04/08/2010 by admin.

The Scientific American has an item by R.D. Fields about the research of U. Hasson (here). It compares the activity in a listener compared to a speaker.

There have been many functional brain imaging studies involving language, but never before have researchers examined both the speaker’s and the listener’s brains while they are communicating to see what is happening inside each brain. The researchers found that when the two people communicate, neural activity over wide regions of their brains becomes almost synchronous, with the listener’s brain activity patterns mirroring those sweeping through the speaker’s brain, albeit with a short lag of about one second. If the listener, however, fails to comprehend what the speaker is trying to communicate, their brain patterns decouple…

(overcoming technical problems) He asked his student to tell an unrehearsed simple story while imaging her brain. Then they played back that story to several listeners and found that the listener’s brain patterns closely matched what was happening inside the speaker’s head as she told the story.

The better matched the listener’s brain patterns were with the speaker’s, the better the listener’s comprehension, as shown by a test given afterward… there is no mirroring of brain activity between two people’s brains when there is no effective communication (except for some regions where elementary aspects of sound are detected. When there is communication, large areas of brain activity become coupled between speaker and listener, including cortical areas involved in understanding the meaning and social aspects of the story.).

Interestingly, in part of the prefrontal cortex in the listener’s brain, the researchers found that neural activity preceded the activity that was about to occur in the speaker’s brain. This only happened when the speaker was fully comprehending the story and anticipating what the speaker would say next.

What an elegant demonstration of communication!

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23/07/2010 by admin.

There is a group of people who are effectively invisible, functioning adults with no language. They are there but we just not not met them. They are born completely deaf and are not taught sign language or lip reading and, in fact, miss out not just on language but on knowledge that language exists. Now that they are known to exist, the question arises, how? Those non-linguistic adults live amongst us without being noticed (unbelievable - wild animals live amongst us in our cities and most of us do not see them). It must be much harder to survive without language than with it. So we must accept that these people are very good at understanding and using their environments. They must be continually solving problems -successfully. No sheltered workplaces, social workers, welfare payments, special education or any aspect of the net that is meant to catch the handicapped is available to them. No help is available from all the written and verbal signposts that litter our streets and airways. They cannot talk with others to ask or tell anything. They survive presumably because they are very intelligent, continuously observe the world and use their cognitive abilities to their up most. A description from neuroanthropology is (Life without language) and I urge you is read it.

So can people have thought without words? Well, the evidence-based answer would seem to be, yes, but it’s not the same sort of thought. Some things appear to be easier to ‘get’ without language (such as imitation of action), other things appear to be a kind of ‘all-at-once’ intuition (such as suddenly realizing all things have names), and other ideas are difficult without language being deeply enmeshed with cognitive development over long periods of time (like an English-based understanding of time as quantitative and spatialized). In other words, language is not simply an either/or proposition, but part of a cognitive developmental niche that shapes both our abilities and (unperceived) disabilities relative to the fully cognitively matured language-less individual.

Here is my take on the difference between cognition with and without language – absolutely speculative exercise in guesswork – take it with a grain of salt.

Problems that involve only sensory precepts or motor actions can be solved with or without consciousness – either way language is not needed. So our language-less man would be aware of his surroundings and his intent/action arcs like an ordinary person and would have memory of that awareness. To this extent his consciousness and his cognition would be like ours. He would even be able to manipulate some concepts or symbols although it is questionable how abstract these non-linguistic concepts can become. We can assume what language is not required for much of the simple communication between people. If other primates can live their lives without language why should a human not be able to do it.

But there is two sorts of thinking that I cannot imagine a language-less person engaging in. This is the kind that uses the cycle of: taking to yourself, being conscious of the inner voice, holding it in working memory, using access to that memory to retrieve the idea in the inner speech. This cycle would allow two parts of the brain that are not well connected in the manner needed, to exchange information through the global access available in consciousness and working memory.

The other type of thought that might be difficult to the person without language is the elaboration of abstract concepts. I believe this depends on nested series of metaphors/analogies. As the child metaphors become more distant from their concrete original parents, they become, in effect, a set of symbols related by a set of relationships. The connection to the senses and actions are lost. Without a ‘language system’ it becomes more and more difficult to handle more and more abstract symbols and relationships. I assume it would only be possible at an elementary level.

We know that handicapped people find ways around their handicaps and so I would expect the language-less to be very resourceful in developing ways to think that bypass the need for language and this might actually make them better at some specific cognitive tasks. But there is a limit.

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17/07/2010 by admin.

I have been avoiding, because of a lack of clarity, saying much about the relationship between language and consciousness. It is obviously important but hard to get a handle on. A recent article has prompted me to focus on this relationship. The article is by G. Lupyan and M. Spivey in PloS ONE, Making the Invisible Visible: Verbal by Not Visual Cues Enhance Visual Detection (here). Below is the abstract.

Can hearing a word change what one sees? Although visual sensitivity is known to be enhanced by attending to the location of the target, perceptual enhancements of following cues to the identity of an object have been difficult to find. Here, we show that perceptual sensitivity is enhanced by verbal, but not visual cues.

Participants completed an object detection task in which they made an object-presence or -absence decision to briefly-presented letters. Hearing the letter name prior to the detection task increased perceptual sensitivity. A visual cue in the form of a preview of the to-be-detected letter did not. Follow-up experiments found that the auditory cuing effect was specific to validly cued stimuli. The magnitude of the cuing effect positively correlated with an individual measure of vividness of mental imagery; introducing uncertainty into the position of the stimulus did not reduce the magnitude of the cuing effect, but eliminated the correlation with mental imagery.

Hearing a word made otherwise invisible objects visible. Interestingly, seeing a preview of the target stimulus did not similarly enhance detection of the target. These results are compatible with an account in which auditory verbal labels modulate lower-level visual processing. The findings show that a verbal cue in the form of hearing a word can influence even the most elementary visual processing and inform our understanding of how language affects perception.

To what extent can high-level cognitive expectation influence low-level sensory processing? Allocating visual attention to a location improves reaction times to probes appearing in that location. The spread of attention is also affected by specific objects: cuing an object speeds responses to a probe within the cued object’s boundaries.

We are dealing here with the edge between subliminal and conscious knowledge, where with a verbal cue the letter rises to conscious awareness but without the verbal cue it is not consciously seen. The results say a lot about perception, language and consciousness.

The results give conformation to the idea that there is top-down influence on very basic and early sensory perception.

The simple detection task is compatible with one of two broad conclusions: a) visual detection processes in visual cortex are influenced by auditory linguistic signals, or b) the process of detecting visual signals includes non-visual areas of cortex which are richly influenced by auditory linguistic signals. Either conclusion requires rejecting the assumption that “simple” visual tasks such as object detection depend only on the visual characteristics of a stimulus. … The present findings appear to conform to … requirements for … cognitive penetrability of early vision because information from outside the visual system (the linguistic label) is affecting visual sensitivity… We conclude based on the present findings that auditory verbal cues actually alter perceptual processing of the named objects rather than alter a higher level decision process.

What happens when an object that is being perceived has been given a name?

One way to understand our results is by conceiving of verbal labels as providing modulatory feedback to the visual system (The Label Feedback Hypothesis). Attention (one form of top-down control) has been shown to affect response properties of neurons in the very first visual area receiving top-down projections—the lateral geniculate nucleus (thalamus area)—and there is a large literature on effects of context, task-demands, and expectations on neural responses in primary visual cortex. The present results offer evidence that verbal labels, by virtue of their pre-existing association with visual stimuli, modulate visual processing by providing a “head-start” to the visual system, facilitating the processing of stimuli associated with the label. This type of continuous interaction between top-down and bottom-up processes is consistent with a number of theoretical frameworks

Currently ongoing experiments indicate that similar results can be obtained for pictures of everyday objects and animals: hearing common nouns can facilitate the detection of pictures from the named category… (Other results) suggest that the format of the cue, in addition to its modality, is important: verbal auditory cues (e.g., “cow”) facilitated visual identification and discrimination more than nonverbal auditory cues (e.g., the sound of a cow mooing”).

There is now accumulating evidence that higher level semantic information can influence visual perception in some surprising ways. For instance, auditory processing of verbs associated with particular directions of motion (e.g., fly, bomb) interferes with visual discrimination tasks along the vertical axis and increases sensitivity to the congruent motion direction in random-dot kinematograms. Moreover, linguistic input can guide visual search in an incremental and automatic fashion. Ascribing meaning to unfamiliar shapes using verbal labels improves the efficiency of visual search for these shapes. In fact, simply hearing a word that labels the target improves the speed and efficiency of search (compared to not hearing the label, but still knowing the target’s identity). For instance, when searching for the number 2 among 5’s, participants are faster to find the target when they actually hear “find the two” immediately prior to the search trial – even when they know that the 2 is the target because is has been so for the entire block of trials.

Words and their meaning have a great influence on the focus of attention, on the content of consciousness and on the details of perceptive processing. This is in keeping with Bolles’ model in the Babel’s Dawn blog (here) of speech being about joint attention, with words being the way to point attention to a particular topic.

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14/06/2010 by admin.

F. Huettig and R. Hartsuiker have a paper in Language and Cognitive Processes, Listening to yourself is like listening to others: External, but not internal, verbal self-monitoring is based on speech perception. (here) The abstract is below.

Theories of verbal self-monitoring generally assume an internal (pre-articulatory) monitoring channel, but there is debate about whether this channel relies on speech perception or on production-internal mechanisms. Perception-based theories predict that listening to one’s own inner speech has similar behavioural consequences as listening to someone else’s speech. Our experiment therefore registered eye-movements while speakers named objects accompanied by phonologically related or unrelated written words. The data showed that listening to one’s own speech drives eye-movements to phonologically related words, just as listening to someone else’s speech does in perception experiments. The time-course of these eye-movements was very similar to that in other-perception (starting 300 ms post-articulation), which demonstrates that these eye-movements were driven by the perception of overt speech, not inner speech. We conclude that external, but not internal monitoring, is based on speech perception.

This appears quite complex. The paper differentiates between our consciousness of our speech when it is not actually produced aloud and when spoken. The implication is that we produce and monitor our speech but are only consciously aware of the speech until we hear it. However, we become conscious of our internal, unspoken speech in a different way. This makes consciousness simpler but language more complicated. Consciousness is again a question of perception. But as BPS Research Digest puts it:

It’s important to clarify: we definitely do monitor our speech internally. For example, speakers can detect their speech errors even when their vocal utterances are masked by noise. What this new research suggests is that this internal monitoring isn’t done perceptually - we don’t ‘hear’ a pre-release copy of our own utterances. What’s the alternative? Huettig and Hartsuiker said error-checking is somehow built into the speech production system, but they admit: ‘there are presently no elaborated theories of [this] alternative viewpoint.’

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24/09/2008 by admin.

A Sciencedaily article, Scientists Watch As Listener’s Brain Predicts Speaker’s Words, is about the prediction of the next word to be uttered by a listener. This has a bearing on the question about how much of our language is conscious; it appears that it is probably similar to any other perception or motor aspect of our lives.

“Previous theories have proposed that listeners can only keep pace with the rapid rate of spoken language—up to 5 syllables per second—by anticipating a small subset of all words known by the listener, much like Google search anticipates words and phrases as you type. This subset consists of all words that begin with the same sounds, such as “candle”, “candy,” and “cantaloupe,” and makes the task of understanding the specific word more efficient than waiting until all the sounds of the word have been presented. But until now, researchers had no way to know if the brain also considers the meanings of these possible words…

‘We had to figure out a way to catch the brain doing something so fast that it happens literally between spoken syllables,’ says Michael Tanenhaus, the Beverly Petterson Bishop and Charles W. Bishop Professor…

‘Frankly, we’re amazed we could detect something so subtle,” says Aslin. “But it just makes sense that your brain would do it this way. Why wait until the end of the word to try to figure out what its meaning is? Choosing from a little subset is much faster than trying to match a finished word against every word in your vocabulary.’…

It seems that although language is most often present in our consciousness - that the cognitive work that is behind the use of language is not revealed in consciousness. The meaning of words is available without being made conscious. Meaning does not rely of consciousness.

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07/08/2008 by admin.

What is the connection between consciousness and language? Some would say that they are two aspects of the same thing. Not me. I have conscious thoughts that I cannot express in language. I have had conscious thoughts that were difficult to put into words and when I did, I was disappointed that the words seemed to change the thought and somehow degraded the feel of it.

The whole sight and sound world is modeled in my consciousness without any need for language. My awareness of my emotions is not verbal. Of course I very often think a category or proper name word for something I recognize, but I don’t exactly need the word to do the recognition.

Fairly often in conversation (interesting, heated or complicated conversation), I say something and it is not in my consciousness until I hear it. So it seems that there is a lot of consciousness without language and some language without consciousness. They cannot be two aspects of the same thing.

On the other hand, I do have an inner voice that seems to narrate my life. And this narration seems very important to the nature of my conscious experience. Language seems to supply a majority of concepts and symbols to the thoughts I am conscious of. It seems to help tie together the stream of consciousness.

I feel four levels of speaking. One level is saying something out loud. How this is done is not in my consciousness. All that is conscious is knowledge of the intent and knowledge that the intent is being carried out. Occasionally, as mentioned above, I do not even have knowledge of the intent to say something. It is also rare for me to completely form the verbal string before speaking. I do not have knowledge of the intent to say a particular sentence, but rather the intent is to say some semi-verbal idea. How it gets to be a fully verbal idea is a bit of a mystery as it does not enter my consciousness.

A second level is that I can speak to myself. This is just the same as speaking out loud including the knowledge that the intent is being carried out. Everything is the same as saying something out loud except that there is no sound and no outward movement of the mouth. This seems to be a motor act but with the ‘volume’ turned down to next to nothing. So a normal linguistic string can be included in my consciousness by speaking to myself. Reading is similar; it produces a sort of speaking to myself.

A third level is what I would call a semi-verbal inner voice. There is no feeling of intent or of the intent being carried out. It does not seem a motor act. It does not seem a linguistic string. It is more like a mixture of words and other symbols and relationships between them. It does seem to be an early part of speaking because when I do speak, it is a bit of this semi-verbal inner voice stream that is picked out to become the object of the intent to speak and so ends up as a normal linguistic string being spoken. The bulk of that inner voice is never spoken out loud or to myself but remains semi-verbal.

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