Steve Mirsky: Hi. Steve here, Steve Mirsky for Scientific American Science Talk. And we've just pulled into Juneau Alaska. It's approximately 7:00 in the morning. It looks like about 7:05 Alaska time, 11:00, 11:05 back in New York. In fact, let me turn on the TV where we have the channel that I told you about in Part One that gives us our position all the time and there we are. I see we're at position 58 degrees, 17 or closer to 18 minutes north latitude, 134 degrees, 24 minutes west. Ship's time is 7:06 AM on August 28th.
And I do have the door to the cabin open so that you can get a little Juneau sound. I'm stepping out onto the veranda. There's a floatplane going by. You could probably hear it. Later today I'll be in a floatplane. We're going to fly over the Mendenhall Glacier. And when last I spoke to you, we were in Ketchikan. We were heading out to see bears and son of a gun, we did see bears and they were picking salmon.
The streams were just loaded with salmon, most of which were either dead or in their death throes, so that it's not tough for a bear to just kind of wander through the stream and reach down and grab one. And they're so plentiful that the bears apparently aren't even bothering to eat most of the meat of the salmon because you could just get the good parts, the egg sac and then toss the carcass away and reach down for the next one as it's flopping around.
And I did record a little bit of the stream and you might be able to hear a salmon flop a few seconds in. [Sound of stream] So we pulled out of Ketchikan after that and we went up to Tracy Arm, which is not far from Juneau and we saw the South Sawyer Glacier, which is pretty spectacular. I had mixed feelings about it because while we were on the ship, we were told that where we were in the water was where the glacier was as recently as 1985.
It's tough to judge distances with sort of a featureless landscape, featureless in the sense of what we're used to, what I'm used to in New York to be able to tell if something is a quarter mile away or a half a mile away or a mile away. So I can't tell if I was a half a mile away, three quarters of a mile. You know, it certainly was many hundreds of yards to the face of the glacier and where we were on the ship was where the glacier used to be. But here's a sample of the kind of announcement that we were getting as we were out on the deck watching, watching the glacier and not just looking at it, watching it because it's in motion.
Female: Right now we're at the point where this was the face of the glacier in 1985. So that's how much it's receded over time. Since 1985 this was the face of the glacier here. The area on the glacier's face that you see that it's very, very blue, that's where the most recent calving has occurred. So keep an eye on that spot because calving likes to happen in the same areas continuously over periods of time. So that is on the starboard side, the furthest of the right-hand side that you can get to.
The gunshot sound that you're hearing, that is called a "fracture." When the calving occurs, it's a huge chunk of ice that falls into the water and the sound you hear after that is called "white thunder." You may also hear some sounds of white thunder, but not see anything happening and that is when the calving occurs under water. And we call those icebergs "shooters" because they could shoot pretty far away and can actually cause some issues. They are considerably larger than the ice chunks that fall from the surface of the face of the glacier. Typically, they're about two to three stories high under water and can be up to nine stories high.
Steve Mirsky: Meanwhile, back on the ship as part of the Bright Horizons Cruise Number 22, we're getting our lectures and one of the lectures yesterday from faculty member here, Larry Cahill. Larry is a brain expert. In fact, he wrote an article for us in 2005 on the male versus the female brain. He handed out reprints of that and if you're interested in what Dr. Cahill's up to – and he's really one of the world's leaders – you can just check that out in our archive. I want to tell you a little bit more about Larry. I'm looking for the speaker's bios here.
Larry Cahill is a professor in the Department of Neurobiology and Behavior at the University of California, Irvine. He first became interested in brain and memory as an undergraduate at Northwestern. After two years at Searle Drug Company working on memory-enhancing drugs, he earned his doctorate in Neuroscience from UC Irvine in 1990, then conducted postdoctoral research in Germany for two years. He returned to Irvine to extend his research to studies of human subjects, which in turn led to his discoveries about sex influences on emotion memory, and to his current general interest in the profoundly important issue of sex influences on brain function.
He is a long-standing leader in the area of brain and memory, and more recently has become arguably the most influential leader in the topic of sex influences on the brain. He's internationally regarded, a dynamic speaker – and that's true – whose work has been highlighted extensively in the press, including in the New York Times, London Times, PBS 60 Minutes. And you can find a couple of 60 minutes reports that he took part in, one of which was about these people who have an amazing memory of individual events of their lives if you tell him – [Sound of floatplane] – there's a floatplane just coming in here, just landed right off the side of the ship.
So Larry was part of the research effort on these folks. If you say to him, "What did you do on Tuesday – what did you do on April 17, 1989?" And they'll think for a second and say exactly what they did. And it's not a trick because if there's a way to verify it – I mean, listen I can tell you I had scrambled eggs for breakfast, then I took a two‑hour walk. You know I can say that, but I'm making it up. These people actually know exactly what they did and if there's a way to objectively verify it, you can do so. The actress Marilu Henner is one of these folks. So Dr. Cahill worked with those people.
Here's a brief section, very brief section of his talk, which I've clipped out of my recording because it's a little exercise that you can take part in. So listen closely and see what you think.
Larry Cahill: Conscious memory. Is this all just perception? Or does your brain – does it go beyond that? Do you build your memories? You can see where I'm going with this. The answer is you build your memories and to show you that, I'm going to give you a little memory test. Oh my God, 8:30 in the morning a quarter to nine, the memory professor is giving you a memory test. And I'd like you to just listen to these words and then I'll ask you which ones you've heard. Everybody ready? Thread, pin, eye, sewing, sharp, point, prick, thimble, haystack, thorn, hurt, injection, syringe, cloth, knitting. Those are the words.
Now, the memory test. Did you hear "sewing"? Raise your hand if you did. Did you hear "door"? Did you hear "needle"? You did not hear "needle." It is an amazingly powerful illusion that works on college students. It works progressively well as people get older and older. But it works very well on 18-year-olds. And it's because you can see that your brain was busy extracting, consciously or unconsciously that, as I was listing those words, they were all kind of needley, sharp, sewing things. And so when you heard the word "needle," you would swear you heard the word "needle," and you didn't.
Steve Mirsky: And finally, I wanted to share with you some of the issues the speakers have to deal with because unlike in their college classrooms, they are often overridden by announcements from the folks that run this ship. So we're in Juneau right now and I'm going to leave you with Dr. Cahill trying to finish his talk and I'll check back in with you when I can. For Scientific American Science Talk, this is Steve Mirsky. Thanks for listening.
Larry Cahill: You heard of Robert Hooke in cell theory, right? Everything is made of cells. There was one holdout. And we're in about the 1900s now. There was one place we just couldn't believe was made of individual cells, and it's your brain. [Sound of intercom] Uh-oh.
Captain: Well, good morning, ladies and gentlemen. It's Captain ____ on the bridge.
Larry Cahill: I guess I should be quiet.
Captain: I thought it be an opportune time to give you a situation report, so to speak. And we're just coming to the northern end of the Chatham Strait and shortly going to turn into the Frederick Sound. Admiralty Island is ahead of us in the mist. There's a slight change of schedule. I learned last night that another vessel was going into Tracy Arm at the same time approximately as us. Slight clash of schedules. In fact, it's a Disney ship, Mickey Mouse, and as a consequence, he's gone in early. He's just about to go in and we're going in a little later.
We'll be at Tracy Arm by 2:00 this afternoon. So we have the place to ourselves rather than another ship. And we'll slowly progress during this beautiful day. As for whales, we've seen one or two already. It was a little uncivilized hours, so obviously didn't make any announcements. And the majority of them last week were a little further north than where we are at present, but the bridge team will do their best to use our scenic cruising PA to let you know if we see them, just a hint.
There's quite strong tidal currents in these waters and you can see them where the water changes color, little ripples, and this tends to bring the graylings to the whales rather than go looking for it. So it's always a good place to start looking in the rippled areas. And we'll keep our eyes peeled here. It's a beautiful day. We're going to have a lovely day in Tracy Arm. So please enjoy. Thank you.