Imaging Language and Communication

Modern Imaging Techniques Reveal the Complexity of Language  

The classic brain areas associated with language – Broca’s and Wernicke’s area – have been identified from patients with brain lesions (see page 8). It is plausible that other regions, such as the auditory cortex for hearing and the visual cortex for reading, also play a role in communication. However, in recent years, imaging has contributed a great deal to a more network-like understanding of the representation of language and communication in the brain and demonstrated its complexity.

via Wikimedia Commons

Different Imaging Modalities 

Imaging studies with combined functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) have shown that the arcuate fascicle directly connects Broca’s with Wernicke’s area [1]. This fiber bundle is thought to represent the dorsal pathway of language. It connects auditory cortices to parietal and frontal lobe networks, and seems to mediate between hearing sounds and articulation of words [2]. Furthermore, a second pathway exists and is represented by the extreme capsule [1]. This ventral stream projects from auditory cortices to the temporal lobe. It is thought to be the connection between hearing sound and understanding the meaning of spoken words [2].

Resting-state fMRI studies demonstrate that the language network is even more extended. MRI signals in Broca’s and Wernicke’s areas have a positive correlation with signals in neighbouring prefrontal, temporal, and parietal regions, but also with subcortical structures like the basal ganglia [3].

Studies on communication and language have also been performed using near-infrared spectroscopy (NIRS). This technique allows subjects to communicate in a natural environment. NIRS has proven useful in examining the brain activity of infants to get an insight into how we learn to speak [4].

It seems that with every fMRI, PET or NIRS study conducted on the subject, it is proven further that the language network is more extended and complex than previously thought.

Clinical Applications 

This more detailed knowledge of the extent of the language network also has direct clinical applications. Brain surgeries on tumor or epilepsy patients need to avoid areas that can affect the ability of the patients to speak. The Wada test, which “switches off” one cerebral hemisphere with barbiturates, was formally the gold standard to determine the dominant hemisphere for language production. Modern imaging methods, like fMRI or navigated transcranial magnetic stimulation (nTMS) can map the individual brain areas involved in language much more precisely and in much more detail. Therefore, these methods are increasingly being used for preoperative planning [5,6] and are considered an adequate replacement for the Wada test [7].
Furthermore, imaging studies are a great tool to help us understand how functional recovery takes place after stroke or surgery, and to what extend other structures can take over functions essential for communication [1]. This further adds to understanding of the language network.

Social Aspects of Communication 
Not only have the structural components of the language network been analyzed with imaging, the social aspects of communication have also taken center stage in recent years.
A study conducted with simultaneous MRI scanning of close female friends showed that neuronal coupling happens during live verbal communication about autobiographical events. The time course of neural activity in language areas was coupled with the time course of neural activity in the friends’ auditory cortex, representing very basic reciprocal mechanisms of social interaction [8]. So-called hyperscanning – the parallel scanning of two subjects who can interact during the session – is a great way to study brain activation during live social interaction.
However, in a social context it is not only the literal meaning of words and sentences that have to be processed, but also the intended meaning of the speaker. This is especially true for metaphors and sarcasm. Differences in brain activations during communication with metaphors and sarcasm have been investigated with fMRI. Interestingly, brain activation related to metaphors was found in the head of the caudate. Sarcasm elicited activation in the left amygdala, which probably represents the processing of the speaker's emotional status [9].
All in all, imaging has given us much insight into the complexity of the language network and its use in social context. To know how the brains of healthy participants function during communication is important to understand conditions such as autism or schizophrenia and has great clinical implications in rehabilitation and surgical planning.

[1] Saur and Hartwigsen, Arch Phys Med Rehab, 2012   

[2] Friederici and Gierhan, Curr Opin Neurobiol, 2013

[3] Tomasi and Volkow, Mol Psychiatry, 2012

[4] Rossi et al, Brain & Language, 2012

[5] Mahvash et al, Clin Neurol Neurosurg, 2014

[6] Picht et al, Neurosurgery, 2013

[7] Papanicolaou et al, Epilepsia, 2014

[8] Spiegelhalder et al, Behav Brain Res, 2014
[9] Uchiyama et al, Cortex, 2012

by Ann-Christin Ostwaldt, PhD Student, AG Fiebach
this article originally appeared 2014 in CNS Volume 7, Issue 4, Communication and Social Media 

Silence on the Line

A False Start in the Study of Communication

There are dozens of ways to study communication scientifically. But this article won’t tell you about a single one of them. Instead, what follows is an exploration of a scientific phenomenon rejected by the international community: Telepathy.

The term, coined by Frederic Myers in 1892, came to envelop a colourful pseudoscience embraced in the late 19^th century [1].Yet for all its lurid history of exposed fraud and scientific malpractice, the history of telepathy research has much to tell us about how we deal with rejected scientific hypotheses today. As a field, it’s bizarre. As a model for perseverance and faith in findings, it’s something else entirely. Furthermore, the story of telepathy can tell us how even the most damning dead ends can have important (and surprising) consequences.

Laying Down the Law
Many people did (and some still do) take telepathy very seriously. For example, both the Society for Psychical Research (SPR) and its American equivalent (the ASPR) were founded in the 1800s to study psychic phenomena. Throughout their long history, the groups have devoted themselves both to investigating the above-mentioned practices and debunking fraudsters [2]. Both organizations continue to have active membership today, and operate several peer-reviewed journals including The Journal of Parapsychology [3].

Communication with tincans,  Source: Wikimedia Commons

Scientists from these groups have also helped to standardize experimental practice. Often, “Zener Cards” are used to test whether a card viewer can transmit information to a subject far away. Another well-known family of experiments relies on the “Ganzfeld”, a sensory deprivation chamber in which participants try to communicate with a “receiver”. Though the setup has been roundly criticized, a meta-analysis published in the more mainstream Psychological Bulletin found a tiny, yet significant statistical effect [4]. In intervening years, however, the methodology of this review has also been called into question [5].
 

EXPERIMENTS STILL SUFFER FROM QUESTIONABLE DESIGN

Perseverance is a critical quality in science, and indeed, the proponents of telepathy research have shown remarkable staunchness. In fact, experiments in extended consciousness have recently moved from Ganzfeld chambers into fMRI scanners. Theoretically, if one can show that one participant’s brain activity simultaneously covaries with another’s, there could be mental forces at work [6,7]. Alas, the promise offered by even the most up-to-date scanners have thus far failed to provide unassailable results. As with earlier techniques, experiments still suffer from questionable design and small sample numbers [7].

Revenge of the Skeptics
Alas, most findings, including the Ganzfeld meta-analysis above, likely represent a fluke. Despite its 100+ year history, there has never been a single experiment that proves the existence of telepathy. But this was certainly not for lack of trying [5,7]. In one memorable example, the US government spent 20 years and more than 20 million dollars on a top-secret project aimed at spying on the Soviet Union through telepathy and related techniques [8]. Formal meta-analyses and revisiting of original scientific data have also led to dead ends, with most effects explained-away through poor experimental design [5,7,9].

NO PROOF FOR TELEPATHY, BUT NOT FOR LACK OF TRYING

This is not to say, however, that “spooky” communication is not real. Humans’ drive to communicate is so strong that it seems we may pick up information from others in the form of subtle body language (see article on page 5). In the past, these phenomena were used to disprove hundreds of experiments, but there are more contemporary explanations of why we can’t shake a nagging feeling that telepathy might be real. For example, JM Rudski was able to show that perceived telepathy could be due to covariation and hindsight bias [9]. Furthermore, expectancy bias and wishful thinking may also contribute [5,7,9].

Dead End or Lively Beginning?
While all may be lost for telepathy, we still have a few wonderful souvenirs of its one-time popularity. Perhaps the best comes from the life-long quest of a scientist to explain mysterious communication between himself and his sister. Driven by this need, he found a way to attach electrodes to a subject’s skull and detect faint electrical activity. Dr. Hans Berger was certain that he had finally discovered telepathy, but instead, was embarrassingly wrong. But through his error, Berger had laid the foundations for electroencephalolographic readings: the substrate for today’s EEG.

TURNS OUT, BERGER WAS EMBARRASSINGLY WRONG

In closing, it seems that Berger might have the last laugh after all. While his dream of a telepathic force met with a dead end, researchers are starting to use EEG and fMRI to detect communicative patterns of activity in patients trapped in a vegetative state [11]. Perhaps one day, electrical transmission of thoughts may be a workable reality, enabling information flow only dreamed about previously. Until then, may the study of telepathy hearten us all with its colorful characters, and perseverance in the face of widespread disdain. Even if you don’t believe in a science, there’s an awful lot that you can learn from those who once did, or still do.


[1] Hamilton, Immortal Longings: F.W.H. Myers and the Victorian Search for Life after Death, 2009
[2] Sommer, Hist Human Sci, 2012
[3] http://bit.ly/1sKZhxl
[4] Storm et al, Psych Bull, 2010
[5] Rouder et al, Psych Bull, 2013
[6] Moulton and Kosslyn, J Cogn Neurosci, 2008
[7] Acunzo et al, Front Hum Neurosci, 2013
[8] http://bit.ly/1zj73ai
[9] Rudski, Psychol Rep, 2002
[10] Haas, J Neurol Neurosurg Psychiatry, 2003
[11] Chennu et al, Neuroimage Clin, 2013

by Constance Holman, PhD Student AG Schmitz
this article originally appeared 2014 in CNS Volume 7, Issue 4, Communication and Social Media