Cognitive neuroscience PhD student. Interested in autism, decision making & visual perception.
Understanding how we read people's emotions from their eyes.
You can tell a lot about what is going on in someone’s mind just by looking at their eyes. Being able to ‘read’ subtle changes in facial expressions and body language is an essential part of cognitive empathy, the ability to recognise and identify different emotions in other people.
As facial expressions are responsible for a large proportion of the non-verbal social cues that we rely on in day-to-day life, we wanted to explore how cognitive empathy might be linked to differences in the automatic neural responses produced by viewing faces.
To do this we used a technique called Steady State Visually Evoked Potential (SSVEP) analysis. This involves flickering different types of images on a screen at unique frequencies and then measuring the relative amplitude of the respective frequency components from EEG recordings.
We investigated whether the inter-individual variation in these neural responses could be explained by differences in cognitive empathy. Cognitive empathy was measured using the Reading the Mind in the Eyes task, a paradigm in which participants are asked to identify a range of emotional states just by viewing cropped photos of the eye region of faces.
Our results showed that the amplitude of these face-specific neural responses was correlated with our behavioural measure of cognitive empathy. Specifically, this effect was found in the left hemispheric fusiform gyrus, an area of the brain known to be involved in processing faces and semantic information.
The great thing about the use of frequency tagging in this approach is that it allows for differences in evoked neural responses to be assessed to a range of different stimuli within a very short period of time. A reduction in task duration like this can be incredibly useful when carrying out research in clinical populations such as, in the case of my research group, autistic individuals.
Abstract: Human performance at categorizing natural visual images surpasses automatic algorithms, but how and when this function arises and develops remain unanswered. We recorded scalp electrical brain activity in 4-6 months infants viewing images of objects in their natural background at a rapid rate of 6 images/second (6 Hz). Widely variable face images appearing every 5 stimuli generate an electrophysiological response over the right hemisphere exactly at 1.2 Hz (6 Hz/5). This face-selective response is absent for phase-scrambled images and therefore not due to low-level information. These findings indicate that right lateralized face-selective processes emerge well before reading acquisition in the infant brain, which can perform figure-ground segregation and generalize face-selective responses across changes in size, viewpoint, illumination as well as expression, age and gender. These observations made with a highly sensitive and objective approach open an avenue for clarifying the developmental course of natural image categorization in the human brain.
Pub.: 03 Jun '15, Pinned: 30 Jun '17
Abstract: Periodic visual stimulation and analysis of the resulting steady-state visual evoked potentials were first introduced over 80 years ago as a means to study visual sensation and perception. From the first single-channel recording of responses to modulated light to the present use of sophisticated digital displays composed of complex visual stimuli and high-density recording arrays, steady-state methods have been applied in a broad range of scientific and applied settings.The purpose of this article is to describe the fundamental stimulation paradigms for steady-state visual evoked potentials and to illustrate these principles through research findings across a range of applications in vision science.
Pub.: 30 May '15, Pinned: 04 Jul '17
Abstract: The "Reading the Mind in the Eyes" test (Eyes test) is an advanced test of theory of mind. Typical sex difference has been reported (i.e., female advantage). Individuals with autism show more difficulty than do typically developing individuals, yet it remains unclear how this is modulated by sex, as females with autism have been under-represented. Here in a large, non-male-biased sample we test for the effects of sex, diagnosis, and their interaction. The Eyes test (revised version) was administered online to 395 adults with autism (178 males, 217 females) and 320 control adults (152 males, 168 females). Two-way ANOVA showed a significant sex-by-diagnosis interaction in total correct score (F(1,711) = 5.090, p = 0.024, ηp2 = 0.007) arising from a significant sex difference between control males and females (p < 0.001, Cohen's d = 0.47), and an absence of a sex difference between males and females with autism (p = 0.907, d = 0.01); significant case-control differences were observed across sexes, with effect sizes of d = 0.35 in males and d = 0.69 in females. Group-difference patterns fit with the extreme-male-brain (EMB) theory predictions. Eyes test-Empathy Quotient and Eyes test-Autism Spectrum Quotient correlations were significant only in females with autism (r = 0.35, r = -0.32, respectively), but not in the other 3 groups. Support vector machine (SVM) classification based on response pattern across all 36 items classified autism diagnosis with a relatively higher accuracy for females (72.2%) than males (65.8%). Nevertheless, an SVM model trained within one sex generalized equally well when applied to the other sex. Performance on the Eyes test is a sex-independent phenotypic characteristic of adults with autism, reflecting sex-common social difficulties, and provides support for the EMB theory predictions for both males and females. Performance of females with autism differed from same-sex controls more than did that of males with autism. Females with autism also showed stronger coherence between self-reported dispositional traits and Eyes test performance than all other groups.
Pub.: 28 Aug '15, Pinned: 04 Jul '17
Abstract: While there is a general consensus in the literature that individuals with autism spectrum disorder have difficulty with cognitive empathy, much less is known about emotional empathy processing in these individuals. Most research has employed subjective self-report measures, which can often be misinterpreted or under-reported/over-reported. More objective measures such as psychophysiological recordings of arousal offer a more objective response. Furthermore, combining physiological responses with self-report ratings allows us to explore the relationship between these two responses to emotionally charged stimuli. A total of 25 individuals with autism spectrum disorder were compared with 25 matched controls on their physiological (arousal) and psychological (self-report) responses to emotionally distressing video scenes. These responses were also then compared with self-report cognitive and emotional trait empathy. Results indicate that while individuals with autism spectrum disorder appear to respond similarly to controls physiologically, their interpretation of this response is dampened emotionally. Furthermore, this dampening of self-report emotional response is associated with a general reduction in trait empathy.
Pub.: 02 Jun '16, Pinned: 03 Jul '17
Abstract: The expertise hypothesis suggests the fusiform face area (FFA) is more responsive to faces than to other categories because of experience individuating faces. Accordingly, individual differences in FFA's selectivity for faces should relate to differences in behavioral face-recognition ability. However, previous studies have not demonstrated this, while the comparable association is often observed with nonface objects. We created a training paradigm with conditions sufficient to observe the same effect with faces. First, we selected subjects with a wide range of behavioral face-recognition abilities, then we manipulated experience with an artificial race of faces based on subjects' pretraining ability, maximizing variability in face individuation. Neural selectivity was measured for Caucasian faces and artificial-race faces relative to control objects. Selecting subjects for greater variability in face-recognition ability revealed an association between behavior and FFA selectivity for Caucasian faces, with an effect exclusive to the middle right FFA (FFA2). Manipulating experience with artificial-race faces led to stronger brain-behavior correlation for artificial-race faces, also in right FFA2. Group analyses showed an overlap of these effects for Caucasian and artificial-race faces in right FFA2. The right FFA2 appears particularly sensitive to experience with faces just as it is for nonface objects.
Pub.: 05 May '17, Pinned: 03 Jul '17
Abstract: Cognitive neuropsychological evidence is widely viewed as inherently flawed or weak, despite well-reasoned arguments to the contrary by many theorists. Rather than attempting yet another defence of cognitive neuropsychology on logical grounds, we point out through examples that in practice, cognitive neuropsychological evidence is widely accepted as valid and important, and has had a major impact on cognitive theory and research. Objections offered in the abstract rarely arise in the context of actual studies. We develop these points through examples from the domain of vision, discussing cerebral achromatopsia and akinetopsia, selective impairment and sparing of face recognition, perception-action dissociations, and blindsight.
Pub.: 27 Jun '17, Pinned: 03 Jul '17
Abstract: Social neuro-science has recently started to investigate the neuronal mechanisms underlying our ability to understand the mental and emotional states of others. In this review, imaging research conducted on theory of mind (ToM or mentalizing) and empathy is selectively reviewed. It is proposed that even though these abilities are often used as synonyms in the literature these capacities represent different abilities that rely on different neuronal circuitry. ToM refers to our ability to understand mental states such as intentions, goals and beliefs, and relies on structures of the temporal lobe and the pre-frontal cortex. In contrast, empathy refers to our ability to share the feelings (emotions and sensations) of others and relies on sensorimotor cortices as well as limbic and para-limbic structures. It is further argued that the concept of empathy as used in lay terms refers to a multi-level construct extending from simple forms of emotion contagion to complex forms of cognitive perspective taking. Future research should investigate the relative contribution of empathizing and mentalizing abilities in the understanding of other people's states. Finally, it is suggested that the abilities to understand other people's thoughts and to share their affects display different ontogenetic trajectories reflecting the different developmental paths of their underlying neural structures. In particular, empathy develops much earlier than mentalizing abilities, because the former relys on limbic structures which develop early in ontogeny, whereas the latter rely on lateral temporal lobe and pre-frontal structures which are among the last to fully mature.
Pub.: 15 Aug '06, Pinned: 30 Jun '17
Abstract: We conducted a genome-wide meta-analysis of cognitive empathy using the 'Reading the Mind in the Eyes' Test (Eyes Test) in 88,056 research volunteers of European Ancestry (44,574 females and 43,482 males) from 23andMe Inc., and an additional 1497 research volunteers of European Ancestry (891 females and 606 males) from the Brisbane Longitudinal Twin Study. We confirmed a female advantage on the Eyes Test (Cohen's d=0.21, P<2.2 × 10(-16)), and identified a locus in 3p26.1 that is associated with scores on the Eyes Test in females (rs7641347, Pmeta=1.58 × 10(-8)). Common single nucleotide polymorphisms explained 5.8% (95% CI: 4.5%-7.2%; P=1.00 × 10(-17)) of the total trait variance in both sexes, and we identified a twin heritability of 28% (95% CI: 13%-42%). Finally, we identified significant genetic correlation between the Eyes Test and anorexia nervosa, openness (NEO-Five Factor Inventory), and different measures of educational attainment and cognitive aptitude.Molecular Psychiatry advance online publication, 6 June 2017; doi:10.1038/mp.2017.122.
Pub.: 07 Jun '17, Pinned: 30 Jun '17
Abstract: The developmental origins of human adults' right hemispheric specialization for face perception remain unclear. On the one hand, infant studies have shown a right hemispheric advantage for face perception. On the other hand, it has been proposed that the adult right hemispheric lateralization for face perception slowly emerges during childhood due to reading acquisition, which increases left lateralized posterior responses to competing written material (e.g., visual letters and words). Since methodological approaches used in infant and children typically differ when their face capabilities are explored, resolving this issue has been difficult. Here we tested 5-year-old preschoolers varying in their level of visual letter knowledge with the same fast periodic visual stimulation (FPVS) paradigm leading to strongly right lateralized electrophysiological occipito-temporal face-selective responses in 4- to 6-month-old infants (de Heering & Rossion, 2015). Children's face-selective response was quantitatively larger and differed in scalp topography from infants', but did not differ across hemispheres. There was a small positive correlation between preschoolers' letter knowledge and a non-normalized index of right hemispheric specialization for faces. These observations show that previous discrepant results in the literature reflect a genuine nonlinear development of the neural processes underlying face perception and are not merely due to methodological differences across age groups. We discuss several factors that could contribute to the adult right hemispheric lateralization for faces, such as myelination of the corpus callosum and reading acquisition. Our findings point to the value of FPVS coupled with electroencephalography to assess specialized face perception processes throughout development with the same methodology.
Pub.: 29 Jun '17, Pinned: 03 Jul '17
Abstract: Individual differences in the personality trait Agreeableness underlie humans' ability to interpret social cues and coordinate effectively with others. However, previous investigations of the neural basis of Agreeableness have yielded largely inconsistent results. Recent evidence has demonstrated that Agreeableness can be divided into two, correlated subdimensions. Compassion reflects tendencies toward empathy, sympathy, and concern for others, while Politeness reflects tendencies toward compliance and refraining from aggression and exploitation. The present study seeks to clarify the neural substrates of Agreeableness by examining whether structural differences in the brain show distinct associations with Compassion and Politeness. Results of a meta-analysis of fMRI studies examining empathy were used to generate hypotheses about the brain regions and networks that underlie trait Compassion. Results of a large-scale structural neuroimaging investigation (N = 275) were largely consistent with the meta-analysis: Compassion was positively correlated with gray matter volume in the bilateral anterior cingulate cortex (ACC) and anterior insula (AI). Further, these differences appear to be associated with Compassion specifically, as opposed to Politeness, suggesting that these two traits have at least partially distinct neuroanatomical substrates.
Pub.: 02 Jul '17, Pinned: 04 Jul '17