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Cognitive Psychology

Terms in this set (65)

On March 27, 1985, Wearing, then an acknowledged expert in early music at the height of his career with BBC Radio 3, contracted Herpesviral encephalitis- a Herpes simplex virus that attacked his central nervous system.[1] Since this point, he has been unable to store new memories. He has also been unable to control emotions (labile mood) and to associate memories effectively.

Wearing developed a profound case of total amnesia as a result of his illness. Because of damage to the hippocampus, an area required to transfer memories from short-term to long-term memory, he is completely unable to form lasting new memories - his memory only lasts between 7 and 30 seconds.[2] He spends every day 'waking up' every 20 seconds, 'restarting' his consciousness once the time span of his short term memory elapses (about 30 seconds). He remembers little of his life before 1985; he knows, for example, that he has children from an earlier marriage, but cannot remember their names. His love for his second wife Deborah, whom he married the year prior to his illness, is undiminished. He greets her joyously every time they meet, either believing he has not seen her in years or that they have never met before, even though she may have just left the room to fetch a glass of water. When he goes out dining with his wife, he can remember the name of the food (e.g. chicken); however he cannot link it with taste, as he has forgotten.[3]

Despite having retrograde as well as anterograde amnesia, and thus only a moment-to-moment consciousness, Wearing still recalls how to play the piano and conduct a choir - all this despite having no recollection of having received a musical education. This is because his procedural memory was not damaged by the virus. As soon as the music stops, however, Wearing forgets that he has just played and starts shaking spasmodically. These jerkings are physical signs of an inability to control his emotions, stemming from the damage to his inferior frontal lobe.[citation needed] His brain is still trying to send information in the form of action potentials to neurostructures that no longer exist. The resulting encephalic electrical disturbance leads to fits.

In a diary provided by his caretakers, Clive was encouraged to record his thoughts. Page after page is filled with entries similar to the following:

8:31 AM: Now I am really, completely awake.
9:06 AM: Now I am perfectly, overwhelmingly awake.
9:34 AM: Now I am superlatively, actually awake.

Earlier entries are usually crossed out, since he forgets having made an entry within minutes and dismisses the writings-he does not know how the entries were made or by whom, although he does recognize his own writing.[4] Wishing to record "waking up for the first time", he still wrote diary entries in 2007, more than two decades after he started them.


Brain scan demonstrages damage to the hippocamps. No short term memory or episodic memory. Nevertheless he remembers semantic info about his life. He does show signs of implicit memory
The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science is a book on neuroplasticity by psychiatrist and psychoanalyst Norman Doidge, M.D. It features numerous case studies of patients suffering from neurological disorders and details how in each case the brain adapts to compensate for the disabilities of the individual patients, often in unusual and unexpected ways. Interviews with the patients, clinicians, and research scientists involved in these studies make up a large portion of the contents. Doidge uses examples of previous work carried out by neuroscientists such as Paul Broca, Sigmund Freud, Aleksandr Luria, Donald O. Hebb, Paul Bach-y-Rita, and Eric Kandel to show that the brain is adaptive, and thus plastic. Through the case studies, Doidge demonstrates both the beneficial and detrimental effects that neuroplasticity can have on a patient, saying, "...neuroplasticity contributes to both the constrained and unconstrained aspects of our nature."[1] However, neuroplasticity "...renders our brains not only more resourceful, but also more vulnerable to outside influences."[2][citation needed]

An important example of neuroplasticity is how humans gain skills. Learning changes the number of neuron connections. Doidge presents an experiment performed by Alvaro Pascual-Leone in which he mapped the brains of blind people learning to read Braille. Braille reading is a motor activity, which involves scanning with a reading finger, and a sensory activity, which involves feeling the raised bumps. The brain maintains a representation of these sensory and motor aspects, which are located in different cortices. The blind subjects practiced two hours a day, Monday through Friday, with an hour of homework. The mapping of their brains took place on Monday, after the weekend, and Friday, immediately after their week cram. What the scans ultimately showed is that the maps dramatically increased in size on Friday scans but returned to a "baseline" size on the following Monday. It took 6 months for the baseline Monday map to gradually increase and by 10 months they plateaued. After the blind subjects took a two month break, they were remapped, and their maps were unchanged from their last Monday mapping. What this shows is that long lasting changes as the result of skill learning took 10 months of repeated practice. The reason why short-term improvements were made based on the Friday mappings, but eventually disappeared, is the result of the type of neuronal connections that were taking place. The Friday mappings were the result of the strengthening of existing neuronal connections. Monday mappings, though showing little progress initially and plateauing at ten months, were the result of the creation of new neural connections.[3]
Driven by our knowledge, beliefs, expectations
-how our brain makes use of the information based on previous experiences
-Higher level processes come into play (memory & thinking)
e.g. Top-down processing suggests that we form our perceptions starting with a larger object, concept, or idea before working our way toward more detailed information. In other words, top-down processing happens when we work from the general to the specific; the big picture to the tiny details. In top-down processing, your abstract impressions can influence the sensory data that you gather.

Top-down processing is also known as conceptually-driven processing, since your perceptions are influenced by expectations, existing beliefs, and cognitions. In some cases you are aware of these influences, but in other instances this process occurs without conscious awareness.

For example, imagine that you are driving down an unfamiliar street and you see a sign for a convenience store. The sign has several missing letters, but you are still able to read it. Why? Because you use top-down processing and rely on your existing knowledge to make an educated guess about what the sign says.

Top-down processing can be useful when we are looking for patterns in our environment, but it can also hinder our ability to perceive things in different ways. Our bias toward viewing objects in a certain way is known as a perceptual set.

A number of things can influence top-down processing, including context and motivation. The context in which an event or object is perceived can influence what we expect to find in that particular situation. If you are reading an article about food and nutrition, for example, you might interpret an ambiguous word as something related to food.

Motivation can also make you more likely to interpret something in a particular way. For example, if you were shown a series of ambiguous images, you might be more motivated to perceive them as food-related when you are hungry.
Human mind organizes information, allowing us to make rapid use of previous knowledge
-Need to evaluate and challenge - protoypes (grouped bases on perceptual similarities) Prototype models of categories suggest that items are grouped into categories based on perceptual similarity, with each category having a central exemplar that is constructed from the average characteristics of all category members (Rosch, 1978; J. D. Smith & Minda, 2000). For example, dogs are grouped into a single category on the basis of similar body shape (e.g., four legs, a tail, fur). A slang expression such as "If it walks like a duck and quacks like a duck, then it probably is a duck" reflects an intuitive understanding of prototypes. In this scheme, entities that share many features with the prototype are the more typical members of the category. Several of the categories suggested by the DSM-IV-TR use this probabilistic approach to classification (Medin, 1989). For example, a diagnosis of major depressive episode can be made if a dysphoric mood and/or loss of interest or pleasure, plus four of nine symptoms have been present for a period of two weeks. categorization. For one thing, prototypes discard a lot of important information (S. W. Allen & Brooks, 1991; Medin, 1998; Medin & Ross, 1989).
Problems with Prototypes: A prototype is an abstraction that reflects the sum of one's experience with an entity or category of entities. Although some degree of abstraction takes place, people's conceptual knowledge also reflects specific memories of that experience. Thus, the availability or presence of a single, salient example can bias or anchor our view of an entire category (see Hastie & Dawes, 2001, for a review). Consider, for example, what the name Osama bin Laden has done to change North Americans' category of "Muslim."

Arbuthnott, Katherine D.; Arbuthnott, Dennis W.; Thompson, Valerie A. (2014-02-04). The Mind in Therapy: Cognitive Science for Practice (Kindle Locations 2732-2737). Taylor and Francis. Kindle Edition.


-Steretoypes With social categories, such information may involve a stereotype, such as stereotypes associated with race or gender. The evidence indicates that we automatically assign category membership to other people based on their racial and gender characteristics (Ito & Urland, 2003). However, whether such categorization activates stereotypic associations depends on the strength of such associations in our memory (Gawronski, Ehrenberg, Banse, Zukova, & Klauer, 2003) and our current intentions. (Ch.8)



-In cognitive science, categories usually refer to the mental representation of such groupings, rather than the collection of objects themselves.
-Categories are groups of objects or experiences judged to be the same for some purpose.
-Social categories include roles, cultural membership, relationships, and the like.
-This is one of the fundamental and automatic ways that the human mind organizes information, allowing us to make rapid use of previous knowledge.
-Diagnoses are essentially categories of human difficulties. One of our most important categories is our self-concept, a category that is often an important target of therapy.
-Categories can be organized according to perceptual similarity (prototype theory) or causal similarity (causal model theory).
-The categories of the DSM-IV-TR are an example of the former (i.e., atheoretical symptom lists), but research indicates that most therapists organize such categories according to their theories about the causes of psychological problems.
-Essentialist beliefs can underlie some category judgments, beliefs that some underlying core element makes a thing what it is. Such beliefs about personality and behavior patterns can underlie therapeutic difficulties, and are often the target of therapeutic intervention.
-Our category decisions are influenced by the judgment context. When we are sorting things into different categories (e.g., anxiety or depression), we attend to characteristics that discriminate between categories (e.g., markers of differential diagnosis such as worrying about the future vs. ruminating about the past). Conversely, when we identify the category of a single example, we attend to the characteristics within the category (e.g., the prototype, such as the cluster of depressive symptoms). Thus, whether weapproach assessment blindly or attempt to verify another's diagnosis will influence what aspects of a client and her situation we notice and consider important to her diagnosis, and thus our final conclusion.
Encoding is the crucial first step to creating a new memory. It allows the perceived item of interest to be converted into a construct that can be stored within the brain, and then recalled later from short-term or long-term memory.

Encoding is a biological event beginning with perception through the senses. The process of laying down a memory begins with attention (regulated by the thalamus and the frontal lobe), in which a memorable event causes neurons to fire more frequently, making the experience more intense and increasing the likelihood that the event is encoded as a memory. Emotion tends to increase attention, and the emotional element of an event is processed on an unconscious pathway in the brain leading to the amygdala. Only then are the actual sensations derived from an event processed.

The perceived sensations are decoded in the various sensory areas of the cortex, and then combined in the brain's hippocampus into one single experience. The hippocampus is then responsible for analyzing these inputs and ultimately deciding if they will be committed to long-term memory. It acts as a kind of sorting centre where the new sensations are compared and associated with previously recorded ones. The various threads of information are then stored in various different parts of the brain, although the exact way in which these pieces are identified and recalled later remains largely unknown. The key role that the hippocampus plays in memory encoding has been highlighted by examples of individuals who have had their hippocampus damaged or removed and can no longer create new memories (see Anterograde Amnesia). It is also one of the few areas of the brain where completely new neurons can grow.

Although the exact mechanism is not completely understood, encoding occurs on different levels, the first step being the formation of short-term memory from the ultra-short term sensory memory, followed by the conversion to a long-term memory by a process of memory consolidation. The process begins with the creation of a memory trace or engram in response to the external stimuli. An engram is a hypothetical biophysical or biochemical change in the neurons of the brain, hypothetical in the respect that no-one has ever actually seen, or even proved the existence of, such a construct.

An organ called the hippocampus, deep within the medial temporal lobe of the brain, receives connections from the primary sensory areas of the cortex, as well as from associative areas and the rhinal and entorhinal cortexes. While these anterograde connections converge at the hippocampus, other retrograde pathways emerge from it, returning to the primary cortexes. A neural network of cortical synapses effectively records the various associations which are linked to the individual memory.
MEMORY CONSOLIDATION
??? Did You Know ???
Studies have shown that we often construct our memories after the fact, and that we are susceptible to suggestions from others that help us fill in the gaps in our memories.
This malleability of memory is why, for example, a police officer investigating a crime should not show a picture of a single individual to a victim and ask if the victim recognizes the assailant.
If the victim is then presented with a line-up and picks out the individual whose picture the victim had been shown, there is no real way of knowing whether the victim is actually remembering the assailant or just the picture.
Consolidation is the processes of stabilizing a memory trace after the initial acquisition. It may perhaps be thought of part of the process of encoding or of storage, or it may be considered as a memory process in its own right. It is usually considered to consist of two specific processes, synaptic consolidation (which occurs within the first few hours after learning or encoding) and system consolidation (where hippocampus-dependent memories become independent of the hippocampus over a period of weeks to years).

Neurologically, the process of consolidation utilizes a phenomenon called long-term potentiation, which allows a synapse to increase in strength as increasing numbers of signals are transmitted between the two neurons. Potentiation is the process by which synchronous firing of neurons makes those neurons more inclined to fire together in the future. Long-term potentiation occurs when the same group of neurons fire together so often that they become permanently sensitized to each other. As new experiences accumulate, the brain creates more and more connections and pathways, and may "re-wire" itself by re-routing connections and re-arranging its organization.