Primary and secondary saccades to goals defined by instructions

1. We investigated cells in the middle temporal visual area (MT) and the medial superior temporal area (MST) that discharged during smooth pursuit of a dim target in an otherwise dark room. For each of these pursuit cells we determined whether the response during pursuit originated from visual stimulation of the retina by the pursuit target or from an extraretinal input related to the pursuit movement itself. We distinguished between these alternatives by removing the visual motion stimulus during pursuit either by blinking off the visual target briefly or by stabilizing the target on the retina. 2. In the foveal representation of MT (MTf), we found that pursuit cells usually decreased their rate of discharge during a blink or during stabilization of the visual target. The pursuit response of these cells depends on visual stimulation of the retina by the pursuit target. 3. In a dorsal-medial region of MST (MSTd), cells continued to respond during pursuit despite a blink or stabilization of the pursuit target. The pursuit response of these cells is dependent on an extraretinal input. 4. In a lateral-anterior region of MST (MST1), we found both types of pursuit cells; some, like those in MTf, were dependent on visual inputs whereas others, like those in MSTd, received an extraretinal input. 5. We observed a relationship between pursuit responses and passive visual responses. MST cells whose pursuit responses were attributable to extraretinal inputs tended to respond preferentially to large-field random-dot patterns. Some cells that preferred small spots also had an extraretinal input. 6. For 92% of the pursuit cells we studied, the pursuit response began after onset of the pursuit eye movement. A visual response preceding onset of the eye movement could be observed in many of these cells if the initial motion of the target occurred within the visual receptive field of the cell and in its preferred direction. In contrast to the pursuit response, however, this visual response was not dependent on execution of the pursuit movement. 7. For the remaining 8% of the pursuit cells, the pursuit discharge began before initiation of the pursuit eye movement. This occurred even though the initial motion of the target was outside the receptive field as mapped during fixation trials. Our data suggest, however, that such responses may be attributable to an expansion of the receptive field that accompanies enhanced visual responses.(ABSTRACT TRUNCATED AT 400 WORDS)

Relation of cortical areas MT and MST to pursuit eye movements. II. Differentiation of retinal from extraretinal inputs

Recent application of theories of embodied or grounded cognition to the recognition and interpretation of facial expression of emotion has led to an explosion of research in psychology and the neurosciences. However, despite the accelerating number of reported findings, it remains unclear how the many component processes of emotion and their neural mechanisms actually support embodied simulation. Equally unclear is what triggers the use of embodied simulation versus perceptual or conceptual strategies in determining meaning. The present article integrates behavioral research from social psychology with recent research in neurosciences in order to provide coherence to the extant and future research on this topic. The roles of several of the brain's reward systems, and the amygdala, somatosensory cortices, and motor centers are examined. These are then linked to behavioral and brain research on facial mimicry and eye gaze. Articulation of the mediators and moderators of facial mimicry and gaze are particularly useful in guiding interpretation of relevant findings from neurosciences. Finally, a model of the processing of the smile, the most complex of the facial expressions, is presented as a means to illustrate how to advance the application of theories of embodied cognition in the study of facial expression of emotion.

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The Simulation of Smiles (SIMS) model: Embodied simulation and the meaning of facial expression

In a within-subjects design that varied whether speakers were allowed to gesture and the difficulty of lexical access, speakers were videotaped as they described animated action cartoons to a listener When speakers were permitted to gesture, they gestured more often during phrases with spatial content than during phrases with other content Speech with spatial content was less fluent when speakers could not gesture than when they could gesture, speech with nonspatial content was not affected by gesture condition Preventing gesturing increased the relative frequency of nonjuncture filled pauses in speech with spatial content, but not in speech with other content Overall, the effects of preventing speakers from gesturing resembled those of increasing the difficulty of lexical access by other means, except that the effects of gesture restriction were specific to speech with spatial content The findings support the hypothesis that gestural accompaniments to spontaneous speech can facilitate access to the menta...

Gesture, Speech, and Lexical Access: The Role of Lexical Movements in Speech Production

Introduction BASIC RESEARCH METHODS AND PROCEDURES 2. Measuring facial actions 3. Vocal expression of affect 4. Proxemics, kinesics and gaze 5. Conducting judgment studies: some methodological issues RESEARCH APPLICATIONS IN NONVERBAL BEHAVIOR 6. Nonverbal behavior and interpersonal sensitivity 7. Nonverbal behavior in education 8. Nonverbal behavior and psychopathology 9. Research methods in detecting deception research 10. Nonverbal communication coding systems of committed couples 11. Macrovariables in affective expression in women with breast cancer participating in support groups SUPPLEMENTARY MATERIALS 12. Technical issues in recording nonverbal behavior Appendix: Methodological issues in studying nonverbal behavior

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The New Handbook of Methods in Nonverbal Behavior Research

IT has been shown recently that the eyes can make sustained smooth eye movements indistinguishable from normal pursuit movements in the absence of a moving visual stimulus if an after-image is tracked1–3. This experimental procedure avoids the objections which can be raised against previous demonstrations of smooth eye movements without moving targets which have involved either alternative sources of information about movement4, or closing the eyes5, or changes in subjects' level of arousal6. But it has not yet been shown that smooth eye movements can be made voluntarily, and it is possible that they can be executed by alert, open-eyed subjects only if the saccadic system is inhibited by a visual target. This is a report on one subject, a 20-yr-old girl undergraduate, C. G., who can make smooth eye movements at will in the dark and can change the velocity of these movements on demand. These eye movements are indistinguishable from normal pursuit, do not resemble the eye movements made by the same subject when tracking an after-image, and seem, therefore, to represent specific voluntary control of the smooth pursuit eye movement system.

Voluntary Control of Smooth Eye Movements and their Velocity

Subjects were required to describe line drawings of two-dimensional shapes at two levels of verbal codability, with and without using hand gestures. Elimination of gesture affected speech performance by changing the semantic content of utterances and the proportion of speaking time spent pausing; numbers of words, numbers of pauses, mean pause length and semantic content were found to be related to the verbal codability of the stimulus material; and the number of hesitations was related to both gesture and level of codability.

Simon Heywood

Papers

Voluntary Control of Smooth Eye Movements and their Velocity

The effects of elimination of hand gestures and of verbal codability on speech performance

Eye movements and the afterimage. I. Tracking the afterimage.

Eye orientation during visual discrimination learning by monkeys.

Eye movements and the after-image—II the effect of foveal and non-foveal after-images on saccadic behaviour