Neurological Aspects of Cognition and Communication Unit #5

Lateralization

When the function of something turns from a two hemisphere function to a one-hemisphere function

Left Hemisphere

Primarily involved with receptive and expressive language (Phonology, morphology, syntax and semantics).

Right hemisphere

Primarily involved in pragmatics, attention, visuoperception, comprehension of linguistic and emotional prosody. Language activation weakens in the right hemisphere in adults. (Comprehension of pragmatics)

Structure #1

Broca’s area - Involved in speech and language production

Structure #2

Inferior frontal gyrus - Involved in speech and language production

Structure #3

Superior temporal gyrus - Involved in speech comprehension

Structure #4

Middle temporal gyrus - Involved in language comprehension

Structure #5

Inferior temporal gyrus - Involved visual processing

Structure #6

Supramarginal gyrus - Involved in phonological processing

Structure #7

Angular gyrus - Involved in language comprehension

Global Aphasia

Issues with fluency, comprehension, and repetition

Broca’s Aphasia (non-fluent aphasia)

Good comprehension but poor fluency (slow and effortful speech)

Wenicke’s Aphasia (fluent aphasia)

Good fluency, but poor comprehension. Usually linked with paraphasias.

Conduction Aphasia

Troubles with repetition

Anomic Aphasia

Troubles with word finding

Paraphasias

Words that sound like real words, but aren’t

What is the condition caused by right hemisphere damage?

Apragmatism

What is the condition caused by left hemisphere damage?

Aphasia

Dorsal Language stream

involved in the motor processing of speech (the output)

Ventral language stream

Involved in the processing of language (the input)

Dorsal prosodic network

Involved in the expressing emotional prosody (the output)

Ventral prosodic network

Involved in the processing of emotional prosody (the input)

Dorsal visual pathway

The “where” pathway. involved in processing information about motion and spatial relationships between objects (pathfinding, sense of self in space)

Ventral visual pathway

The “what” pathway. involved in processing information about form, color, shape, faces, letters, and other visual stimuli.

Apragmatism

A right hemisphere disorder relating to deficits in communication (difficulty with figurative language, emotional prosody, egocentrism, etc) and cognition (attention, executive dysfunction, and memory deficits).

Dorsal Attention Network

Function: Running when we have sustained and focused attention to contralateral spaces.

Structures: Dorsal parietal fields, frontal eye fields, and the superior longitudinal fascicules.

Ventral Attention Network

Function: Running when alerting, attention to novel or sudden stimuli

Structures: Frontal lobe, insula, superior temporal gyrus, and temporoparietal junction.

Default mode network

Function: Running when at rest or mind drifting

Structures: Prefrontal cortex, cingulate, and intraparietal sulcus

Attention control network

Function: Running when we are using alternating and divided attention

Structures: Prefrontal cortices, cerebellum, basal ganglia, and thalamus.

Theory of mind

Understanding that others have different thoughts, feelings, ideas, and knowledge.

Declarative memory

Explicit and conscious memory

Semantic memory

Fact-based memory

Episodic memory

Experience-based memories

Non-declarative

Unconscious and implicit memory (actions/behaviors)

Procedural memory

Memories of how to do something

Working memory

Processes and temporally stores memories

Meta-memory

Knowledge about one’s own memory abilities

Prospective memory

Remembering to do something in the future

Focused attention

Being able to attend to 1 stimulus without distractions

Sustained attention

Holding focused attention over time

Selective attention

Attending to a stimulus while ignoring other internal or external distractions

Divided attention

Splitting attention between 2 stimuli or task

Alternating attention

Switching focus between 2 stimuli or tasks

Encoding

Function: Analyzing information (visualization, chunking, etc)

Structures: Frontal lobes + modality-specific regions (e.g., temporal lobes for auditory stimuli)

Consolidation

Function: Converting short-term to long-term memories

Structures: Hippocampus

Storage

Function: Memory stored for later retrieval

Structures: Temporal lobes, modality-specific areas

Retrieval

Function: Accessing information

Structures: Frontal lobes

Post-traumatic amnesia

Period of anterograde amnesia that shrinks over time

Retrograde amnesia

Loss of memories prior to a brain injury

Anterograde amnesia

Reduced ability to form new memories

Causes of amnesia

Strokes, tumors, TBI

Portion #1 of the prefrontal cortices

Dorsolateral / Dorsomedial prefrontal cortices (COLD)

Portion #2 of the prefrontal cortices

Ventrolateral / Ventromedial Prefrontal cortices (HOT)

Portion #3 of the prefrontal cortices

Orbitofrontal prefrontal cortices (HOT)

The paradox of assessing executive functions in a clinical setting

Clinical environments do not have as much external stimuli that could impact executive functioning as real-world environments

Hot executive functions

The use of executive functions in emotionally charged situations. Processed in the orbitofrontal/ventromedial prefrontal cortices

Cold executive functions

When executive functions are used without an emotional connection. Processed in the dorsolateral prefrontal cortices

Executive functions

High-level cognitive functions (organization, prioritizing, goal-setting, decision-making, planning, reasoning and problem-solving, self-regulation, initiation, cognitive flexibility, etc.)

Neuroplasticity

How the brain adapts and changes from the things you do, your environment and your environment

Maladaptive neuroplasticity

When a therapy activity is different from the context a person will use it in– making that activity difficult to do when out of therapy.

Functional reactivation

The regrowth of neurons within a former penumbra. This can cause new neuronal branching inside the ischemic core or the infarct region

Functional reorganization

When another area of the brain takes over the functions of the damaged areas.

Neuromodulation

The process of changing nerve activity in the nervous system. This can help relieve some neurological symptoms and pain.