Tagged: perception
Music to my Ears?… Just Kidding
It was an average Wednesday night at 8, and I was channel surfing. As I changed the channels I heard singing; I knew instantly that the show was American Idol. Most of you watch or have watched the show in the past and time and time again it befuddles me to think how these individuals think that they can sing. Most of the singers not only have piercing voices, but they are off key and sound terrible. After most auditions, the contestants – although I know it was horrible – still believe their rendition of a Whitney Houston song was outstanding. If you are like me then you want to know why.
Tone-deaf individuals do not have brain damage or trouble hearing, and they are definitely not suffering from a lack of exposure to music. So what actually makes people unable to understand their inability to sing? Researchers conducted an experiment that tested the connectivity of the arcuate fasciculus (AF), which connects the temporoparietal junction (the place where the temporal and parietal lobes meet), with the frontal cortex in the brain. This junction allows neural substrates of sound perception and production to be connected. The researchers hypothesized that there are structural and functional abnormalities that contribute to tone deafness.
To test their hypothesis, structural MRIs with diffusion tensor imaging (DTI) were performed on the patients. DTI is a type of MRI that allows researchers to map internal structures with the diffusion of water. After processing the information, the maps identified that the right superior AF was diminished compared to control, signifying that the AF is disrupted in tone-deaf individuals. Also, resultant fibers in tone-deaf individuals projected dorsally toward the parietal lobe and/or translocally to the left hemisphere and not toward the ipsilateral inferior frontal gyrus where normal individuals have projections.The imaging and testing of the AF led researchers to conclude that the superior branch is responsible for fine-grained discrimination, and the inferior branch is responsible for automatic matching of sound output to its target. They also tested the volume of the fibers connecting each part of the brain and discovered that tone-deaf individuals have a lower volume of fibers than the control, which is important for conscious pitch determination and the degree of action-perception mismatch. According to the experiment, both the superior and inferior branches of the AF are needed for accurate perception and production.
Figure 1: A comparison between the regions of interest of the posterior superior temporal gyrus (pSTG) and the posterior inferior frontal gyrus (pIFG) of the right side of the brain
Tone-deafness is a new disconnection syndrome that deals with impaired pitch perception and vocal sound projection. There are no known genes that are associated with this condition that affects the AF fibers and their connection between the superior and inferior areas of the brain. So for all of you non-tone-deaf American Idol viewers, you will just have to sit through the next episode and know that most of singers cannot help but obliviously sing off-key.
Other Reading of Interest:
Tone Deafness – Scientific American
The amusic brain – BRAIN: A Journal of Neurology
A Portrait of Perception
Many a scientist has noted in the light of recent discovery that what has been scientifically elucidated has often been artistically intuited even hundreds of years before. Many phenomena of psychology or even physics have been illuminated first through the intuition and hypersensitive refl
ection of art. Illusions within the visual arts that modify perception of space and movement understand the psychology of perception without being themselves a science. Looking at a painting, one may begin to question why and how the painting gives us a sense of light or space. Neuroscientists at the University of Leicester are putting this principle to use in a scientific study, teaming up with a well-known international artist whose pieces specialize in manipulating human percepts. They hope to work with him towards a greater understanding of how the mind apprehends visual stimuli.
The neuroscientist, Rodrigo Quian Quiroga, attained renowned status after discovering a particular type of neuron that fired in an ‘abstract’ manner to pictures of different individuals, allowing for some predictive value of whom the person was looking at from a data of their neuronal firing. Fascinated with human perception, he teamed up with well-known Argentinean artist Mariano Molina to study the mind’s perception of art, particularly in juxtaposition to its perception of regular photos and individuals. Molina will spend five months working in the lab, learning about how perception works from a scientific viewpoint. In turn, Quiroga will get a look at perception through an artist’s frame.
Molina has discovered that many of his pieces of art intuit unconscious principles of perception that science had previously identified. Consider one of Molina’s paintings: “The Center of Gaze.” Staring into it, one’s eyes are immediately drawn to the center. Center? How do I know that’s the center? At least, that would be the afterthought of one with a normal sense of perception. Upon further study, conscious reflection dwells on the “how” behind what the eye has intuited. This process that an individual feels within herself, the ex post facto rationalization of a quick and thoughtless, yet insightful, perception is akin to the methodology of the project itself.
Molina will complete a dozen pieces of art within a five month period, helping to draw insight into perceptual processes intuited by the artist. Molina believes that his artistic ability will also benefit from the scientific understanding of perception. Scheduled to begin in November, the project is hoped to bring scientific knowledge as well as an enriched appreciation for art, and encourage communication between the sciences and the arts that is of mutual benefit.
How Do We Perceive Art? Artist in Residence to Work Alongside Neuroscience Research Lab -Univ. Leicester
Dream Bigger, Darling.
As my good friend Cobb once told me, “Dreams feel real while we’re in them. It’s only when we wake up that we realize something was actually strange.”
OK, fine, Leonardo DiCaprio’s character from Inception isn’t real, but he does make a valid point. Oneirologists, those who study dreams, have traditionally viewed dreams as uncontrollable streams of sounds and images with the ability to induce a tremendous spectrum of emotion. However, the idea of lucid dreaming has caused the conventional understanding of dreams to collapse. A “lucid dream," terminology coined by the Dutch psychiatrist Frederik van Eeden, is one in which the sleeper is aware that he or she is dreaming. This example of dissociation is wonderfully paradoxical in that it exhibits components of both waking and dreaming consciousness.
An American psychiatrist and dream researcher named Allan Hobson specializes in the quantification of mental events and their corresponding brain activities. Although he vehemently dismisses the idea of hidden meanings in dreams, he has embarked on a search along with other neurobiologists and cognitive scientists to decipher the neurological basis of consci
ousness. Hobson hypothesizes that subjects may learn to become lucid, self-awaken, and regulate plot control by intercalating voluntary decisions into the involuntary nature of the dream.
The validation of this idea would imply that the mind is capable of experiencing a waking and a dreaming state at the same time. Consequently, Hobson states, “…it may be possible to measure the physiological correlates of three conscious states, waking, non-lucid dreaming, and lucid dreaming in the laboratory.” If there is a psychological distinction between the three, there should also be a physiological difference.
The advent of lucid dreaming experimentation has not only benefitted Hollywood, but it has also provided possible treatment options for those hindered by frequent nightmares or post-traumatic stress disorder (PTSD). Methodologically speaking, the study of lucid dreaming presents a formidable challenge, but it is becoming an important component of the cognitive neurosciences.
Josefin Gavie and Antti Revonsuo have built on Hobson’s theories by proposing a technique termed lucid dreaming treatment (LDT). The key to this treatment is that the subject learns how to identify cues that facilitate lucidity during a dream, and the subject learns to manipulate the environment once lucidity is attained. The phenomenon of lucidity may prove to be a useful device in that it offers the sleeper a method to control components of the dream - altering and diminishing any threatening situation. Although the investigation of LDT is extremely new and incontestably controversial, it has shown promising preliminary results in its ability to lower the frequency of nightmares in the selected subjects.
The premise of the film Inception may be wildly hypothetical, but it has expertly amplified the current research on lucid dreams. However, researchers in the field should take a word of advice from the character of Eames: “You mustn’t be afraid to dream a little bigger, darling.”
The Neurobiology of Consciousness: Lucid Dreaming Wakes Up - J. Allan Hobson
The Future of Lucid Dreaming Treatment (PDF) - Josefin Gavie and Antti Revonsuo
Opening Eyes to Learning Difficulties
Learning difficulty and disability has long been a problem for many children, parents and school teachers alike. Dysfunctions such as dyslexia and motor disability have hindered the progress of countless adolescents across the country and continue to do so with every passing day. Now, studies have been performed that may centralize learning difficulties to the eye, rather than the brain itself.
Researchers at the Norwegian University of Science and Technology are conducting research that creates a causal link between motor and learning disabilities and dysfunction in visual perception. For example, people who cannot quickly learn a simple motor task such as catching a ball may have difficulty because the cells in their eyes are not perceiving the stimulus properly. The same rings true in individuals with dyslexia - their eyes may not be correctly processing the visual stimuli of words on the page.
Learning disability has long puzzled victims, observers and scientists.
The ocular cells in contest here are deemed "magno cells" and detect rapid movements in our visual field, creating the movie-like perception we experience on a daily basis. Without these, life would look like a disconnected string of frames - much like a comic book. In a test conducted by the researchers, it was found that individuals with difficulty in mathematics also showed difficulty in tracking the randomized movement of a dot on a screen with their eyes, elucidating a link between eye function efficiency, detection of rapid changes in the environment and learning ability.
In a greater context, this finding may have implications in special education and may change the mindset of those working with individuals with additional learning needs. With this new information, learning disability can be combated from the angle of visual field perception. Techniques aiming to strengthen visual perception and eye efficiency (such as eye movement and tracking exercises) could act as a therapy for learning or motor disability previously thought to be localized in the brain itself.
Source: Science Daily via The Norwegian University of Science and Technology
