tex2

• Context is more important in recall than in recognition.
• See Baddeley experiment (context dependent learning- scuba diving experiment)
• Phelps- binding item to context (press a button whenever you see a lopsided "T")
• Davachi- Dissociation in the hippocampal formation (presented with list of 40 words written in 4 different colors, uses fMRI while studying, then asked to recall whether they saw the word on the list, and what color it was)

The scuba diving experiment- participants are given a list of words to memorize while 50' underwater. Recall performance is better if participants are in the same context in which they studied the words. Experiment shows that context dependent learning helps in a recall task, but doesn't have much effect on recognition.

Phelps used amnesiacs and controls to study amnesiacs' memory deficits. Participants were presented, on a screen, with various geometrical figures that resembled the letter "T". The participants' task was to press a button whenever they saw a lopsided "T". Whenever the target letter appeared (lopsided T) a pattern of geometrical figures was also present. By identifying this patter one could answer faster if the the lopsided "T" was on the screen the whole configuration acted as a cue. Results show that whereas controls were able to use the configuration and respond faster to the target letter (implicit memory for the context to find the letter faster), the amnesiacs were not able to use the configuration to improve their reaction times to recognize the target letter. This means that the problem with the amnesiacs is not that they have poor explicit memories and good implicit memory, but that they can't attach a spatio-temporal context to their memories, so they have problems binding items to contexts.

• In support of context biding problems.
• Participants are presented with a list of 40 words written in 4 different colors.
• While studying this list, she uses a fMRI to scan their brains. Later in the recall task, the participants complete a recognition task. First, they are asked to say if they saw the word, then they say in what color it was presented. Based on recall performance she was able to go back in the study phase and record the brain activation for words that were forgotten, or words recognized (but the color was wrong), or for words recognized (and color remembered). She was able to show that the hippocampus was active when participants encoded words that they later recognized (both word and color), while the perirhinal cortex was active with words encoded that were later recognized (but color forgotten). Hippocampus is responsible for relational memories, and the perirhinal cortex is responsible for item memories.

Amnesiacs are relatively unimpaired on some explicit memory tasks (like recognition) but are impaired on some implicit memory tasks (like binding items to context). Thus, if amnesiacs performance on both explicit and implicit memory tasks is used to make the distinction between explicit and implicit memory than we can say that this distinction is not as sharp as it might seem at first glance. Context is what matters in both tasks, and amnesiacs are unable to bind context to content.

• Episodic Memory is a type of LTM for which one has time and space reference (spatio-temporal context). For example, remembering your HS graduation is an episodic memory, because you can also remember the time and space coordinates of this memory.
• Semantic Memory refers to memory of factual knowledge, for this type of memory one does not have a time and space reference although one did have it sometime, immediately after acquiring the knowledge. For example, usually people do not have a spatio-tempral context for the moment they learned their mother's maiden name, so this make it a semantic memory.

• spatio-temporal context
• one can clearly remember the source of the memory
• organized spatio-temporally
• have reference to the self
• a sense of intimacy
• retrieval through spatio-tempora cues
• volatile

• no spatio-temporal context
• one can NOT remember the source of the memory
• organized conceptually
• have no necessary reference to the self
• no sense of intimacy
• retrieval through conceptual cues

• There are studies arguing that the two types of memories have distinct neurobiological pathways.
• H.M., for example, could acquire new vocabulary terms (semantic memory), but could not remember that he met the experimenters 5 minutes after they left the room.
• Vargha-Khadem reports that patient with severe anterograde amnesia (had no hippocampus) performed well in school (had good semantic memory) but couldn't tell you what they did yesterday (had poor episodic memory). You don't need an episodic memory to form a semantic memory.
• Source Amnesia- happens when people are hypnotized and, during the trance, they learn obscure facts. They are then given hypnotic suggestions to forget everything that happened during the session. Afterwards, if asked, they remember the obscure face (they retain the semantic memory), but they do not know where they learned it (they lose the episodic memory).
• K.C. an anterograde amnesia patient- he was a lay worker and he knew how to use a lathe but didn't know about the Missasauga train crash.
• Damage to the right frontal lobe will cause problems for the retrieval of episodic memories, but not semantic memories

Gilber Ryle said there is a distinction between "knowing how" and "knowing that". These are qualitatively different things.

Declarative memory (explicit memory) is the type of memory that stores facts and experiences. It is so called because it refers to memories that can be consciously discussed, or declared. Both semantic and episodic memory are part of this category. It refers to knowing "that".

Procedural memory (non-declarative memory or implicit memory) is the long-term memory of skills and procedures, or "how to" knowledge. It is characterized by a lack of conscious awareness in the act of recollection. By contrast, explicit memory requires conscious recollection of previous experience. Procedural memory is often not easily verbalized. It refers to knowing "how".

They gave both amnesiacs and controls a mirror reading task, in which participants had to read words as reflected in a mirror. Each trial presented them with a triplet (three words); some of the triplets were repeated. The results show that both amnesiacs and controls improve their mirror reading skills at about the same rate, but the difference was in the reading times of the repeated triplets. The control subjects recognized the triplet and were able to read it faster than the amnesiacs, who did not recognize it. This suggests that amnesiacs have a good procedural memory, but a poor declarative memory.

Priming, Perceptual Identification Task, Famous Person Task, & Behavioral Dissociations

• Priming- a type of task in which subjects are presented with a list of words: armchair, wall, garage, horse, foot, then they are either asked "what was the word from the list that began with GAR__?" (cued recall task- addresses explicit memory) or they are asked "what is the first words that comes to mind and begins with GAR__" (stem completion task/fragment completion task addresses implicit memory). Previous exposure primes people to the word GARAGE rather than say GARLIC.
• Perceptual Identification Task- participants presented with a list of words: armchair, wall, garage, horse, foot, etc. then they are presented with a very fast exposure of a word on the screen. They get a point on accuracy scale if they can ID the word and say whether or not it was on the list. This is a test of implicit memory.
• Famous Person Task- participants presented with a list of famous and non famous names, a day later they are presented with another list consisting of a combination of the previous days list as well as new famous and non famous names. A sense of familiarity with the non famous names from the first list lead them to be more likely to list them as famous. Participants used their sense of familiarity to evaluate whether the names were famous or not. Results show that part of the remembering experience has to do with the sense of familiarity- task suggests that familiarity drives implicit memory.
• Behavioral dissociations- point out that at first glance implicit and explicit memories are distinctive. 1) Depth of processing affects explicit but not implicit memory 2) Interference affects explicit but not implicit 3)Modality specificity (acoustic or semantic input) is important for implicit but not explicit memory tasks 4) Amnesiacs show preserved implicit memory but disrupted explicit memory.