Physiological Psychology: Key Concepts and Disorders

Hemispheric Lateralization

Lateralization is the localization of a function in one hemisphere or the other; for example, Broca's area on the left is for language while the right corresponds to singing.

Split-Brain operation

Corpus callosotomy, where pathways connecting the right and left cerebral hemispheres are severed to treat epilepsy, resulting in no change in personality, intelligence, or speech.

How is the Split-Brain Operation performed?

the cortex is retracted to access the corpus callosum, which is then severed; Joseph Bogen's classic procedure involved severing all four commissures.

Lateralization in Autism Spectrum Disorder

Research shows reduced lateralization in individuals with autism spectrum disorder compared to typical individuals.

Language

Defined as a system of communicating thoughts and feelings using arbitrary signals, such as sounds, gestures, or written signals, found in all human cultures.

Origins of language

No human culture exists without language; possible existence of an independent 'language module' in the brain and genes related to aspects of language (FOXP2) show important mutations about 100,000 years ago.

Patient Tan

Paul Broca's patient (real name Leborgne) experienced significant damage in Broca's area, indicating the importance of localization of language functions.

Broca's and Wernicke's Aphasias

Broca's aphasia is characterized by a lack of ability to speak clearly with slight deficits in comprehension, while Wernicke's aphasia features rapid and fluent speech that is meaningless with poor comprehension.

Conduction aphasia

Difficulty repeating speech. Damage to the arcuate fasciculus and the adjacent cortex. Speech remains fluent and comprehension is fairly good.

Difficulty repeating speech

Damage to the arcuate fasciculus and the adjacent cortex

Global aphasia

Loss of all language functions

Transcortical aphasias

Types of aphasia characterized by the ability to repeat speech despite other language impairments

Transcortical motor aphasia

Speech is not fluent, but words can be repeated; affects higher cognitive aspects of speech production

Transcortical sensory aphasia

Fluent speech with impaired cognition and deficits in word meanings

Alexia

Normal speech and comprehension but unable to read or recognize letters

Agraphia

Inability to write

Dyslexia

Most common learning disability characterized by difficulty learning to read, with a genetic component and related to asymmetry

Phonological awareness

Overactivation of rostral language areas and lack of activation of posterior language areas

Stuttering

Producing repetitions or prolonging of sounds, primarily genetic in origin, more common in males

Network states of intelligence

Describes the brain in terms of modular organization, with contributions from most areas of the brain

Crystallized Intelligence

Use of knowledge that is easy to reach

Fluid Intelligence

Ability to manage novel situations such as problem-solving, identifying patterns, and reaction time, which is difficult to reach

Neuropsychologists

Licensed doctoral level clinical psychologists (PhD or PsyD) who complete specialized training and often work in collaboration with neurologists or neurosurgeons

Genetic cause of Alzheimer's Disease

Risk increases with age; the e4 variant of the APOE gene increases risk significantly

Diagnostic methods for Alzheimer's Disease

Include autopsy, biomarkers in CSF and blood, PET and MRI scanning

Amyloid plaques identification

Identified in the brain using a PET scan that shows much more amyloid in patients with Alzheimer's disease compared to healthy individuals

Vascular disease (Stroke)

Occurs when the brain's blood supply is interrupted

Transient ischemic attacks (TIA)

Mimic stroke symptoms and predict stroke

Types of Traumatic Brain Injury (TBI)

Include physical damage to the brain from open head injuries and closed head injuries (concussions)

Open head injuries

Involve penetration of the skull and have worst consequences when affecting ventricles, both hemispheres, and multiple lobes of the brain

Closed head injuries

Result from a blow to the head, including coup and countercoup injuries

Chronic Traumatic Encephalopathy (CTE)

A condition more likely to develop in athletes, exemplified by the case of former NFL player Phillip Adams

Chronic Traumatic Encephalopathy (CTE)

A condition that can produce a range of problems including dementia and impulsivity, often seen in sports with increased likelihood of head injuries.

Transmissible Spongiform Encephalopathies (TSEs)

Disorders resulting from abnormal proteins called prions.

Bovine Spongiform Encephalopathy (BSE)

Also known as mad-cow disease, a type of TSE.

Creutzfeldt-Jakob Disease (CJD)

A rare prion disease that can be genetic or caused by infection from unclean surgical equipment.

Kuru

A prion disease similar to CJD that results from cannibalism.

Fatal Familial Insomnia

A genetic prion disease that leads to severe insomnia and ultimately death.

Brain Tumors

Independent growths of new tissue in the brain that lack purpose.

Primary Tumors

Rare tumors of the brain with unknown causes, but radiation is a risk factor.

Secondary Tumors

Tumors that arise from glial cells, meninges, and ependymal cells, and are the most common type of tumor until age 19.

Malignant Tumors

Tumors that can spread to other parts of the body.

Benign Tumors

Tumors that do not spread and are unlikely to return after removal.

Metastasis

The process by which tumors spread to the brain from other locations in the body.

Glioma

A tumor arising in glial cells.

Meningioma

A tumor that arises in the meninges that envelop the brain.

Treatment for Brain Tumors

Includes surgical removal, whole brain radiation, stereotaxic radiosurgery, ultrasound therapy, chemotherapy, thalidomide, and experimental delivery of stem cells with anticancer genes.

Neurocysticercosis

A condition caused by pork tapeworm eggs that can produce partial seizures.

Encephalitis

Inflammation of the brain after a viral infection, with herpes simplex being the most dangerous.

Meningitis

Inflammation of the meninges, which can be bacterial, viral (most common and least dangerous), or fungal (rare).

Epilepsy

A condition characterized by repeated, unprovoked seizures due to uncontrolled electrical disturbances in the brain.

Partial Seizures

Seizures that can be simple (no change in consciousness) or complex (altered consciousness).

Aura

A premonition of an impending seizure.

Generalized Seizures

Seizures that symmetrically affect both sides of the brain and include tonic-clonic and absence seizures.

Treatment for Epilepsy

Includes antiepileptic drugs (usually GABA agonists), surgery, and a ketogenic diet in children.

Multiple Sclerosis

An autoimmune condition where the immune system attacks oligodendrocytes, leading to demyelination of axons.

Possible Causes of Multiple Sclerosis

Includes modest heritability, exposure to viruses (e.g., Epstein-Barr), and lack of vitamin D due to lack of sunlight.

left hemisphere

language and logical thought

right hemisphere

spatial processing

corpus callosotomy

split brain operation

Four commissures connect the two cerebral hemispheres

the corpus callosum, the anterior commissure, the massa intermedia, and the hippocampal commissure

dorsal pathway

connects the superior temporal gyrus, which contains both the primary auditory cortex and Wernicke’s area, to Broca’s area and the frontal operculum, a part of the frontal lobe.This pathway supports the conversion of sound to movements necessary for speech.

ventral pathway

connects the superior temporal sulcus to the inferior temporal gyrus and the middle temporal gyrus and supports the conversion of sound to meaning.

High activity here in stuttering

basal ganglia

How are Amyloid plaques identified in the brain in a living person?

PET scan

Broca’s aphasia

Lack of ability to speak clearly  Slight deficits in comprehension  Can still understand other people’s speech

Wernicke’s aphasia

Speech is rapid and fluent but meaningless. Poor comprehension. Can’t understand other people’s speech

Aphasia

A total or partial loss of the ability to either produce or comprehend spoken language.

Treatments for Stuttering

Reducing rates and which speech is produced and stress associated with the disordere

A stroke occurs when brain blood supply is interrupted by

Cerebral hemorrhage (balloon-like artery) or sudden blockage of a blood vessel

ischemia

low oxygen levels

infarct

area of dead tissue

Trombosis

blockage that does not move

Embolism

blockage that does move

Causes of sudden blockage of blood vessels

ischemia, infarct, transient ischemic attacks, thrombosis, embolism

coup

point of impactc

countercoup

point of second impactthat occurs on the opposite side of the brain from the original impact.

treatment for multiple sclerosis

medications slow progression, quit smoking and exercise

Types of Generalized Seizures

Tonic-clonic and absence

Tonic-Clonic

grand mal, violent complusions

Absence

petit mal, mild seizure with brief unconsciousness

earliest form of human language

click language