Bag of Worms Yet Words

104. Langerhans Cells Acquire Antigens on Skin with Dendrites

Stella M. Hurtley, "Immunology: Taking A Peek,"

Science 15 January 2010: Vol. 327. no. 5963, p. 251 DOI: 10.1126/science.327.5963.251-d

Summarizing an article by KUBO ET AL., J. EXP. MED. 206, 2937 (2009)

"Our bodies are covered by epithelial layers inside and out, which keeps the outside out and the inside in. How then can the immune system, which sits inside the wall of epithelial cells, sense potentially pathogenic antigens without making holes in this protective barrier? Kubo et al. show that during inflammation, epidermal Langerhans cells acquire external antigens by extending cellular protrusions, known as dendrites, through the tight seals between keratinocytes in the skin. Receptors on the tips of the dendrites bind to external antigens, which are then internalized and brought inward to the cell body for further processing. In order to maintain the seal despite breaching the tight junctions, the Langerhans cells form secondary junctions with the surrounding keratinocytes. This ability to screen incoming antigens provides an important first defense against attack."

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Why should the targets of the Langerhans cells be limited to antigens? Presumably, the Langerhans cells don't "know" the molecules they grab and bring inside the body for identification are dangerous antigens. Why wouldn't they also grab for identification other  organic molecules, such as pheromones and other aerosol molecular identifiers emitted by other persons, such as molecules emitted by women in ovulation or molecules emitted by men when they respond to women? Possibly they do this, implying that the meaning of "antigens" here is quite broad and not all "antigens" are pathological. Or that, if pathological, the antigens provide information useful for mate selection. If they would, this would make the skin a large sensory organ with a function like the nose.

Such an epidermal sensory organ would provide additional evidence that human beings are motivated to behavior by a suite of sensory organs whose biochemical stimulation of behavior is preconscious.

103. Can A Pig Know What Another Pig Sees?

"Mike Mendl, Professor of animal behavior and welfare at Bristol University, and Suzanne Held have been conducting research into a pig's capacity to understand another pig. They have found that pigs might be able to tell what other pigs are thinking. With their colleague Richard Byrne of St. Andrews University, they set up an experiment in which they blocked a subject pig's view of where food was being placed. On either side of the pig were two companion pigs, one whose view was also blocked and one who had a clear view of the food. The subject pig was not able to see what the other pigs could see. When the researchers removed the barriers and the companion pigs were released, the subject pig did, in fact, follow the companion pig who had seen where he food was placed rather than the one who had not. The study suggests that it is possible that a pig can understand what another pig sees. This is referred to as visual perspective taking and is an indication of complex cognition." (Amy Hatkoff, The Inner World of Farm Animals [Steward, Tabori & Chang, New York, 2009],  p. 72. Identification of Bailey, pp. 99-100.)

I don't think the experiment, if the summary is accurate, could demonstrate the finding, which is presented as indication that pigs have a theory of mind. It is more likely that the pig who could see the food responded to the food as a stimulus with hormonal emissions or salivation (do pigs salivate?) or food seeking behavior, which the companion pig could sense, without having any clue to what was the visual perspective of the pig who saw the food. It would be useful to know what the other companion pig, on the same side of the barrier as the one that could see the food, did when released. Did it too follow the pig who saw the food? If so, then that would evidence of behaviorial cues, not mind reading.

102. Cows Have Mental Map Memory

"Cows have excellent memories. They can keep at least fifty bovine faces and ten human faces in mind for several years. They can also tell people apart, relying mostly on visual cues such as clothing, colors, faces, and height. They can distinguish people  based on their posture and the way they move. Even young calves are able to recognize differences in people.

"Cows can remember the location of things in their environment such as migration paths, shelter, water, fences, and grazing spots. 'Cows can quickly learn these things and remember them for long periods,'  comments Derek Bailey [professor of animal science and range scienes, New Mexico State University], who, along with his colleagues, devised two differently shaped mazes to detremine a cow's capacity to remember. They placed buckets of grain in different spots in each maze. The cows found and ate the food in the buckets, and they almost never returned to one they had already emptied. 'Prior to these experiments, cows' movements were thought to be random,' comments Baily. 'We didn't realize that they were forming a mental map and basing their current choices on their previous experiences. What this meant was that they had a working memory and were able to keep track of information.' " (Amy Hatkoff, The Inner World of Farm Animals [Steward, Tabori & Chang, New York, 2009],  p. 72. Identification of Bailey, p. 68.)

101. Can Cows Read Signs?

"Jenny Jago, a scientist at Dexcel in New Zealand, and her colleagues are teaching cows to go through gates using signs to identify the correct one. The cows are beginning to understand what the signs mean. The researchers are trying to determine the criteria upon which the cows are basing their decisions and exploring if the cows are using the cues of shape or color." (Amy Hatkoff, The Inner World of Farm Animals [Steward, Tabori & Chang, New York, 2009],  p. 66.)

It would be difficult, from this simple summary, to decide whether the cows were behaving simply by conditioning associations or whether they could "understand" what the signs mean.

100. Cows Appear To React Emotionally To Solving A Problem

"Research shows that cows enjoying solving problems. In an experiment led by Donald M. Broom, professor of animal welfare at Cambridge University, young dairy cows appeared to be excited when they successfully learned how to unlatch a gate to obtain food. Their heart rates accelerated and their behavior became more animated. Some of the cows even jumped! Professor Broom and his colleagues described it as a 'eureka' moment for the cows. The group that received the food without unlatching the gate did not show these changes in their beheavior or heart rates.

"These findings indicate that it is possible that cows have an emotional reaction to their own learning and achievement. This is particularly significant because it indicates that they have self-awareness, one of the key components of consciousness." (Amy Hatkoff, The Inner World of Farm Animals [Steward, Tabori & Chang, New York, 2009],  p. 62.)

99. Turkeys Have Extensive Knowledge of Terrain

"William Healy [William H. Healy, former Research Wildlife Biologist with the United States Forest Service] concurs that turkeys are excellent at geography. They quickly learn to navigate the places they frequent daily. Given the opportunity, they can learn the details of a terrain of more than one thousand acres in the course of a year and keep that information in mind. They are very perceptive and acutely aware if something in their environment changes." (Amy Hatkoff, The Inner World of Farm Animals [Steward, Tabori & Chang, New York, 2009],  pp. 55. Healy identification, p. 49.)

98. Do Chickens' Vocalizations Have Semantic Meaning?

"Chris Evans of Australia's Macquarie University, and Peter Marler, formerly of University of California, Davis, found that when different predator alarm calls are played back on a tape to hens or roosters, they make the appropriate response calls. However, they will only emit a warning call if there is another chicken present to hear it. This is referred to as audience effects and is another indication of intentionality in their communication.

"Recognition of this level of complexity in a chicken's communication was considered groundbreaking. 'Until very recently, we believed only primates were capable of such sophisticated communication,' comments Professor Kaplan. 'It proves that birds have a semantic way of communicating and these are the rudiments of language.' " (Amy Hatkoff, The Inner World of Farm Animals [Steward, Tabori & Chang, New York, 2009],  pp. 40-41.)

97. Chickens Have Over Thirty-one Different Calls

"Chickens have highly developed communication skills. According to Dr. Gisela Kaplan, a professor at the University of New England, 'the voices of birds involve learned, complex vocalizations.' Researchers have identified more than thirty-one different call types with very specific meanings. Chickens use separate alarm calls, for example, depending on whether a predator is traveling by land or in the sky. Karen Davis of United Poultry Concerns describes numerous calls, including distress calls, nesting and mating calls, laying calls, threat calls, 'all clear' calls, contented calls, and contact calls. Davis comments that 'each rooster can recognize the crow of at least thirty other roosters, probably more.' Australian scientists recently discovered that some hens emit high-pitched sounds to signal they have found food. The more they prefer a particular food, the faster they 'speak.' " (Amy Hatkoff, The Inner World of Farm Animals [Steward, Tabori & Chang, New York, 2009],  p. 40.)

The distinction between object and emotion calls is not clear from the text. Presumably, all calls point to objects in the fowls' environment. Some calls appear to point, also, to emotions being experienced by calling chicken--such as "distress" and "contented" calls. But even the "emotion" calls probably have less to do with the state of the animal's mind (if the animal could be said to have a state of mind) and more to do with the state of world in which the animal is situated.

At all events, I would think that all calls are located in or capable of being located in a chicken's mental map of the environment in which the chicken is located. It is not clear whether the chicken would be aware of the difference between (if such a difference can even be postulated) between its mental map of the world and the layout of the world that it views.  So at the most basic level, the calls are signs that signify by pointing to a state of the real world. They are not obviously symbolic or symbol manipulation.

96. Chickens Can Count

"Chickens have even demonstrated the ability to count! Vallortigara and Regolin with Rosa Rugani of the University of Padua, trained chickens to peck for food at the fourth container in a series of ten containers. They then changed the spacing between the containers so that they were all in different positions. The chicks, however, were still able to select the fourth container, meaning they were able to identify the container through counting rather than relying on its location. The researchers proved the chickens' ability to count in other experiments as well." (Amy Hatkoff, The Inner World of Farm Animals [Steward, Tabori & Chang, New York, 2009],  p. 33.)

95. Chickens Maneuver in Geometrical Space

"Villortigara and his colleagues [Giorgio Vallortigara of the University of Trento and Lucia Regolin of the University of Padua] also found that chickens can perform basic geometry. They placed chicks in a rectangular room with an object in one corner. They then removed the object and the chicks from the room and brought the chicks back with the task of identifying the corner in which the object was previously located. This is an extraordinarily difficult task with no straightforward solution. Chicks, however, can solve this problem with ease. The researchers believe that he chickens use the different lengths of the walls and the angular positions to reorient themselves. They can learn, for instance, that the correct corners are the ones with a short wall on the left and a long wall on the right." (Amy Hatkoff, The Inner World of Farm Animals [Steward, Tabori & Chang, New York, 2009],  p. 34.)

This geometric capability is probably an expression of mental mapping of reality. If honey bees have mental maps, surely the chickens do. In the chicks' behavior, we can distinguish between frame perception and an object perception. This perception must be euclidean.