Dorsal stream deficits suggest hidden dyslexia among deaf poor readers: correlated evidence from reduced perceptual speed and elevated coherent motion detection thresholds

Prelingual deafness and developmental dyslexia have confounding developmental effects on reading acquisition. Therefore, standard reading assessment methods for diagnosing dyslexia in hearing people are ineffective for use with deaf people. Recently, Samar, Parasnis, and Berent (2002) reported visual evoked potential evidence that deaf poor readers, compared to deaf good readers, have dorsal stream visual system deficits like those previously found for hearing dyslexics. Here, we report new psychometric and psychophysical evidence that deficits in dorsal stream function, likely involving extrastriate area MT, are associated with relatively poor reading comprehension in deaf adults. Poorer reading comprehension within a group of 23 prelingually deaf adults was associated with lower scores on the Symbol Digit Modality Test, a perceptual speed test commonly used to help identify dyslexia in hearing people. Furthermore, coherent dot motion detection thresholds, which reflect the functional status of area MT, correlated negatively with reading scores in each visual quadrant. Elevated motion thresholds for deaf poor readers were not due to general cognitive differences in IQ but were specifically correlated with poor perceptual speed. With IQ controlled, a highly reliable right visual field advantage for coherent motion detection was found. Additional analyses suggested that the functional status of dorsal stream motion detection mechanisms in deaf people is related to reading comprehension, but the direction and strength of lateralization of those mechanisms is independent of reading comprehension. Our results generally imply that dyslexia is a hidden contributor to relatively poor reading skill within the deaf population and that assessment of dorsal stream function may provide a diagnostic biological marker for dyslexia in deaf people.     

Hostility and facial affect recognition: effects of a cold pressor stressor on accuracy and cardiovascular reactivity

The effects of hostility and a cold pressor stressor on the accuracy of facial affect perception were examined in the present experiment. A mechanism whereby physiological arousal level is mediated by systems which also mediate accuracy of an individual’s interpretation of affective cues is described. Right-handed participants were classified as high hostile (N=28) or low hostile (N=28) using the Cook Medley Hostility Scale. The high-hostile group met joint selection criteria. Only high-hostile participants who showed cardiovascular reactivity to the cold pressor, with systolic BP change exceeding the group mean were included. Groups were further subdivided into cold pressor and non-cold pressor test conditions. It was predicted that high-hostile men, relative to low-hostile men, would show decreased perceptual accuracy when presented with happy, angry, and neutral facial configurations within the left visual field (LVF). Results indicated that high-hostile men were less accurate than low-hostile men in the LVF. Further, pre-stress accuracy scores in the high-hostile men were similar to the post-stress accuracy scores of the low-hostile men. The lateralization of affective function and the role of physiological arousal in affective facial perception are discussed.     

Preference for human direct gaze in infant chimpanzees (Pan troglodytes)

We studied gaze perception in three infant chimpanzees (Pan troglodytes), aged 10-32 weeks, using a two-choice preferential-looking paradigm. The infants were presented with two photographs of a human face: (a) with the eyes open or closed, and (b) with a direct or an averted gaze. We found that the chimpanzees preferred looking at the direct-gaze face. However, in the context of scrambled faces, the infants showed no difference in gaze discrimination between direct and averted gazes. These findings suggest that gaze perception by chimpanzees may be influenced by the surrounding facial context. The relationship between gaze perception, face processing, and the adaptive significance of gaze perception are discussed from an evolutionary perspective.     

Fleeting Signs of the Course of Life: Facial Expression and Personal Adjustment

In this article, we consider whether facial expressions of emotion relate in theoretically interesting ways to personal adjustment. We first consider the conceptual benefits of this line of inquiry. Then, to anticipate why brief samples of emotional behavior should relate to personal adjustment, we review evidence indicating that facial expressions of emotion correspond to intrapersonal processes and social outcomes. We then review studies showing that facial expressions relate in theoretically significant ways to adjustment after the death of a spouse, in long-term relationships, and in the context of chronic psychological disorders.     

A differing bidirectional impact on the recognition accuracy of facial expression

This study explored a bidirectional impact on the recognition accuracy of various facial expressions deriving from both the observer and sender in a sample of Chinese participants. A facial manipulation task was used to examine the ability of an observer's facial feedback to modulate the recognition of various facial expressions. Furthermore, the effect of a sender's facial expression with an open or closed mouth on recognition accuracy was investigated. The results showed that only recognition accuracy of a sad facial expression was influenced simultaneously by bidirectional sources from a sender and observer. Moreover, the impact of the unidirectional cue of a sender's facial feature (i.e., mouth openness) on happy and neutral faces was found to influence the recognition accuracy of these faces, but not the observer's bodily state. These findings indicate that the bidirectional impact derived from an observer and sender on facial expression recognition accuracy differs for emotional and neutral expressions.     

Implicit need for affiliation is associated with increased corrugator activity in a non-positive, but not in a positive social interaction

Affective changes in response to motive-relevant stimuli are a defining feature of implicit motives. We therefore expected to find an effect of individual differences in the implicit need for affiliation (nAff) on corrugator supercilii activity, an indicator of affect, when participants were confronted with nonverbal indicators of a conversational partner’s withdrawal. Participants’ nAff was assessed with a Picture Story Exercise (PSE). They were then involved in an interaction with a smiling or a neutral experimenter while their corrugator activity was measured with electromyography (EMG). As expected, we found higher corrugator activity for people high in nAff compared to people low in nAff when the experimenter kept a neutral facial expression throughout the interaction but not when he/she was smiling.     

At face value: Categorization goals modulate vigilance for angry faces

The present research demonstrates that the attention bias to angry faces is modulated by how people categorize these faces. Since facial expressions contain psychologically meaningful information for social categorizations (i.e., gender, personality) but not for non-social categorizations (i.e., eye-color), angry facial expression should especially capture attention during social categorization tasks. Indeed, in three studies, participants were slower to name the gender of angry compared to happy or neutral faces, but not their color (blue or green; Study 1) or eye-color (blue or brown; Study 2). Furthermore, when different eye-colors were linked to a personality trait (introversion, extraversion) versus sensitivity to light frequencies (high, low), angry faces only slowed down categorizations when eye-color was indicative of a social characteristic (Study 3). Thus, vigilance for angry facial expressions is contingent on people's categorization goals, supporting the perspective that even basic attentional processes are moderated by social influences.     

Would I lie to you? “leakage” in deceptive facial expressions relates to psychopathy and emotional intelligence

This was the first investigation of individual differences in adopting deceptive universal emotional expressions. We hypothesized that psychopathic traits would lead to a heightened ability to suppress emotional expressions and exhibit less “leakage” of inconsistent emotions during deceptive displays. Further, we predicted that emotional intelligence (EI) would lead to a heightened ability to simulate emotional expressions. Participants (N = 100) viewed emotionally arousing (happy, sad, fearful, disgusting) images, responding to each with a genuine or deceptive expression. Each video frame (30/sec) was coded for emotion (in)consistent with the intended expression (365,550 frames coded for 2437 expressions). As predicted, psychopathic traits - specifically, high levels of interpersonal manipulation - were related to shorter durations of unintended emotional “leakage” during deceptive expressions. In contrast, the erratic lifestyle element of psychopathy predicted greater emotional inconsistency during deceptive displays. Individuals higher in EI - specifically, the ability to perceive and express emotion - feigned emotions more convincingly than others but were not more immune to emotional leakage.     

Representational momentum in older adults

Humans have a tendency to perceive motion even in static images that simply “imply” movement. This tendency is so strong that our memory for actions depicted in static images is distorted in the direction of implied motion - a phenomenon known as representational momentum (RM). In the present study, we created an RM display depicting a pattern of implied (clockwise) rotation of a rectangle. Young adults viewers’ memory of the final position of the test rectangle was biased in the direction of continuing rotation, but older adults did not show a similar memory bias. We discuss several possible explanations for this group difference, but argue that the failure of older adults to shown an RM effect most likely reflects age-related changes in areas of the brain involved in processing real and implied motion.     

Two-step communication for the interaction between automated vehicles and pedestrians

An important challenge of automated vehicles (AV) will be the cooperative interaction with surrounding road users such as pedestrians. One solution to compensate for the missing driver-pedestrian interaction might be explicit communication via external human machine interfaces (eHMIs). Additionally, implicit communication such as a vehicle pitch motion might support AVs when interacting with pedestrians. While previous work explored various explicit and implicit communication cues, these concepts communicated the intention of the AV at one single time point. Currently, empirical findings on two-step communication lack so far. In this study, we empirically test the effect of a two-step AV communication that uses an implicit cue at a long distance and subsequently provides an implicit or explicit cues at a short distance. We compared its efficiency to single-step communication concepts providing implicit or explicit cues at the shorter distance only. To explore whether the right communication cue is used at the right distance, we analyzed pedestrians’ fixations while approaching an AV using an eye tracking device.We conducted a virtual reality study (N = 30) with AV communication concept that provided an active pitch motion or an eHMI and compared them with a two-step AV communication concept that provided an additional active pitch motion at a long distance when approaching the pedestrian. Furthermore, we recorded pedestrians’ fixation behavior while the AV approached.Consistently to previous work, single-step AV communication showed a beneficial effect on crossing behavior. Pedestrians initiated their crossing earlier while approaching an AV with an active pitch motion or an eHMI compared to the baseline condition. While active pitch motion reduced subjective safety feeling, eHMI increased it. However, the two-step communication concept did not further improve pedestrians’ crossing initiation times and their safety feeling. The pattern of fixation behavior differed as a function of AV distance. When the approaching AV was far away, pedestrians exclusively looked at the environment. During the approach, pedestrians gradually fixated the bumper and the hood and only then the windshield of the AV. Hence, it seems to be useful to present an AV intent communication at a certain distance from the pedestrian. These findings posit the importance of considering pedestrians’ fixation behavior when developing communication concepts between AVs and pedestrians.