in presence of different conflicts, the sequence of stimulus identification and response selection could not move forward in a linear serial direction, but it may involve further effort, mirrored in posterior late components and response time prolongation.

Prosody perception and production by children with cochlear implants

The perception and production of emotional and linguistic (focus) prosody were compared in children with cochlear implants (CI) and normally hearing (NH) peers. Thirteen CI and thirteen hearing-age-matched school-aged NH children were tested, as baseline, on non-verbal emotion understanding, non-word repetition, and stimulus identification and naming. Main tests were verbal emotion discrimination, verbal focus position discrimination, acted emotion production, and focus production. Productions were evaluated by NH adult Dutch listeners. All scores between groups were comparable, except a lower score for the CI group for non-word repetition. Emotional prosody perception and production scores correlated weakly for CI children but were uncorrelated for NH children. In general, hearing age weakly predicted emotion production but not perception. Non-verbal emotional (but not linguistic) understanding predicted CI children's (but not controls’) emotion perception and production. In conclusion, increasing time in sound might facilitate vocal emotional expression, possibly requiring independently maturing emotion perception skills.