Tjeerd Jellema
University of Hull, Psychology, Faculty Member
Research Interests: Cognitive Science, Computer Science, Magnetic Resonance Imaging, Electroencephalography, Motion perception, and 15 moreCognitive Neuroscience, Medicine, Cognitive, Brain Mapping, Humans, Form perception, Human Motion, Female, Object Recognition, Male, Biological Motion, Motion, Oxygen, Adult, and Neurosciences
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Research Interests: Cognitive Psychology, Autism, Attention, Adolescent, Humans, and 15 moreChild, Judgment, Illusion, Cues, Female, Biological Motion, Interpersonal Relations, Clinical Neurology, Autism Spectrum Disorder, Clinical Sciences, Association, Adult, Asperger Syndrome, General Neuroscience, and Autistic disorder
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This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular... more
This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
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Viewing photographs of objects in motion evokes higher fMRI activation in human MT+ than similar photographs without this implied motion. MT+ is traditionally considered to be involved in motion perception. Therefore, this finding... more
Viewing photographs of objects in motion evokes higher fMRI activation in human MT+ than similar photographs without this implied motion. MT+ is traditionally considered to be involved in motion perception. Therefore, this finding suggests feedback from object-recognition areas to MT+. To investigate this hypothesis, we measured EEG, which provides information on the involvement of different brain areas over time. Pictures of biological agents with and without implied motion, and random-dot patterns (stationary, coherently moving, and flickering) were displayed. The difference potential between responses to pictures with and without implied motion was maximal at 260 to 320 ms after stimulus onset. Source analysis of this difference revealed one bilateral, symmetric dipole pair in the border region of the occipital-temporal-parietal lobe. In contrast, differences between the three types of random-dot patterns occurred from 100 ms onwards, and corresponded to cascades of dipole activation in a larger area, including that activated by implied motion. Latencies of the implied motion activations are consistent with a feedback projection onto MT+ following object recognition in higher-level temporal areas.
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This chapter reviews recent ideas about visual processing pathways and mechanisms in the brains of human and non-human primates that support social cognition. We will attempt to show how detection of visual cues provides a basis for... more
This chapter reviews recent ideas about visual processing pathways and mechanisms in the brains of human and non-human primates that support social cognition. We will attempt to show how detection of visual cues provides a basis for guiding the observer's behaviour in ...
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Research Interests: Psychology and Perception
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Using eye-tracking, we studied allocation of attention to faces where the emotional expression and eye-gaze dynamically changed in an ecologically-valid manner. We tested typically-developed (TD) adults low or high in autistic-like traits... more
Using eye-tracking, we studied allocation of attention to faces where the emotional expression and eye-gaze dynamically changed in an ecologically-valid manner. We tested typically-developed (TD) adults low or high in autistic-like traits (Experiment 1), and adults with high-functioning autism (HFA; Experiment 2). All groups fixated more on the eyes than on any of the other facial area, regardless of emotion and gaze direction, though the HFA group fixated less on the eyes and more on the nose than TD controls. The sequence of dynamic facial changes affected the groups similarly, with reduced attention to the eyes and increased attention to the mouth. The results suggest that dynamic emotional face scanning patterns are stereotypical and differ only modestly between TD and HFA adults.
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Face memory research in autism has largely neglected memory for facial expressions, in favor of memory for identity. This study in three experiments examined the role of gaze direction and type of expression on memory for facial... more
Face memory research in autism has largely neglected memory for facial expressions, in favor of memory for identity. This study in three experiments examined the role of gaze direction and type of expression on memory for facial expressions in relation to the autism spectrum. In the learning phase, four combinations of facial expressions (joy/anger) and gaze direction (toward/away), displayed by 16 different identities, were presented. In a subsequent surprise test the same identities were presented displaying neutral expressions, and the expression of each identity had to be recalled. In Experiment 1, typically-developed (TD) individuals with low and high Autism Quotient (AQ) scores were tested with three repetitions of each emotion/gaze combination, which did not produce any modulations. In Experiment 2, another group of TD individuals with low and high AQ scores were tested with eight repetitions, resulting in a "happy advantage" and a "direct gaze advantage", but no interactions. In Experiment 3, individuals with high-functioning autism (HFA) and a matched TD group were tested using eight repetitions. The HFA group revealed no emotion or gaze effects, while the matched TD group showed both a happy and a direct gaze advantage, and again no interaction. The results suggest that in autistic individuals the memory for facial expressions is intact, but is not modulated by the person's expression type and gaze direction. We discuss whether anomalous implicit learning of facial cues could have contributed to these findings, its relevance for social intuition, and its possible contribution to social deficits in autism. LAY SUMMARY: It has often been found that memory for someone's face (facial identity) is less good in autism. However, it is not yet known whether memory for someone's facial expression is also less good in autism. In this study, the memory for expressions of joy and anger was investigated in typically-developed (TD) individuals who possessed either few or many autistic-like traits (Experiments 1 and 2), and in individuals with high-functioning autism (Experiment 3). The gaze direction was also varied (directed either toward, or away from, the observer). We found that TD individuals best remembered expressions of joy, and remembered expressions of both joy and anger better when the gaze was directed at them. These effects did not depend on the extent to which they possessed autistic-like traits. Autistic participants remembered the facial expression of a previously encountered person as good as TD participants did. However, in contrast to the TD participants, the memory of autistic participants was not influenced by the expression type and gaze direction of the previously encountered persons. We discuss whether this may lead to difficulties in the development of social intuition, which in turn could give rise to difficulties in social interaction that are characteristic for autism.
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The metathoracic fast extensor tibiae (FETi) motor neurone of locusts is unusual amongst insect motor neurones because it makes output connections within the central nervous system as well as in the periphery. It makes excitatory chemical... more
The metathoracic fast extensor tibiae (FETi) motor neurone of locusts is unusual amongst insect motor neurones because it makes output connections within the central nervous system as well as in the periphery. It makes excitatory chemical synaptic connections to most if not all of the antagonist flexor tibiae motor neurones. The gain of the FETi-flexor connection is dependent on the peripheral conditions at the time of the FETi spike. This dependency has two aspects. First, sensory input resulting from the extensor muscle contraction can sum with the central excitatory postsynaptic potential (EPSP) to augment its falling phase if the tibia is restrained in the flexed position (initiating a tension-dependent reflex) or is free to extend (initiating a movement-dependent resistance reflex). This effect is thus due to simple postsynaptic summation of the central EPSP with peripheral sensory input. Second, the static tibial position at the time of the FETi spike can change the amplitude of the central EPSP, in the absence of any extensor muscle contraction. The EPSP can be up to 30 % greater in amplitude if FETi spikes with the tibia held flexed rather than extended. The primary sense organ mediating this effect is the femoral chordotonal organ. Evidence is presented suggesting that the mechanism underlying this change in gain may be specifically localised to the FETi-flexor connection, rather than being due to general position-dependent sensory feedback summing with the EPSP. The change in the amplitude of the central EPSP is probably not caused by general postsynaptic summation with tonic sensory input, since a diminution in the amplitude of the central EPSP caused by tibial extension is often accompanied by overall tonic excitation of the flexor motor neurone. Small but significant changes in the peak amplitude of the FETi spike have a positive correlation with changes in the EPSP amplitude, suggesting a likely presynaptic component to the mechanism of gain control. The change in amplitude of the EPSP can alter its effectiveness in producing flexor motor output and, thus, has functional significance. The change serves to augment the effectiveness of the FETi-flexor connection when the tibia is fully flexed, and thus to increase its adaptive advantage during the co-contraction preceding a jump or kick, and to reduce the effectiveness of the connection when the tibia is partially or fully extended, and thus to reduce its potentially maladaptive consequences during voluntary extension movements such as thrusting.
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Which episodes from our lives will be remembered and which will be forgotten, and why? This question has still not been answered satisfactorily by research into autobiographical memory. Previous work has shown that retrieval-induced... more
Which episodes from our lives will be remembered and which will be forgotten, and why? This question has still not been answered satisfactorily by research into autobiographical memory. Previous work has shown that retrieval-induced forgetting (RIF) might be a factor responsible for forgetting parts of the autobiographical memory content. However, none of the previous studies assessed RIF in memories for recent, controlled, personal events. We report here the results of an experiment in which autobiographical memories of real-life events were induced in a controlled, but fully naturalistic, manner under the disguise of team-building exercises, while an adapted RIF paradigm was applied to these memories. Results clearly showed the influence of RIF on autobiographical memory retrieval. These findings demonstrate conclusively that RIF occurs in everyday life when remembering personal events.
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This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular... more
This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac