7 Frey et al., 1988; Frey et al., 1993.
8 The term consolidation is also used to refer to a separate process in which memory is said to be “transferred” from the hippocampus to the neocortex over the course of time. This systems-level consolidation is another reason that memories become less sensitive to interference and erasure over time (Hardt et al., 2010).
9 Goelet et al., 1986.
10 One of the first studies to document that a simple form of memory in a mollusk was accompanied by the formation of new synapses was performed by Bailey and Chen, 1988. Now there are many documented correlative findings in which learning or experience alters the structure and morphology of neurons and synapses. These studies are reviewed in Holtmaat and Svoboda (2009).
11 Misanin et al., 1968; Nader et al., 2000.
12 Sara, 2000; Dudai, 2006.
13 Brainerd and Reyna, 2005.
14 “Family settles ‘recovered memory’ case. Therapist faulted on false rape charge,” Boston Globe, November 16, 1996, as cited in Brainerd and Reyna (2005), p. 366.
15 This study was performed by Ceci et al. (1993). It should be noted that interpreting these results is complicated by the fact that the percent of false responses did not increase over the interview sessions. It is possible that in some of these studies the results do not actually reflect false memories, but rather a child learning the boundary between reporting the truth and what he believes the adults want to hear (Gilstrap and Ceci, 2005; Pezdek and Lam, 2007; Wade et al., 2007).
16 The news program Frontline produced a special “Innocence Lost” segment on the Little Rascal case. The transcript is available at http://www.pbs.org/wgbh/pages/frontline/shows/
innocence/etc/script.html. Other sources include: Associated Press, “Couple gives $430,000 to former Little Rascals defendants,” The [Durham, NC] Herald-Sun, June 26, 1997; Joseph Neff, “10-year Little Rascals sexual-abuse scandal expires quietly,” The News and Observer, October 3, 1999.
17 Schacter (1996), p. 254.
18 Debiec and Ledoux, 2004; Monfils et al., 2009; Tollenaar et al., 2009. Some experiments suggest that after longer periods of time, memories are no longer sensitive to reconsolidation (Milekic and Alberini, 2002).
19 Standing, 1973.
20 For studies on memory capacity see Standing, 1973; Vogt and Magnussen, 2007; Brady et al., 2008. The estimate of 6600 pictures comes from taking into account that 83 percent correct corresponds to 33 percent above the chance level of 50 percent—the estimate of memorized items works out to be 2 × 33%.
21 In this study 23.9 percent of errors were among “new” items, and 45 percent of errors were among “old” items—thus subjects were more likely to make false-negative, than false-positive, errors (Laeng et al., 2007).]
22 Cohen, 1990.
23 It has been stated that “Most of us recognize hundreds or thousands of faces and countless visual scenes” (Rosenzweig et al., 2002, p. 549).
24 The human genome contains around 3 billion bases. Since there are four possible nucleotides, each one corresponds to 2 bits, for a total of 6 billion bits, close to 1 GB.
25 Foer, 2006.
26 Zelinski and Burnight, 1997; Schacter, 2001.
27 Cahill and McGaugh, 1996; Chun and Turk-Browne, 2007.
28 Schacter and Addis, 2007.
29 Borges, 1964.
30 Treffert and Christensen, 2005.
31 Parker et al., 2006.
CHAPTER 3: BRAIN CRASHES
1 Melzack, 1992; Flor, 2002.
2 Lord Nelson’s argument has been cited by a number of authors (Riddoch, 1941; Herman, 1998; Ramachandran and Blakeslee, 1999), but I am not familiar with the original reference.
3 Somatoparaphrinia is not a “pure” syndrome; it almost never occurs in the absence of other functional deficits, and it generally subsides over time (Halligan et al., 1995; Vallar and Ronchi, 2009).
4 Sacks, 1970.
5 Marshall et al., 1937; Penfield and Boldrey, 1937. There are four primary maps each specialized to submodalities of touch, such as fine tactile discrimination or activation of receptors deep within the epidermis (Kaas et al., 1979; Kandel et al., 2000).
6 Romo et al., 1998; Romo and Salinas, 1999.
7 For a discussion of the theories and mechanisms underlying phantom limbs, see Melzack, 1992; Flor et al., 1995; Flor, 2002.
8 Merzenich et al., 1983; Jenkins et al., 1990; Wang et al., 1995; Buonomano and Merzenich, 1998.
9 Elbert et al., 1995; Sterr et al., 1998.
10 It is not simply use of an area, but the amount of attention and behavioral relevance that seem to be critical for cortical reorganization (Kilgard and Merzenich, 1998; Kujala et al., 2000; Polley et al., 2006; Recanzone et al., 1993).
11 Bienenstock et al., 1982; Buonomano and Merzenich, 1998; Abbott and Nelson, 2000.
12 Bienenstock et al., 1982; Turrigiano et al., 1998; Mrsic-Flogel et al., 2007; Turrigiano, 2007.
13 Van Essen et al., 1992.
14 Sadato et al., 1996; Kujala et al., 2000; Roder et al., 2002. One study used transcranial magnetic stimulation to alter processing of the “visual” cortex (that is, the occipital cortex which is critical to vision in people with normal vision) in blind people (Kupers et al., 2007.
15 For a review on the differences in sensory perception in blind people, and the cortical plasticity associated with blindness and sensory deprivation, see Merabet and Pascual-Leone, 2010.
16 For one of the few papers that discusses echolocation in humans, see Edwards et al. (2009). Few scientific studies, however, have been performed on echolocation in blind people. News reports on one boy, Ben Underwood (who passed away in 2009), can be found on a number of Web sites (for example, http://www.youtube.com/watch?v=YBv79LKfMt4). Most of us can echolocate in a very simple fashion. For example, if you clap your hands in a closet, in a room, or outside, you can probably hear the difference.
17 Groopman, 2009.
18 Salvi et al., 2000.
19 Norena, 2002.
20 Eggermont and Roberts, 2004; Rauschecker et al., 2010.
21 Herculano-Houzel, 2009.
22 Shepherd, 1998.
23 Gross, 2000; Gould, 2007.
24 Pakkenberg and Gundersen, 1997; Sowell et al., 2003; Taki et al., 2009.
25 Markram et al., 1997; Koester and Johnston, 2005; Oswald and Reyes, 2008.
26 For a review on alien hand syndrome, see Fisher (2000). One of the patient quotes is from the following video: http://www.youtube.com/watch?v=H0uaNn_cl14.
27 Hirstein and Ramachandran, 1997; Edelstyn and Oyebode, 1999.
28 De Pauw and Szulecka, 1988.
29 This book was written by an advocate of phrenology in 1910, and provides a guide to determine the true character of your friends: Olin (1910/2003).
30 Damasio et al., 1994.
31 Assal et al., 2007.
32 Edelstyn and Oyebode, 1999; Linden, 2007.
33 Certain types of chronic pain may also be related to maladaptive brain plasticity (Flor et al., 2006; Moseley et al., 2008). In complex regional pain syndrome, parts of the body that were injured but have fully healed can continue to hurt. A number of studies have observed a decrease in the amount of primary somatosensory cortex representing the body part exhibiting chronic pain (Juottonen et al., 2002; Maihofner et al., 2003; Vartiainen et al., 2009).
CHAPTER 4: TEMPORAL DISTORTIONS
1 In fairness, it should be noted that there is also an asymmetry in the rules that favor the patron. If my cards add up to 21, I immediately win, even if the dealer also gets 21—in other words, I win this tie. However, the likelihood of getting 21 is significantly below that of busting, thus ensuring the casino’s advantage.
2 Pavlov states that presenting the unconditioned stimulus before the conditioned stimulus does not generally result in generation of the conditioned response (Pavlov, 1927, p. 27). However, it is not the case that animals do not learn anything about the conditioned stimulus and unconditioned stimulus when the
y are presented in reverse order. They often learn that the conditioned stimulus will not predict the unconditioned stimulus, a phenomenon termed conditioned inhibition (Mackintosh, 1974).
3 Gormezano et al., 1983.
4 Clark and Squire, 1998.
5 It has been noted that there are manipulations that help animals learn delayed-reinforcement conditions. Nevertheless, the longer the delay, the more difficult learning is, and there is little evidence that most animals will learn cause-and-effect relationships with delays on the order of many minutes, hours, or days. For discussions on delayed reinforcement and operant conditioning, see Dickinson et al. (1992) and Lieberman et al. (2008).
6 A well-known exception to this rule is conditioned taste-aversion. Humans and animals can learn the association between a given taste and becoming sick even if the delay between these two events is many hours.
7 Frederick et al., 2002.
8 This study was performed by Stevens et al., 2005. For an additional study on temporal discounting in monkeys see Hwang et al. (2009).
9 Gilbert, 2007. Some scientists have argued that animals do think and plan for the future. For example, scrub jays (a species of bird that caches food for future consumption) will store food in locations that they have learned they are likely to be hungry in—as if they are planning for the future rather than instinctively squirreling away food (Raby et al., 2007). The interpretation of these findings, however, continues to be debated.
10 McClure et al., 2004; Kable and Glimcher, 2007.
11 Joana Smith, “Payday loan crackdown,” Toronto Star, April 1, 2008.
12 Lawrence and Elliehausen, 2008; Agarwal et al., 2009.
13 The study in children is described in Siegler and Booth, 2004. The study in Amazonian Indians is described in Dehaene et al., 2008. Additionally, the fact that the brain represents numbers in a nonlinear fashion is supported by neurophysiological studies that have recorded “number-selective” neurons in the brains of monkeys (Nieder and Merten, 2007).
14 Kim and Zauberman, 2009; Zauberman et al., 2009.
15 Loftus et al., 1987.
16 In this example, the volunteers knew they would be asked to estimate the elapsed time before they began (Hicks et al., 1976).
17 Zauberman et al., 2010.
18 When amnesic patient H. M. was asked to reproduce a 20-second interval, his performance was approximately normal. In contrast, when asked to estimate a 150-second interval, his estimates were close to 50 seconds (Richards, 1973).
19 Tallal, 1994.
20 Drullman, 1995; Shannon et al., 1995. The duration of the so-called phrasal boundaries contributes to comprehension. For instance, “Amy or Ana, and Bill will come to the party” versus “Amy, or Ana and Bill will come to the party”—the pause after “Amy” and “Ana” contributes to determining the meaning of each sentence (Aasland and Baum, 2003).
21 Temporal distortions can be caused by drugs (Meck, 1996; Rammsayer, 1999) as well by the characteristics of the stimuli and what actions are being performed, as demonstrated by the stopped clock illusion (Yarrow et al., 2001; Park et al., 2003).
22 Harris, 2004; van Wassenhove et al., 2008; Droit-Volet and Gil, 2009.
23 The described study was performed by Sugita and Suzuki (2003). For related studies on simultaneity perception see Fujisake et al. (2004) and Miyazaki et al. (2006).
24 When deciding whether two events are simultaneous, the brain is faced with two opposing dilemmas. On the physical side, light travels faster than sound, so the sight of the cymbals clashing arrives at the eye before the sound arrives at the ear. However, there is the complicating factor of how long the eye and ear take to relay this information to the relevant areas in the brain. It turns out that the ear is actually much quicker than the eye. While it might take more than 200 milliseconds to press a button in response to a light going on, it can take 160 milliseconds to respond to a tone. This is in large part due to the physiology of the retina, which relies on comparatively slow biochemical reactions to transduce light into bioelectrical signals, whereas sound relies on the more-rapid physical movements of specialized cilia to generate electrical signals. Thus, strictly speaking, even when we experience close-up events, and sight and sound arrive effectively simultaneously, the perception of simultaneity is still somewhat “fudged” because the auditory signal arrives in the brain first. What we judge as simultaneous is not as much about whether the physical signatures of two events arrive simultaneously in our brain, but whether through hardwiring and experience our brain opts to provide the illusion of simultaneity.
25 McDonald et al., 2005.
26 Nijhawan, 1994; Eagleman and Sejnowski, 2000. An example of this illusion can be found at www.brainbugs.org.
27 Maruenda, 2004; Gilis et al., 2008.
28 Ivry and Spencer, 2004.
29 Mauk and Buonomano, 2004; Buhusi and Meck, 2005; Buonomano, 2007.
30 Konopka and Benzer, 1971; Golden et al., 1998; King and Takahashi, 2000; McClung, 2001.
31 King and Takahashi, 2000; Panda et al., 2002.
32 Buonomano and Mauk, 1994; Medina et al., 2000; Buonomano and Karmarkar, 2002.
33 Goldman, 2009; Liu and Buonomano, 2009; Fiete et al., 2010.
34 Lebedev et al., 2008; Pastalkova et al., 2008; Jin et al., 2009; Long et al., 2010. Additionally, it has been shown that even in isolated cortical networks, activity patterns in neurons may establish a population clock for time (Buonomano, 2003).
35 This may be the case in some contemporary hunter-gatherer groups (Everett, 2008).
36 Mischel et al., 1989; Eigsti et al., 2006.
37 Wittmann and Paulus, 2007; Seeyave et al., 2009.
CHAPTER 5: FEAR FACTOR
1 Close to 3000 people died during the terrorist attacks on September 11, 2001, in New York and Washington. There were 168 fatalities in the Oklahoma City bombings of 1995. A summary of weather-related fatalities can be found at www.weather.gov/os/hazstats.shtml.
2 For fatal car accident deaths from 2002 through 2006 see http://www-nrd.nhtsa.dot.gov/Pubs/810820.pdf. For mortality rates and causes in 2005 see http://www.cdc.gov/nchs/data/dvs/LCWK9_2005.pdf or http://www.cdc.gov/nchs/data/hus/hus05.pdf for the complete report.
3 A Gallup poll conducted in 2006 asked, “How likely is it that there will be acts of terrorism in the United States over the next several weeks?” Approximately 50 percent of the responders answered very/somewhat likely, a number that was still at 39 percent in 2009 (http://www.gallup.com/poll/124547/Majority-Americans-Think-Near-Term-Terrorism-Unlikely.aspx).
4 Breier et al., 1987; Sapolsky, 1994.
5 LeDoux, 1996.
6 Pinker, 1997.
7 Quote from Darwin (1839), p. 288. By the time Darwin arrived on the Galapagos Islands, humans had already visited it for over a hundred years, and he comments that according to previous accounts it appeared that the birds were even tamer in the past.
8 A bug in the early Intel Pentium chips was rarely of consequence and likely affected very few users; however, if you were a user that needed to calculate (4195835 × 3145727)/3145727, and were expecting the first number in return, you’d be in trouble.
9 Pongracz and Altbacker, 2000; McGregor et al., 2004.
10 Tinbergen, 1948. Attempts to replicate Tinbergen and Lorenz’s original reports have been mixed. Canty and Gould (1995) discusses the reasons for this, and replicates Tinbergen and Lorenz’s principal observations.
11 For papers on the effect of Toxoplasma infections on fear in rats see Berdoy et al. (2000); Gonzalez et al. (2007); Vyas et al. (2007). For a general discussion of neuroparasitism and behavioral manipulation see Thomas et al. (2005).
12 Katkin et al., 2001.
13 Craske and Waters, 2005; Mineka and Zinbarg, 2006.
14 For reviews of the role of the amygdala in mediating fear see LeDoux (1996); Fendt and Fanselow (1999); Kandel et al. (2000).
15 Adolphs et al., 1994; Adolphs, 2008; Kandel et al., 2000; Sabatinelli et al., 2005.
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16 Fendt and Faneslow, 1999; Blair et al., 2001; Sah et al., 2008.
17 These experiments are described in McKernan and Shinnick-Gallagher (1997). For a related set of experiments see Tsvetkov et al. (2002) and Zhou et al. (2009).
18 In this case the presynaptic activity corresponds to the tone, and the postsynaptic activity corresponds to activity produced by the shock during fear conditioning. Note that the shock, an innately painful and fear-inducing experience, would naturally be able to drive neurons in the amygdala in the absence of learning.
19 In some cases blocking the NMDA receptors can also alter the expression of fear, presumably because the NMDA receptors also play a role in driving neuronal activity. But at least two studies show that NMDA blockers primarily affect learning and not expression of previously learned fear-conditioned responses (Rodrigues et al., 2001; Goosens and Maren, 2004).
20 Han et al., 2009.
21 Quirk et al., 2006; Herry et al., 2008.
22 Milekic and Alberini, 2002; Dudai, 2006.
23 Monfils et al., 2009; Schiller et al., 2010.
24 Darwin, 1871, p. 73.
25 Cook and Mineka, 1990; Ohman and Mineka, 2001; Nelson et al., 2003.
26 Askew and Field, 2007; Dubi et al., 2008.
27 Esteves et al., 1994; Katkin et al., 2001.
28 Williams et al., 2004; Watts et al., 2006.
29 De Waal, 2005, p. 139.
30 For a brief discussion of fear of strangers in animal and human infants see Menzies and Clark (1995).
31 Manson et al., 1991.
32 De Waal, 2005.
33 Darwin, 1871; Bowles, 2009.
34 Olsson and Phelps, 2004; Olsson and Phelps, 2007. Even mice can learn to fear certain places by observing other mice receiving shocks within that context. Even more surprisingly, the magnitude of learning is higher if the demonstrator mouse is related to or the partner of the observer mouse (Jeon et al., 2010).
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