neuro weeks 9+10- cognition

Limbic System

• Network located on the medial and inferior aspects of the brain

• Includes the limbic cortex (cingulate and parahippocampal gyri), hippocampal formation, amygdala, olfactory cortex, parts of the diencephalon, parts of the basal ganglia, and septal area

• Major roles: homeostasis, olfaction, memory, emotion, motivation, and drives

Limbic System Functions (HOME)

• H = Homeostasis → hypothalamus

• O = Olfaction → olfactory cortex

• M = Memory → hippocampal formation

• E = Emotion and drives → amygdala

Hypothalamus

• Central regulator of homeostasis

• Controls or influences hunger, thirst, sexual desire, sleep-wake cycles, endocrine functions, autonomic functions, and limbic/emotional functions

• HEAL: Homeostasis, Endocrine, Autonomic, Limbic

Amygdala

• Nuclear complex in the anteromedial temporal lobe

• Attaches emotional significance to stimuli

• Important in fear, anxiety, aggression, emotional responses, and emotional learning

Olfactory System Connection to Memory

• Olfactory receptor neurons → olfactory bulb → lateral olfactory stria → primary olfactory cortex → entorhinal cortex

• The entorhinal cortex connects with memory-related structures, including the hippocampus

• This direct limbic connection allows odors to evoke vivid memories and emotions

Olfactory Cortex

• Includes the piriform cortex and periamygdaloid cortex

• Unique because it receives direct sensory input without an obligatory initial relay through the thalamus

Hippocampal Formation

• Composed of the dentate gyrus, hippocampus proper (cornu Ammonis), and subiculum

Dentate Gyrus

• One of the three major components of the hippocampal formation

• Participates in hippocampal memory processing

Hippocampus Proper (Cornu Ammonis)

• One of the three major components of the hippocampal formation

• Important for memory formation and processing

Subiculum

• One of the three major components of the hippocampal formation

• Major output structure of the hippocampal formation

Hippocampus Functions

• Consolidates short-term declarative memories into long-term storage

• Supports relational memory

• Important for spatial navigation

Relational Memory

• Ability to remember objects, events, or information in relation to their context or other information

Hippocampus Input

• Association cortex provides input to the entorhinal cortex

• Information enters the hippocampal formation through the perforant pathway and alvear pathway

Hippocampus Output

• Main output originates from the subiculum

• Travels through the fornix

• Projects to the diencephalon and septal nuclei

Perforant Pathway

• Pathway through which information from the entorhinal cortex enters the hippocampal formation

Alvear Pathway

• Pathway involved in carrying information from the entorhinal cortex to the hippocampal formation

Hippocampal Commissure

• White matter pathway

• Allows transfer of information between the hippocampi of the two cerebral hemispheres

Fornix

• Arch-shaped white matter structure

• Major subcortical output pathway of the hippocampal formation

• Carries information primarily from the subiculum

• Projects toward the diencephalon and septal nuclei

Declarative Memory (Explicit Memory)

• Conscious recollection of information

• Includes semantic memory (facts and concepts) and episodic memory (personally experienced events)

Nondeclarative Memory (Implicit Memory)

• Nonconscious learning and memory

• Includes procedural skills, habits, acquired behaviors, and priming

• Does not require conscious recollection of the learned skill

Declarative Memory Structures

• Medial temporal lobe: hippocampal formation and parahippocampal gyrus

• Medial diencephalic areas: mediodorsal thalamic nucleus, anterior thalamic nucleus, and mammillary bodies

Nondeclarative Memory Structures

• Basal ganglia, especially the caudate nucleus for habits

• Cerebellum

• Motor cortex

Consolidation

• Process of converting immediate or short-term memories into more permanent long-term storage

• Mediated by medial temporal and diencephalic structures

Long-Term Potentiation (LTP)

• Form of synaptic plasticity

• High-frequency neural activity produces a long-lasting increase in synaptic strength

• Important fundamental mechanism of memory formation

Stages of Memory

• Attention and registration: may last less than 1 second

• Working memory: seconds to minutes

• Consolidation: minutes to years

• Long-term storage: relatively permanent storage of information

Short-Term Memory

• Temporary memory system

• Receives information from sensory/perceptual memory and long-term memory

• Includes primary memory and working memory

Primary Memory (Immediate Recall)

• Ability to hold a limited amount of information

• Duration is approximately 30 seconds

• Involves immediate recall of information

Working Memory

• Holds information temporarily while also manipulating or processing it

• May involve determining meaning, organizing information, preparing information for long-term storage, and retrieving and using information from long-term memory

• Limited capacity

• Primarily associated with the prefrontal cortex, especially the dorsolateral prefrontal cortex

Long-Term Memory

• Relatively permanent memory system

• Stores information over extended periods of time

• Includes declarative/explicit memory and nondeclarative/implicit memory

Procedural Memory

• Type of nondeclarative/implicit memory

• Involves skills and behaviors performed automatically

• Does not require conscious manipulation

• Examples: riding a bicycle and tying shoes

Recent Memory

• Ability to recall newly learned information after a brief delay

• Common delay is approximately 3-5 minutes

• Often used to assess recent learning and memory consolidation

Remote Memory

• Ability to recall verifiable personal or historical events from years in the past

• Example: remembering where you attended school as a child

Episodic Memory

• Type of declarative/explicit memory

• Involves personally relevant facts and events

• Examples: remembering what you ate for breakfast or where and when you got married

Prospective Memory

• Ability to remember to perform a task or action in the future

Retrospective Memory

• Ability to remember past events or information

Semantic Memory

• Type of declarative/explicit memory

• Involves knowledge and beliefs about facts, concepts, and general information

• Does not require remembering how, when, or under what circumstances the information was learned

• Example: being able to list animals

Anterograde Amnesia

• Inability to learn new information or form new memories after a brain injury or disease has occurred

Retrograde Amnesia

• Inability to recall memories or events that occurred before the onset of a brain injury or disease

Transient Global Amnesia

• Abrupt, temporary memory disorder

• May involve both anterograde and retrograde amnesia

• Generally occurs without other major neurological deficits

Psychogenic Amnesia

• Memory loss primarily attributed to psychological distress or trauma

• Not primarily caused by structural brain damage

Infantile Amnesia

• Normal inability of adults to recall most events from the first few years of life

Age-Related Memory Change

• Normal, mild decline in memory recall associated with aging

• Does not significantly interfere with everyday functioning

Unimodal Association Cortex

• Higher-order processing area for a single sensory or motor modality

• Examples: visual association cortex and motor association cortex

Heteromodal Association Cortex

• Higher-order association area

• Integrates information from multiple sensory modalities, motor modalities, and limbic systems

• Example: prefrontal cortex

Frontal Lobe

• Involved in executive functions, motor planning, behavior, motivation, judgment, inhibition, organization, and aspects of language

Frontal Lobe Regions

• Lateral surface: prefrontal cortex, premotor cortex, and Broca's area

• Medial surface: supplementary motor area and anterior cingulate cortex

• Orbitofrontal surface: orbitofrontal cortex

Frontal Lobe Functions (RIO)

• R = Restraint: judgment and inhibition

• I = Initiative: motivation and creativity

• O = Order: planning, organization, and working memory

Executive Function

• Higher-level cognitive function that coordinates and controls more basic cognitive processes

• May include initiation, planning, monitoring, working memory, cognitive flexibility, and inhibition

Initiation

• Ability to start a task, begin an activity, or inquire when information is not known

Planning

• Ability to think ahead and prepare for an activity or task that will be performed in the future

Monitoring

• Uses metacognitive skills to monitor performance, recognize problems or errors, and correct errors

Cognitive Flexibility

• Ability to change or shift thinking or behavior when unexpected events occur

• Ability to adapt to changing situations rather than refusing change

Inhibition

• Ability to control impulses, behaviors, emotions, and thoughts

• Examples: controlling what you say, avoiding overeating, and stopping an impulsive action

Dysexecutive Syndrome

• Collection of impairments resulting from prefrontal damage

• May include poor judgment, impulsivity, apathy, lack of organization, impaired planning, and difficulty controlling behavior

Disconnection Syndromes

• Cognitive or behavioral deficits caused by lesions in white matter pathways

• Lesions disconnect otherwise functional cortical areas

• Example: alexia without agraphia

Consciousness System

• Widely distributed network regulating consciousness

• Includes frontoparietal cortex, brainstem, reticular formation, thalamus, hypothalamus, and basal forebrain

Consciousness

• State or process involving awareness of oneself, the environment, and ongoing experiences

• Depends on the interaction of alertness, attention, awareness, and memory

AAA of Consciousness

• A = Alertness

• A = Attention

• A = Awareness

Alertness

• Ability to be awake and responsive to internal and external stimuli

Arousal

• State of responsiveness to sensory stimulation or excitability

Attention

• Ability to selectively focus mental resources on relevant information or tasks

Awareness

• Ability to recognize and have knowledge of oneself, the environment, and ongoing experiences

Nexus of Consciousness

• Critical point where attention meets memory

• Represents a final gateway where information may be consciously processed and encoded into long-term declarative memory

Detect, Pulse, Switch, and Wave Model

• Detect: initial perception of an event

• Pulse: subcortical surge of arousal

• Switch: turns off interfering or competing networks

• Wave: broad cortical processing of the event

Sustained Attention (Vigilance)

• Ability to maintain attention and concentration over an extended period

• Example: listening to a lecture for a given period of time

Selective Attention (Directed Attention)

• Ability to focus on a primary task or stimulus

• Requires ignoring irrelevant or competing distractors

• Example: listening to a lecture despite a conversation occurring in the background

Alternating/Switching Attention

• Ability to shift attention from one task to another and then return attention to the original task

Divided Attention

• Ability to attend to two or more tasks or stimuli at the same time

• Requires dividing attentional resources

• Example: walking while talking on the phone

Default Mode Network (Task-Negative Network)

• More active during rest, internal reflection, mind-wandering, and internally focused thought

• Decreases activity during externally oriented tasks

BIMS (Brief Interview for Mental Status)

• Standardized cognitive screening tool

• Evaluates temporal orientation, word recall, and recent memory

Mini-Cog

• Brief cognitive screening tool

• Combines three-word recall with the Clock Drawing Test

• Assesses memory, executive function, and spatial analysis

Clock Drawing Test (CDT)

• Cognitive screening task involving drawing a clock

• May require drawing the clock face, placing numbers appropriately, and setting the hands to a specified time

• Assesses executive function, visuospatial ability, planning, and spatial analysis

Mental Status Exam (Critical Components)

• Level of alertness and attention

• Orientation

• Memory

• Language

• Calculations

• Praxis/apraxia

• Neglect

Functional Cognition

• Use of cognitive skills within meaningful, real-world tasks

• Applies skills such as attention, memory, and executive functions to meaningful occupations

Cognitive Processes vs. Functional Cognition

• Cognitive processes: underlying client factors such as attention, memory, and executive functions

• Functional cognition: application of cognitive abilities during meaningful occupations and real-world tasks

Intellectual Awareness

• Ability to understand or know that a particular function is impaired

• Basic level of awareness

Emergent Awareness

• Ability to recognize that a problem or error is occurring while actively performing a task

Anticipatory Awareness

• Highest level of awareness

• Ability to predict that a problem will occur because of an impairment before beginning an action or task

Pyramid Model of Awareness

• Intellectual awareness: knows an impairment exists

• Emergent awareness: recognizes a problem while it is occurring

• Anticipatory awareness: predicts a problem before it occurs

Metacognition

• Ability to think about and monitor one's own thinking and performance

• Includes knowing that a problem exists, recognizing a problem when it occurs, and anticipating that a problem may occur

Dynamic Interactional Model (DIM)

• Cognition is a continuous product of the interaction between the person, task, and environment

• Cognitive performance can change depending on the interaction among these factors

Multicontext Approach

• Strategy-based treatment approach derived from the Dynamic Interactional Model

• Uses metacognitive strategies to help clients recognize errors, develop strategies, and generalize strategies across tasks and environments

CO-OP (Cognitive Orientation to Daily Occupational Performance)

• Client-centered problem-solving approach

• Client learns to discover and apply strategies to improve occupational performance

• Uses the Goal-Plan-Do-Check framework

CO-OP Goal-Plan-Do-Check Framework

• Goal: identify the desired outcome

• Plan: develop a strategy for completing the task

• Do: carry out the plan

• Check: evaluate performance and determine whether the strategy worked

Neurofunctional Approach

• Highly specific compensatory approach

• Often used with individuals with severe brain injury

• Focuses on retraining the functional skill itself through repetition and practice

• Does not primarily focus on restoring the underlying cognitive impairment

Cognitive Disabilities Model

• Based on Allen Cognitive Levels

• Matches environmental and task demands to the client's remaining global cognitive abilities

• Emphasizes safety and adapting tasks and environments

OTPF-IV Client Factors Related to Cognition

• Specific mental functions: attention, memory, and executive functions

• Global mental functions: consciousness and orientation

OTPF-IV Process Skills

• Observable performance skills used during task performance

• Examples: heeding, choosing, sequencing, and initiating

Trauma-Related Brain Changes

• Trauma may be associated with reduced volume or shrinkage of the prefrontal cortex, corpus callosum, and hippocampus

• The amygdala may become enlarged and hyper-reactive

• These changes can affect emotion regulation, cognition, and stress responses

Schizophrenia (Neuroanatomy)

• Associated with dopamine abnormalities

• May involve subtle volume decreases or abnormalities in the amygdala, hippocampal formation, and prefrontal cortex

OCD (Neuroanatomy)

• Linked to dysfunction involving the caudate nucleus, basal ganglia, orbitofrontal cortex, and anterior cingulate gyrus

Anxiety and Depression (Neuroanatomy)

• Anxiety is associated with the amygdala and fear-related circuits

• Anxiety and depression are associated with frontal and limbic circuit dysfunction

• Depression may present as a frontal-like syndrome involving reduced initiation, reduced motivation, and impaired executive functioning