December 29, 2002

IDA on Will: It’s no Illusion

franklinidaimage.gifThe issue of free will is perhaps the most oft debated single issue in the history of philosophy (For annotated bibliographies see Whether philosophers or scientists, most modern materialists, believe the universe, at scales beyond the quantum, is deterministic. This leads them to class free will with magic. It’s only an illusion.

But it seems abundantly clear from introspection, even to us materialistic scientists, that we do exercise will, even if it’s not free, that is, not magical. We make choices, even if they are deterministic, at least in principle. Sloman has made this distinction between will and free will quite convincingly (1992/3, see also Franklin 1995 pp. 35-40).

However, scientists have also learned not to be too trusting of introspection. There are too many examples of beliefs that are introspectively “abundantly clear” and, at the same time, just plain wrong. In the case of will, this is precisely the contention of D. M. Wegner’s “The Illusion of Conscious Will” (2002). The context of this essay is Thomas W. Clark’s review of Wegner’s book, which recently appeared on SCR.

Read more... Comments (1)Print This Post

August 24, 2002

Seeing sounds, hearing tastes – Synesthesia in brain and mind

SCR Feature,altered states — thomasr @ 11:35 am

article_image.jpegDo all people experience stimulation of each sense independently? Accumulating evidence suggests that a special kind of perceptual phenomenon – syhesthesia – leads to a confusion of the specific senses. The problem is to relate these personal accounts to the science of the brain.
In 1915, the Russian composer Alexander Scriabin had his “Prometheus” played for the first time. The orchestral piece was originally written for orchestra, piano, pipe organ, choir and light organ — literally an organ that creates light. You may ask what a light organ is, and you would be perfectly right if you guessed that there is no such thing. So why did Scriabin compose a piece of music for a fictive instrument? The answer lies in the concept of “synesthesia”: the perceptual crossover between senses. Scriabin probably did not believe that one could ever play what he had composed for the light organ – he simply did not know of any other way to describe his conception of the music when the “Prometheus” was played. Although it is still debated whether Scriabin was a “true” synesthete, the Prometheus is often regarded as one of many examples of the phenomenon.

Read more... Comments (4)Print This Post

July 12, 2002

“Synaptic Self. How our brains become who we are"

SCR Feature,needsfixing,reviews — thomasr @ 11:54 pm
Read more... Comments (1)Print This Post

June 3, 2002

An Attention-Based Control Model of Consciousness (CODAM)

SCR Feature,cognitive science,needsfixing — thomasr @ 10:48 pm

Despite the recent ‘Race for consciousness’, many neuro-scientific approaches have failed to use the concept of ‘attention’ as a guide to consciousness. In this review, John G. Taylor claims that consciousness can be more fruitfully regarded as created by processes arising from the movement of attention.

Read more... Comments (1)Print This Post

May 29, 2002

Consciousness under anesthesia

SCR Feature,neuroscience — thomasr @ 10:40 pm


A breakthrough in testing unconsciousness during anesthesia

So you thought that research in consciousness did not have any practical applications? Now, researchers are monitoring your level of consciousness during deep anesthesia. Imagine that you are anesthesized before a surgical operation. You would probably expect to “black out,” and then wake up some time afterward. What then if you suddenly found yourself conscious of the surgeon’s knife – during the operation? Even worse, you might not be able to let anyone know you are aware.

Read more... Comments (4)Print This Post

May 28, 2002

Nonconscious goals and ‘mysterious moods’

SCR Feature,self-awareness — thomasr @ 10:34 pm

/2002/article_image_3.jpegAre you in control of your faculties? When you suddenly are in a bad mood, do you really know why?

Why you can be in a bad mood without knowing why

Carl Gustav Jung, one of the early psychoanalysts, once said that just as we cannot see stars in daytime because it is too bright, dreams never stop when we are awake; we just cannot see them. In the same manner, the core hypothesis of Sigmund Freud’s psychodynamic theory was that most mental activity is unconscious. But scientific evidence on this issue has been rather sparse.

Read more... Comments (1)Print This Post

May 27, 2002

Tilt after-effect from invisible patterns

SCR Feature,cognitive science — thomasr @ 10:24 pm

/2002/article_image1.jpegEven if you do not see the fine graitings on a screen, it might cause alterations to how you experience a stimulus afterwards.

What you don’t see now will affect what you see next

Vision is not perfect. The human eye is only receptive to certain wavelengths. And, due to the relatively low temporal resolution of the eyes, you cannot see the flickering images on the TV screen. So, what you see right now is only a fragment of the total visual scene. But what if you were told that what you did not see previously has an impact on what you see now? Would you believe it?

Read more... Comments (1)Print This Post

May 26, 2002

Touching what is out there

SCR Feature,cognitive science — thomasr @ 10:20 pm

/2002/article_image_1.jpegThe conscious sensation of touch is felt at the location of the tactile stimulus: we feel the key or the pen that we pick up at our fingertips rather than in the brain where the sensory signals end up. If we use a tool to explore our surroundings, such as a walking-stick, something even more curious happens. We feel the sensation of touch taking place out there at the tip of the stick. How is that possible; after all, there certainly are no sensory receptors located at the tip of the stick!

Yamamoto and Kitazawa (2001a,b) have recently reported two studies in Nature What does it mean to say that the sensations are “referred to” the tips of the sticks? Neuroscience that may elucidate this mystery. When two stimuli were given in rapid succession to the fingertips of uncrossed hands, the subjects were remarkably good at judging which hand was stimulated first. But if the arms were crossed, reversing the spatial locations of the hands, subjects tended to misreport the order unless there was about one second between the successive stimuli. This experiment shows that the judgement of subjective temporal order is based on a reconstruction of the spatial locations of the stimuli within an internal spatial representation. It also demonstrates that the binding together of a unified body image takes time, especially when the default mapping of locations is violated.

Read more... Comments (1)Print This Post

Motion induced blindness

SCR Feature,cognitive science — thomasr @ 4:21 pm

/2002/article_image8.gifEven if you fix your gaze at one of these yellow dots, it will eventually disappear! A newly uncovered visual illusion poses problems for theories of conscious vision.

Striking visual disappearance in normal-sighted observers under natural conditions

Of all that your eyes capture, how much do you really see? Many are aquainted with visual illusions, such as the Necker cube, where the viewer is put in a state where two or more percepts of the same physical presentation are both coherent and mutually exclusive. Other figures might produce a so-called “filling in” effect, where parts of a visual scene are (gradually) left out. This might be shown with a demonstration of the blind spot, a part of the visual scene that corresponds to the region where the optic nerve leaves the retina, and there are no retinal receptors. Another example is the famous Kanizsa triangle.

Read more... Comments (2)Print This Post

May 25, 2002

Consciousness Science 2002: past, present, and future.

SCR Feature,sociology — thomasr @ 4:15 pm

/2002/article_image2.jpegWhat is the current state of the science of consciousness? In this editorial, Annti Revonsuo shares his view on this matter, that consciousness science should strive to become more unified. The present wave of the scientific study of consciousness could soon celebrate its 10th anniversary. It was sometime in the early 1990′s when the topic of consciousness made a final breakthrough and the multidisciplinary studies on consciousness became a distinct, respectable field of scientific inquiry, with its own academic journals, conferences and societies. The pioneering spirit of the 1990′s seems to have been driven by the conviction, explicit in conference slogans and book titles, that we are steadily progressing towards a Science of Consciousness.

At this point in the development of the field it might be a good idea for We need to discontinue endless arguments about philosophical alternatives the field to take stock and evaluate what has been achieved, and where to head next. At the theoretical and philosophical level, the main achievement is that the different options as to the fundamental nature of consciousness have been systematically charted and vigorously explored. However, it still remains unclear what kind of a philosophical approach should be taken as the basis of the Science of Consciousness. In any case, one thing is clear: If we want to have a genuine SCIENCE of consciousness, at some point the consciousness research community will have to discontinue endlessly arguing about the philosophical alternatives and for the time being just settle with something reasonably plausible in order to make progress with the actual empirical science of consciousness.

Read more... Comments (1)Print This Post

May 23, 2002

Automaticity, unconsciousness and speech production

SCR Feature,unconscious states — thomasr @ 11:24 am

/2002/article_image_11.jpegIs the human brain able to preserve functions, or fragments of functions, in isolated specialised units while the brain at a global level is severely damaged? Furthermore, could one imagine preserved functions in a brain that did not support any mental events?

These are questions that are addressed in a paper entitled “Words without mind” in a recent issue of Journal of Cognitive Neuroscience by Nicholas Schiff and his colleagues at New York Hospital and the New York Medical Centre. Here, they describe a 49-year old woman (LR) who spontaneously utters words that are unrelated to any environmental context, despite the fact that she has been deeply unconscious for 20 years. LR has suffered from three successive hemorrhages – brain damage due to blood flow from ruptured blood vessels – and brain scans with MRI (Magnetic Ressonance Imagery) showed severe damage to a number of brain regions, first of all most of her cerebral cortex of the right hemisphere, and some deeper structures, a.o. her right basal ganglia and thalamus. Only few, isolated islands of LR’s brain were left relatively unharmed after the hemorrhages, some of which were Broca’s and Wernicke’s area in the left hemisphere. They have long been known as the neural basis of the articulation of words and the understanding of words, respectively. But even those areas, though less affected than the rest of the brain, had a metabolism of 66% of the normal value in the case of Wernicke’s area, and only 50% for Broca’s area.

Read more... Comments (1)Print This Post

May 22, 2002

"The Illusion of Conscious Will", by DM Wegner

SCR Feature,reviews — thomasr @ 10:16 am

Reviewed by Thomas W. ClarkIn neuroscientific circles, it is simply commonsense physicalism that the brain conducts business on its own. It doesn’t need a further, non-physical agent to orchestrate the dauntingly complex operations that constitute awareness, cognition, and control of behavior. Nevertheless, it’s also become clear that for us to successfully navigate the world, the brain must conjure a stable sense of a self, acting within an environment represented as distinctly non-self (for example Antonio Damasios “The feeling of what happens”. Even though there’s no one in charge of its operations, the brain generates a strong intuition of personal agency, borne out by the obvious fact that persons accomplish all sorts of things in all manner of ways.

Read more... Comments (2)Print This Post

Empty mind — a brain disorder?

SCR Feature,abnormal states — thomasr @ 6:55 am

/2002/article_image_21.jpegA French neurological team has described a surprising new brain disorder — a deficit of spontaneous conscious thinking. LaPlane and Dubois describe it as “auto-activation deficit.” (*) People with this problem lose spontaneous conscious feelings, thought and actions — until they are asked to do something. Then they act perfectly well.


Maybe it should be called Standby Disorder The neurologists write, “They tend to stay in the same place all day long, sitting on a chair or lying on their bed, taking no initiatives and asking no questions, although they answer questions appropriately. They do not move around or engage in spontaneous activity.” But “the most enigmatic symptom encountered in these patients is mental emptiness. Their mind is ‘empty, a total blank,’ they say. In most typical cases, they have no thoughts and no projections for the future.”

Read more... Comments (6)Print This Post

May 10, 2002

The brain basis of a "consciousness monitor"

SCR Feature,unconscious states — thomasr @ 9:10 pm

Imagine that you are anesthesized before a surgical operation. You would probably expect to “black out,” and then wake up some time afterward. What then if you suddenly found yourself conscious of the surgeon’s knife – during the operation? Even worse, you might not be able to let anyone know you are aware.

In 1979 a “medically qualified lady” wrote an editorial called On Being Aware in the British Journal of Anesthesia, describing her own experience of waking up in the middle of a Caesarean section – an incision of her abdomen to facilitate giving birth. “I went unconscious very suddenly,” she wrote, “literally as though someone had switched the lights out. After a gap of uncertain time I gradualy became aware of a mental haze in front of me. I was profoundly confused. This relatively happy state was interrupted by a voice in the space above me (some remark about my bladder) and I instantly understood my predicament: that I was lying there, covered in green towels, my abdomen split open Immediately following this there came three rough stripes across my abdomen. Almost before the third stripe was finished, it was followed by the pain – as suddenly as though I had been stabbed. It was bad from the onset, and it increased in severity. The nearest comparison would be the pain of a tooth drilled without local anesthetic – when the drill hits a nerve. Multiply this pain and then pour a steady stream of molten lead into it. ”

Read more... Comments (1)Print This Post

April 10, 2002

Pain Resources

web resource — thomasr @ 9:34 pm

In the recent Webscan on HMS Beagle, Cindy Siewert localizes some of the web resources for the present knowledge on pain and related issues. Some of the features are links to brain scans of subjects in both chronic and acute pain.

WebscanIn the recent Webscan on HMS Beagle, Cindy Siewert localizes some of the web resources for the present knowledge on pain and related issues. Some of the features are links to brain scans of subjects in both chronic and acute pain.

“Pain – like few other things – unites all humans. We all suffer from it, at least now and then, regardless of age, ethnicity, gender, nationality, race, or sexual orientation. Nevertheless, all of us experience pain in solitude, and communicating the actual experience is notoriously difficult. What one person considers a simple touch might be felt as painful by another. Pain can even be felt in parts of the body that no longer exist, as is clear from the perception of aches in phantom limbs, which are “invisible” limbs that often appear following amputation. According to The Pain Web, over 1,200 online sites – containing over 3 million pages – address the topic of pain. Consequently, this WebScan just scratches the surface of available resources.”

BioMedNet WebScan

Read more... Comments (0)Print This Post

Subliminal sights educate brain

cognitive science — thomasr @ 9:33 pm

You must pay attention to learn, teachers say. Not necessarily, US psychologists now argue: sights we are unaware of can have a lasting impact on our brains.

Subliminal training can improve our ability to see moving dots, Takeo Watanabe and his co-workers at Boston University, Massachusetts, have found. “Without noticing, we are unconsciously learning,” Watanabe says. Repeated exposure to objects we are oblivious to “could have a tremendous effect on our brains”, he says.

Nature ScienceUpdate

Read more... Comments (0)Print This Post

Consciousness & Cognition, 10 (3)

journal — thomasr @ 9:32 pm

Selected articles:

Confidence and Accuracy of Near-Threshold Discrimination Responses

Craig Kunimoto, Jeff Miller, Harold Pashler

This article reports four subliminal perception experiments using the relationship between confidence and accuracy to assess awareness. Subjects discriminated among stimuli and indicated their confidence in each discrimination response. Subjects were classified as being aware of the stimuli if their confidence judgments predicted accuracy and as being unaware if they did not. In the first experiment, confidence predicted accuracy even at stimulus durations so brief that subjects claimed to be performing at chance. This finding indicates that subjects’s claims that they are “just guessing” should not be accepted as sufficient evidence that they are completely unaware of the stimuli. Experiments 2-4 tested directly for subliminal perception by comparing the minimum exposure duration needed for better than chance discrimination performance against the minimum needed for confidence to predict accuracy. The latter durations were slightly but significantly longer, suggesting that under certain circumstances people can make perceptual discriminations even though the information that was used to make those discriminations is not consciously available.

The Central Role of the Parietal Lobes in Consciousness

J. G. Taylor

There are now various approaches to understand where and how in the brain consciousness arises from neural activity, none of which is universally accepted. Difficulties among these approaches are reviewed, and a missing ingredient is proposed here to help adjudicate between them, that of “perspectivalness.” In addition to a suitable temporal duration and information content of the relevant bound brain activity, this extra component is posited as being a further important ingredient for the creation of consciousness from neural activity. It guides the development of what is termed the “Central Representation,” which is supposed to be present in all mammals and extended in humans to support self-consciousness as well as phenomenal consciousness. Experimental evidence and a theoretical framework for the existence of the central representation are presented, which relates the extra component to specific buffer working memory sites in the inferior parietal lobes, acting as attentional coordinators on the spatial maps making up the central representation. The article closes with a discussion of various open questions.

Read more... Comments (0)Print This Post

Sensations’s ghost. The non-sensory "fringe" of consciousness

philosophy — thomasr @ 9:30 pm

PSYCHE: an interdisciplinary journal of research on consciousness

PSYCHE 7 (18)

Non-sensory experiences represent almost all context information in consciousness. They condition most aspects of conscious cognition including voluntary retrieval, perception, monitoring, problem solving, emotion, evaluation, meaning recognition. Many peculiar aspects of non-sensory qualia (e.g., they resist being ‘grasped’ by an act of attention) are explained as adaptations shaped by the cognitive functions they serve. The most important nonsensory experience is coherence or “rightness.” Rightness represents degrees of context fit among contents in consciousness, and between conscious and non-conscious processes. Rightness (not familiarity) is the feeling-of-knowing in implicit cognition. The experience of rightness suggests that neural mechanisms “compute” signals indicating the global dynamics of network integration.


Read more... Comments (0)Print This Post

Brain Scans Show Deaf Subjects ‘Hear’ Vibrations

brain imaging — thomasr @ 9:29 pm

Deaf people use the region of the brain associated with hearing to sense vibrations, a new study shows. “These findings illustrate how altered experience can affect brain organization,” says investigator Dean Shibata of the University of Washington. He presented his results yesterday at the annual meeting of the Radiological Society of North America.

Scientific American

Read more... Comments (0)Print This Post

International Journal of Psychopysiology

journal — thomasr @ 9:28 pm

Thalamo-cortical relations in attention and consciousness. C.H.M. Brunia

- Attention, consciousness, and electrical wave activity within the cortical column D. LaBerge

The present issue of the International Journal of Psychophysiology consists of six papers presented at a meeting on Thalamo-Cortical Relations in Attention and Consciousness held in October 2000 at Tilburg University.

Read more... Comments (0)Print This Post
Next Page »