Memory and memory systems Flashcards
Memory
The processes by which information is encoded, stored, and retrieved for the purposes of remembering the past, informing current behavior, and planning the future.
Encoding
Converting the information acquired by your senses into patterns of activity within groups of neurons within the brain.
Storage:
The retention of information acquired by your senses.
Retrieval:
The recollection of information stored in memory.
“Tip of the tongue” phenomenon:
A type of retrieval failure accompanied by the strong feeling that temporarily forgotten information is on the verge of being recalled.
Sensory memory
The persisting representation of a sensory stimulus for a brief period after it is no longer physically present. There are three types : Iconic memories , Echoic memories and Haptic memories
Ionic memories
persisting representations of visual information after it has faded. It is stored for less than 500 milliseconds. it is interpreted in the visual cortex but also in cortical areas beyond their sensory areas.
Echoic memories
persisting representations of sounds after they have faded. These representations were found to persist for up to 10 seconds. it is processed in he auditory cortex but also beyond their sensory areas.
Haptic memories
representations for tactile information after it has faded. haptic memory is approximately 2 seconds .important for manipulating and recognizing objects by touch. somatosensory cortex for haptic memory but also beyond that part
Working memory:
A memory register of limited capacity for both the amount of information it can store and the time for which information is retained.
vulnerability to disruption. Items in working memory are easily forgotten if they cease being the focus of attention or if other processes interfere with the rehearsal of information.
multicomponent working memory model
fluid system because its components are activated only temporarily.
(1)a visuospatial sketch pad, in which visual images are stored; (2) a phonological loop, in which verbal information is rehearsed by subvocalization and visual images are converted into a phonological code; (3) an episodic buffer, which integrates information from the visuospatial sketch pad and the phonological loop with a sense of time, so that memories can be experienced as sequences of events;
Central executive :to focus attention, to divide attention, to permit switching from task to task, and to interface with long-term memory.
working memory and long term memory
a subset of the information stored in working memory may eventually be stored in long-term memory. Second, as mentioned earlier, information in working memory comes from focusing on incoming sensory information and/or information stored in long-term memory.
Delayed-response task:
A behavioral task that requires holding a stimulus in working memory, after it has disappeared from view, to later make a correct choice.
Oculomotor delayed-response task:
A delayed-response task in which the location of a stimulus on a screen has to be held in short-term memory to later perform a correct response, as demonstrated by moving the eyes toward the area in which the stimulus previously appeared.
the prefrontal cortex was important for maintaining information in working memory.
Experiments involved in the short term memory
The areas of the prefrontal cortex mostly associated with working memory are the dorsolateral and ventrolateral prefrontal cortices
This task is divided into three phases. In the first phase (the cue phase), food is randomly placed in one of two food wells visible to the monkey. In the second phase (the delay phase), the food wells are covered, and a screen is lowered to obstruct the monkey’s view for a predetermined period. In the third phase (the response phase), the screen is raised, and the monkey reaches for the food. It is thought that to be able to reach for the food at the correct location, the monkey has to keep a representation of the location of the food in working memory during the delay.
Long-term memory:
A memory register of potentially unlimited capacity for both the amount of information it can store and the time for which information is retained.
Declarative memories:
explicit memories
Long-term memories that require the conscious recollection of information.
Nondeclarative memories:
implicit memories,
Memories that are expressed only through the performance of tasks and habits, without the need for conscious recollection of information.
Semantic memories
Declarative memories that comprise learned facts and life events.
Episodic memories
Declarative memories that comprise life events; rich in contextual details including the time and place in which an event occurred.
Mental time travel: The ability to travel back in time, in your mind’s eye, to reexperience an event.
Autonoetic consciousness:
The ability to reflect upon past events while being aware that those are your own memories.
Chronesthesia:
The awareness of the passage of subjective time.
Classical conditioning of emotional responses
exposure to a previously neutral stimulus by itself can give rise to the same emotional response experienced when the aversive stimulus was present. Conditioned emotional responses are thought to be a way in which people acquire phobias
Classical Conditioning of motor responses
exposing a person or an animal to a stimulus likely to trigger a motor response, such as blinking in response to a puff of air to the eye, along with a neutral stimulus such as a tone. Later exposure to the previously neutral stimulus by itself (i.e., the tone) gives rise to the same motor response triggered by the stimulus that originally produced the response
Priming
refers to a type of nondeclarative memory in which exposure to a stimulus influences your response to a stimulus presented later
e primed words automatically come to mind and the similar piece of clothing seems to “pop out” without conscious effort You have also not made any conscious effort to remember the information with the goal of influencing your response to subsequent stimuli.
Procedural memory
that leads to the performance of skills and habit without the need for the conscious recollection of information . I remembered only the first two. Being quite embarrassed by this, I told him to follow me to the office door. Much to my amazement, I automatically pressed the correct combination of numbers as he watched
the brain areas involved in declarative memory
the medial temporal lobes. These include the hippocampus and related cortical areas known as the perirhinal, entorhinal, and parahippocampal cortices as well as the amygdala.
Another region important for declarative memory is the medial diencephalon. This area includes the thalamus and the mammillary bodies of the hypothalamus (Figure 12.11). The hippocampus is connected to structures of the medial diencephalon via a bundle of nerve fibers known as the fornix. The connections between the hippocampus and the medial diencephalon need to be intact for declarative memories to be stored and retrieved normally.
The fornix also links the hippocampus to the septum, which provides it with cholinergic innervation (input from neurons that use acetylcholine for neurotransmitter).
Amnesia:
Memory deficits resulting from brain damage or psychological trauma.
Anterograde amnesia
The inability to form new memories since brain damage has occurred.
Retrograde amnesia:
Memory loss for information acquired before brain damage.
Temporally graded retrograde amnesia:
A type of amnesia in which information acquired shortly before brain damage is lost but memories formed at a more remote period are preserved.
HM STUDY
Amnesia it is mostly the declarative memory and not the non declarative memory . ( with episodic affected more than somantic)
Medial Diencephalon
The foil damaged his left dorsomedial thalamus and the mammillary bodies on both sides. He suffered considerable anterograde amnesia as well as some retrograde amnesia. Similarly to HM, NA suffered no impairments of nondeclarative memory.
non-declarative
What you need to remember is that each of these types of nondeclarative memory depends on areas located outside of the hippocampus and diencephalon.
