Alzheimer's disease

Alzheimer’s disease is an irreversible, progressive brain disease that slowly destroys memory and thinking skills, and eventually even the ability to carry out the simplest tasks. In most people with Alzheimer’s, symptoms first appear after age 60. Estimates vary, but experts suggest that as many as 5.1 million Americans may have Alzheimer’s disease. Alzheimer’s disease is the most common cause of dementia among older people. Dementia is the loss of cognitive functioning—thinking, remembering, and reasoning—and behavioral abilities, to such an extent that it interferes with a person’s daily life and activities. Dementia ranges in severity from the mildest stage, when it is just beginning to affect a person’s functioning, to the most severe stage, when the person must depend completely on others for basic activities of daily living.

Alzheimer’s disease is named after Dr. Alois Alzheimer. In 1906, Dr. Alzheimer noticed changes in the brain tissue of a woman who had died of an unusual mental illness. Her symptoms included memory loss, language problems, and unpredictable behavior. After she died, he examined her brain and found many abnormal clumps (now called amyloid plaques) and tangled bundles of fibers (now called neurofibrillary tangles). Plaques and tangles in the brain are two of the main features of Alzheimer’s disease. The third is the loss of connections between nerve cells (neurons) in the brain.

H.M. case study

Henry Gustav Molaison (February 26, 1926 – December 2, 2008), famously known as HM or H.M., was an American memory disorder patient who was widely studied from late 1957 until his death. His case played a very important role in the development of theories that explain the link between brain function and memory, and in the development of cognitive neuropsychology,  branch of psychology that aims to understand how the structure and function of the brain relates to specific psychological processes. Before his death, he resided in a care institute located in Windsor Locks, Connecticut,  he was the subject of ongoing investigation. His brain now resides at UC San Diego where it was sliced into histological sections on December 4, 2009.

The most famous case study in the history of neuropsychology is that of an anonymous memory-impaired man usually referred to only by the initials H.M. This patient has one of the most severe cases of amnesia ever observed; he has been followed for over 40 years by more than 100 researchers, and is the subject of dozens of research papers and book chapters. The early studies of H.M. provide a basis for modern neuropsychology, and the findings of those who have studied him are today a cornerstone in memory research.

H.M. had brain surgery in 1953 when he was 27 yrs old. The surgery involved removal of part of the brain known as the hippocampus to alleviate the severe symptoms of epilepsy. Although the surgery controlled the epileptic seizures H.M. suffered serious and debilitating memory impairment as a side effect. His short-term memory was normal but he was completely unable to transfer any new information into his long-term memory.

French & Richards

French and Richards (1993) found that subjects asked to draw from memory a clock that had Roman numerals on its face typically represented the number four on the clock face as "IV" rather than the correct "IIII", whereas those merely asked to copy it typically drew "IIII". The current experiments followed the methodology of French and Richards, but then went on to examine the subsequent memorial representation of the number four. Subjects drew a clock with Roman numerals on its face, either from memory (with or without forewarning) or while the clock remained in full view. Subsequently, subjects were asked to recall the exact form in which the numbers were represented on the clock (Experiment 1) or were asked to recognise which of two clocks had been presented earlier (Experiment 2). Findings supported the idea that subjects in the copy condition were more likely than subjects in other conditions to draw the clock without invoking schematic knowledge of Roman numerals. The basic effect reported by French and Richards was replicated in both experiments. Furthermore, in both experiments, subjects who correctly drew the clock with the number four represented as "IIII" were more likely to misrepresent it as "IV" in the subsequent memory task if they were in the copy condition rather than the two memory conditions. The results are interpreted in terms of schema theory.

Frederic Bartlett

Frederic Bartlett was born on Oct. 22, 1886. He was educated privately and at St. John's College, Cambridge, of which he became a fellow. Strongly influenced by the physician, ethnologist, and psychologist W.H.R. Rivers, Bartlett showed early leanings toward anthropology; but circumstances, not the least of which was the outbreak of World War I, led him to a career in psychology. After the war Bartlett returned to Cambridge, succeeding C.S. Myers as director of the psychological laboratory in 1922 and becoming professor of experimental psychology in 1931, a post which he held until his retirement in 1952. He died at Cambridge on Sept. 30, 1969

The War Of The Ghosts

Two men from Edulac went fishing. While thus occupied by the river they heard a noise in the distance. "It sounds like a cry ", said one, and presently there appeared some men in canoes who invited them to join the party on their adventure. One of the young men refused to go, on the ground of family ties, but the other offered to go. "But there are no arrows", he said. "The arrows are in the boat", was the reply. He thereupon took his place, while his friend returned home. The party paddled up the river to Kaloma, and began to land on the banks of the river. The enemy came rushing upon them, and some sharp fighting ensued. Presently some one was injured, and the cry was raised that the enemy were ghosts.
The party returned down the stream, and the young man arrived home feeling none the worse for his experience. The next morning at dawn he endeavoured to recount his adventures. While he was talking something black issued from his mouth. Suddenly he uttered a cry and fell down. His friends gathered round him. But he was dead.


In his major work, Remembering: A Study in Experimental and Social Psychology (1932), Bartlett advanced the concept that memories of past events and experiences are actually mental reconstructions that are coloured by cultural attitudes and personal habits, rather than being direct recollections of observations made at the time. In experiments beginning in 1914, Bartlett showed that very little of an event is actually perceived at the time of its occurrence but that, in reconstructing the memory, gaps in observation or perception are filled in with the aid of previous experiences. A later work, Thinking: An Experimental and Social Study (1958), broke no new theoretical ground but added observations on the social character of human thinking.

Loftus & Palmer

Elizabeth Loftus was born in October 16, 1944 in Los Angeles, California. She received her bachelor's degree in mathematics and psychology from the University of California, Los Angeles in 1966 and her MA (1967) and Ph.D (1970) in psychology from Stanford University. Psychologist Elizabeth Loftus has been particularly concerned with how subsequent information can affect an eyewitness’s account of an event. Her main focus has been on the influence of (mis)leading information in terms of both visual imagery and wording of questions in relation to eyewitness testimony.


To test their hypothesis that the language used in eyewitness testimony can alter memory. So, they aimed to show that leading questions could distort eyewitness testimony accounts and so have a confabulating effect, as the account would become distorted by cues provided in the question.

To test this Loftus and Palmer (1974) asked people to estimate the speed of motor vehicles using different forms of questions. Estimating vehicle speed is something people are generally poor at and so they may be more open to suggestion.

The estimated speed was affected by the verb used. The verb implied information about the speed, which systematically affected the participants’ memory of the accident. Participants who were asked the “smashed” question thought the cars were going faster than those who were asked the “hit” question. The participants in the “smashed” condition reported the highest speeds, followed by “collided”, “bumped”, “hit”, and “contacted” in descending order. When people were asked a week after viewing the film whether they saw any broken glass at the scene (there was none), people in the smashed group were more likely to say yes. Therefore, a leading question that encouraged them to remember the vehicles going faster also encouraged them to remember that they saw non-existent broken glass. The question appears to have modified the memory itself.

Conclusions: This research suggests that memory is easily distorted by questioning technique and information acquired after the event can merge with original memory causing inaccurate recall or reconstructive memory.

Experiment:

The participants were 45 students of the University of Washington. They were each shown seven film-clips of traffic accidents. The clips were short excerpts from safety films made for driver education. The clips ranged from 5 to 30 seconds long.

Following each clip, the students were asked to write an account of the accident they had just seen. They were also asked to answer some specific questions but the critical question was to do with the speed of the vehicles involved in the collision.

There were five conditions in the experiment (each with nine participants) and the independent variable was manipulated by means of the wording of the questions.

Condition 1: 'About how fast were the cars going when they smashed into each other?'

Condition 2: 'About how fast were the cars going when they collided into each other?'

Condition 3: 'About how fast were the cars going when they bumped into each other?'

Condition 4: 'About how fast were the cars going when they hit each other?

Condition 5: 'About how fast were the cars going when they contacted each other?'

The basic question was therefore 'About how fast were the cars going when they ____ each other?'. In each condition, a different word or phrase was used to fill in the blank. These words were; smashed, collided, bumped, hit, contacted. The entire experiment lasted about an hour and a half and a different ordering of the films was presented to each group of participants. The dependent variable was the speed estimates given by the participants.