Neural Correlates Exam 1

Are all brains one size fits all?

NO

-all brains slightly different (like snowflakes)

-cognition different too! everyone thinks differently

-we need to do research and take each person clinically

Logic of Lesion-Deficit Associations

The idea that damage to a specific brain area can reveal the cognitive function that area supports.

Functional Segregation

The concept that different brain regions perform distinct cognitive functions.

Functional Integration

The principle that separate brain areas work together in networks to support complex behaviors.

Lesion Mapping

The process of correlating specific brain damage with behavioral deficits to infer function.

Double Dissociation

A finding showing that two cognitive functions are independent, based on contrasting lesion patterns.

Limitations of Lesion Studies

Constraints such as variability in lesion size, location, and patient recovery affecting conclusions.

Voxel-Based Lesion-Symptom Mapping (VLSM)

A neuroimaging method linking voxel-level brain damage with behavioral performance.

Cognitive-Anatomic Organization

The structured relationship between cognitive processes and neural substrates.

White Matter Tracts

Bundles of axons connecting gray matter regions to enable communication across the brain.

Example: Arcuate Fasciculus

A white matter tract connecting Broca's and Wernicke's areas, important for repetition and speech fluency.

Aphasia

A language disorder caused by brain injury affecting comprehension, expression, or both.

Disconnection Approach

The theory that cognitive deficits result from disrupted communication between brain regions.

Cognitive Neuroscience Approach

A model focusing on distributed networks supporting cognitive functions.

Classic Model (Broca-Wernicke-Arcuate Fasciculus)

Traditional view linking Broca's area to production, Wernicke's to comprehension, and the arcuate fasciculus to repetition.

Broca's Area

Region in the left inferior frontal gyrus involved in speech production and syntax.

Wernicke's Area

Posterior superior temporal gyrus involved in language comprehension.

Arcuate Fasciculus

White matter tract connecting Broca's and Wernicke's areas, supporting repetition.

Angular Gyrus

Region implicated in reading, writing, and semantic processing.

White Matter Integrity

The degree to which white matter pathways are preserved; linked to communication efficiency.

Broca's Aphasia

Nonfluent, effortful speech with relatively good comprehension and poor repetition.

Wernicke's Aphasia

Fluent but nonsensical speech with poor comprehension and impaired repetition.

Conduction Aphasia

Fluent speech and good comprehension but impaired repetition due to arcuate fasciculus damage.

Anomic Aphasia

Word-finding difficulty with otherwise fluent and grammatical speech.

Global Aphasia

Severe language impairment across all modalities due to large perisylvian lesion.

Transcortical Motor Aphasia

Nonfluent speech with good repetition; lesion anterior or superior to Broca's area.

Transcortical Sensory Aphasia

Fluent speech with poor comprehension but preserved repetition.

Isolation of Speech Area

A rare syndrome with preserved repetition but severe comprehension and production deficits.

Paraphasias

Errors in speech such as sound substitutions or word errors.

Confabulations

Invented or distorted statements used to fill memory or language gaps.

Perseverations

Unintentional repetition of previous words, phrases, or responses.

Stereotypical Utterances

Repetitive, automatic phrases often used in severe aphasia.

Dysprosodia

Abnormal rhythm, pitch, or melody of speech.

Echolalia

Automatic repetition of another person's speech.

Lexical Representations

Mental storage of word forms and meanings.

Lexical Processing

Recognition, retrieval, and use of words during comprehension and production.

Semantic Lexicon

Mental store of word meanings.

Phonological Lexicon

Mental store of word sounds.

Orthographic Lexicon

Mental store of written word forms.

Alexia

Acquired reading disorder due to brain injury.

Visual Word Form Area (VWFA)

Region in left occipitotemporal cortex specialized for recognizing written words.

Agraphia

Acquired impairment in writing ability.

Syntactic Processing

Understanding and production of sentence structure.

Semantic Processing

Comprehension of word and sentence meaning.

Semantic Control

Ability to access and manipulate word meanings flexibly.

Thalamic Role in Semantics

Thalamus involvement in regulating semantic retrieval and attention.

Semantic Retrieval

Process of accessing stored word meanings from memory.

Dorsomedial BA6 (pre-SMA)

Region involved in selection and initiation of word retrieval and verbal fluency.

Semantic Representation Regions

Brain areas storing conceptual and categorical knowledge.

Summary of Aphasia Model Limitations

Classic models oversimplify language processing, ignoring distributed and dynamic brain networks.

Apraxia

Motor planning disorder impairing the ability to perform learned movements.

Limb Apraxia

Inability to execute purposeful limb movements despite normal strength and comprehension.

Ideomotor Apraxia

Difficulty performing gestures on command, though spontaneous movements may occur.

Ideational Apraxia

Impaired ability to perform sequences of actions involving object use.

Conceptual Apraxia

Loss of knowledge about tool use or gesture meaning.

Constructional Apraxia

Inability to copy or construct spatial designs.

Dressing Apraxia

Difficulty dressing due to spatial or sequencing deficits.

Buccofacial (Orofacial) Apraxia

Impairment in voluntary movements of face or mouth unrelated to weakness.

Callosal Apraxia

Unilateral limb apraxia due to disconnection between hemispheres via corpus callosum damage.

Gesticulation

Spontaneous hand movements that accompany speech for emphasis or meaning.

Praxis System

Network of brain regions supporting skilled voluntary movement.

Parietal Lobe Role in Apraxia

Stores movement rep