Researchers have multiple theories of the underlying causes of obsessions and compulsions of obsessive-compulsive disorder. A quote by Robinson and Freeston (2014) sums it up the philosophical debate pretty […]

Neurosurgery is by no means a modern invention. Deep brain stimulation (DBS) is instead a result of millennia of humans trying to impact behavior and health by physically altering the brain. The first post in this blog gave an overview of what DBS is and why it is used. This post will briefly cover the history of neurosurgery; looking at the advances that lead to DBS as a viable therapeutic method.

Trepanning: Trepanning was a widespread phenomenon. The left image shows tools used in the procedure from South America in the first millennium. The right image show a Neolithic skull from 5100 with evidence of the procedure (Robinson et al., 2012)

The earliest example of neurosurgery that we have evidence of is trepanning. This was the practice of drilling a hole in the skull in order to relieve a patient of some malady. Some postulate it was thought that demons causing psychological symptoms needed to be released. The earliest example is a Neolithic burial in Alsace France, dating to 5100BC. The holes in the skull have evidence of healing, suggesting that it was done intentionally, and not a result of an accident  (Robinson et al., 2012). Even the idea of stimulating the brain as a medical treatment is not novel. Scribonius Largo, a roman physician in 46 AD applied electric eels to patient’s foreheads and reportedly demonstrated amelioration of headaches(Sironi, 2011).

Frontal Lobotomy. Axial and sagittal views of a lobotomy. Notice the diffuse damage in the images, most notably the bright white swath across both hemispheres on the left. (Lapidus, 2013).

Functional neurosurgery had a resurgence around the First World War. Mental asylums were packed, a situation made worse war veterans returning home and a lage number advanced syphilis cases before penicillin was discovered. This environment influenced the development and popularization of the frontal lobotomy by Egas Moniz and Walter Freeman. The transcranial frontal lobotomy had severe consequences for patients. They often showed a reduction of their initial psychological symptoms, but at the cost of extreme apathy and personality defects. The demure state of these patients meant less work for mental institutions, but the procedure soon became obsolete under a critical public eye (Robinson et al., 2012).

A stereotaxic device: An early example of a stereotaxic device from 1908. The first human stereotaxic experiments were not done until 1947(Robinson et al., 2012).

The next frontier in neurosurgery was ablative therapy. This was the lesioning, often by radioactive rods, of areas in the brain. Initially a crude procedure, it was refined with the the advent stereotaxic technique in 1947. Stereotaxic technique is the practice of holding the head in a fixed position, and then using reference points on the brain, skull, imaging techniques and prior knowledge of brain mapping to precisely access areas of the brain. This technique saw the rise of lesions as an effective treatment for many disorders (Sironi, 2011)

Stimulation of the periventricular/periaqueductal grey matter as well as some areas of the thalamus was demonstrated to be extremely effective at controlling pain that was difficult to treat pharmaceutically (Kumar et al., 1990). In large part due to these treatments, it was shown that high frequency electric currents had a similar effect as ablative therapies. At the time, surgeons were treating tremor disorders and Parkinson’s disease by thalamotomy, or destruction of areas of the thalamus. While this treatment improved symptoms, it often caused dysarthria, an issue with the motor control of speaking. The stimulation of DBS was shown to be as, if not more, effective that ablation, with fewer side effects, and less surgeries needed (Tasker 1998). Further evolution of the technique looked at specific nuculi of the thalamus as well as the palladium (Limousin-Dowsey et al., 1999).

This prior body of scientific work lead to excitement about the use of DBS and the exploration of how it could be used in treating other neurological and psychiatric disorders. Obsessive disorders were among the first affective disorders to be treated in the early 21st century. The role of DBS in depression therapies has only very recently been studied (Lapidus et al, 2013). The background of neurosurgery is necessary to establish the context in which current research of depression is operating. We will examine the current theories and specifics of deep brain stimulation for depression in our next post.

References:

Kumar, K., Wyant, G., & Nath, R. Deep brain stimulation for control on intractable pain in humans, present and future: A ten-year follow-up. (1990). Neurosurgery, 26(5), 774-782. Retrieved October 23, 2014.

Lapidus, K., Kopell, B., Ben-Haim, S., Rezai, A., & Goodman, W. (2013). History of Psychosurgery: A Psychiatrist’s Perspective. World Neurosurgery, 80, S27.e1-S27.e16. Retrieved September 26, 2014, from PubMed.

Limousin-Dowsey, P., Pollak, P., Van Blercom, N., Krack, P., Benazzouz, A., & Benabid, A.(1999). Thalamic, subthalamic nucleus and internal pallidum stimulation in Parkinson’s disease. Journal of Neurology, (246), 42-45. Retrieved October 23, 2014.

Robison, R., Taghva, A., Liu, C., & Apuzzo, M. (2012). Surgery of the Mind, Mood, and Conscious State: An Idea in Evolution. World Neurosurgery, 77, 662-686. Retrieved September 26, 2014, from PubMed

Tasker, R. (1998). Deep Barin Stimulation is Preferable to Thalomotomy for Tremor Suppression. Functional Neurosurgery, (49), 145-154. Retrieved October 23, 2014.

I’ve always believed that my memory is better when I’m relaxed versus when I’m stressed, and it seems like most people agree. There are, of course, people who absolutely thrive under stress. They probably just […]

In this post I will focus on the interplay of an eye gaze and emotion as they relate to perceiver-target interactions. Eye gaze plays an important factor in social interactions. It cues us to know when someone is talking to us. It can also convey information about the environment. Imagine that you see a mouse run across the room. You yell in fear and look in that direction. The direction of your eye gaze tells everyone else in a room that there is a potential threat, and where to watch out for it. In this way, emotion and eye gaze complement each other to convey your specific message in a social environment. I’ll explore this interplay from various angles. First, I’ll describe some research about how the gaze conveyed by a target influences a perceiver’s perception of target’s emotion. Next I’ll describe some evidence purporting that a target’s eye gaze can influence the emotional experience of a perceiver. And finally, I’ll discuss how a perceiver’s emotional disposition can influence their gaze towards emotional faces. Overall, I’ll attempt to convey to you that this interaction between eye-gaze and emotion plays an important role in all aspects of social interactions.
A target’s facial emotion and eye gaze influence a perceiver
Adams and Kleck (2005) examined how eye gaze influences perception of emotional faces. They first examined whether eye gaze direction would influence which emotions people attribute to neutral faces. Participants were presented with emotionally neutral faces,half depicting direct eye gaze and the other half depicting averted eye gaze. After looking at each face, participants rated the likelihood that the person in the picture would experience the emotions anger, fear, sadness, and joy, on a scale from 1 to 7. The results demonstrated that when looking at a picture of a neutral face displaying direct eye gaze, participants were more likely to attribute approach-related emotions of joy and anger. Conversely, averted target gaze facilitated participants’ attributions of avoidance-related emotions, sadness and fear.

Example of emotionally ambiguous stimuli used in Adams and Kleck (2005) blending fear and anger, depicting direct gaze (left) and averted gaze (right).

Next, they examined how direct versus averted eye gaze would influence participants’ emotional attributions in response to emotionally ambiguous faces. Following a similar procedure, participants made emotional attributions of 4 emotions (anger, fear, sadness, joy) using a 7-point scale. This time, instead of looking at neutral faces, participants were presented with face stimuli that blended two emotions: anger and fear. Consistent with the previous study, they found that direct eye gaze facilitated perceptions of anger in the ambiguous face while averted gaze facilitated perceptions of fear.

In a final study, they measured the extent to which gaze direction influenced perceptions of emotional intensity among highly prototypical emotional faces. Participants viewed faces depicting prototypical representations of anger, fear, happiness, and sadness, depicting either direct or averted gaze and rated the emotional intensity of the target’s emotion. They found that direct gaze increased participants’ intensity ratings when it was depicted on an angry or happy face, and that averted gaze increased participants’ intensity ratings when it was depicted on a fearful or sad face. Therefore, across three studies, they demonstrate a link between gaze direction and emotion: direct gaze facilitates perception of approach-related emotions such as anger and happiness while averted gaze facilitates perception of avoidance-related emotions, such as fear and sadness.
Target’s gaze influences a perceiver’s emotion
Other work has examined the extent to which direct versus averted eye gaze elicits biological responses associated with viewing approach versus avoidance behaviors. Previous work has demonstrated that stronger EEG activation in the left and right frontal cortices is associated with approach- and avoidance-related behaviors, respectively (Van Hon & Schutter, 2006). Furthermore, skin conductance (SCR) has been associated with arousal (Andreassi, 2000). Based on this previous work Hietanen, Leppänen, Peltola, Linna-Aho, and Ruuhiala (2008) set out to explore the effect of direct versus averted eye gaze on participants’ physiological reactions to faces. Recognizing a dearth of research employing real-life faces (and a n abundance of research using photographs of faces), the authors also compared participants’ responses to real-life faces versus photographs of faces.

The participants viewed either a real-life face or a photograph of a face depicting a neutral expression and either direct or averted eye gaze. Researchers collected participant’s skin conductance and EEG data, and asked participants to report subjective ratings of arousal. Consistent with the original hypotheses, the results demonstrate greater right-side EEG activation when participants viewed the face demonstrating direct eye gaze. Conversely, greater left-side EEG activation was observed participants viewed the face demonstrating averted eye gaze. Furthermore, SCR results demonstrate that participants experience greater arousal when viewing faces depicting direct gaze. Importantly, all patterns of significant results were elicited only from the conditions in which participants viewed live faces, suggesting that photographic face stimuli may not be sufficient from eliciting certain approach- and avoidance-related responses.
Perceiver’s emotional state influences target perception
Next, I’ll explore some evidence that a perceiver’s emotional disposition can influence their gaze orientation towards a target (Mogg, Garner & Bradley, 2007). Mogg and colleagues recruited two groups of participants: high-anxiety and low-anxiety individuals to participate in an eye-tracking experiment. Participants’ eye movements were recorded as they looked at an array of stimuli that conveyed fear or anger along a continuum.

They found that both groups of participants preferentially directed their eye gaze towards threat-related emotions of anger and fear (compared to neutral emotional faces). They also found that compared to low-anxiety participants, high-anxiety participants demonstrated stronger gaze orientation towards the threat-related stimuli when the faces depicted highly prototypical angry or fearful expressions. The differences they observed among high- and low-anxiety participants are consistent with theories of anxiety that posit anxious individuals are more sensitive to threat-related cues (Mogg and Bradley, 1998). One way in which this heightened sensitivity can manifest is through greater attention towards threat cues (Mogg and Bradley, 1998).

So to wrap this up, we’ve explored ideas related to ways that emotion and gaze interact to influence all aspects of interpersonal perception. One thing you may notice is that much of the current work focuses on anger and fear, while ignoring many other emotions. It will be interesting to see how the literature develops as we begin to explore other emotional domains.

References

Adams, R. B., & Kleck, R. E. (2005). Effects of direct and averted gaze on the perception of facially communicated emotion. Emotion (Washington, D.C.), 5(1), 3–11. doi:10.1037/1528-3542.5.1.3
Andreassi, J. L. (2000). Psychophysiology: Human behavior & physiological response (4th ed.). NewJersey: Lawrence Erlbaum Associate.
Hietanen, J. K., Leppänen, J. M., Peltola, M. J., Linna-Aho, K., & Ruuhiala, H. J. (2008). Seeing direct and averted gaze activates the approach-avoidance motivational brain systems. Neuropsychologia, 46(9), 2423–30. doi:10.1016/j.neuropsychologia.2008.02.029
Mogg, K., Garner, M., & Bradley, B. P. (2007). Anxiety and orienting of gaze to angry and fearful faces. Biological Psychology, 76(3), 163–9. doi:10.1016/j.biopsycho.2007.07.005
Mogg, K., Bradley, B.P., 1998. A cognitive-motivational analysis of anxiety. Behaviour Research and Therapy 36, 809–848.

Welcome back to my blog series about emotion and our senses! Last post, we learned about our senses in general interact with our emotions. This post will specifically focus on how our visual system helps us navigate the world of emotion. It will also explore how the emotions of those with non-functioning visual systems are impacted.

Think of a mystery movie. The characters just entered somewhere to investigate. What is the first thing that one character says to another? They say “what do you see?” Our eyes help us in our acquisition of information (including emotional information). We understand emotions through visual cues. If you saw someone in tears, what would you say? You would ask them why they were sad. This is due to the aid of our vision in identifying and processing emotion.

What emotion is she displaying? The tears are a visual cue that tell us she is sad.

How we define something as emotional starts with our vision. Schupp et. al (2003) believed that visual cues were responsible for emotional categorization. Participants sawpictures and categorized them as pleasant, unpleasant, or neutral. Their reactions were measured using ERPs. There were stronger, more negative ERP responses in visual areas of the brain. This shows that we quickly identify something as emotional from visual cues. From an evolutionary standpoint this makes sense. You identify someone as sad by tears rather than by a distinct smell. One step further than just categorization, our visual cortex helps us process emotion.

This graph shows the dramatic difference in visual activation during the Lang et. al (1998) study.

Lang et. al (1998) studied our visual cortex in relation to emotional processing. The Participants were in an fMRI scanner and saw emotional or neutral pictures. Lang found that for emotional pictures there was more activation of the visual cortices. They concluded that emotional processing begins with vision. I agree with this, but I would be curious to see another follow up study. What would happen if the same image was presented more than once? Would the activation lower? It may be possible that the visual activation happens only as a note to the brain to continue to process something. Once something has been fully processed perhaps the visual signals are less important. I have mentioned how vision helps in categorizing and processing emotion, but what about people who have non-functioning visual systems? Can they still emote “normally”?

The athlete on the left is blind. Can you tell that just from her expression? Probably not!

We learn a lot about the world from interacting with others. Galati et. al (2001) believe, however, that our spontaneous emotional expression does not need to be visually learned. They tested this by showing participants videos of blind or sighted children making expressions. They triggered these emotions in various ways such as taking a snack away(anger) or being with a caregiver (happiness). Surprisingly, accurate participant judgment was not significantly different between the two groups. Galati et. al (2001) argue that the physical expression of emotion is independent of our visual learning. They believe spontaneous expressions are thus innate and not visually learned. A similar conclusion was drawn by Matsumoto and Willingham (2009). When they compared and coded photographs of blind and seeing athletes, they found emotional expression to be statistically the same. This emphasizes that emotional expression is independent of visual learning.

Our visual system has a complex relationship with emotion. In some aspects it is very involved: our visual cortex is activated to help us process and identify emotions. In other ways, it is less involved: visual learning of emotion may be minimal. This could mean that expressing emotion (despite it being something that is inherently seen) functions through a different system. This makes sense, since blind individuals still need to express emotions in order to adapt and operate in social situations. Next week, we will see how our sense of hearing affects our emotions. Stay tuned!

 
References:
[Crying Woman Photograph] Retrieved October 24, 2014, from: http://www.apa.org/monitor/2014/02/cry.aspx

[Blind and Seeing Athlete Photographs] Retrieved October 24, 2014, from: http://blogs.scientificamerican.com/psysociety/2014/02/17/olympics1/

Galati, D., Miceli, R., & Sini, B. (2001). Judging and coding facial expression of emotions in congenitally blind children. International Journal of Behavioral Development, 25(3), 268-278.

Lang, P. J., Bradley, M. M., Fitzsimmons, J. R., Cuthbert, B. N., Scott, J. D., Moulder, B., & Nangia, V. (1998). Emotional arousal and activation of the visual cortex: an fMRI analysis. Psychophysiology, 35(2), 199-210.

Matsumoto, D., & Willingham, B. (2009). Spontaneous facial expressions of emotion of congenitally and noncongenitally blind individuals. Journal of Personality and Social Psychology, 96(1), 1.

Schupp, H. T., Markus, J., Weike, A. I., & Hamm, A. O. (2003). Emotional facilitation of sensory processing in the visual cortex. Psychological science, 14(1), 7-13.

Our final Open Access post for the week is a guest post from Judy Rabinowitz, one of our Research & Instruction librarians and a member of Tufts Scholarly Communications Team: 

Open vs. Public Access:  What’s […]