Module 5 Interconnected systems Limbic system, Language, Cognition

Limbic system meaning

Limbic = "border"; structures on the border between cortical and subcortical areas

Limbic system main structures

Cingulate gyrus; Fornix; Hippocampus; Amygdala; Anterior thalamus; Hypothalamus; Olfactory cortices

Limbic system: cingulate gyrus

Involved in emotional processing, attention, and integrating cognitive + emotional information

Limbic system: fornix

Major output tract of the hippocampus; important for memory circuits

Limbic system: hippocampus

Located in medial temporal lobe; critical for encoding memories (STM→LTM) and spatial navigation

Limbic system: amygdala

Emotion regulation; emotional memory; learned responses (anxiety, fear); reward circuits

Limbic system: anterior thalamus

Memory and emotion; connected to hippocampus, cingulate gyrus, frontal lobe

Limbic system: hypothalamus

Controls endocrine system; hormones; autonomic functions; circadian rhythms; drives (eating, drinking, sex); temperature; stress responses

Pituitary gland

Connected to hypothalamus via pituitary stalk; synthesizes and secretes hormones

Thalamic nuclei: Mediodorsal nucleus connections

Prefrontal cortex, hippocampus, limbic system, amygdala

Thalamic nuclei: Mediodorsal nucleus functions

Regulates mood, emotion, cognition, personality, memory, and language

Thalamic nuclei: Anterior nucleus connections

Hippocampus, cingulate gyrus, frontal lobe

Thalamic nuclei: Anterior nucleus functions

Memory, emotion, and executive functioning

Limbic system—main functions

Homeostasis; Olfaction; Memory; Emotion

Homeostasis (limbic function)

Survival mechanisms: drives (eating, drinking, sex); autonomic + endocrine regulation; temperature; stress responses; circadian rhythms

Olfaction (limbic role)

Smell/taste linked to memory and emotion; safety (detect fire or spoiled food)

Memory: hippocampus role

Critical for encoding new memories; STM→LTM consolidation

Memory distribution

Memory stored across frontal lobes, basal ganglia, cerebellum, all lobes, limbic structures

Working memory definition

Temporary storage + processing

Declarative memory definition

Explicit memory: facts + events (semantic + episodic)

Non-declarative memory definition

Implicit memory: skills, habits, emotional associations, conditioned reflexes

Implicit memory brain regions

Basal ganglia, cerebellum, neocortex, amygdala

Emotion: amygdala outputs

Hypothalamus + reticular formation; initiates behavioral responses

Three domains of language

Form, Content, Use

Language form definition

Structure of language: phonology, morphology, syntax

Language content definition

Meaning of language: semantics

Language use definition

Pragmatics—language in context, intent, social rules

Syntax brain network

Left-lateralized; temporal → inferior frontal pathway

Semantics brain network

Primarily left hemisphere, but also right; temporo-frontal networks

Prosody: linguistic

Bilateral network: RH + LH

Prosody: emotional

Right hemisphere network

LH general functions

Analytic, linear, sequential; language form + content; auditory processing

RH general functions

Holistic, visual-spatial, emotional prosody, pragmatics, creativity

Key LH language areas

Broca's area; Wernicke's area; angular gyrus; supramarginal gyrus

Posterior LH role

Language comprehension

Anterior LH role

Language production

Dorsal language pathway

Posterior STG → cortex; auditory-motor integration

Ventral language pathway

STG → frontal operculum; sound-to-meaning mapping

Primary deficit with posterior LH damage

Language comprehension problems

Primary deficit with anterior LH damage

Expressive language problems

Broca's aphasia characteristics

Non-fluent speech; good comprehension; poor repetition; expressive deficits

Wernicke's aphasia characteristics

Fluent speech; poor comprehension; poor repetition; semantic errors

Global aphasia

Non-fluent; poor comprehension; poor repetition (all impaired)

Conduction aphasia

Fluent speech; good comprehension; poor repetition

Anomic aphasia

Word-finding difficulty; good comprehension; good repetition

Apraxia of Speech cause

Damage to anterior inferior frontal lobe (near Broca's area)

Apraxia of Speech characteristics

Motor programming disorder; sound/syllable errors; aware of errors; difficulty correcting

Definition: Pragmatics

Conveying intended meaning through linguistic, paralinguistic, and extralinguistic cues in context

RH damage communication disorder

Apragmatism

Apragmatism definition

Impaired ability to convey or interpret context-dependent meaning using linguistics, prosody, or non-verbal cues

Apragmatism—linguistic production

Verbose, tangential, disorganized speech; inappropriate wording or grammar

Apragmatism—linguistic comprehension

Difficulty understanding gist, making inferences, or interpreting non-literal language

Apragmatism—paralinguistic production

Flat, unemotional voice (expressive aprosodia)

Apragmatism—paralinguistic comprehension

Difficulty interpreting tone of voice (receptive aprosodia)

Apragmatism—extralinguistic production

Reduced gestures, facial expressions, body language

Apragmatism—extralinguistic comprehension

Misinterprets gestures, facial expressions, and nonverbals

Executive functions definition

Goal-directed behaviors: planning, organizing, reasoning, problem solving, insight, awareness

Types of attention

Focused, sustained, alternating, divided

Memory cortical areas

Medial temporal lobe; medial diencephalon; neocortex; cerebellum; amygdala

Social cognition definition

Understanding others' thoughts, beliefs, emotions; interpreting social cues

Social cognition cortical areas

Superior temporal gyrus; temporoparietal junction; inferior frontal region; orbitofrontal region; superior frontal region

Cerebrocerebellum function

Timing, planning, programming, executing movement; also cognition (working memory, language, social cognition, sense of time)

Cognitive disorders—attention/perception

Impaired sustained focus; distractibility; unilateral neglect

Cognitive disorders—executive function

Problems with organization, sequencing, reasoning, judgment, awareness

Unilateral neglect definition

Lack of awareness of one side of space; often with poor insight to deficits

Visuospatial deficits examples

Clock drawing errors; writing errors; spatial organization problems

Line or letter cancellation tasks meaning

Used to detect visuospatial neglect or attentional deficits

TBI attention deficits

Difficulty sustaining attention and resisting distractions

TBI memory deficits

Impaired short-term and long-term memory

TBI executive deficits

Problems with problem solving, reasoning, insight, awareness

TBI communication deficits

Impaired pragmatics, theory of mind, emotion recognition, code switching, topic selection

Concussion definition

Mild traumatic brain injury

Concussion cognitive symptoms

Feeling foggy or slow; memory/learning problems; poor concentration

Concussion physical symptoms

Headache; blurry vision; nausea; dizziness; low energy; poor balance; light/noise sensitivity

Concussion emotional symptoms

Irritability; sadness; nervousness; increased emotional reactivity

Concussion sleep symptoms

Too much/too little sleep; trouble falling asleep

Neural connections principle

All functions arise from neural connections

Meaning through neural patterns

Patterns of signals + location in cortex create meaning

Gray vs white matter

Gray = cell bodies; White = myelinated axons for communication

Motor pathways

Direct 2-synapse path + complex integrated circuits for refined movement

Sensory pathways

Basic 3-synapse somatosensory path; complex special-sense pathways

Language/cognition/emotion

Depend on extensive, interconnected networks

Brain-behavior relationship

Deficits reflect which brain systems/regions are damaged

Nervous system adaptaability

The nervous system is adaptable, well protected, but fragile