Neuroscience Exploring the Brain Chapter 23

1. Types of memory and forgetting

Declarative and non-declarative memory

long term memory and short term memory

amnesia

1. Declarative and non-declarative memory
   • Declarative memory (explicit memory): Memory for facts and events. (medial temporal lobe, midbrain)
   • Non-declarative memory (implicit memory): Procedural memory, the memory of skills, habits and behaviors.
2. long term memory and short term memory
   • Long-term memory: Memory in which information stored days, months, or years ago can still be recalled.
   • Short-term memory: lasts from seconds to hours and is easily destroyed
3. amnesia
   • Retrograde amnesia: Loss of memory for events that occurred before the injury.
   • Anterograde amnesia: The inability to form new memories after brain injury.
   • Anterograde amnesia: Sudden anterograde amnesia, accompanied by short-term retrograde amnesia.

2. Looking for traces of memory

1. Lashley's study of maze learning in rats
   • Memory traces exist in specific cortical association areas.
   • The degree of learning and memory loss is related to the area of ​​the brain injury, not the location of the brain injury. (Later proved to be wrong)
2. Heb and cell collection
   • Cell ensemble: A group of neurons that activate simultaneously. As long as the connections within the cell assembly continue to be activated, the internal reflection of external objective objects can always be stored as short-term memory.
   • in conclusion:
     • Memory traces are widely distributed within the cellular connections of collections of cells.
     • Memory may also include neurons involved in sensation and perception.
3. Declarative memory storage areas in the neocortex.
   • Research using monkeys as experimental subjects: The inferior temporal cortex is both the visual center and the memory storage area.
   • Research with human subjects: Consistency. The cortical areas of the brain can both process sensory information and store memories.
4. Electrical stimulation of the human temporal lobe
   • Electrical stimulation of the temporal lobe occasionally causes more complex perceptions than stimulation of other parts of the brain.

3. Temporal lobe and declarative memory

The temporal neocortex in the temporal lobe is the storage site for long-term memory.

1. Consequences of temporal lobe resection. The temporal lobe is particularly important for learning and memory. Removal can cause "mental blindness", which is the inability to understand what one sees or does. Can cause severe anterograde amnesia.

2. Internal testing of the temporal lobe and memory processes.

   • The hippocampus, nearby cortex, and the pathways connecting these structures to other parts of the brain play an important role in the consolidation of declarative memories.
   • The hippocampus is a folded structure on the inside of the lateral ventricle
   • Ventral hippocampus: There are three important cortices surrounding the olfactory groove: entorhinal cortex, perirhinal cortex, and parahippocampal cortex.
   • The inner temporal lobe receives input from contact areas of the cerebral cortex and contains refined information from all sensory modalities.
   • 
   • Delayed non-matching sample task

3. Diencephalon and memory processes

   • The three diencephalon areas related to the recognition memory process are: a. The anterior nucleus of the thalamus. b. Dorsal medial nucleus. 3. The mammillary bodies of the hypothalamus.
   • The main output of the hippocampal formation is a fornix composed of a bundle of axons. Most of these axons project to the mammillary bodies. Neurons within the mammillary bodies project to the anterior nucleus of the thalamus. A loop is formed from the hippocampus to the hypothalamus, to the anterior nucleus, and then to the cingulate cortex.
   • The dorsomedial nucleus of the thalamus also receives afferent information from temporal lobe structures, including the amygdala and inferotemporal neocortex, and always projects to all areas of the entire frontal cortex.

4. Memory functions of the hippocampus.

   • Important role of the medial temporal lobe: Involvement in declarative memory and consolidation processes.
   • The hippocampus is involved in various learning and memory functions.
   • Working memory: Retains information used to guide sexual behavior.
   • Positional domain: The location that elicits the greatest response from the cell.
   • Place cells: Neurons in the hippocampus that fire at specific locations.

5. The striatum and procedural memory

   • There are two main parts of the basal ganglia: the caudate nucleus and the putamen, which together form the striatum.
   • The striatum receives input from the temporal and parietal cortices and outputs information to the thalamus and cortical motor areas.
   • The striatum is located at a critical site in motor circuits.
   • The striatum plays a key role in procedural memory that forms behavioral habits.
   • There was no effect on the DNMS task after striatum damage, indicating that declarative memory can still be formed.

4. Neocortex and working memory

1. Prefrontal cortex and working memory.
   • Primates have large frontal lobes, unlike other mammals. The prefrontal cortex at the rostral end of the frontal lobe is particularly developed.
   • The prefrontal cortex is involved in working memory for problem solving and planning behavior.
2. Lateral intraparietal cortex (area LIP) and working memory
   • The LIP area is thought to be involved in directing eye movements. (working memory)

Chapter 23 Homework Questions

1. Walking consciously is declarative memory.
2. The primary evidence is studies of injury. Patients with damage to the hippocampus and temporal lobes are unable to form declarative memories, but procedural memories remain. Damage to the striatum prevents the formation of procedural memory, but declarative memory remains intact.
3. Have basic mobility capabilities, and previous behaviors and memories will not be affected. Longer memories cannot be formed through memory consolidation.
4. In his mouse maze experiment, as the damage to the cortical area increased, the mice took longer to exit the maze. Overturn: The damaged area is too large, and more than one brain area may be damaged each time; while damaging learning and memory functions, it may also affect other functions of the mouse.
5. Using monkeys as experimental subjects: By recording the responses of IT neurons, it was found that the memory of faces can be encoded. Using human subjects: Through functional MRI, it was found that faces can specifically activate a small area of ​​the brain. Experts in their respective fields responded more strongly to seeing things in their field than the control group.
6. The brain area can be removed or the neurons can be inactivated to observe its long-term memory.
7. To distinguish between perception and memory, you can observe the response pattern of neurons after repeated presentations of human faces. If the response of the neurons is always the same, regardless of the frequency of the stimulus, it is only related to perception. Otherwise, the perception may not be his. Only function. If the changes are regular, it may be related to memory, producing a consistent pattern.
8. Place cells are found in the hippocampus. They are most activated when the animal is in a certain position. The difference is that place cells activate without vision and change with the environment.
9. Spatial memory is the ability to create a spatial map of the environment. The role of the hippocampus in spatial memory can be seen from the hippocampal place cells. Working memory is the ability to retain recently acquired information. The concept of associative memory attempts to integrate the two, arguing that highly processed sensory information enters the hippocampus and nearby cortex, and memory proceeds in a way that connects everything going on at the time. In relational memory, neurons encode information about a place into associations with nearby objects and co-occurring sounds and smells.
10. Working memory is a form of temporary information storage that has limited capacity and requires repetition. There are multiple temporary storage areas in the brain, the hippocampus, and the prefrontal cortex.