Posts Tagged ‘Grandmother Cell’

Conscious Thought

August 14, 2011

The topic of consciousness has been addressed in a number of Healthymemory Blog Posts (“Change Your Brain by Transforming Your Mind,” “We Are the Law: Free Will, The Human Mind, and the Limits of Determinism,” “Consciousness and the Grandmother Cell,” “Fluid Intelligence and Working Memory,” “What is Incubation,” “How Do We See,” “Brain, Mind, and Body,” “What is Consciousness,”, and “Attention”) because it is an important topic. For most lay people, consciousness is psychology. It is how we deal with the world on a daily, and nightly, basis. It is a tad ironic, that for many academic psychologists consciousness is an epiphenomenon that we view in our minds, and that most, if not all, behavior and thought occur below the level of consciousness. So consciousness is viewed by some as a movie we see in our head as we proceed through our life. The believe it has no real function.

Consequently, it was refreshing to hear the presentation by Ray F. Baumeister at this year’s annual meeting of the American Psychological Association (APA) titled the “What, Why, and How of Consciousness.”1 Most theories that contend that consciousness is epiphenomenal focus on input and or output processes. Baumgartner does not address these theories as for him the role of consciousness is central to what occurs between input and output processes. He argues that conscious thought is for internal processing that facilitates downstream interaction with the social and cultural environment. Consciousness enables the construction of meaningful, sequential thought. These constructions are found in sentences and narratives, logical reasoning, quantification, causal understanding, and narratives. In short, it accounts for intellectual and social life. It is used for the simulation of events.

It is estimated that people focus an average of 30% to 40% of their thoughts on concerns that are unrelated to their present behavior. Some people’s minds wander from the here and now more than 90% of the time. Even when tied to present behavior, conscious thoughts are often used for to recall similar behaviors from the past, anticipating the consequences of present behaviors, or considering alternative courses of action.

Baumeister contends that thought sequences resemble film clips that the brain makes for itself, allowing different parts of the brain and mind to share information. The production of conscious thought is linked to the production of speech, because the human mind evolved to facilitate social communication and information sharing. This led to culture and the adaptive success of humankind as the social species.

1Although it might be difficult obtaining this address, much of its content and the citations found in this blog post can be found in “Conscious Thought Is For Faciliting Social and ‘Cultural Interactions: How Mental Simulations Serve the Animal-Cultural Interface” by Roy F. Baumeister and E.J. Masicampo in the Psychological Review, (2010), 117. 945-971.

© Douglas Griffith and healthymemory.wordpress.com, 2011. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.

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Consciousness and the Grandmother Cell

February 27, 2011

The notion of a grandmother cell is that there are specific neurons that represent a specific concept of object, such as your grandmother. Initially this concept was not generally accepted. The primary criticism was that too many cells would be needed to identify each individual face because each orientation, expression, and lighting on the face would be different. Moreover, the appearance of the face would change over time.

However, recent research summarized in a Scientific American Mind article1, not only resurrects the notion of the grandmother cell, but also relates it to the phenomenon of consciousness. This research involves placing electrodes in the brain to measure electrical activity. This procedure is so invasive that it is only justified for medical diagnosis and treatment. Neurons in the medial temporal lobe are the source of many epileptic seizures. This region includes the hippocampus and turns visual and other sensory percepts into memories. Although most neurons respond to categories of objects, a few of the neurons were much more discriminating. One hippocampal neuron responded only to photos of Jennifer Aniston, and not to pictures of other actresses. Moreover, the cell responded to seven different pictures of Jennifer Aniston. They also found cells that responded to images of Mother Theresa, to cute little animals, and to the Pythagorean theorem.

Further research, by a highly creative and painstaking research team, developed a technique for making concepts visible. They took a volunteer patient and recorded from a neuron that responded to images of the actor Josh Brolin (who was in her favorite movie) and to another neuron that fired in response to the scene of Marilyn Monroe standing on a subway grill. The patient looked at a monitor where these two images were superimposed. The activity of the two cells controlled the extent to which she saw Brolin or Monroe in the hybrid image. When the patient focused her thoughts on Brolin, the neuron associated with Brolin fired more strongly. Similarly when the patient focused her thoughts on Monroe, the neuron associated with Monroe fired more strongly. Feedback was arranged such that the more one cell fired relative to the other, the more visible that image became as the competing image faded. The image on the screen kept changing until only Brolin or only Monroe remained on the screen. The patient loved it and felt that she was controlling what she saw, which she was.

We know that we can control what we are thinking about and that corresponding neurons and neural circuits respond. But this is, as far as I know, the first demonstration of this phenomenon. By using and controlling the appropriate memory circuits we are able to build and maintain our minds.

1Koch, C. (2011). Being John Malkovich. Scientific American Mind, March/April, 18-19. 

© Douglas Griffith and healthymemory.wordpress.com, 2011. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.