hmmm. I will check out your suggestions. But on face value the thrust of the research you mentioned does seem counter-intuitive to say the least. For the brain to make it seem we know before we know...hmm For example a simple strobelight effect on a dance floor. The frequency is surely much shorter than a half second and yet an observer would be able to perceive the positions of numerous dancers at each strobe. The conglomeration of dancing postions thus revealed would (I think) be fairly unpredictable (predictive events being the only basis which I can see that would allow the brain to make it seem as though we knew before we did).
Thats why my initial thoughts revolved around the "temporal two-point limit" of sequential flashes as an indicator of the lower limit of conscious awareness. For example, an 'x' msec delay between the flashing of two LEDs will be reported as occurring simultaneously at some point. Thanks for the information. --Mike P.S. I dont think I like Bayesian filters :-) --- On Fri, 10/31/08, Marc Carter <[EMAIL PROTECTED]> wrote: From: Marc Carter <[EMAIL PROTECTED]> Subject: RE: [SPAM] - [tips] A couple of psychophysics questions please and thank you - Bayesian Filter detected spam To: "Teaching in the Psychological Sciences (TIPS)" <[email protected]> Date: Friday, October 31, 2008, 5:53 AM I think a good way to go at this is to look at some of Libet's work on conscious awareness and how that likely works. The upshot is that Libet shows that it takes a good half-second of cortical stimulation for the stimulus to evoke awareness, but it doesn't seem that way. So the question is how the brain makes it seem as though we're aware of things before we're actually aware of them; the theories on this are many and varied (and some deny that there is a half-second delay at all). If you can get hold of a copy of Susan Blackmore's intro to consciousness, that research is discussed in a few chapters. You might also look at Dan Wegner's work on the illusion of conscious will; that's relevant, too. Sometimes things are not at all as they appear to be. And then, sometimes they are. m ------- Marc L Carter Associate Professor and Chair Department of Psychology Baker University College of Arts & Sciences ------- From: Michael Smith [mailto:[EMAIL PROTECTED] Sent: Thursday, October 30, 2008 11:24 PM To: Teaching in the Psychological Sciences (TIPS) Subject: [SPAM] - [tips] A couple of psychophysics questions please and thank you - Bayesian Filter detected spam For the psychophysicists (or others) among us I wonder if you can supply comments/answers on these statements/questions: 1. My understanding is that it takes about .25 sec for a person to become consciously aware of a visual stimulus. Is this estimate still accurate? 2. However I dont think it takes this long for us to perceive visual events in the world. That is, with a 'stream of consciousness' we can presumably perceive events closer in time. So my question here is: What is the lower temporal limit a person can perceive sequential flashes of a visual stimulus as distinct? This timeframe would presumably indicate the lower limit of conscious awareness of visual events in a normal visual environment. 3. Does our visual awareness have to be reset? That is, if we come out of a coma (and open our eyes) presumably we would need the .25 sec to perceive our first visual stimulation from the environment (ignoring obvious other problems :-) ). If this is so, do we actually do this upon waking every morning. Any input would be appreciated. --Mike --- To make changes to your subscription contact: Bill Southerly ([EMAIL PROTECTED]) --- To make changes to your subscription contact: Bill Southerly ([EMAIL PROTECTED]) --- To make changes to your subscription contact: Bill Southerly ([EMAIL PROTECTED])
